source
stringlengths 31
207
| text
stringlengths 12
1.5k
|
---|---|
https://en.wikipedia.org/wiki/Rhodamine%20B
|
Rhodamine B is a chemical compound and a dye. It is often used as a tracer dye within water to determine the rate and direction of flow and transport. Rhodamine dyes fluoresce and can thus be detected easily and inexpensively with fluorometers.
Rhodamine B is used in biology as a staining fluorescent dye, sometimes in combination with auramine O, as the auramine-rhodamine stain to demonstrate acid-fast organisms, notably Mycobacterium. Rhodamine dyes are also used extensively in biotechnology applications such as fluorescence microscopy, flow cytometry, fluorescence correlation spectroscopy and ELISA.
Other uses
Rhodamine B is often mixed with herbicides to show where they have been used.
It is also being tested for use as a biomarker in oral rabies vaccines for wildlife, such as raccoons, to identify animals that have eaten a vaccine bait. The rhodamine is incorporated into the animal's whiskers and teeth. Rhodamine B is an important hydrophilic xanthene dye well known for its stability and is widely used in the textile industry, leather, paper printing, paint, coloured glass and plastic industries.
Rhodamine B (BV10) is mixed with quinacridone magenta (PR122) to make the bright pink watercolor known as Opera Rose.
Properties
Rhodamine B can exist in equilibrium between two forms: an "open"/fluorescent form and a "closed"/nonfluorescent spirolactone form. The "open" form dominates in acidic condition while the "closed" form is colorless in basic condition.
The fluo
|
https://en.wikipedia.org/wiki/Kloosterman%20sum
|
In mathematics, a Kloosterman sum is a particular kind of exponential sum. They are named for the Dutch mathematician Hendrik Kloosterman, who introduced them in 1926 when he adapted the Hardy–Littlewood circle method to tackle a problem involving positive definite diagonal quadratic forms in four as opposed to five or more variables, which he had dealt with in his dissertation in 1924.
Let be natural numbers. Then
Here x* is the inverse of modulo .
Context
The Kloosterman sums are a finite ring analogue of Bessel functions. They occur (for example) in the Fourier expansion of modular forms.
There are applications to mean values involving the Riemann zeta function, primes in short intervals, primes in arithmetic progressions, the spectral theory of automorphic functions and related topics.
Properties of the Kloosterman sums
If or then the Kloosterman sum reduces to the Ramanujan sum.
depends only on the residue class of and modulo . Furthermore and if .
Let with and coprime. Choose and such that and . Then
This reduces the evaluation of Kloosterman sums to the case where for a prime number and an integer .
The value of is always an algebraic real number. In fact is an element of the subfield which is the compositum of the fields
where ranges over all odd primes such that and
for with .
The Selberg identity:
was stated by Atle Selberg and first proved by Kuznetsov using the spectral theory of modular forms. Nowadays elementary proofs of
|
https://en.wikipedia.org/wiki/Kuiper%27s%20theorem
|
In mathematics, Kuiper's theorem (after Nicolaas Kuiper) is a result on the topology of operators on an infinite-dimensional, complex Hilbert space H. It states that the space GL(H) of invertible bounded endomorphisms of H is such that all maps from any finite complex Y to GL(H) are homotopic to a constant, for the norm topology on operators.
A significant corollary, also referred to as Kuiper's theorem, is that this group is weakly contractible, ie. all its homotopy groups are trivial. This result has important uses in topological K-theory.
General topology of the general linear group
For finite dimensional H, this group would be a complex general linear group and not at all contractible. In fact it is homotopy equivalent to its maximal compact subgroup, the unitary group U of H. The proof that the complex general linear group and unitary group have the same homotopy type is by the Gram-Schmidt process, or through the matrix polar decomposition, and carries over to the infinite-dimensional case of separable Hilbert space, basically because the space of upper triangular matrices is contractible as can be seen quite explicitly. The underlying phenomenon is that passing to infinitely many dimensions causes much of the topological complexity of the unitary groups to vanish; but see the section on Bott's unitary group, where the passage to infinity is more constrained, and the resulting group has non-trivial homotopy groups.
Historical context and topology of spheres
It is a
|
https://en.wikipedia.org/wiki/Tensor%20product%20of%20modules
|
In mathematics, the tensor product of modules is a construction that allows arguments about bilinear maps (e.g. multiplication) to be carried out in terms of linear maps. The module construction is analogous to the construction of the tensor product of vector spaces, but can be carried out for a pair of modules over a commutative ring resulting in a third module, and also for a pair of a right-module and a left-module over any ring, with result an abelian group. Tensor products are important in areas of abstract algebra, homological algebra, algebraic topology, algebraic geometry, operator algebras and noncommutative geometry. The universal property of the tensor product of vector spaces extends to more general situations in abstract algebra. The tensor product of an algebra and a module can be used for extension of scalars. For a commutative ring, the tensor product of modules can be iterated to form the tensor algebra of a module, allowing one to define multiplication in the module in a universal way.
Balanced product
For a ring R, a right R-module M, a left R-module N, and an abelian group G, a map is said to be R-balanced, R-middle-linear or an R-balanced product if for all m, m′ in M, n, n′ in N, and r in R the following hold:
The set of all such balanced products over R from to G is denoted by .
If φ, ψ are balanced products, then each of the operations and −φ defined pointwise is a balanced product. This turns the set into an abelian group.
For M and N fixed,
|
https://en.wikipedia.org/wiki/Marek%20Karpinski
|
Marek Karpinski is a computer scientist and mathematician known for his research in the theory of algorithms and their applications, combinatorial optimization, computational complexity, and mathematical foundations. He is a recipient of several research prizes in the above areas.
He is currently a Professor of Computer Science, and the Head of the Algorithms Group at the University of Bonn. He is also a member of Bonn International Graduate School in Mathematics BIGS and the Hausdorff Center for Mathematics.
See also
List of computer scientists
List of mathematicians
References
Theoretical computer scientists
Mathematical logicians
Graph theorists
Academic staff of the University of Bonn
American computer scientists
20th-century Polish mathematicians
21st-century Polish mathematicians
Members of Academia Europaea
Polish computer scientists
Living people
Year of birth missing (living people)
|
https://en.wikipedia.org/wiki/A%20Sharp%20%28.NET%29
|
A# is a port of the Ada programming language to the Microsoft .NET platform. A# is freely distributed by the Department of Computer Science at the United States Air Force Academy as a service to the Ada community under the terms of the GNU General Public License.
AdaCore took over this development in 2007, and announced "GNAT for .NET", which is a fully supported .NET product with all of the features of A# and more. As of 2021, A# has fallen dramatically in popularity and is considered by some to be a dead language (there are no known users or implementations).
Examples
hello world
with Ada.Text_IO;
use Ada.Text_IO;
procedure Hello_Dotnet is
begin
Put_Line(Item => “Hello .NET world!”);
end Hello_Dotnet;
References
External links
A# for .NET
Ada Sharp .NET Programming environment
Ada (programming language)
.NET programming languages
|
https://en.wikipedia.org/wiki/Lewis%20number
|
In fluid dynamics and thermodynamics, the Lewis number (denoted ) is a dimensionless number defined as the ratio of thermal diffusivity to mass diffusivity. It is used to characterize fluid flows where there is simultaneous heat and mass transfer. The Lewis number puts the thickness of the thermal boundary layer in relation to the concentration boundary layer. The Lewis number is defined as
.
where:
is the thermal diffusivity,
is the mass diffusivity,
is the thermal conductivity,
is the density,
is the mixture-averaged diffusion coefficient,
is the specific heat capacity at constant pressure.
In the field of fluid mechanics, many sources define the Lewis number to be the inverse of the above definition.
The Lewis number can also be expressed in terms of the Prandtl number () and the Schmidt number ():
It is named after Warren K. Lewis (1882–1975), who was the first head of the Chemical Engineering Department at MIT. Some workers in the field of combustion assume (incorrectly) that the Lewis number was named for Bernard Lewis (1899–1993), who for many years was a major figure in the field of combustion research.
Literature
References
Dimensionless numbers
Fluid dynamics
Dimensionless numbers of fluid mechanics
Combustion
|
https://en.wikipedia.org/wiki/Schmidt%20number
|
In fluid dynamics, the Schmidt number (denoted ) of a fluid is a dimensionless number defined as the ratio of momentum diffusivity (kinematic viscosity) and mass diffusivity, and it is used to characterize fluid flows in which there are simultaneous momentum and mass diffusion convection processes. It was named after German engineer Ernst Heinrich Wilhelm Schmidt (1892–1975).
The Schmidt number is the ratio of the shear component for diffusivity (viscosity divided by density) to the diffusivity for mass transfer . It physically relates the relative thickness of the hydrodynamic layer and mass-transfer boundary layer.
It is defined as:
where (in SI units):
is the kinematic viscosity (m2/s)
is the mass diffusivity (m2/s).
is the dynamic viscosity of the fluid (Pa·s = N·s/m2 = kg/m·s)
is the density of the fluid (kg/m3).
The heat transfer analog of the Schmidt number is the Prandtl number (). The ratio of thermal diffusivity to mass diffusivity is the Lewis number ().
Turbulent Schmidt Number
The turbulent Schmidt number is commonly used in turbulence research and is defined as:
where:
is the eddy viscosity in units of (m2/s)
is the eddy diffusivity (m2/s).
The turbulent Schmidt number describes the ratio between the rates of turbulent transport of momentum and the turbulent transport of mass (or any passive scalar). It is related to the turbulent Prandtl number, which is concerned with turbulent heat transfer rather than turbulent mass transfer. It is useful
|
https://en.wikipedia.org/wiki/Albuquerque%20%26%20Takaoka
|
Albuquerque & Takaoka is one of the most significant and active architecture, civil engineering, and real estate development private companies of São Paulo, Brazil. It is mostly known for its role in creating the innovative Alphaville concept of business and gated residential condominia.
The firm was founded in 1951 by two young civil engineers, Renato de Albuquerque and Yojiro Takaoka, graduated together in 1949 from Escola Politécnica da Universidade de São Paulo (Polytechnic School), a traditional and respected engineering college in São Paulo. Initially the small firm developed residential houses and small public and commercial buildings, including a church. With the boom of public works in the state, they began working in heavy construction, such as bridges and viaducts, canals, and larger public buildings. The company also built several housing projects for the poor.
In the 1970s, the company diversified into building residential high rises in the city of São Paulo, and created the concept of gated vertical condominia with the first of its kind, "Ilhas do Sul", in 1973. In the succeeding years, it developed the first "Alphaville", in the county of Barueri, and two other luxury condominia, "Aldeia da Serra" (near Alphaville) and "Toque-Toque Pequeno", in the beaches of the Northern coast of the state.
With the death of Yojiro Takaoka, the company changed its name to Albuquerque & Takaoka Participações, Ltda. and the Alphaville projects were passed to Alphaville Urban
|
https://en.wikipedia.org/wiki/Alex%20Fraser%20%28scientist%29
|
Alex Fraser (1923 – 14 July 2002) was a major innovator in the development of the computer modeling of population genetics and his work has stimulated many advances in genetic research over the past decades.
His efforts in the 1950s and 1960s had a profound impact on the development of computational models of evolutionary systems. His seminal work, "Simulation of genetic systems by automatic digital computers" (1958), is quoted in the literature to this day.
Fraser was born in London, England, and lived in Hong Kong for most of his youth. He studied at the University of New Zealand, and later went to the University of Edinburgh, and subsequently to the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Sydney, Australia.
It was at the CSIRO where Fraser made his seminal contributions to evolutionary computation.
His earliest work was done on the SILIAC computer that was installed for the University of Sydney in 1956. The SILIAC was the Australian cousin to the ILLIAC machine that was developed at the University of Illinois. The machine was said to be running well when one could hear a 'rhythmic clicking of the relays inside it.' The clicking indicated that the computer was processing the iterations of the program correctly. Fraser began using it to simulate genetic selection processes.
Fraser also starred in multiple TV shows during the early days of Australian television. His time with "Science in Close-Up" ended in a dramatic departure when c
|
https://en.wikipedia.org/wiki/Crosstalk%20%28biology%29
|
Biological crosstalk refers to instances in which one or more components of one signal transduction pathway affects another. This can be achieved through a number of ways with the most common form being crosstalk between proteins of signaling cascades. In these signal transduction pathways, there are often shared components that can interact with either pathway. A more complex instance of crosstalk can be observed with transmembrane crosstalk between the extracellular matrix (ECM) and the cytoskeleton.
Crosstalk between signalling pathways
One example of crosstalk between proteins in a signalling pathway can be seen with cyclic adenosine monophosphate's (cAMP) role in regulating cell proliferation by interacting with the mitogen-activated protein (MAP) kinase pathway. cAMP is a compound synthesized in cells by adenylate cyclase in response to a variety of extracellular signals. cAMP primarily acts as an intracellular second messenger whose major intracellular receptor is the cAMP-dependent protein kinase (PKA) that acts through the phosphorylation of target proteins. The signal transduction pathway begins with ligand-receptor interactions extracellularly. This signal is then transduced through the membrane, stimulating adenylyl cyclase on the inner membrane surface to catalyze the conversion of ATP to cAMP.
ERK, a participating protein in the MAPK signaling pathway, can be activated or inhibited by cAMP. cAMP can inhibit ERKs in a variety of ways, most of which involve the
|
https://en.wikipedia.org/wiki/Theta%20correspondence
|
In mathematics, the theta correspondence or Howe correspondence is a mathematical relation between representations of two groups of a reductive dual pair. The local theta correspondence relates irreducible admissible representations over a local field, while the global theta correspondence relates irreducible automorphic representations over a global field.
The theta correspondence was introduced by Roger Howe in . Its name arose due to its origin in André Weil's representation theoretical formulation of the theory of theta series in . The Shimura correspondence as constructed by Jean-Loup Waldspurger in and may be viewed as an instance of the theta correspondence.
Statement
Setup
Let be a local or a global field, not of characteristic . Let be a symplectic vector space over , and the symplectic group.
Fix a reductive dual pair in . There is a classification of reductive dual pairs.
Local theta correspondence
is now a local field. Fix a non-trivial additive character of . There exists a Weil representation of the metaplectic group associated to , which we write as .
Given the reductive dual pair in , one obtains a pair of commuting subgroups in by pulling back the projection map from to .
The local theta correspondence is a 1-1 correspondence between certain irreducible admissible representations of and certain irreducible admissible representations of , obtained by restricting the Weil representation of to the subgroup . The correspondence was defined
|
https://en.wikipedia.org/wiki/Weierstrass%E2%80%93Enneper%20parameterization
|
In mathematics, the Weierstrass–Enneper parameterization of minimal surfaces is a classical piece of differential geometry.
Alfred Enneper and Karl Weierstrass studied minimal surfaces as far back as 1863.
