2,434 research outputs found
Influence of temperature on pulsed focused laser beam testing
The temperature dependence of radiation-induced charge collection under 1.06 and 0.53 mu m focused laser beams is investigated in experiments and numerical simulation. The essential sensitivity of the collected charge to temperature was obtained only for a 1.06 mu m wavelength. (10 refs)
Mathematical Structure of Relativistic Coulomb Integrals
We show that the diagonal matrix elements where
are the standard Dirac matrix operators
and the angular brackets denote the quantum-mechanical average for the
relativistic Coulomb problem, may be considered as difference analogs of the
radial wave functions. Such structure provides an independent way of obtaining
closed forms of these matrix elements by elementary methods of the theory of
difference equations without explicit evaluation of the integrals. Three-term
recurrence relations for each of these expectation values are derived as a
by-product. Transformation formulas for the corresponding generalized
hypergeometric series are discussed.Comment: 13 pages, no figure
Advanced Molecular-Genetic Methods and Prospects for Their Application for the Indication and Identification of <i>Yersinia pestis</i> Strains
The review provides an analysis of the literature data on the use of various modern molecular-genetic methods for the indication and identification of Yersinia pestis strains with different properties and degree of virulence, which is caused by the diverse natural conditions in which they circulate. The methods are also considered from the perspective of their promising application at three levels (territorial, regional and federal) of the system for laboratory diagnosis of infectious diseases at the premises of Rospotrebnadzor organizations to solve the problem of maintaining the sanitary and epidemiological well-being of the country’s population. The main groups of methods considered are as follows: based on the analysis of the lengths of restriction fragments (ribo- and IS-typing, pulse gel electrophoresis); based on the analysis of specific fragments (DFR typing, VNTR typing); based on sequencing (MLST, CRISPR analysis, SNP analysis); PCR methods (including IPCR, SPA); isothermal amplification methods (LAMP, HDA, RPA, SEA, PCA, SHERLOCK); DNA-microarray; methods using aptamer technology; bio- and nano-sensors; DNA origami; methods based on neural networks. We can conclude that the rapid development of molecular diagnostics and genetics is aimed at increasing efficiency, multi-factorial approaches and simplifying the application of techniques with no need for expensive equipment and highly qualified personnel for analysis. At all levels of the system for laboratory diagnosis of infectious diseases at the Rospotrebnadzor organizations, it is possible to use methods based on PCR, isothermal amplification, SHERLOCK, biosensors, and small-sized sequencing devices. At the territorial level, at plague control stations, the use of immuno-PCR and SPA for the indication of Y. pestis is viable. At the regional level, introduction of the technologies based on the use of aptamers and DNA chips looks promising. For the federal level, the use of DNA origami methods and new technologies of whole genome sequencing is a prospect within the framework of advanced identification, molecular typing and sequencing of the genomes of plague agent strains
Crystal structure of mixed fluorites Ca(1-x)Sr(x)F(2) and Sr(1-x)Ba(x)F(2) and luminescence of Eu(2+) in the crystals
Within the framework of the virtual crystal method implemented in the shell
model and pair potential approximation the crystal structure of mixed fluorites
Ca(1-x)Sr(x)F(2) and Sr(1-x)Ba(x)F(2) has been calculated. The impurity center
Eu(2+) and the distance Eu(2+)-F in this crystals have been also calculated.
The low level position of excited 4f65d configuration of the Eu(2+) ion has
been expressed using phenomenological dependence on distance E(2+)-F. The
dependences of Stokes shift and Huang-Rhys factor on concentration x have been
received for yellow luminescence in Sr(1-x)Ba(x)F(2):Eu(2+). The value x, for
which the eg -level of Eu(2+) ion will be in conduction band in
Sr(1-x)Ba(x)F(2):Eu(2+) has been calculated.Comment: 8 pages, 3 figures. The manuscript is sent to journal 'Physics of the
solid state'. The results will be submitted on inernational conference
SCINTMAT'2002 in oral session (june,20-22,2002,Ekaterinburg,Russia).
Corresponding author e-mail: [email protected]
Generalized modularity matrices
Various modularity matrices appeared in the recent literature on network
analysis and algebraic graph theory. Their purpose is to allow writing as
quadratic forms certain combinatorial functions appearing in the framework of
graph clustering problems. In this paper we put in evidence certain common
traits of various modularity matrices and shed light on their spectral
properties that are at the basis of various theoretical results and practical
spectral-type algorithms for community detection
A search on Dirac equation
The solutions, in terms of orthogonal polynomials, of Dirac equation with
analytically solvable potentials are investigated within a novel formalism by
transforming the relativistic equation into a Schrodinger like one. Earlier
results are discussed in a unified framework and certain solutions of a large
class of potentials are given.Comment: 9 page
Effective Mass Dirac-Morse Problem with any kappa-value
The Dirac-Morse problem are investigated within the framework of an
approximation to the term proportional to in the view of the
position-dependent mass formalism. The energy eigenvalues and corresponding
wave functions are obtained by using the parametric generalization of the
Nikiforov-Uvarov method for any -value. It is also studied the
approximate energy eigenvalues, and corresponding wave functions in the case of
the constant-mass for pseudospin, and spin cases, respectively.Comment: 12 page
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