609 research outputs found
Geometry of a Centrosymmetric Electric Charge
The gravitational description given for an electric on the basis of exact
solution of the Einstein-Maxwell equations eliminates Coulomb divergence. The
internal pulsating semiconfined world formed by neutral dust is smoothly joined
with parallel Reissner-Nordstrem vacuum worlds via two static bottlenecks. The
charge, rest mass, and electric field are expressed in terms of the space
curvatures. The internal and external parameters of the maximon, electron, and
the universe form a power series.Comment: 12 pages, 2 figures, 1 tabl
The Boltzmann equation for colourless plasmons in hot QCD plasma. Semiclassical approximation
Within the framework of the semiclassical approximation, we derive the
Boltzmann equation describing the dynamics of colorless plasmons in a hot QCD
plasma. The probability of the plasmon-plasmon scattering at the leading order
in the coupling constant is obtained. This probability is gauge-independent at
least in the class of the covariant and temporal gauges. It is noted that the
structure of the scattering kernel possesses important qualitative difference
from the corresponding one in the Abelian plasma, in spite of the fact that we
focused our study on the colorless soft excitations. It is shown that
four-plasmon decay is suppressed by the power of relative to the process of
nonlinear scattering of plasmons by thermal particles at the soft momentum
scale. It is stated that the former process becomes important in going to the
ultrasoft region of the momentum scale.Comment: 41, LaTeX, minor changes, identical to published versio
Field of homogeneous Plane in Quantum Electrodynamics
We study quantum electrodynamics coupled to the matter field on singular
background, which we call defect. For defect on the infinite plane we
calculated the fermion propagator and mean electromagnetic field. We show that
at large distances from the defect plane, the electromagnetic field is constant
what is in agreement with the classical results. The quantum corrections
determining the field near the plane are calculated in the leading order of
perturbation theory.Comment: 16 page
Application of Johnson disribution to the problemof aerospace images classification
Solving the problem of aerospace images classification it was suggested to approximate distribution density of image characteristics by Johnson distribution. The possibilities of such approach were investigated and its availability was show
STRUCTURE AND ADJUVANTICITY IMMUNE PROPERTIES OF MURAMYLDIPEPTIDE
Muramyl dipeptide (MDP) is a minimal peptidoglycan motif common to Gram-negative and Gram-positive bacteria, activate both innate and. adaptive immunity. MDP are recognized by Nod2-like-receptor that triggers of cell signaling pathways induction, activates of proinflammatory cytokine synthesis. In present review we consider structure, functions, adjuvanticity, immune properties and. clinical usage perspectives of MDP and. other muropeptides
Synthesis of Roxbyite Cu58S32 Thin Solid Films
This work was supported by the Government of the Russian Federation (program 211, project # 02.A03.21.0006) and by the state assignment for the Institute of Solid State Chemistry UB RAS
Casimir type effects for scalar fields interacting with material slabs
We study the field theoretical model of a scalar field in presence of spacial
inhomogeneities in form of one and two finite width mirrors (material slabs).
The interaction of the scalar field with the defect is described with
position-dependent mass term. For the single layer system we develop a rigorous
calculation method and derive explicitly the propagator of the theory, S-matrix
elements and the Casimir self-energy of the slab. Detailed investigation of
particular limits of self-energy is presented, and connection to know cases is
discussed. The calculation method is found applicable to the two mirrors case
as well. By means of it we derive the corresponding Casimir energy and analyze
it. For particular values of the parameters of the model the obtained results
recover the Lifshitz formula. We also propose a procedure to obtain
unambiguously the finite Casimir \textit{self}-energy of a single slab without
reference to any renormalizations. We hope that our approach can be applied to
calculation of Casimir self-energies in other demanded cases (such as
dielectric ball, etc.)Comment: 22 pages, 3 figures, published version, significant changes in
Section 4.
Nonlinear dynamics of soft fermion excitations in hot QCD plasma III: Soft-quark bremsstrahlung and energy losses
In general line with our early works [Yu.A. Markov, M.A. Markova, Nucl. Phys.
A770 (2006) 162; 784 (2007) 443] within the framework of a semiclassical
approximation the general theory of calculation of effective currents and
sources generating bremsstrahlung of an arbitrary number of soft quarks and
soft gluons at collision of a high-energy color-charged particle with thermal
partons in a hot quark-gluon plasma, is developed. For the case of one- and
two-scattering thermal partons with radiation of one or two soft excitations,
the effective currents and sources are calculated in an explicit form. In the
model case of `frozen' medium, approximate expressions for energy losses
induced by the most simple processes of bremsstrahlung of soft quark and soft
gluon, are derived. On the basis of a conception of the mutual cancellation of
singularities in the sum of so-called `diagonal' and `off-diagonal'
contributions to the energy losses, an effective method of determining color
factors in scattering probabilities, containing the initial values of Grassmann
color charges, is suggested. The dynamical equations for Grassmann color
charges of hard particle used by us early are proved to be insufficient for
investigation of the higher radiative processes. It is shown that for correct
description of these processes the given equations should be supplemented
successively with the higher-order terms in powers of the soft fermionic field.Comment: 93 pages, 20 figure
Coherent Stranski-Krastanov growth in 1+1 dimensions with anharmonic interactions: An equilibrium study
The formation of coherently strained three-dimensional islands on top of the
wetting layer in Stranski-Krastanov mode of growth is considered in a model in
1+1 dimensions accounting for the anharmonicity and non-convexity of the real
interatomic forces. It is shown that coherent 3D islands can be expected to
form in compressed rather than in expanded overlayers beyond a critical lattice
misfit. In the latter case the classical Stranski-Krastanov growth is expected
to occur because the misfit dislocations can become energetically favored at
smaller island sizes. The thermodynamic reason for coherent 3D islanding is the
incomplete wetting owing to the weaker adhesion of the edge atoms. Monolayer
height islands with a critical size appear as necessary precursors of the 3D
islands. The latter explains the experimentally observed narrow size
distribution of the 3D islands. The 2D-3D transformation takes place by
consecutive rearrangements of mono- to bilayer, bi- to trilayer islands, etc.,
after exceeding the corresponding critical sizes. The rearrangements are
initiated by nucleation events each next one requiring to overcome a lower
energetic barrier. The model is in good qualitative agreement with available
experimental observations.Comment: 12 pages text, 15 figures, Accepted in Phys.Rev.B, Vol.61, No2
Improvement of a test-system for the botulinus toxin screening in dot-immunoanalysis
We constructed a test system for dot-immunoassay (DIA) to accelerate definition and identification of botulinus toxins and also to refuse from application of laboratory animals for routine screening of clinical samples, foodstuff and environments. This system permitted to detect botulinus toxin during approximately 2 h in the tested samples. Sensitivity of this DIA in some cases exceeded the mice biotest. This improved method has minimum reaction to nonspecific exposures from the investigated biological substrata. It is simple to conduct. It is high efficient and expressive, does not require to use expensive equipment and the reactants, special training for the personnel. Lyophilization conditions for the immune reagents used for the test system preparation for botulinus toxin dot-immunoassay were selected. High sensitivity, specificity of the analysis are remained, stability of the preparations (periods of storage) is increased. This method is convenient to use in field conditions at extreme situations, in particular, in mobile autolaboratories for epidemiological survey
- …