Let and be functions on either the entire complex plane or the unit disk, where is meromorphic and is analytic, such that wherever has a pole of order , has a zero of order (or equivalently, such that the product is holomorphic), and let be constants. Then the surface with coordinates is minimal, where the are defined using the real part of a complex integral, as follows:
The converse is also true: every nonplanar minimal surface defined over a simply connected domain can be given a parametrization of this type.
For example, Enneper's surface has , .
Parametric surface of complex variables
The Weierstrass-Enneper model defines a minimal surface () on a complex plane (). Let (the complex plane as the space), the Jacobian matrix of the surface can be written as a column of complex entries:
where and are holomorphic functions of .
The Jacobian represents the two orthogonal tangent vectors of the surface:
The surface normal is given by
The Jacobian leads to a number of important properties: , , , . The proofs can be found in Sharma's essay: The Weierstrass representation always gives a minimal surface. The derivatives can be used to construct the first fundamental form matrix:
and the second fundamental form matrix
Finally, a point on the compl
|
https://en.wikipedia.org/wiki/Don%20L.%20Anderson
|
Don Lynn Anderson (March 5, 1933 – December 2, 2014) was an American geophysicist who made significant contributions to the understanding of the origin, evolution, structure, and composition of Earth and other planets. An expert in numerous scientific disciplines, Anderson's work combined seismology, solid state physics, geochemistry and petrology to explain how the Earth works. Anderson was best known for his contributions to the understanding of the Earth's deep interior, and more recently, for the plate theory hypothesis that hotspots are the product of plate tectonics rather than narrow plumes emanating from the deep Earth. Anderson was Professor (Emeritus) of Geophysics in the Division of Geological and Planetary Sciences at the California Institute of Technology (Caltech). He received numerous awards from geophysical, geological and astronomical societies. In 1998 he was awarded the Crafoord Prize by the Royal Swedish Academy of Sciences along with Adam Dziewonski. Later that year, Anderson received the National Medal of Science. He held honorary doctorates from Rensselaer Polytechnic Institute (where he did his undergraduate work in geology and geophysics) and the University of Paris (Sorbonne), and served on numerous university advisory committees, including those at Harvard, Princeton, Yale, University of Chicago, Stanford, University of Paris, Purdue University, and Rice University. Anderson's wide-ranging research resulted in hundreds of published papers in the fi
|
https://en.wikipedia.org/wiki/Advances%20in%20Physics
|
Advances in Physics is a bimonthly scientific journal published by Taylor & Francis that was established in 1952. The journal is also issued as a supplement to the Philosophical Magazine. Peer review is determined on a case-by-case basis. The editors-in-chief are Paolo Radaelli and Joerg Schmalian.
The frequency of this publication varied from 1952 until 2007, when it became a bimonthly journal.
Aims and scope
The focus of the journal is critical reviews that are relevant to condensed matter physicists. Each review is intended to present the author's perspective. Readers are expected to have a fundamental knowledge of the subject. These reviews are sometimes complemented by a "Perspectives" section which publishes shorter articles that may be controversial, with the intention of stimulating debate. The intended audience consists of physicists, materials scientists, and physical chemists working in universities, industry, and research institutes.
Broad, interdisciplinary coverage includes topics ranging from condensed matter physics, statistical mechanics, quantum information, cold atoms, and soft matter physics to biophysics.
Impact factor and ranking
The impact factor for Advances in Physics 23.750 in 2021.
Abstracting and indexing
This journal is indexed in the following databases:
See also
List of physics journals
References
External links
Alternate online access
Physics journals
Physics review journals
Academic journals established in 1952
Taylor & Francis aca
|
https://en.wikipedia.org/wiki/Absolute%20Galois%20group
|
In mathematics, the absolute Galois group GK of a field K is the Galois group of Ksep over K, where Ksep is a separable closure of K. Alternatively it is the group of all automorphisms of the algebraic closure of K that fix K. The absolute Galois group is well-defined up to inner automorphism. It is a profinite group.
(When K is a perfect field, Ksep is the same as an algebraic closure Kalg of K. This holds e.g. for K of characteristic zero, or K a finite field.)
Examples
The absolute Galois group of an algebraically closed field is trivial.
The absolute Galois group of the real numbers is a cyclic group of two elements (complex conjugation and the identity map), since C is the separable closure of R and [C:R] = 2.
The absolute Galois group of a finite field K is isomorphic to the group
(For the notation, see Inverse limit.)
The Frobenius automorphism Fr is a canonical (topological) generator of GK. (Recall that Fr(x) = xq for all x in Kalg, where q is the number of elements in K.)
The absolute Galois group of the field of rational functions with complex coefficients is free (as a profinite group). This result is due to Adrien Douady and has its origins in Riemann's existence theorem.
More generally, let C be an algebraically closed field and x a variable. Then the absolute Galois group of K = C(x) is free of rank equal to the cardinality of C. This result is due to David Harbater and Florian Pop, and was also proved later by Dan Haran and Moshe Jarden using algebra
|
https://en.wikipedia.org/wiki/Bauer%E2%80%93Fike%20theorem
|
In mathematics, the Bauer–Fike theorem is a standard result in the perturbation theory of the eigenvalue of a complex-valued diagonalizable matrix. In its substance, it states an absolute upper bound for the deviation of one perturbed matrix eigenvalue from a properly chosen eigenvalue of the exact matrix. Informally speaking, what it says is that the sensitivity of the eigenvalues is estimated by the condition number of the matrix of eigenvectors.
The theorem was proved by Friedrich L. Bauer and C. T. Fike in 1960.
The setup
In what follows we assume that:
is a diagonalizable matrix;
is the non-singular eigenvector matrix such that , where is a diagonal matrix.
If is invertible, its condition number in -norm is denoted by and defined by:
The Bauer–Fike Theorem
Bauer–Fike Theorem. Let be an eigenvalue of . Then there exists such that:
Proof. We can suppose , otherwise take and the result is trivially true since . Since is an eigenvalue of , we have and so
However our assumption, , implies that: and therefore we can write:
This reveals to be an eigenvalue of
Since all -norms are consistent matrix norms we have where is an eigenvalue of . In this instance this gives us:
But is a diagonal matrix, the -norm of which is easily computed:
whence:
An Alternate Formulation
The theorem can also be reformulated to better suit numerical methods. In fact, dealing with real eigensystem problems, one often has an exact matrix , but knows only an approximate eig
|
https://en.wikipedia.org/wiki/Logical%20Methods%20in%20Computer%20Science
|
Logical Methods in Computer Science (LMCS) is a peer-reviewed open access scientific journal covering theoretical computer science and applied logic. It opened to submissions on September 1, 2004. The editor-in-chief is Stefan Milius (Friedrich-Alexander Universität Erlangen-Nürnberg).
History
The journal was initially published by the International Federation
for Computational Logic, and then by a dedicated non-profit. It moved to the . platform in 2017. The first editor-in-chief was Dana Scott. In its first year, the journal received 75 submissions.
Abstracting and indexing
The journal is abstracted and indexed in Current Contents/Engineering, Computing & Technology, Mathematical Reviews, Science Citation Index Expanded, Scopus, and Zentralblatt MATH. According to the Journal Citation Reports, the journal has a 2016 impact factor of 0.661.
References
External links
Academic journals established in 2005
Computer science journals
Open access journals
Logic journals
Logic in computer science
Formal methods publications
Quarterly journals
English-language journals
|
https://en.wikipedia.org/wiki/Tatyana%20Nikitina
|
Tatyana Khashimovna Nikitina (, born 31 December 1945) is a prominent Russian bard. She usually performs together with her husband, Sergey Nikitin.
Biography
She was born Tatiana Sadykova in Dushanbe (currently Tajikistan) on December 31, 1945. In 1971, she graduated from the Department of Physics of Moscow State University. In 1968, she began singing in a quintet led by her husband, Sergey Nikitin. They worked together as biophysicists (both have Ph.D.s in Physics) as well as singers, creating many popular songs. Together they recorded more than 15 CDs and Vinyls (see works).
In 1990, she abandoned her research work to become the Manager for Culture of the October District ispolkom of Moscow, then became Deputy Prefect of the Central District of Moscow, and in 1992–1995 she was a deputy to the Minister for Culture of Russia. From 1998 to 2012, she worked as a manager at Kartina, an Italo-Swiss firm that organized art exhibitions.
She and her husband Sergei are very close friends with and, beginning in 2002, the three of them provided funding to improve the Smolensk Special School for the Blind and Visually Impaired Children ().
References
External links
Biography of Tatiana and Sergey Nikitins
Biography of Tatiana Nikitina
1945 births
Living people
People from Dushanbe
Moscow State University alumni
Russian bards
20th-century Russian women politicians
Soviet physicists
Soviet women singers
Soviet women singer-songwriters
Soviet singer-songwriters
20th-century Russia
|
https://en.wikipedia.org/wiki/Facilitated%20variation
|
The theory of facilitated variation demonstrates how seemingly complex biological systems can arise through a limited number of regulatory genetic changes, through the differential re-use of pre-existing developmental components. The theory was presented in 2005 by Marc W. Kirschner (a professor and chair at the Department of Systems Biology, Harvard Medical School) and John C. Gerhart (a professor at the Graduate School, University of California, Berkeley).
The theory of facilitated variation addresses the nature and function of phenotypic variation in evolution. Recent advances in cellular and evolutionary developmental biology shed light on a number of mechanisms for generating novelty. Most anatomical and physiological traits that have evolved since the Cambrian are, according to Kirschner and Gerhart, the result of regulatory changes in the usage of various conserved core components that function in development and physiology. Novel traits arise as novel packages of modular core components, which requires modest genetic change in regulatory elements. The modularity and adaptability of developmental systems reduces the number of regulatory changes needed to generate adaptive phenotypic variation, increases the probability that genetic mutation will be viable, and allows organisms to respond flexibly to novel environments. In this manner, the conserved core processes facilitate the generation of adaptive phenotypic variation, which natural selection subsequently propagat
|
https://en.wikipedia.org/wiki/Lund%20Observatory
|
Lund Observatory is the official English name for the astronomy department at Lund University. Between 1867-2001 "Lund Observatory" was also the name of the Observatory building, which is now referred to as the "Lund Old Observatory". As of January 2010, Lund Observatory is part of the Department of Astronomy and Theoretical Physics at Lund University. It is located in Lund, Sweden.
History
The institution was founded in 1749, but was preceded by an observatory built by astronomy professor Anders Spole (the grandfather of Anders Celsius) in 1672, which was destroyed at the Battle of Lund in 1676. The now old observatory from 1867 is located in a cultural-heritage protected observatory park just outside the medieval city boundaries. The department left these premises in 2001 for a new building on the northern campus of Lund University, inaugurated in 2001, using the nearby old water tower as their new location for astronomical observations. The history of astronomy in Lund through five centuries is told in the book Lundaögon mot stjärnorna
Activities
Today Lund Observatory research activity focuses on observational and theoretical astrophysics. Areas covered include galaxy formation and evolution, exoplanet research, laboratory astrophysics, high-energy astrophysics, star clusters, and astrometry (Hipparcos and Gaia).
The Lund Panorama of the Milky Way
Towards the middle 20th century astronomer professor Knut Lundmark, of the Lund Observatory in Sweden, supervised the tw
|
https://en.wikipedia.org/wiki/Solvatochromism
|
In chemistry, solvatochromism is the phenomenon observed when the colour of a solution is different when the solute is dissolved in different solvents.
The solvatochromic effect is the way the spectrum of a substance (the solute) varies when the substance is dissolved in a variety of solvents. In this context, the dielectric constant and hydrogen bonding capacity are the most important properties of the solvent. With various solvents there is a different effect on the electronic ground state and excited state of the solute, so that the size of energy gap between them changes as the solvent changes. This is reflected in the absorption or emission spectrum of the solute as differences in the position, intensity, and shape of the spectroscopic bands. When the spectroscopic band occurs in the visible part of the electromagnetic spectrum, solvatochromism is observed as a change of colour. This is illustrated by Reichardt's dye, as shown in the image.
Negative solvatochromism corresponds to a hypsochromic shift (or blue shift) with increasing solvent polarity. An examples of negative solvatochromism is provided by 4-(4-hydroxystyryl)-N-methylpyridinium iodide, which is red in 1-propanol, orange in methanol, and yellow in water.
Positive solvatochromism corresponds to a bathochromic shift (or red shift) with increasing solvent polarity. An example of positive solvatochromism is provided by 4,4'-bis(dimethylamino)fuchsone, which is orange in toluene, red in acetone.
The main va
|
https://en.wikipedia.org/wiki/Asymptotic%20distribution
|
In mathematics and statistics, an asymptotic distribution is a probability distribution that is in a sense the "limiting" distribution of a sequence of distributions. One of the main uses of the idea of an asymptotic distribution is in providing approximations to the cumulative distribution functions of statistical estimators.
Definition
A sequence of distributions corresponds to a sequence of random variables Zi for i = 1, 2, ..., I . In the simplest case, an asymptotic distribution exists if the probability distribution of Zi converges to a probability distribution (the asymptotic distribution) as i increases: see convergence in distribution. A special case of an asymptotic distribution is when the sequence of random variables is always zero or Zi = 0 as i approaches infinity. Here the asymptotic distribution is a degenerate distribution, corresponding to the value zero.
However, the most usual sense in which the term asymptotic distribution is used arises where the random variables Zi are modified by two sequences of non-random values. Thus if
converges in distribution to a non-degenerate distribution for two sequences {ai} and {bi} then Zi is said to have that distribution as its asymptotic distribution. If the distribution function of the asymptotic distribution is F then, for large n, the following approximations hold
If an asymptotic distribution exists, it is not necessarily true that any one outcome of the sequence of random variables is a convergent sequence of
|
https://en.wikipedia.org/wiki/Branched%20covering
|
In mathematics, a branched covering is a map that is almost a covering map, except on a small set.
In topology
In topology, a map is a branched covering if it is a covering map everywhere except for a nowhere dense set known as the branch set. Examples include the map from a wedge of circles to a single circle, where the map is a homeomorphism on each circle.
In algebraic geometry
In algebraic geometry, the term branched covering is used to describe morphisms from an algebraic variety to another one , the two dimensions being the same, and the typical fibre of being of dimension 0.
In that case, there will be an open set of (for the Zariski topology) that is dense in , such that the restriction of to (from to , that is) is unramified. Depending on the context, we can take this as local homeomorphism for the strong topology, over the complex numbers, or as an étale morphism in general (under some slightly stronger hypotheses, on flatness and separability). Generically, then, such a morphism resembles a covering space in the topological sense. For example, if and are both compact Riemann surfaces, we require only that is holomorphic and not constant, and then there is a finite set of points of , outside of which we do find an honest covering
.
Ramification locus
The set of exceptional points on is called the ramification locus (i.e. this is the complement of the largest possible open set ). In general monodromy occurs according to the fundamental group of
|
https://en.wikipedia.org/wiki/Torelli%20theorem
|
In mathematics, the Torelli theorem, named after Ruggiero Torelli, is a classical result of algebraic geometry over the complex number field, stating that a non-singular projective algebraic curve (compact Riemann surface) C is determined by its Jacobian variety J(C), when the latter is given in the form of a principally polarized abelian variety. In other words, the complex torus J(C), with certain 'markings', is enough to recover C. The same statement holds over any algebraically closed field. From more precise information on the constructed isomorphism of the curves it follows that if the canonically principally polarized Jacobian varieties of curves of genus are k-isomorphic for k any perfect field, so are the curves.
This result has had many important extensions. It can be recast to read that a certain natural morphism, the period mapping, from the moduli space of curves of a fixed genus, to a moduli space of abelian varieties, is injective (on geometric points). Generalizations are in two directions. Firstly, to geometric questions about that morphism, for example the local Torelli theorem. Secondly, to other period mappings. A case that has been investigated deeply is for K3 surfaces (by Viktor S. Kulikov, Ilya Pyatetskii-Shapiro, Igor Shafarevich and Fedor Bogomolov) and hyperkähler manifolds (by Misha Verbitsky, Eyal Markman and Daniel Huybrechts).
Notes
References
Algebraic curves
Abelian varieties
Moduli theory
Theorems in complex geometry
Theorems in alg
|
https://en.wikipedia.org/wiki/Max%20Planck%20Institute%20for%20Chemistry
|
The Max Planck Institute for Chemistry (Otto Hahn Institute; ) is a non-university research institute under the auspices of the Max Planck Society (German: Max-Planck-Gesellschaft) in Mainz, Germany. It was created as the Kaiser Wilhelm Institute for Chemistry in 1911 in Berlin.
In 2016 research at the Max Planck Institute for Chemistry in Mainz aims at an integral understanding of chemical processes in the Earth system, particularly in the atmosphere and biosphere. Investigations address a wide range of interactions between air, water, soil, life and climate in the course of Earth history up to today's human-driven epoch, the Anthropocene. The institute consists of five scientific departments (Atmospheric Chemistry, Climate Geochemistry, Biogeochemistry, Multiphase Chemistry, and Particle Chemistry) and additional research groups. The departments are independently led by their directors.
Research
The institute consists of five scientific departments and additional research groups.
Atmospheric Chemistry Department: The Atmospheric Chemistry Department which is led by Prof. Dr. Jos Lelieveld focuses on the study of ozone and other atmospheric photo-oxidants, their chemical reactions and global cycles. The researchers use kinetic and photochemical laboratory investigations, in situ and remote sensing measurements. The Atmospheric Chemistry department also develops numerical models to describe meteorological and chemical processes in the atmosphere, to simulate the complex
|
https://en.wikipedia.org/wiki/Diazine
|
In organic chemistry, diazines are a group of organic compounds having the molecular formula . Each contains a benzene ring in which two of the C-H fragments have been replaced by isolobal nitrogen. There are three structural isomers:
pyridazine (1,2-diazine)
pyrimidine (1,3-diazine)
pyrazine (1,4-diazine)
See also
6-membered rings with one nitrogen atom: pyridines
6-membered rings with three nitrogen atoms: triazines
6-membered rings with four nitrogen atoms: tetrazines
6-membered rings with five nitrogen atoms: pentazines
6-membered rings with six nitrogen atoms: hexazines
References
Simple aromatic rings
|
https://en.wikipedia.org/wiki/Noether%20normalization%20lemma
|
In mathematics, the Noether normalization lemma is a result of commutative algebra, introduced by Emmy Noether in 1926. It states that for any field k, and any finitely generated commutative k-algebra A, there exist algebraically independent elements y1, y2, ..., yd in A such that A is a finitely generated module over the polynomial ring S = k[y1, y2, ..., yd]. The integer d is equal to the Krull dimension of the ring A; and if A is an integral domain, d is also the transcendence degree of the field of fractions of A over k.
The theorem has a geometric interpretation. Suppose A is the coordinate ring of an affine variety X, and consider S as the coordinate ring of a d-dimensional affine space . Then the inclusion map induces a surjective finite morphism of affine varieties : that is, any affine variety is a branched covering of affine space.
When k is infinite, such a branched covering map can be constructed by taking a general projection from an affine space containing X to a d-dimensional subspace.
More generally, in the language of schemes, the theorem can equivalently be stated as: every affine k-scheme (of finite type) X is finite over an affine n-dimensional space. The theorem can be refined to include a chain of ideals of R (equivalently, closed subsets of X) that are finite over the affine coordinate subspaces of the corresponding dimensions.
The Noether normalization lemma can be used as an important step in proving Hilbert's Nullstellensatz, one of the most fun
|
https://en.wikipedia.org/wiki/Shlomi%20Dolev
|
Shlomi Dolev (; born December 5, 1958) is a Rita Altura Trust Chair Professor in Computer Science at Ben-Gurion University of the Negev (BGU) and the head of the BGU Negev Hi-Tech Faculty Startup Accelerator.
Biography
Shlomi Dolev received B.Sc. in Civil Engineering and B.A. in Computer Science in 1984 and 1985, and his M.Sc. and D.Sc. in computer science in 1990 and 1992 from the Technion Israel Institute of Technology. From 1992 to 1995 he was at Texas A&M University as a visiting research specialist.
Academic career
In 1995 Dolev joined the Department of Mathematics and Computer Science at BGU. He was the founder and first department head of the Computer Science Department, established in 2000. After 15 years, the department was ranked among the first 150 best departments in the world.
He is the author of Self-Stabilization published by MIT Press in 2000. From 2011 to 2014, Dolev served as Dean of the Natural Sciences Faculty. From 2010 he has served for six years, as the Head of the Inter University Computation Center of Israel.
He is a co-founder, board member and CSO of Secret Double Octopus. He is also a co-founder of Secret Sky (SecretSkyDB) Ltd. In 2015 Dolev was appointed head of the steering committee on computer science studies of the Israeli Ministry of Education.
Dolev together with Yuval Elovici and Ehud Gudes established the Telekom Innovation Laboratories at Ben-Gurion University. Dolev was instrumental in establishing the IBM Cyber Security Center of
|
https://en.wikipedia.org/wiki/Kennesaw%20Mountain%20High%20School
|
Kennesaw Mountain High School is a public high school located in Kennesaw, Cobb County, Georgia, United States. It was founded in 2000 as a magnet school specializing in science and mathematics, and is one of sixteen high schools in the Cobb County School District.
History
Students
Kennesaw Mountain High School was founded in 2000. The high school, built on a site, was intended to have a capacity of 2,000 students, but due to the rapid population growth in Cobb County, the school quickly became overcrowded. Before the school was built, juniors, as opposed to freshman and sophomores, from Harrison High School (the main output) were given the choice whether to stay at their current school or change to Kennesaw Mountain. Approximately 240 juniors decided to change, which was much more than expected.
Construction
Construction of the five buildings at the campus began in August 1999 and was completed in 14 months. The design, by Passantino & Bavier, Inc., used steel bowstring joists to allow for an arched roofline and the clear span required for the gymnasium. Design and construction of the campus is the only Georgia project featured by the Steel Joist Institute. Included in the design, as requested by the school, was a plan so 70% of classrooms would have windows.
Magnet program
The Academy of Mathematics, Science, & Technology at Kennesaw Mountain is one of seven magnet schools at the high school level in the Cobb County School District. For the class of 2023, the Academ
|
https://en.wikipedia.org/wiki/Disjunctive%20sum
|
In the mathematics of combinatorial games, the sum or disjunctive sum of two games is a game in which the two games are played in parallel, with each player being allowed to move in just one of the games per turn. The sum game finishes when there are no moves left in either of the two parallel games, at which point (in normal play) the last player to move wins.
This operation may be extended to disjunctive sums of any number of games, again by playing the games in parallel and moving in exactly one of the games per turn. It is the fundamental operation that is used in the Sprague–Grundy theorem for impartial games and which led to the field of combinatorial game theory for partisan games.
Application to common games
Disjunctive sums arise in games that naturally break up into components or regions that do not interact except in that each player in turn must choose just one component to play in. Examples of such games are Go, Nim, Sprouts, Domineering, the Game of the Amazons, and the map-coloring games.
In such games, each component may be analyzed separately for simplifications that do not affect its outcome or the outcome of its disjunctive sum with other games. Once this analysis has been performed, the components can be combined by taking the disjunctive sum of two games at a time, combining them into a single game with the same outcome as the original game.
Mathematics
The sum operation was formalized by . It is a commutative and associative operation: if two game
|
https://en.wikipedia.org/wiki/Adaptive%20beamformer
|
An adaptive beamformer is a system that performs adaptive spatial signal processing with an array of transmitters or receivers. The signals are combined in a manner which increases the signal strength to/from a chosen direction. Signals to/from other directions are combined in a benign or destructive manner, resulting in degradation of the signal to/from the undesired direction. This technique is used in both radio frequency and acoustic arrays, and provides for directional sensitivity without physically moving an array of receivers or transmitters.
Motivation/Applications
Adaptive beamforming was initially developed in the 1960s for the military applications of sonar and radar. There exist several modern applications for beamforming, one of the most visible applications being commercial wireless networks such as LTE. Initial applications of adaptive beamforming were largely focused in radar and electronic countermeasures to mitigate the effect of signal jamming in the military domain.
Radar uses can be seen here Phased array radar. Although not strictly adaptive, these radar applications make use of either static or dynamic (scanning) beamforming.
Commercial wireless standards such as 3GPP Long Term Evolution (LTE (telecommunication)) and IEEE 802.16 WiMax rely on adaptive beamforming to enable essential services within each standard.
Basic Concepts
An adaptive beamforming system relies on principles of wave propagation and phase relationships. See Constructive interfe
|
https://en.wikipedia.org/wiki/F.%20Peter%20Guengerich
|
Frederick Peter Guengerich is a professor of biochemistry and the director of the Center in Molecular Toxicology at Vanderbilt University, Nashville, Tennessee. Guengerich is the author or co-author of over 500 peer-reviewed scientific articles, and a researcher in toxicology working on cytochromes P450, DNA damage and carcinogenesis, and drug metabolism. In 2005 he received the William C. Rose Award for his research.
References
External links
Vanderbilt University Center in Molecular Toxicology
American biochemists
Living people
Vanderbilt University faculty
Year of birth missing (living people)
Fellows of the American Society for Pharmacology and Experimental Therapeutics
|
https://en.wikipedia.org/wiki/Leslie%20Valiant
|
Leslie Gabriel Valiant (born 28 March 1949) is a British American computer scientist and computational theorist. He was born to a chemical engineer father and a translator mother. He is currently the T. Jefferson Coolidge Professor of Computer Science and Applied Mathematics at Harvard University. Valiant was awarded the Turing Award in 2010, having been described by the A.C.M. as a heroic figure in theoretical computer science and a role model for his courage and creativity in addressing some of the deepest unsolved problems in science; in particular for his "striking combination of depth and breadth".
Education
Valiant was educated at King's College, Cambridge, Imperial College London, and the University of Warwick where he received a PhD in computer science in 1974.
Research and career
Valiant is world-renowned for his work in Theoretical Computer Science. Among his many contributions to Complexity Theory, he introduced the notion of #P-completeness ("Sharp-P completeness") to explain why enumeration and reliability problems are intractable. He created the Probably Approximately Correct or PAC model of learning that introduced the field of Computational Learning Theory and became a theoretical basis for the development of Machine Learning. He also introduced the concept of Holographic Algorithms inspired by the Quantum Computation model. In computer systems, he is most well-known for introducing the Bulk Synchronous Parallel processing model. Analogous to the von Neum
|
https://en.wikipedia.org/wiki/Innsbruck%20Observatory
|
Innsbruck Observatory (Universitäts-Sternwarte Innsbruck) is an astronomical observatory owned and operated by the institutes of astrophysics out of the University of Innsbruck. It is located in Innsbruck, Austria.
See also
List of astronomical observatories
References
External links
Innsbruck Observatory
Astronomical observatories in Austria
Buildings and structures in Innsbruck
Education in Tyrol (state)
|
https://en.wikipedia.org/wiki/Vijay%20Vazirani
|
Vijay Virkumar Vazirani (; b. 1957) is an Indian American distinguished professor of computer science in the Donald Bren School of Information and Computer Sciences at the University of California, Irvine.
Education and career
Vazirani first majored in electrical engineering at Indian Institute of Technology, Delhi but in his second year he transferred to MIT and received his bachelor's degree in computer science from MIT in 1979 and his Ph.D. from the University of California, Berkeley in 1983. His dissertation, Maximum Matchings without Blossoms, was supervised by Manuel Blum.
After postdoctoral research with Michael O. Rabin and Leslie Valiant at Harvard University, he joined the faculty at Cornell University in 1984. He moved to the IIT Delhi as a full professor in 1990, and moved again to the Georgia Institute of Technology in 1995. He was also a McKay Visiting Professor at the University of California, Berkeley, and a Distinguished SISL Visitor at the Social and Information Sciences Laboratory at the California Institute of Technology. In 2017 he moved to the University of California, Irvine as distinguished professor.
Research
Vazirani's research career has been centered around the design of algorithms, together with work on computational complexity theory, cryptography, and algorithmic game theory.
During the 1980s, he made seminal contributions to the classical maximum matching problem, and some key contributions to computational complexity theory, e.g., the isol
|
https://en.wikipedia.org/wiki/Pozna%C5%84%20Observatory
|
Poznań Observatory ( or "OA UAM", obs. code: 047) is an astronomical observatory owned and operated by the physics department of Adam Mickiewicz University in Poznań. It is located in Poznań, Poland and was founded in 1919.
In January 1953, asteroid 1572 Posnania (), discovered at Poznań, was after the city and the discovering observatory (). Asteroid 97786 Oauam, discovered by astronomers Petr Pravec and Peter Kušnirák at Ondřejov in 2000, was also named in honor of the observatory. The official was published by the IAU on 16 June 2021.
References
External links
Poznań Observatory
Asteroid (1572) Posnania
Astronomical observatories in Poland
Buildings and structures in Poznań
|
https://en.wikipedia.org/wiki/Pyrates
|
Pyrates is a 1991 comedy film, starring Kevin Bacon and Kyra Sedgwick about a couple who experience pyrokinesis after having sex. Directed and written by Noah Stern, the film was released on VHS on December 18, 1991.
Plot
When Ari (Kevin Bacon) and Sam (Kyra Sedgwick) first meet they realise that there is chemistry between them. When they have sex with each other, they experience pyrokinesis. However, as their love affair does not run smoothly, their friends Liam (Bruce Martyn Payne) and Pia (Kristin Dattilo) intervene to try to help. At one point when Sam is angry with Ari, Liam helps Ari to serenade her with a rendition the Soft Cell song Tainted Love.
Cast
Kevin Bacon as Ari
Kyra Sedgwick as Sam
Bruce Martyn Payne as Liam
Kristin Dattilo as Pia
Buckley Harris as Dr. Weiss
Deborah Falconer as Rivkah
David Pressman as Carlton
Raymond O'Connor as Fireman
Byrne Piven as Rabbi Lichtenstein
Ernie Lee Banks as Wee Willie
Mickey Jones as Wisconsin Del
Petra Verkaik as Basia
Clifford David as Advisor
Tom Adams as Calico Jack (uncredited)
Reception
Reviews for Pyrates were generally negative. Derek Adams of Time Out criticized the film for containing few laughs, stating that "the first time a lava lamp explodes, the second time round though, and the joke's already gone too far". No Byline stated that 'with the principals coming across as charmlessly self-centred, this cornucopia of copulation is, despite an attempt at kooky episodic to-camera chit-chat, more hot air than hot stu
|
https://en.wikipedia.org/wiki/Hradec%20Kr%C3%A1lov%C3%A9%20Observatory
|
Hradec Králové Observatory () is part astronomical observatory and part planetarium. Also housed in the same building are the Institute of Atmospheric Physics and the Czech Hydrometeorological Institute. It is located on the southern outskirts of Hradec Králové in the Czech Republic, and was founded in 1961.
See also
List of astronomical observatories
References
External links
Observatory and Planetarium Hradec Králové
Astronomical observatories in the Czech Republic
Planetaria in the Czech Republic
Buildings and structures in Hradec Králové
1961 establishments in Czechoslovakia
20th-century architecture in the Czech Republic
|
https://en.wikipedia.org/wiki/Working%20set
|
Working set is a concept in computer science which defines the amount of memory that a process requires in a given time interval.
Definition
Peter Denning (1968) defines "the working set of information of a process at time to be the collection of information referenced by the process during the process time interval ".
Typically the units of information in question are considered to be memory pages. This is suggested to be an approximation of the set of pages that the process will access in the future (say during the next time units), and more specifically is suggested to be an indication of what pages ought to be kept in main memory to allow most progress to be made in the execution of that process.
Rationale
The effect of the choice of what pages to be kept in main memory (as distinct from being paged out to auxiliary storage) is important: if too many pages of a process are kept in main memory, then fewer other processes can be ready at any one time. If too few pages of a process are kept in main memory, then its page fault frequency is greatly increased and the number of active (non-suspended) processes currently executing in the system approaches zero.
The working set model states that a process can be in RAM if and only if all of the pages that it is currently using (often approximated by the most recently used pages) can be in RAM. The model is an all or nothing model, meaning if the pages it needs to use increases, and there is no room in RAM, the process is swa
|
https://en.wikipedia.org/wiki/Mathematics%20Subject%20Classification
|
The Mathematics Subject Classification (MSC) is an alphanumerical classification scheme that has collaboratively been produced by staff of, and based on the coverage of, the two major mathematical reviewing databases, Mathematical Reviews and Zentralblatt MATH. The MSC is used by many mathematics journals, which ask authors of research papers and expository articles to list subject codes from the Mathematics Subject Classification in their papers. The current version is MSC2020.
Structure
The MSC is a hierarchical scheme, with three levels of structure. A classification can be two, three or five digits long, depending on how many levels of the classification scheme are used.
The first level is represented by a two-digit number, the second by a letter, and the third by another two-digit number. For example:
53 is the classification for differential geometry
53A is the classification for classical differential geometry
53A45 is the classification for vector and tensor analysis
First level
At the top level, 64 mathematical disciplines are labeled with a unique two-digit number. In addition to the typical areas of mathematical research, there are top-level categories for "History and Biography", "Mathematics Education", and for the overlap with different sciences. Physics (i.e. mathematical physics) is particularly well represented in the classification scheme with a number of different categories including:
Fluid mechanics
Quantum mechanics
Geophysics
Optics and el
|
https://en.wikipedia.org/wiki/Polish%20School%20of%20Mathematics
|
The Polish School of Mathematics was the mathematics community that flourished in Poland in the 20th century, particularly during the Interbellum between World Wars I and II.
Overview
The Polish School of Mathematics subsumed:
the Lwów School of Mathematics - mostly focused on functional analysis;
the Warsaw School of Mathematics - mostly focused on set theory, mathematical logic and topology; and
the Kraków School of Mathematics - mostly focused on differential equations, analytic functions, differential geometry.
Nomenclature
Poland's mathematicians provided a name to Polish notation and Polish space.
Background
It has been debated what stimulated the exceptional efflorescence of mathematics in Poland after World War I. Important preparatory work had been done by the Polish "Positivists" following the disastrous January 1863 Uprising. The Positivists extolled science and technology, and popularized slogans of "organic work" and "building from the foundations." In the 20th century, mathematics was a field of endeavor that could be successfully pursued even with the limited resources that Poland commanded in the interbellum period.
Historical Influences
Over the centuries, Polish mathematicians have influenced the course of history. Copernicus used mathematics to buttress his revolutionary heliocentric theory. Four hundred years later, Marian Rejewski — subsequently assisted by fellow mathematician-cryptologists Jerzy Różycki and Henryk Zygalski — in December 19
|
https://en.wikipedia.org/wiki/Orthology
|
Orthology may refer to:
Orthology (biology) - Homologous sequences originate from the same ancestors (homolog e.g. all globin protein), which are separated from each other after a speciation event, e.g. human beta and chimp beta globin. An orthologous gene is a gene in different species that evolved from a common ancestor by speciation. Normally orthologous genes retain the same function in the course of evolution.
Orthology (language) - the study of the correct use of words.
|
https://en.wikipedia.org/wiki/Taubes%27s%20Gromov%20invariant
|
In mathematics, the Gromov invariant of Clifford Taubes counts embedded (possibly disconnected) pseudoholomorphic curves in a symplectic 4-manifold, where the curves are holomorphic with respect to an auxiliary compatible almost complex structure. (Multiple covers of 2-tori with self-intersection 0 are also counted.)
Taubes proved the information contained in this invariant is equivalent to invariants derived from the Seiberg–Witten equations in a series of four long papers. Much of the analytical complexity connected to this invariant comes from properly counting multiply covered pseudoholomorphic curves so that the result is invariant of the choice of almost complex structure. The crux is a topologically defined index for pseudoholomorphic curves which controls embeddedness and bounds the Fredholm index.
Embedded contact homology is an extension due to Michael Hutchings of this work to noncompact four-manifolds of the form , where Y is a compact contact 3-manifold. ECH is a symplectic field theory-like invariant; namely, it is the homology of a chain complex generated by certain combinations of Reeb orbits of a contact form on Y, and whose differential counts certain embedded pseudoholomorphic curves and multiply covered pseudoholomorphic cylinders with "ECH index" 1 in . The ECH index is a version of Taubes's index for the cylindrical case, and again, the curves are pseudoholomorphic with respect to a suitable almost complex structure. The result is a topological in
|
https://en.wikipedia.org/wiki/Craig%20Hawker
|
Craig Jon Hawker (born 11 January 1964) is an Australian-born chemist. His research has focused on the interface between organic and polymer chemistry, with emphasis on the design, synthesis, and application of well-defined macromolecular structures in biotechnology, microelectronics, and surface science. Hawker holds more than 45 U.S. patents, and he has co-authored over 300 papers in the areas of nanotechnology, materials science, and chemistry. He was listed as one of the top 100 most cited chemists worldwide over the decade 1992–2002, and again in 2000–2010.
In 2021, Hawker was elected a member of the National Academy of Engineering for contributions to polymer chemistry through synthetic organic chemistry concepts and the advancement of molecular engineering principles. He is the director of the California Nanosystems Institute and holds a number of other laboratory directorships at the University of California, Santa Barbara.
He was elected a member of the National Academy of Sciences in 2022.
Education
Hawker was born in Australia and attended high school in Queensland. It was in high school that he developed his interest in chemistry because, as he put it, "it really allowed me to develop things with my hands. Chemistry is a very hands-on science." He studied at the University of Queensland and graduated with a Chemistry degree. He worked with Professor Alan R. Battersby at Cambridge University on his post-graduate studies achieving his PhD in bio-organic chemistry
|
https://en.wikipedia.org/wiki/Null%20%28mathematics%29
|
In mathematics, the word null (from meaning "zero", which is from meaning "none") is often associated with the concept of zero or the concept of nothing. It is used in varying context from "having zero members in a set" (e.g., null set) to "having a value of zero" (e.g., null vector).
In a vector space, the null vector is the neutral element of vector addition; depending on the context, a null vector may also be a vector mapped to some null by a function under consideration (such as a quadratic form coming with the vector space, see null vector, a linear mapping given as matrix product or dot product, a seminorm in a Minkowski space, etc.). In set theory, the empty set, that is, the set with zero elements, denoted "{}" or "∅", may also be called null set. In measure theory, a null set is a (possibly nonempty) set with zero measure.
A null space of a mapping is the part of the domain that is mapped into the null element of the image (the inverse image of the null element). For example, in linear algebra, the null space of a linear mapping, also known as kernel, is the set of vectors which map to the null vector under that mapping.
In statistics, a null hypothesis is a proposition that no effect or relationship exists between populations and phenomena. It is the hypothesis which is presumed true—unless statistical evidence indicates otherwise.
See also
0
Null sign
References
Mathematical terminology
0 (number)
|
https://en.wikipedia.org/wiki/Particle%20shower
|
In particle physics, a shower is a cascade of secondary particles produced as the result of a high-energy particle interacting with dense matter. The incoming particle interacts, producing multiple new particles with lesser energy; each of these then interacts, in the same way, a process that continues until many thousands, millions, or even billions of low-energy particles are produced. These are then stopped in the matter and absorbed.
Types
There are two basic types of showers. Electromagnetic showers are produced by a particle that interacts primarily or exclusively via the electromagnetic force, usually a photon or electron. Hadronic showers are produced by hadrons (i.e. nucleons and other particles made of quarks), and proceed mostly via the strong nuclear force.
Electromagnetic showers
An electromagnetic shower begins when a high-energy electron, positron or photon enters a material. At high energies (above a few MeV), in which the photoelectric effect and Compton scattering are insignificant, photons interact with matter primarily via pair production — that is, they convert into an electron-positron pair, interacting with an atomic nucleus or electron in order to conserve momentum. High-energy electrons and positrons primarily emit photons, a process called bremsstrahlung. These two processes (pair production and bremsstrahlung) continue, leading to a cascade of particles of decreasing energy until photons fall below the pair production threshold, and energy
|
https://en.wikipedia.org/wiki/Biharmonic%20equation
|
In mathematics, the biharmonic equation is a fourth-order partial differential equation which arises in areas of continuum mechanics, including linear elasticity theory and the solution of Stokes flows. Specifically, it is used in the modeling of thin structures that react elastically to external forces.
Notation
It is written as
or
or
where , which is the fourth power of the del operator and the square of the Laplacian operator (or ), is known as the biharmonic operator or the bilaplacian operator. In Cartesian coordinates, it can be written in dimensions as:
Because the formula here contains a summation of indices, many mathematicians prefer the notation over because the former makes clear which of the indices of the four nabla operators are contracted over.
For example, in three dimensional Cartesian coordinates the biharmonic equation has the form
As another example, in n-dimensional Real coordinate space without the origin ,
where
which shows, for n=3 and n=5 only, is a solution to the biharmonic equation.
A solution to the biharmonic equation is called a biharmonic function. Any harmonic function is biharmonic, but the converse is not always true.
In two-dimensional polar coordinates, the biharmonic equation is
which can be solved by separation of variables. The result is the Michell solution.
2-dimensional space
The general solution to the 2-dimensional case is
where , and are harmonic functions and is a harmonic conjugate of .
Just as h
|
https://en.wikipedia.org/wiki/Controlled%20NOT%20gate
|
In computer science, the controlled NOT gate (also C-NOT or CNOT), controlled-X gate, controlled-bit-flip gate, Feynman gate or controlled Pauli-X is a quantum logic gate that is an essential component in the construction of a gate-based quantum computer. It can be used to entangle and disentangle Bell states. Any quantum circuit can be simulated to an arbitrary degree of accuracy using a combination of CNOT gates and single qubit rotations. The gate is sometimes named after Richard Feynman who developed an early notation for quantum gate diagrams in 1986.
The CNOT can be expressed in the Pauli basis as:
Being both unitary and Hermitian, CNOT has the property and , and is involutory.
The CNOT gate can be further decomposed as products of rotation operator gates and exactly one two qubit interaction gate, for example
In general, any single qubit unitary gate can be expressed as , where H is a Hermitian matrix, and then the controlled U is .
The CNOT gate is also used in classical reversible computing.
Operation
The CNOT gate operates on a quantum register consisting of 2 qubits. The CNOT gate flips the second qubit (the target qubit) if and only if the first qubit (the control qubit) is .
If are the only allowed input values for both qubits, then the TARGET output of the CNOT gate corresponds to the result of a classical XOR gate. Fixing CONTROL as , the TARGET output of the CNOT gate yields the result of a classical NOT gate.
More generally, the inputs are all
|
https://en.wikipedia.org/wiki/General%20selection%20model
|
The general selection model (GSM) is a model of population genetics that describes how a population's allele frequencies will change when acted upon by natural selection.
Equation
The General Selection Model applied to a single gene with two alleles (let's call them A1 and A2) is encapsulated by the equation:
where:
is the frequency of allele A1
is the frequency of allele A2
is the rate of evolutionary change of the frequency of allele A2
are the relative fitnesses of homozygous A1, heterozygous (A1A2), and homozygous A2 genotypes respectively.
is the mean population relative fitness.
In words:
The product of the relative frequencies, , is a measure of the genetic variance. The quantity pq is maximized when there is an equal frequency of each gene, when . In the GSM, the rate of change is proportional to the genetic variation.
The mean population fitness is a measure of the overall fitness of the population. In the GSM, the rate of change is inversely proportional to the mean fitness —i.e. when the population is maximally fit, no further change can occur.
The remainder of the equation, , refers to the mean effect of an allele substitution. In essence, this term quantifies what effect genetic changes will have on fitness.
See also
Darwinian fitness
Hardy–Weinberg principle
Population genetics
References
Population genetics
|
https://en.wikipedia.org/wiki/Euler%20method
|
In mathematics and computational science, the Euler method (also called the forward Euler method) is a first-order numerical procedure for solving ordinary differential equations (ODEs) with a given initial value. It is the most basic explicit method for numerical integration of ordinary differential equations and is the simplest Runge–Kutta method. The Euler method is named after Leonhard Euler, who first proposed it in his book Institutionum calculi integralis (published 1768–1770).
The Euler method is a first-order method, which means that the local error (error per step) is proportional to the square of the step size, and the global error (error at a given time) is proportional to the step size.
The Euler method often serves as the basis to construct more complex methods, e.g., predictor–corrector method.
Geometrical description
Purpose and why it works
Consider the problem of calculating the shape of an unknown curve which starts at a given point and satisfies a given differential equation. Here, a differential equation can be thought of as a formula by which the slope of the tangent line to the curve can be computed at any point on the curve, once the position of that point has been calculated.
The idea is that while the curve is initially unknown, its starting point, which we denote by is known (see Figure 1). Then, from the differential equation, the slope to the curve at can be computed, and so, the tangent line.
Take a small step along that tangent line up
|
https://en.wikipedia.org/wiki/Margaret%20Boden
|
Margaret Ann Boden (born 26 November 1936) is a Research Professor of Cognitive Science in the Department of Informatics at the University of Sussex, where her work embraces the fields of artificial intelligence, psychology, philosophy, and cognitive and computer science.
Early life and education
Boden was educated at the City of London School for Girls in the late 1940s and 1950s. At Newnham College, Cambridge, she took first class honours in medical sciences, achieving the highest score across all Natural Sciences. In 1957 she studied the history of modern philosophy at the Cambridge Language Research Unit run by Margaret Masterman.
Career
Boden was appointed lecturer in philosophy at the University of Birmingham in 1959. She became a Harkness Fellow at Harvard University from 1962 to 1964, then returned to Birmingham for a year before moving to a lectureship in philosophy and psychology at Sussex University in 1965, where she was later appointed as Reader then Professor in 1980. She was awarded a PhD in social psychology (specialism: cognitive studies) by Harvard in 1968.
She credits reading "Plans and the Structure of Behavior" by George A. Miller with giving her the realisation that computer programming approaches could be applied to the whole of psychology.
Boden became Dean of the School of Social Sciences in 1985. Two years later she became the founding Dean of the University of Sussex's School of Cognitive and Computing Sciences (COGS), precursor of the universi
|
https://en.wikipedia.org/wiki/Riemann%E2%80%93Roch%20theorem%20for%20smooth%20manifolds
|
In mathematics, a Riemann–Roch theorem for smooth manifolds is a version of results such as the Hirzebruch–Riemann–Roch theorem or Grothendieck–Riemann–Roch theorem (GRR) without a hypothesis making the smooth manifolds involved carry a complex structure. Results of this kind were obtained by Michael Atiyah and Friedrich Hirzebruch in 1959, reducing the requirements to something like a spin structure.
Formulation
Let X and Y be oriented smooth closed manifolds,
and f: X → Y a continuous map.
Let vf=f*(TY) − TX in the K-group
K(X).
If dim(X) ≡ dim(Y) mod 2, then
where ch is the Chern character, d(vf) an element of
the integral cohomology group H2(Y, Z) satisfying
d(vf) ≡ f* w2(TY)-w2(TX) mod 2,
fK* the Gysin homomorphism for K-theory,
and fH* the Gysin homomorphism for cohomology
.
This theorem was first proven by Atiyah and Hirzebruch.
The theorem is proven by considering several special cases.
If Y is the Thom space of a vector bundle V over X,
then the Gysin maps are just the Thom isomorphism.
Then, using the splitting principle, it suffices to check the theorem via explicit computation for line
bundles.
If f: X → Y is an embedding, then the
Thom space of the normal bundle of X in Y can be viewed as a tubular neighborhood of X
in Y, and excision gives a map
and
.
The Gysin map for K-theory/cohomology is defined to be the composition of the Thom isomorphism with these maps.
Since the theorem holds for the map from X to the Thom space of N,
and since the Chern chara
|
https://en.wikipedia.org/wiki/Nancy%20D.%20Griffeth
|
Nancy Davis Griffeth (born October 26, 1945) is an American computer scientist notable for approaches to the feature interaction problem. In 2014, she is a professor at Lehman College of The City University of New York and is modelling biological systems in computational biology.
Early life
Griffeth was born in Oak Park, Illinois and lived in Laurel, Mississippi and Memphis, Tennessee as a child. She received a bachelor's degree from Harvard University, a master's degree from Michigan State University, and a PhD degree from the University of Chicago.
Career
Griffeth did seminal work in the feature interaction problem as a founding organizer of the feature interaction workshops and co-author of one of the most cited papers in feature interactions, "A Feature Interaction Benchmark for IN and Beyond."
The feature interaction problem is a software problem that arises when one feature interacts with another in such a way that it changes what the feature does. This can cause serious issues for developers and users of the software. The problem was first documented as features were added to telecommunications systems. If new features on a telecommunications network were either undetected or unwanted, they could cause confusion and dissatisfaction among customers if not handled properly.
Griffeth also researched the related problem of how to test networks to see how well they work together, called "interoperability".
She worked at the Next Generation Networking Lab at Lucent
|
https://en.wikipedia.org/wiki/Gabriel%20Gruber
|
Gabriel Gruber, SJ (4 May 1740 – 7 April 1805) was an Austrian cleric and polymath of Slovenian descent. Aside from his classical formation for the priesthood, his interests ranged across agriculture, architecture, astronomy, engineering, hydrology, physics, chemistry and art. Between 1773 and 1784 he was the engineer at the court of Emperor Joseph II. Having moved to Russia where Vatican law did not apply, he was welcomed at the Court of Catherine the Great as an engineer and saw there an opportunity to resume his monastic career among his exiled Jesuit brethren. He became the second Superior General of the Society of Jesus in Russia during the Holy See's suppression of the Society in Europe and its colonies and manifested great political skill in safeguarding the survival of the Jesuit order.
Early years and education
Gabriel Gruber, born in Vienna to a Slovenian family. His father was an armourer by trade. In 1755 he entered the Society of Jesus, aged 15. His three younger brothers, Anton, Johann-Nepomuk and Tobias, also followed him into the Jesuits.
His initial formation and studies took place in Austria, including Latin and Greek in Leoben (1757–1758), theology, philosophy and mathematics in Graz (1758–60), languages in Vienna (1760–61), mathematics at Trnava Jesuit university then in Hungary (1761–62), and again theology in Vienna (1763–67). In addition he undertook special studies in drawing, painting, music, mathematics, physics and medicine (specialising in surge
|
https://en.wikipedia.org/wiki/Helge%20Tverberg
|
Helge Arnulf Tverberg (March 6, 1935December 28, 2020) was a Norwegian mathematician. He was a professor in the Mathematics Department at the University of Bergen, his speciality being combinatorics; he retired at the mandatory age of seventy.
He was born in Bergen. He took the cand.real. degree at the University of Bergen in 1958, and the dr.philos. degree in 1968. He was a lecturer from 1958 to 1971 and professor from 1971 to his retirement in 2005. He was a visiting scholar at the University of Reading in 1966 and at the Australian National University, in Canberra, from 1980 to 1981, 1987 to 1988 and in 2004. He was a member of the Norwegian Academy of Science and Letters.
Tverberg, in 1965, proved a result on intersection patterns of partitions of point configurations that has come to be known as Tverberg's partition theorem. It inaugurated a new branch of combinatorial geometry, with many variations and applications. An account by Günter M. Ziegler of Tverberg's work in this direction appeared in the issue of the Notices of the American Mathematical Society for April, 2011.
See also
Geometric separator
References
1935 births
Living people
20th-century Norwegian mathematicians
Combinatorialists
Academic staff of the University of Bergen
University of Bergen alumni
Members of the Norwegian Academy of Science and Letters
|
https://en.wikipedia.org/wiki/Zeta%20function%20regularization
|
In mathematics and theoretical physics, zeta function regularization is a type of regularization or summability method that assigns finite values to divergent sums or products, and in particular can be used to define determinants and traces of some self-adjoint operators. The technique is now commonly applied to problems in physics, but has its origins in attempts to give precise meanings to ill-conditioned sums appearing in number theory.
Definition
There are several different summation methods called zeta function regularization for defining the sum of a possibly divergent series
One method is to define its zeta regularized sum to be ζA(−1) if this is defined, where the zeta function is defined for large Re(s) by
if this sum converges, and by analytic continuation elsewhere.
In the case when an = n, the zeta function is the ordinary Riemann zeta function. This method was used by Euler to "sum" the series 1 + 2 + 3 + 4 + ... to ζ(−1) = −1/12.
showed that in flat space, in which the eigenvalues of Laplacians are known, the zeta function corresponding to the partition function can be computed explicitly. Consider a scalar field φ contained in a large box of volume V in flat spacetime at the temperature T = β−1. The partition function is defined by a path integral over all fields φ on the Euclidean space obtained by putting τ = it which are zero on the walls of the box and which are periodic in τ with period β. In this situation from the partition function he computes e
|
https://en.wikipedia.org/wiki/Microsoft%20Visual%20SourceSafe
|
Microsoft Visual SourceSafe (VSS) is a discontinued source control program oriented towards small software development projects. Like most source control systems, SourceSafe creates a virtual library of computer files. While most commonly used for source code, SourceSafe can handle any type of file in its database, but older versions were shown to be unstable when used to store large amounts of non-textual data, such as images and compiled executables.
History
SourceSafe was originally created by a North Carolina company called One Tree Software. One Tree SourceSafe had gone through several releases in their 1.x to 2.x cycles, supporting DOS, OS/2 (with a Presentation Manager GUI), Windows, Windows NT, Mac, and Unix. When Microsoft bought OneTree in 1994, they immediately ceased development on all versions except for Windows. Microsoft SourceSafe 3.1, Windows 16-bit-only and Macintosh, rebranded One Tree 3.0 versions, were briefly available before Microsoft released a Version 4.0. With the acquisition of One Tree Software, Microsoft discontinued its source code control product at the time, Microsoft Delta. After the acquisition, Mainsoft Corporation developed SourceSafe for UNIX in cooperation with Microsoft.
Later, Metrowerks, Inc. developed Visual SourceSafe for Macintosh in cooperation with Microsoft.
Overview
SourceSafe was initially not a client/server Source Code Management, but rather a local only SCM system. Architecturally, this serves as both a strength and weakn
|
https://en.wikipedia.org/wiki/Maximum%20entropy%20thermodynamics
|
In physics, maximum entropy thermodynamics (colloquially, MaxEnt thermodynamics) views equilibrium thermodynamics and statistical mechanics as inference processes. More specifically, MaxEnt applies inference techniques rooted in Shannon information theory, Bayesian probability, and the principle of maximum entropy. These techniques are relevant to any situation requiring prediction from incomplete or insufficient data (e.g., image reconstruction, signal processing, spectral analysis, and inverse problems). MaxEnt thermodynamics began with two papers by Edwin T. Jaynes published in the 1957 Physical Review.
Maximum Shannon entropy
Central to the MaxEnt thesis is the principle of maximum entropy. It demands as given some partly specified model and some specified data related to the model. It selects a preferred probability distribution to represent the model. The given data state "testable information" about the probability distribution, for example particular expectation values, but are not in themselves sufficient to uniquely determine it. The principle states that one should prefer the distribution which maximizes the Shannon information entropy,
This is known as the Gibbs algorithm, having been introduced by J. Willard Gibbs in 1878, to set up statistical ensembles to predict the properties of thermodynamic systems at equilibrium. It is the cornerstone of the statistical mechanical analysis of the thermodynamic properties of equilibrium systems (see partition function)
|
https://en.wikipedia.org/wiki/Fred%20Cummings
|
Frederick W. Cummings (November 21, 1931 - January 31, 2019) was an American theoretical physicist and professor at the University of California, Riverside. He specialised in cavity quantum electrodynamics, many-body theory, non-linear dynamics, and biophysics.
Discoveries
Cummings obtained his PhD with Edwin Thompson Jaynes at Stanford University in 1962. After thirty years at University of California Riverside Physics department, Cummings became emeritus professor in 1993. He then lived in Marin County, California.
Some of his important discoveries include the "Jaynes–Cummings model", one atom interacting with a quantized e-m field; as well as the extension of this to N atoms, the "Tavis-Cummings model". In the last twenty years his interest has turned to questions of biophysics of development and evolution.
Academic career
Cummings was full professor at U.C. Riverside when he retired (emeritus) after thirty years at UCR.
Research interests
His major researh interests were
theoretical physics,
the biophysics of development,
cavity quantum electrodynamics,
many-body theory, and
non-linear dynamics.
Education
He received his BS from Louisiana State University in 1955 and his Ph.D. from Stanford University in 1960.
Biography
Cummings was born in New Orleans, Louisiana, in 1931.
He served in the U.S. Army from 1950 to 1952, in the infantry in Korea.
He studied for his BS in physics and math major at LSU 1952–1955.
He then was in the Physics Department of Stanford Univer
|
https://en.wikipedia.org/wiki/Max%20Long
|
Max Long is the name of:
Max Freedom Long (1890–1971), American teacher and philosopher
Maxie Long (1878–1959), American athlete and Olympic medalist
In computer science, the term max long may also refer to the maximum value that can be represented by a long integer data type.
|
https://en.wikipedia.org/wiki/Spin-1/2
|
In quantum mechanics, spin is an intrinsic property of all elementary particles. All known fermions, the particles that constitute ordinary matter, have a spin of . The spin number describes how many symmetrical facets a particle has in one full rotation; a spin of means that the particle must be rotated by two full turns (through 720°) before it has the same configuration as when it started.
Particles having net spin include the proton, neutron, electron, neutrino, and quarks. The dynamics of spin- objects cannot be accurately described using classical physics; they are among the simplest systems which require quantum mechanics to describe them. As such, the study of the behavior of spin- systems forms a central part of quantum mechanics.
Stern–Gerlach experiment
The necessity of introducing half-integer spin goes back experimentally to the results of the Stern–Gerlach experiment. A beam of atoms is run through a strong heterogeneous magnetic field, which then splits into N parts depending on the intrinsic angular momentum of the atoms. It was found that for silver atoms, the beam was split in two—the ground state therefore could not be an integer, because even if the intrinsic angular momentum of the atoms were the smallest (non-zero) integer possible, 1, the beam would be split into 3 parts, corresponding to atoms with Lz = −1, +1, and 0, with 0 simply being the value known to come between −1 and +1 while also being a whole-integer itself, and thus a valid quantized
|
https://en.wikipedia.org/wiki/Grothendieck%20spectral%20sequence
|
In mathematics, in the field of homological algebra, the Grothendieck spectral sequence, introduced by Alexander Grothendieck in his Tôhoku paper, is a spectral sequence that computes the derived functors of the composition of two functors , from knowledge of the derived functors of and .
Many spectral sequences in algebraic geometry are instances of the Grothendieck spectral sequence, for example the Leray spectral sequence.
Statement
If and are two additive and left exact functors between abelian categories such that both and have enough injectives and takes injective objects to -acyclic objects, then for each object of there is a spectral sequence:
where denotes the p-th right-derived functor of , etc., and where the arrow '' means convergence of spectral sequences.
Five term exact sequence
The exact sequence of low degrees reads
Examples
The Leray spectral sequence
If and are topological spaces, let and be the category of sheaves of abelian groups on and , respectively.
For a continuous map there is the (left-exact) direct image functor .
We also have the global section functors
and
Then since and the functors and satisfy the hypotheses (since the direct image functor has an exact left adjoint , pushforwards of injectives are injective and in particular acyclic for the global section functor), the sequence in this case becomes:
for a sheaf of abelian groups on .
Local-to-global Ext spectral sequence
There is a spectral sequence relatin
|
https://en.wikipedia.org/wiki/Laboratory%20of%20Solid%20State%20Microstructure%2C%20Nanjing%20University
|
Laboratory of Solid State Microstructure (LSSMS) is located in Nanjing University, China. It is a key laboratory in physics, associated with such faculties as schools of physics and electronics and department of materials of engineering school at Nanjing University.
The Laboratory has accomplished many achievements and enjoys international fame. Nature magazine listed it as one of the two best research groups approaching/with world-class standards in East Asia apart from Japan. The Institute for Scientific Information listed it as the No. 1 laboratory in China as published in Science magazine.
History
In 1984, Nanjing University Institute of Solid State Physics was changed to State Key Laboratory of Solid State Microstructures of Nanjing University, which was mainly associated with the Department of Physics of Nanjing University at the time.
Nanjing National Laboratory of Microstructures, which mainly based upon LSSMS and LCC (State Key Laboratory of Coordination Chemistry) at Nanjing University, was formally started to establish in 2006, with estimated investment of RMB 300 million, and before that, in 2004, NU received endowment of RMB 50 million from Cyrus Tang Foundation for its establishment, and the National Microstructures Laboratory Building - Cyrus Tang Building, was completed in 2007.
Research areas
Physics of microstructured dielectric materials
Nano-structured materials and physics
Aggregations and pattern formation under non-equilibrium conditions
Dynamics of
|
https://en.wikipedia.org/wiki/Gerald%20Meyer
|
Gerald J. Meyer is an active researcher and professor of inorganic chemistry at the University of North Carolina at Chapel Hill. He was previously the Bernard N. Baker Chair In Chemistry at Johns Hopkins University. His research interests include inorganic photochemistry with emphasis on solar energy, using interfacial electron transfer processes
and dye-sensitized solar cells.
Education
Meyer earned a B.S. in chemistry from the University at Albany, SUNY in 1985.
In 1989 he earned his Ph.D. in chemistry at the University of Wisconsin–Madison, where he worked with Arthur B. Ellis.
From 1989-1991, he did postdoctoral work at the University of North Carolina at Chapel Hill with Thomas J. Meyer.
Career
In 1991, Meyer joined Johns Hopkins University. Meyer was a director of the NSF Collaborative Research Activities in Environmental Science Center (CRAEMS) from 2002-2007. Meyer held the Bernard N. Baker Chair In Chemistry at Johns Hopkins University from 2009 to 2013, and served as chairman of the chemistry department at Johns Hopkins University from 2011 to 2013.
As of January 2014, he became professor in chemistry at the University of North Carolina at Chapel Hill. He is the director of the University of North Carolina's Center for Solar Fuels (UNC EFRC), an Energy Frontier Research Center funded by the United States Department of Energy.
He has served on the editorial advisory boards of the American Chemical Society journals Langmuir, Inorganic Chemistry, Chemistry o
|
https://en.wikipedia.org/wiki/Gelfand%20pair
|
In mathematics, a Gelfand pair is a pair (G,K) consisting of a group G and a subgroup K (called an Euler subgroup of G) that satisfies a certain property on restricted representations. The theory of Gelfand pairs is closely related to the topic of spherical functions in the classical theory of special functions, and to the theory of Riemannian symmetric spaces in differential geometry. Broadly speaking, the theory exists to abstract from these theories their content in terms of harmonic analysis and representation theory.
When G is a finite group the simplest definition is, roughly speaking, that the (K,K)-double cosets in G commute. More precisely, the Hecke algebra, the algebra of functions on G that are invariant under translation on either side by K, should be commutative for the convolution on G.
In general, the definition of Gelfand pair is roughly that the restriction to K of any irreducible representation of G contains the trivial representation of K with multiplicity no more than 1. In each case one should specify the class of considered representations and the meaning of contains.
Definitions
In each area, the class of representations and the definition of containment for representations is slightly different. Explicit definitions in several such cases are given here.
Finite group case
When G is a finite group the following are equivalent
(G,K) is a Gelfand pair.
The algebra of (K,K)-double invariant functions on G with multiplication defined by convolution i
|
https://en.wikipedia.org/wiki/Formal%20moduli
|
In mathematics, formal moduli are an aspect of the theory of moduli spaces (of algebraic varieties or vector bundles, for example), closely linked to deformation theory and formal geometry. Roughly speaking, deformation theory can provide the Taylor polynomial level of information about deformations, while formal moduli theory can assemble consistent Taylor polynomials to make a formal power series theory. The step to moduli spaces, properly speaking, is an algebraization question, and has been largely put on a firm basis by Artin's approximation theorem.
A formal universal deformation is by definition a formal scheme over a complete local ring, with special fiber the scheme over a field being studied, and with a universal property amongst such set-ups. The local ring in question is then the carrier of the formal moduli.
References
Moduli theory
Algebraic geometry
Geometric algebra
|
https://en.wikipedia.org/wiki/Christopher%20Wills
|
Christopher J. Wills (born 1938) is Professor Emeritus of Biology at UCSD.
He received his Ph.D. from UC Berkeley. As a Guggenheim Fellow, he worked at the Karolinska Institute, Stockholm, on protein chemistry and evolution.
He is the author of The Runaway Brain: The Evolution of Human Uniqueness (1994), Children Of Prometheus, The Accelerating Pace Of Human Evolution (1999), The Spark Of Life: Darwin And The Primeval Soup (2001) and The Darwinian Tourist: Viewing the World Through Evolutionary Eyes (late 2010). Children of Prometheus was a finalist for the Aventis Prize in 2000. He received the 1998 Award for the Public Understanding of Science and Technology from the American Association for the Advancement of Science.
References
External links
UCSD page
1938 births
Living people
Human evolution theorists
American biochemists
University of California, San Diego faculty
University of California, Berkeley alumni
|
https://en.wikipedia.org/wiki/Luk%20Van%20Parijs
|
Luk Van Parijs was an associate professor of biology at the Massachusetts Institute of Technology (MIT) Center for Cancer Research. After investigating for a year, MIT fired Van Parijs for research misconduct. Van Parijs admitted to fabricating and falsifying research data in a paper, several unpublished manuscripts, and grant applications. In March 2011, Van Parijs pleaded guilty in a U.S. District Court in Boston to one count of making a false statement on a federal grant application. The government asked Judge Denise Casper for a 6-month jail term because of the seriousness of the fraud, which involved a $2-million grant. After several prominent scientists including Van Parijs' former post-doc supervisor pleading for clemency on his behalf, on 13 June, Van Parijs was finally sentenced six months of home detention with electronic monitoring, plus 400 hours of community service and a payment to MIT of $61,117 - restitution for the already-spent grant money that MIT had to return to the National Institutes of Health .
Van Parijs' area of research was in the use of short-interference RNA in studying disease mechanisms, especially in autoimmune diseases. He was studying normal immune cell function and defects in these cells during disease development.
Timeline
About 1970: Born in Belgium.
Before 1997: Receives undergraduate education at Cambridge University in England.
About 1993 - 1997: Works in the laboratory of Harvard professor Dr. Abul Abbas at Brigham and Women's H
|
https://en.wikipedia.org/wiki/Asian%20Pacific%20Mathematics%20Olympiad
|
The Asian Pacific Mathematics Olympiad (APMO) starting from 1989 is a regional mathematics competition which involves countries from the Asian Pacific region. The United States also takes part in the APMO. Every year, APMO is held in the afternoon of the second Monday of March for participating countries in the North and South Americas, and in the morning of the second Tuesday of March for participating countries on the Western Pacific and in Asia.
APMO's Aims
the discovering, encouraging and challenging of mathematically gifted school students in all Pacific-Rim countries
the fostering of friendly international relations and cooperation between students and teachers in the Pacific-Rim Region
the creating of an opportunity for the exchange of information on school syllabi and practice throughout the Pacific Region
the encouragement and support of mathematical involvement with Olympiad type activities, not only in the APMO participating countries, but also in other Pacific-Rim countries.
Scoring and Format
The APMO contest consists of one four-hour paper consisting of five questions of varying difficulty and each having a maximum score of 7 points. Contestants should not have formally enrolled at a university (or equivalent post-secondary institution) and they must be younger than 20 years of age on 1 July of the year of the contest.
APMO Member Nations/Regions
Observer Nations
Honduras and South Africa
Results
https://cms.math.ca/Competitions/APMO/
https://www.apmo-
|
https://en.wikipedia.org/wiki/Current%20%28mathematics%29
|
In mathematics, more particularly in functional analysis, differential topology, and geometric measure theory, a k-current in the sense of Georges de Rham is a functional on the space of compactly supported differential k-forms, on a smooth manifold M. Currents formally behave like Schwartz distributions on a space of differential forms, but in a geometric setting, they can represent integration over a submanifold, generalizing the Dirac delta function, or more generally even directional derivatives of delta functions (multipoles) spread out along subsets of M.
Definition
Let denote the space of smooth m-forms with compact support on a smooth manifold A current is a linear functional on which is continuous in the sense of distributions. Thus a linear functional
is an m-dimensional current if it is continuous in the following sense: If a sequence of smooth forms, all supported in the same compact set, is such that all derivatives of all their coefficients tend uniformly to 0 when tends to infinity, then tends to 0.
The space of m-dimensional currents on is a real vector space with operations defined by
Much of the theory of distributions carries over to currents with minimal adjustments. For example, one may define the support of a current as the complement of the biggest open set such that
whenever
The linear subspace of consisting of currents with support (in the sense above) that is a compact subset of is denoted
Homological theory
Integration over a co
|
https://en.wikipedia.org/wiki/Dichotomic%20search
|
In computer science, a dichotomic search is a search algorithm that operates by selecting between two distinct alternatives (dichotomies) at each step. It is a specific type of divide and conquer algorithm. A well-known example is binary search.
Abstractly, a dichotomic search can be viewed as following edges of an implicit binary tree structure until it reaches a leaf (a goal or final state). This creates a theoretical tradeoff between the number of possible states and the running time: given k comparisons, the algorithm can only reach O(2k) possible states and/or possible goals.
Some dichotomic searches only have results at the leaves of the tree, such as the Huffman tree used in Huffman coding, or the implicit classification tree used in Twenty Questions. Other dichotomic searches also have results in at least some internal nodes of the tree, such as a dichotomic search table for Morse code. There is thus some looseness in the definition. Though there may indeed be only two paths from any node, there are thus three possibilities at each step: choose one onwards path or the other, ''or' stop at this node.
Dichotomic searches are often used in repair manuals, sometimes graphically illustrated with a flowchart similar to a fault tree.
See also
Binary search algorithm
References
xlinux.nist.gov, Dictionary of Algorithms and Data Structures: Dichotomic search
National Institute of Standards and Technology, Dictionary of Algorithms and Data Structures: Dichotomic search
|
https://en.wikipedia.org/wiki/K-homology
|
In mathematics, K-homology is a homology theory on the category of locally compact Hausdorff spaces. It classifies the elliptic pseudo-differential operators acting on the vector bundles over a space. In terms of -algebras, it classifies the Fredholm modules over an algebra.
An operator homotopy between two Fredholm modules and is a norm continuous path of Fredholm modules, , Two Fredholm modules are then equivalent if they are related by unitary transformations or operator homotopies. The group is the abelian group of equivalence classes of even Fredholm modules over A. The group is the abelian group of equivalence classes of odd Fredholm modules over A. Addition is given by direct summation of Fredholm modules, and the inverse of is
References
N. Higson and J. Roe, Analytic K-homology. Oxford University Press, 2000.
K-theory
Homology theory
|
https://en.wikipedia.org/wiki/Matthew%20Kapell
|
Matthew Wilhelm Kapell is a historian and anthropologist, with master's degrees in each discipline, who has a Ph.D. in American Studies.
Early in his career he co-authored chapters on the genetics of human growth and the effects of poverty on growth. The majority of this work appeared while he taught anthropology at the University of Michigan–Dearborn. Included among these are essays published mainly in edited European and Indian (Asia) works attacking ideas of genetic factors in determining development of height and body shape. Other publications include works on the computer game Civilization, Holocaustal images in Star Trek: Deep Space Nine, the American speculative fiction and socialist writer Mack Reynolds re-working of the Utopian fiction of Edward Bellamy, and Christian Romance fiction.
Kapell has also published a number of essays in the journal Extrapolation, and elsewhere, on speculative fiction in the United States as intellectual history. His work in history is mainly focused American frontier ideology in the contemporary period, though he has also published on the representation of race in the Detroit media during World War II and the legal history of British colonial marriage law in Africa.
Kapell was educated at Schoolcraft College, The University of Michigan–Dearborn, Wayne State University, all in Michigan, United States, and at Swansea University, Wales, UK.
He is best known for his work in media studies and frontier ideology in American history.
Frontie
|
https://en.wikipedia.org/wiki/Primary%20ideal
|
In mathematics, specifically commutative algebra, a proper ideal Q of a commutative ring A is said to be primary if whenever xy is an element of Q then x or yn is also an element of Q, for some n > 0. For example, in the ring of integers Z, (pn) is a primary ideal if p is a prime number.
The notion of primary ideals is important in commutative ring theory because every ideal of a Noetherian ring has a primary decomposition, that is, can be written as an intersection of finitely many primary ideals. This result is known as the Lasker–Noether theorem. Consequently, an irreducible ideal of a Noetherian ring is primary.
Various methods of generalizing primary ideals to noncommutative rings exist, but the topic is most often studied for commutative rings. Therefore, the rings in this article are assumed to be commutative rings with identity.
Examples and properties
The definition can be rephrased in a more symmetric manner: an ideal is primary if, whenever , we have or or . (Here denotes the radical of .)
An ideal Q of R is primary if and only if every zero divisor in R/Q is nilpotent. (Compare this to the case of prime ideals, where P is prime if and only if every zero divisor in R/P is actually zero.)
Any prime ideal is primary, and moreover an ideal is prime if and only if it is primary and semiprime (also called radical ideal in the commutative case).
Every primary ideal is primal.
If Q is a primary ideal, then the radical of Q is necessarily a prime ideal P, an
|
https://en.wikipedia.org/wiki/Direct%20image%20functor
|
In mathematics, the direct image functor is a construction in sheaf theory that generalizes the global sections functor to the relative case. It is of fundamental importance in topology and algebraic geometry. Given a sheaf F defined on a topological space X and a continuous map f: X → Y, we can define a new sheaf f∗F on Y, called the direct image sheaf or the pushforward sheaf of F along f, such that the global sections of f∗F is given by the global sections of F. This assignment gives rise to a functor f∗ from the category of sheaves on X to the category of sheaves on Y, which is known as the direct image functor. Similar constructions exist in many other algebraic and geometric contexts, including that of quasi-coherent sheaves and étale sheaves on a scheme.
Definition
Let f: X → Y be a continuous map of topological spaces, and let Sh(–) denote the category of sheaves of abelian groups on a topological space. The direct image functor
sends a sheaf F on X to its direct image presheaf f∗F on Y, defined on open subsets U of Y by
This turns out to be a sheaf on Y, and is called the direct image sheaf or pushforward sheaf of F along f.
Since a morphism of sheaves φ: F → G on X gives rise to a morphism of sheaves f∗(φ): f∗(F) → f∗(G) on Y in an obvious way, we indeed have that f∗ is a functor.
Example
If Y is a point, and f: X → Y the unique continuous map, then Sh(Y) is the category Ab of abelian groups, and the direct image functor f∗: Sh(X) → Ab equals the global se
|
https://en.wikipedia.org/wiki/Discriminant%20of%20an%20algebraic%20number%20field
|
In mathematics, the discriminant of an algebraic number field is a numerical invariant that, loosely speaking, measures the size of the (ring of integers of the) algebraic number field. More specifically, it is proportional to the squared volume of the fundamental domain of the ring of integers, and it regulates which primes are ramified.
The discriminant is one of the most basic invariants of a number field, and occurs in several important analytic formulas such as the functional equation of the Dedekind zeta function of K, and the analytic class number formula for K. A theorem of Hermite states that there are only finitely many number fields of bounded discriminant, however determining this quantity is still an open problem, and the subject of current research.
The discriminant of K can be referred to as the absolute discriminant of K to distinguish it from the relative discriminant of an extension K/L of number fields. The latter is an ideal in the ring of integers of L, and like the absolute discriminant it indicates which primes are ramified in K/L. It is a generalization of the absolute discriminant allowing for L to be bigger than Q; in fact, when L = Q, the relative discriminant of K/Q is the principal ideal of Z generated by the absolute discriminant of K.
Definition
Let K be an algebraic number field, and let OK be its ring of integers. Let b1, ..., bn be an integral basis of OK (i.e. a basis as a Z-module), and let {σ1, ..., σn} be the set of embeddings of K int
|
https://en.wikipedia.org/wiki/Sticking
|
Sticking may refer to:
Sticking coefficient, a surface physics concept
Sticking knife, an agricultural tool used for bleeding out livestock in home butchering
See also
Stick (disambiguation)
Stuck (disambiguation)
|
https://en.wikipedia.org/wiki/Paul%20Luzio
|
J Paul Luzio FMedSci (born 15 August 1947) is a British biologist who is Professor of Molecular Membrane Biology, Department of Clinical Biochemistry at the University of Cambridge, and was Master of St Edmund's College, Cambridge until 2014, as well as Director of the Cambridge Institute for Medical Research.
He was a student at Clare College, Cambridge reading Natural Sciences (Part II Biochemistry) as an undergraduate and studying for a Ph.D. in the Department of Biochemistry. After a period in Cardiff as a lecturer of medical biochemistry at the Welsh National School of Medicine, he returned to Cambridge where he became a lecturer in clinical biochemistry. He was subsequently promoted to Reader and then Professor.
Luzio's research is largely concerned with intracellular membrane traffic pathways in mammalian cells and his research group is funded by a programme grant from the Medical Research Council and project grant support from the Wellcome Trust.
He is an Honorary Fellow of St Edmund's College, Cambridge.
References
http://www.cimr.cam.ac.uk/
https://web.archive.org/web/20111108143021/http://www.st-edmunds.cam.ac.uk/fellows/individuals/index.php?recid=75
Living people
1947 births
Masters of St Edmund's College, Cambridge
Academics of the University of Cambridge
20th-century British biologists
21st-century British biologists
Alumni of Clare College, Cambridge
|
https://en.wikipedia.org/wiki/John%20P.%20Barber
|
John P. Barber is a pioneer of railgun technology.
Dr. Barber received the Bachelor of Science degree in Engineering Physics from the University of Saskatchewan in 1967 and his Ph.D. in Engineering Physics from Australian National University in 1972. He joined the University of Dayton Research Institute in 1974 and directed the Impact Physics Group there until 1979 when he resigned to go into business. Dr. Barber co-founded IAP Research in 1981 and has served as President since.
Dr. Barber has had a distinguished career in research and development. His graduate work on electromagnetic guns became the foundation for the ongoing program in the US to develop railgun technology for a variety of military and aerospace applications. His contributions to the development of electromagnetic gun technology were recognized in 1988 when he was awarded the Peter Mark Medal. He holds seven patents in magnetics and superconductivity.
Dr. Barber is a member of the Institute of Electrical and Electronics Engineers, the American Institute of Aeronautics and Astronautics, the American Defense Preparedness Association, and the Metal Powder Industry Federation. He serves on the Board and Executive Committee of the Edison Materials Technology Center, and is a member of the Materials and Process Advisory Panel of the Miami Valley Economic Development Coalition.
References
Year of birth missing (living people)
Living people
University of Saskatchewan alumni
Australian National University alumni
|
https://en.wikipedia.org/wiki/John%20Caswell%20Davis
|
John Caswell Davis (August 19, 1888 – October 25, 1953) was a Canadian senator.
Biography
Early career
Born in Montreal, Quebec in 1888 and after graduating from McGill University with a degree in civil engineering he moved to Saint Boniface, Manitoba where his bilingual Montreal upbringing fostered quick assimilation into the local French and Metis culture.
Political career
Bilingual and bicultural, John Caswell Davis's political abilities were appreciated as a bridge to unify a French minority intent on asserting itself culturally and politically within a Canada dominated by the English majority. Member of the Liberal Party and gifted orator John Caswell Davis entered the senate in 1949. His promising political career was cut short by his untimely death in 1953 while only 65 years old.
Other work
Caswell Davis was a gifted, inspired, and prolific artist who worked in numerous media including pencil, pen and ink, watercolour, and pastels. His landscapes captured the changing and often vanishing natural beauty of the forests, prairie, and mountains of western Canada. His cityscapes are low key but very revealing explorations of a Canadian society in process of urbanisation after centuries of rural existence. As a draughtsman, his linear ability was used in the documentation of the everyday life of French Canada and his adopted home St. Boniface. Adept at representation, his numerous portraits of friends and family members demonstrate a brilliance in capturing and reveali
|
https://en.wikipedia.org/wiki/Intercalation
|
Intercalation may refer to:
Intercalation (chemistry), insertion of a molecule (or ion) into layered solids such as graphite
Intercalation (timekeeping), insertion of a leap day, week or month into some calendar years to make the calendar follow the seasons
Intercalation (university administration), period when a student is officially given time off from studying for an academic degree
Intercalation (geology), a special form of interbedding, where two distinct depositional environments in close spatial proximity migrate back and forth across the border zone
Intercalary chapter, a chapter in a novel that does not further the plot. See also frame story (sometimes called intercalation).
In biology:
Intercalary segment, an appendage-less segment in the segmental composition of the heads of insects and Myriapoda
Intercalation (biochemistry), process discovered by Leonard Lerman by which certain drugs and mutagens insert themselves between base pairs of DNA
Intercalated cells of the amygdala
Intercalated cells of the collecting duct
Intercalated disc of cardiac muscle
Intercalated duct of exocrine glands
|
https://en.wikipedia.org/wiki/Finite%20potential%20well
|
The finite potential well (also known as the finite square well) is a concept from quantum mechanics. It is an extension of the infinite potential well, in which a particle is confined to a "box", but one which has finite potential "walls". Unlike the infinite potential well, there is a probability associated with the particle being found outside the box. The quantum mechanical interpretation is unlike the classical interpretation, where if the total energy of the particle is less than the potential energy barrier of the walls it cannot be found outside the box. In the quantum interpretation, there is a non-zero probability of the particle being outside the box even when the energy of the particle is less than the potential energy barrier of the walls (cf quantum tunnelling).
Particle in a 1-dimensional box
For the 1-dimensional case on the x-axis, the time-independent Schrödinger equation can be written as:
where
is the reduced Planck's constant,
is Planck's constant,
is the mass of the particle,
is the (complex valued) wavefunction that we want to find,
is a function describing the potential energy at each point x, and
is the energy, a real number, sometimes called eigenenergy.
For the case of the particle in a 1-dimensional box of length L, the potential is outside the box, and zero for x between and . The wavefunction is considered to be made up of different wavefunctions at different ranges of x, depending on whether x is inside or outside of the box. Therefor
|
https://en.wikipedia.org/wiki/Harald%20Fuchs
|
Harald Fuchs (born April 15, 1951) is a Professor of Experimental Physics at the University of Münster, Germany, Scientific Director of the Center of Nanotechnology (CeNTech) in Münster, and co-director of the Institute of Nanotechnology (INT) in Karlsruhe. His research focuses on nanoscale science and nanotechnology, ranging from scanning probe microscopy to self organized nanostructure fabrication, and nano–bio systems. He has published more than 450 scientific articles in various journals as an author or co-author. He was awarded the Philip Morris Research Prize "Challenge Future" in 1994 and the Münsterland Innovation Prize in 2001. He is currently member of the German Academy of Natural Scientists Leopoldina, the German "National Academy of Science and Engineering" (acatech) as well as "The world academy of sciences" (TWAS). He holds two guest professorships in China. He is a cofounder of several nanotechnology companies and a member of the Editorial Boards in several international journals. In 2015 he received an Honorary Professorship at the Nanjing-Tech-University, China.
Publications
H. Fuchs, Rastersondenmikroskopie Bergmann-Schaefer, Lehrbuch der Experimentalphysik, Band 3: "Optik", 10. Aufl., S. 1133–1159, , de Gruyter Verlag (2004)
H. Fuchs, H. Hölscher, A. Schirmeisen, Scanning Probe Microscopy, Encyclopedia of Materials: Science and Technology, S. 1–12, , Elsevier (2005)
External links
Uni Münster
CeNTech
Nanotechnologie Forschungszentrum Karlsruhe
Nanjing-T
|
https://en.wikipedia.org/wiki/Chart%20%28disambiguation%29
|
A chart is a graphical representation of data.
Chart or CHART may also refer to:
A specific type of map, for example:
Aeronautical chart, a representation of airspace and ground features relevant to aviation
Nautical chart, a representation of a maritime area and adjacent coastal regions
Chart, in computer science, a data structure used by a chart parser to store partial hypothesized results for re-use
Chart (magazine), a Canadian music publication
Chart, in geometry or topology, a coordinate chart for a manifold
CHART (Coordinated Highways Action Response Team), part of the Maryland State Highway Administration
Chart of accounts, an accounting term
Chart Records, a record label
Chord chart, a form of sheet music
Medical record, a medical file
Project CHART, a digital history project in Brooklyn, New York
Record chart, for music popularity rankings
See also
Charl (name)
Charo (disambiguation)
Charter
Charting (disambiguation)
Chartres
|
https://en.wikipedia.org/wiki/Exoelectron%20emission
|
In atomic physics, exoelectron emission (EE) is a weak electron emission, appearing only from pretreated (irradiated, deformed etc.) objects. The pretreatment ("excitation") turns the objects into an unequilibrial state. EE accompanies the relaxation of these unequilibria. The relaxation can be stimulated e.g. by slight heating or longwave illumination, not causing emission from untreated samples. Accordingly, thermo- and photostimulated EE (TSEE, PSEE) are distinguished. Thus, EE is an electron emission analogue of such optical phenomena as phosphorescence, thermo- and photostimulated luminescence.
References
Atomic, molecular, and optical physics
|
https://en.wikipedia.org/wiki/Georgi%20Bliznakov
|
Georgi Bliznakov ( (14 November 1920 – April 2004) was an eminent Bulgarian chemist. He was head of the Department of Inorganic Chemistry and rector at Sofia University, director of the Institute of Inorganic Chemistry of the Bulgarian Academy of Sciences and vice-chairman of the academy.
Biography
Bliznakov was born in 1920 in Berkovitsa, Bulgaria. After graduating in chemistry in 1943 from Sofia University he worked in industry until 1946, when he joined the University of Varna as an assistant in inorganic and physical chemistry. In 1949 he joined the Department of Physical Chemistry at the Polytechnic Institute in Sofia (now the University of Chemical Technology and Metallurgy) as an assistant where he stayed until moving to the Department of Inorganic Chemistry at Sofia University in 1951, becoming full professor and head of department in 1960. He stayed in that post until 1989, serving as university rector from 1981 to 1985.
Academic interests
Bliznakov's main area of research was crystallization. He was the first to introduce adsorption as a thermodynamic factor in crystal growth, and studied catalysis, particular in relation to ammonia oxidation, the preparation of pure substances, radiochemical processes, and the effect of impurities on the linear crystallization rate.
He is the co-author of some of the most popular secondary school chemistry text books in Bulgaria.
References
Bulgarian physical chemists
1920 births
2004 deaths
People from Berkovitsa
20th-century
|
https://en.wikipedia.org/wiki/Ljubomir%20Chakaloff
|
Ljubomir Chakaloff (or Lubomir Nikolov Chakalov) was a Bulgarian mathematician. He was born in 1886 in Samokov and died in 1963 at the age of 77. He was unmarried at the time of his death.
He graduated from Sofia University in June 1908, with an honors degree in mathematics and physics. In 1925, he received a doctoral degree in mathematics from the University of Naples defending a thesis (Le equazioni di Riccati) about Riccati equations, having as advisor Ernesto Pascal.
His main contributions are in the areas of real and complex analysis, number theory, differential equations, elementary mathematics and some work on the arithmetical properties of infinite series.
Lubomir Chakalov was a member of the Royal Czech Academy of Sciences, Warsaw Academy of Sciences, and a permanent member of the Bulgarian Academy of Sciences since 1930. In 1950 he received the Dimitrov Prize and in 1963 he was awarded the title "People's figure of culture."
He was an Invited Speaker of the ICM in 1932 in Zurich and in 1936 in Oslo.
The National Gymnasium of Natural Sciences and Mathematics "Academician Lyubomir Chakalov" is named after him.
References
Liubomir Nikolov Chakalov
20th-century Bulgarian mathematicians
Members of the Bulgarian Academy of Sciences
People from Samokov
Rectors of Sofia University
1886 births
1963 deaths
|
https://en.wikipedia.org/wiki/Asen%20Zlatarov
|
Asen Zlatarov (, Assin Zlataroff) (4 February 1885 – 22 December 1936) was a Bulgarian biochemist, writer and social activist.
Life
He was born in Haskovo on 4 February 1885. He studied chemistry at the University of Geneva (1904-07). In 1908 he became a Ph.D. in Chemistry and Physics at Grenoble University. He taught in Plovdiv, and in Munich (1909-1910). He edited the magazines "Chemistry and Industry" and "Nature and Science" and the libraries "Naturfilosophical Reading" and "Science and Life".
From 1924, he was visiting professor, and from 1935 a regular professor at the Sofia University. He is the author of literary articles, poems, lyrical prose and a novel. In the period (1925 - 1927) he is a member of the literary circle "Sagittarius". He collaborated with the literary period in the 1930s. An active participant is in the Bulgarian People's Maritime Agreement.
Prof. Assen Zlatarov participated in the establishment of the Committee for the Protection of the Jews, together with the widow of the statesman Petko Karavelov - the public actress Ekaterina Karavelova, the writer Anton Strashimirov, Prof. Petko Staynov and others. The former "Mir" and "Word" newspapers published articles against the established committee, saying that it was not the job of Bulgaria, even more so for individual citizens, to be confused with the affairs of great Germany. On July 3, 1933, a meeting was thwarted, where lecturers were Ekaterina Karavelova and Anton Strashimirov.
“Prof. D-r. Asse
|
https://en.wikipedia.org/wiki/Georgi%20Manev
|
Georgi Manev () (15 January 1884 – 15 July 1965) was a Bulgarian physicist, founder of the Sofia University Department of Theoretical Physics, rector of Sofia University (1936–37) and education minister of Bulgaria (1938). His work, mostly known as the Manev field, is used today in aerospace science.
The articles he published in the 1920s have been noticed by Yusuke Hagihara and have been further analysed by Florin Diacu and co-workers.
Letter from Albert Einstein
Manev's gravitational theory ran counter to Albert Einstein’s theory of relativity. Einstein's less-than-glowing assessment of Manev’s theory had complicated his colleague’s prospects for a full professorship at Sofia University. In July 1929, Einstein wrote an apologetic letter to Manev, offering to help make the situation “good again.”
The typewritten letter, signed “A. Einstein,” belongs to Manev's family and was subject of an art restoration project at the Winterthur/University of Delaware Program in Art Conservation (WUDPAC). The letter was creased, partly from being folded, mailed, and tucked into a book for safekeeping during World War II. The creases were retained, removing the adhesive tape without damaging the typed words on the paper.
References
1884 births
1965 deaths
Bulgarian physicists
People from Veliko Tarnovo
Academic staff of Sofia University
Rectors of Sofia University
|
https://en.wikipedia.org/wiki/Nikola%20Obreshkov
|
Nikola Dimitrov Obreshkov (; March 6, 1896 in VarnaAugust 11, 1963 in Sofia) was a prominent Bulgarian mathematician, working in complex analysis.
See also
Obreschkoff–Ostrowski theorem
References
European Mathematics Society Newsletter No. 51 (PDF), page 28.
Nikola Obrechkoff
20th-century Bulgarian mathematicians
1896 births
1963 deaths
Members of the Bulgarian Academy of Sciences
People from Varna, Bulgaria
|
https://en.wikipedia.org/wiki/Reza%20Amirkhani
|
Reza Amirkhani (; born 16 May 1973) is a contemporary Iranian novelist.
He started writing in high school with the Ermia novel.
He has studied mechanical engineering at Sharif University of Technology and is a graduate of National Organization for Development of Exceptional Talents; he also writes essays and researches about scientific & social problems.
There are also Dastan-e-Sistan and Nasht-e-Nesha written by him that describe some social problems and their solutions.
Man-e-oo (His Ego) is one of Amirkhani's most well-known works, having been reprinted 38 times. It has been translated into Arabic, Russian, and Turkish.
Works
1996:Ermia
2000:Naser Armani (Armenian Nasser- 11 Stories)
2002:Az Be (From - To)
2003:Dastan-e-Sistan (about ten-day travel with the supreme leader of Iran)
2005:Nasht-e-Nesha (an article about Iranian brain drain)
2008:Bi Vatan ("Homelandless")
2010:Sar-Lohe-Ha ( His notes in Louh website)
2010:Nafahat -e- naft (an essay about oil management)
2012:Gheydar (Kedar)
2018:Rahesh (An essay about Management and development of urban imbalance)
2021: A Half of One-Sixth of Pyongyang
Awards
Reza Amirkhani's work "Salvation" ("Rahesh"), about the effects of urban expansion on a young couple living in Tehran, was named best novel at the 11th Jalal Al-e Ahmad Literary Awards.
For his work "Salvation," Amirkhani was nominated for the Islamic Revolution Artist of the Year award in 2019.
References
External links
Author's website
Hom
|
https://en.wikipedia.org/wiki/Ternary%20search%20tree
|
In computer science, a ternary search tree is a type of trie (sometimes called a prefix tree) where nodes are arranged in a manner similar to a binary search tree, but with up to three children rather than the binary tree's limit of two. Like other prefix trees, a ternary search tree can be used as an associative map structure with the ability for incremental string search. However, ternary search trees are more space efficient compared to standard prefix trees, at the cost of speed. Common applications for ternary search trees include spell-checking and auto-completion.
Description
Each node of a ternary search tree stores a single character, an object (or a pointer to an object depending on implementation), and pointers to its three children conventionally named equal kid, lo kid and hi kid, which can also be referred respectively as middle (child), lower (child) and higher (child). A node may also have a pointer to its parent node as well as an indicator as to whether or not the node marks the end of a word. The lo kid pointer must point to a node whose character value is less than the current node. The hi kid pointer must point to a node whose character is greater than the current node. The equal kid points to the next character in the word.
The figure below shows a ternary search tree with the strings "cute","cup","at","as","he","us" and "i":
c
/ | \
a u h
| | | \
t t e u
/ / | / |
s p e i s
As with
|
https://en.wikipedia.org/wiki/TRAIL
|
In the field of cell biology, TNF-related apoptosis-inducing ligand (TRAIL), is a protein functioning as a ligand that induces the process of cell death called apoptosis.
TRAIL is a cytokine that is produced and secreted by most normal tissue cells. It causes apoptosis primarily in tumor cells, by binding to certain death receptors. TRAIL and its receptors have been used as the targets of several anti-cancer therapeutics since the mid-1990s, such as Mapatumumab. However, as of 2013, these have not shown significant survival benefit. TRAIL has also been implicated as a pathogenic or protective factor in various pulmonary diseases, particularly pulmonary arterial hypertension.
TRAIL has also been designated CD253 (cluster of differentiation 253) and TNFSF10 (tumor necrosis factor (ligand) superfamily, member 10).
Gene
In humans, the gene that encodes TRAIL is located at chromosome 3q26, which is not close to other TNF family members. The genomic structure of the TRAIL gene spans approximately 20 kb and is composed of five exonic segments 222, 138, 42, 106, and 1245 nucleotides and four introns of approximately 8.2, 3.2, 2.3 and 2.3 kb.
The TRAIL gene lacks TATA and CAAT boxes and the promoter region contains putative response elements for transcription factors GATA, AP-1, C/EBP, SP-1, OCT-1, AP3, PEA3, CF-1, and ISRE.
The TRAIL gene as a drug target
TIC10 (which causes expression of TRAIL) was investigated in mice with various tumour types.
Small molecule ONC201 causes
|
https://en.wikipedia.org/wiki/Bosonization
|
In theoretical condensed matter physics and quantum field theory, bosonization is a mathematical procedure by which a system of interacting fermions in (1+1) dimensions can be transformed to a system of massless, non-interacting bosons.
The method of bosonization was conceived independently by particle physicists Sidney Coleman and Stanley Mandelstam; and condensed matter physicists Daniel C. Mattis and Alan Luther in 1975.
In particle physics, however, the boson is interacting, cf, the Sine-Gordon model, and notably through topological interactions, cf. Wess–Zumino–Witten model.
The basic physical idea behind bosonization is that particle-hole excitations are bosonic in character. However, it was shown by Tomonaga in 1950 that this principle is only valid in one-dimensional systems. Bosonization is an effective field theory that focuses on low-energy excitations.
Mathematical descriptions
A pair of chiral fermions , one being the conjugate variable of the other, can be described in terms of a chiral boson
where the currents of these two models are related by
where composite operators must be defined by a regularization and a subsequent renormalization.
Examples
In particle physics
The standard example in particle physics, for a Dirac field in (1+1) dimensions, is the equivalence between the massive Thirring model (MTM) and the quantum Sine-Gordon model. Sidney Coleman showed the Thirring model is S-dual to the sine-Gordon model. The fundamental fermions of the
|
https://en.wikipedia.org/wiki/Helicity%20%28particle%20physics%29
|
In physics, helicity is the projection of the spin onto the direction of momentum.
Overview
The angular momentum J is the sum of an orbital angular momentum L and a spin S. The relationship between orbital angular momentum L, the position operator r and the linear momentum (orbit part) p is
so L's component in the direction of p is zero. Thus, helicity is just the projection of the spin onto the direction of linear momentum. The helicity of a particle is positive (" right-handed") if the direction of its spin is the same as the direction of its motion and negative ("left-handed") if opposite.
Helicity is conserved. That is, the helicity commutes with the Hamiltonian, and thus, in the absence of external forces, is time-invariant. It is also rotationally invariant, in that a rotation applied to the system leaves the helicity unchanged. Helicity, however, is not Lorentz invariant; under the action of a Lorentz boost, the helicity may change sign. Consider, for example, a baseball, pitched as a gyroball, so that its spin axis is aligned with the direction of the pitch. It will have one helicity with respect to the point of view of the players on the field, but would appear to have a flipped helicity in any frame moving faster than the ball.
Comparison with chirality
In this sense, helicity can be contrasted
to chirality, which is Lorentz invariant, but is not a constant of motion for massive particles. For massless particles, the two coincide: The helicity is equal to the
|
https://en.wikipedia.org/wiki/Boustrophedon%20transform
|
In mathematics, the boustrophedon transform is a procedure which maps one sequence to another. The transformed sequence is computed by an "addition" operation, implemented as if filling a triangular array in a boustrophedon (zigzag- or serpentine-like) manner—as opposed to a "Raster Scan" sawtooth-like manner.
Definition
The boustrophedon transform is a numerical, sequence-generating transformation, which is determined by an "addition" operation.
Generally speaking, given a sequence: , the boustrophedon transform yields another sequence: , where is likely defined equivalent to . The entirety of the transformation itself can be visualized (or imagined) as being constructed by filling-out the triangle as shown in Figure 1.
Boustrophedon Triangle
To fill-out the numerical Isosceles triangle (Figure 1), you start with the input sequence, , and place one value (from the input sequence) per row, using the boustrophedon scan (zigzag- or serpentine-like) approach.
The top vertex of the triangle will be the input value , equivalent to output value , and we number this top row as row 0.
The subsequent rows (going down to the base of the triangle) are numbered consecutively (from 0) as integers—let denote the number of the row currently being filled. These rows are constructed according to the row number () as follows:
For all rows, numbered , there will be exactly values in the row.
If is odd, then put the value on the right-hand end of the row.
Fill-out the interior of
|
https://en.wikipedia.org/wiki/786%20%28number%29
|
786 (seven hundred [and] eighty-six) is the natural number following 785 and preceding 787.
In mathematics
786 is:
a sphenic number.
a Harshad number in bases 4, 5, 7, 14 and 16.
the aliquot sum of 510.
part of the 321329-aliquot tree. The complete aliquot sequence starting at 498 is: 498, 510, 786, 798, 1122, 1470, 2634, 2646, 4194, 4932, 7626, 8502, 9978, 9990, 17370, 28026, 35136, 67226, 33616, 37808, 40312, 35288, 37072, 45264, 79728, 146448, 281166, 281178, 363942, 424638, 526338, 722961, 321329, 1, 0
50 can be partitioned into powers of two in 786 different ways .
786 might be the largest n for which the value of the central binomial coefficient is not divisible by an odd prime squared. If there is a larger such number, it would have to be at least 157450 (see ).
Area code
786 is a United States telephone area code in Miami-Dade County. As an overlay area code, it shares the same geographic numbering plan area with other codes for a larger pool of telephone numbers.
In other fields
80786 - 7th generation x86 like Athlon and Intel Pentium 4
The USSD code 786, typically dialed as ##786# or *#786#, opens the RTN dialog on some cell phones. "RTN" is 786 when dialed on an E.161 telephone pad.
In the New General Catalogue, NGC786 is a magnitude 13.5 spiral galaxy in the constellation Aries. Additionally, 786 Bredichina is an asteroid.
In juggling, 786 as fourhanded Siteswap is also known as French threecount.
In Islam, 786 is often used to represent the Arabic phras
|
https://en.wikipedia.org/wiki/Methylglyoxal
|
Methylglyoxal (MGO) is the organic compound with the formula CH3C(O)CHO. It is a reduced derivative of pyruvic acid. It is a reactive compound that is implicated in the biology of diabetes. Methylglyoxal is produced industrially by degradation of carbohydrates using overexpressed methylglyoxal synthase.
Chemical structure
Gaseous methylglyoxal has two carbonyl groups, an aldehyde and a ketone. In the presence of water, it exists as hydrates and oligomers. The formation of these hydrates is indicative of the high reactivity of MGO, which is relevant to its biological behavior.
Biochemistry
Biosynthesis and biodegradation
In organisms, methylglyoxal is formed as a side-product of several metabolic pathways. Methylglyoxal mainly arises as side products of glycolysis involving glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. It is also thought to arise via the degradation of acetone and threonine. Illustrative of the myriad pathways to MGO, aristolochic acid caused 12-fold increase of methylglyoxal from 18 to 231 μg/mg of kidney protein in poisoned mice. It may form from 3-aminoacetone, which is an intermediate of threonine catabolism, as well as through lipid peroxidation. However, the most important source is glycolysis. Here, methylglyoxal arises from nonenzymatic phosphate elimination from glyceraldehyde phosphate and dihydroxyacetone phosphate (DHAP), two intermediates of glycolysis. This conversion is the basis of a potential biotechnological route to the
|
https://en.wikipedia.org/wiki/Hasse%E2%80%93Witt%20matrix
|
In mathematics, the Hasse–Witt matrix H of a non-singular algebraic curve C over a finite field F is the matrix of the Frobenius mapping (p-th power mapping where F has q elements, q a power of the prime number p) with respect to a basis for the differentials of the first kind. It is a g × g matrix where C has genus g. The rank of the Hasse–Witt matrix is the Hasse or Hasse–Witt invariant.
Approach to the definition
This definition, as given in the introduction, is natural in classical terms, and is due to Helmut Hasse and Ernst Witt (1936). It provides a solution to the question of the p-rank of the Jacobian variety J of C; the p-rank is bounded by the rank of H, specifically it is the rank of the Frobenius mapping composed with itself g times. It is also a definition that is in principle algorithmic. There has been substantial recent interest in this as of practical application to cryptography, in the case of C a hyperelliptic curve. The curve C is superspecial if H = 0.
That definition needs a couple of caveats, at least. Firstly, there is a convention about Frobenius mappings, and under the modern understanding what is required for H is the transpose of Frobenius (see arithmetic and geometric Frobenius for more discussion). Secondly, the Frobenius mapping is not F-linear; it is linear over the prime field Z/pZ in F. Therefore the matrix can be written down but does not represent a linear mapping in the straightforward sense.
Cohomology
The interpretation for sheaf c
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.