The concentration dependence of microstructure in Al-Mn alloys
The concentration dependence of microstructure in Al-Mn alloys
V.S. Stepanyuk, G.M. Kalibaeva, A.A. Katsnel'son
Al-Mn alloys with Mn concentrations 14%, 18%, 22.5%, and 25% were modeled by the method of molecular dynamics. The microstructure of these alloys with different concentrations of Mn were found to differ substantially. The structure of all the alloys contained a high percentage of icosahedral microclusters, and the maximum number of the icosahedron-like structures was observed at a concentration of 22.5%.
Show AbstractSpace-time topology as a consequence of the dynamics of closed boson strings. II. The second approximation
Space-time topology as a consequence of the dynamics of closed boson strings. II. The second approximation
N.F. Nelipa, M.Yu. Pekar
The possibility of constructing a theory where the space-time topology would be determined by the dynamics of closed boson strings is analyzed. The analysis has the form of an expansion into a series with respect to the coupling constant. The second-order expansion is considered. Some new constraints on the admissible space-time topology are found in addition to those in the first-order approximation.
Show AbstractThe inverse problem for a one-dimensional singular oscillator
The inverse problem for a one-dimensional singular oscillator
V.B. Gostev, A.R. Frenkin
The inverse problem for the one-dimensional Schr$\stackrel{..}{o}$dinger equation with a singular potential is solved using an oscillator with perturbation $\lambda x^{-2}$ as an example. The corrections to the potential were found to possess a weaker singularity as compared to the seed potential.
Show AbstractSolution asymptotics for nonlinear dissipative equations at large $x$ aud $t$
Solution asymptotics for nonlinear dissipative equations at large $x$ aud $t$
P.I. Naumkin
An asymptotic representation is obtained at large $x$ and $t$ for the solution to Cauchy's problem for the following nonlinear dissipative equations: the Korteweg-de Vries-Burgers equation, the Kolmogorov-Petrovskii-Piskunov equation. the Ott-Sudan-Ostrovskii equation and the Burgers equation with linear damping.
Show AbstractRenormalization in terms of the observables
Renormalization in terms of the observables
D.A. Slavnov
A procedure is described that makes it possible to express uniquely all observable quantities in terms of several base quantities. The result does not depend on the applied renormalization scheme.
Show AbstractOn the uniqueness in one of the coefficient problems relating to technological processes
On the uniqueness in one of the coefficient problems relating to technological processes
V.B. Glasko, I.E. Stepanova
Consideration is given to a problem relating to technological treatment of a blank whose structure is nonhomogeneous in the transverse direction, which manifests itself in the dependence of the diffusion (or thermal conductivity) coefficient on the transverse coordinate. The uniqueness of the determination of this coefficient from the given concentration (or temperature) profile at an instant close to the end of the process is proved.
Show AbstractAccumulation of a photosensitizer in cells with allowance for the passage of its charged forms across the membrane
Accumulation of a photosensitizer in cells with allowance for the passage of its charged forms across the membrane
L.V. Zhorina, N.V. Stepanova
A mathematical model has been constructed and studied of the penetration of hematoporphyrin (HP) ions into cells and their accumulation there. HP is a photosensitizer most frequently used in the photodynamic therapy of tumors. It is shown that the selectivity of HP accumulation in tumors depends on the following factors: {a) the lowered acidity inside malignant cells and in the surrounding medium and {b) the higher concentration in tumor cells of lipids, to which the HP molecules bind.
Show AbstractOn the role of double collisions in $(е, 2е)$ processes
On the role of double collisions in $(е, 2е)$ processes
Yu.V. Popov, N.M. Kuz'mina
The region of efficiency of the second Born approximation (SBA) in the theory of ionization of atoms by fast electrons is considered. A model (ASBA) is constructed for approximate calculations of the SBA contribution to the differential cross section $d^3\sigma$. The calculations are compared with a large array of experimental values of $d^3\sigma$ in the reaction $Н(е,2е)Н^+$.
Show AbstractNonlinear waves in a laminar Brillouin electron beam propagating in a strip-line
Nonlinear waves in a laminar Brillouin electron beam propagating in a strip-line
0.I. Vasilenko
The multiscaling method of the perturbation theory was used to examine the nonlinear waves propagating in the Brillouin electron beam in vacuo between two plane parallel electrodes. A dispersion correlation was obtained, and the amplitude of the waves was shown to be described by the Korteweg-de Vries equation that admits soliton solutions. The equation coefficients were determined as a function of parameters of the equillibrium unperturbed beam. A kind of one-soliton solution is presented.
Show AbstractAcoustooptic filtering of electromagnetic radiation using two Bragg diffraction modes
Acoustooptic filtering of electromagnetic radiation using two Bragg diffraction modes
V.B. Voloshinov, A.N. Uskov
The results are given of a theoretical study of the feasibility of spectral filtering of uncollimated optical beams by means of acoustooptic filters based on a paratellurite crystal. The parameters of a sophisticated filter with two piezo-electric transducers are calculated. The device can operate in various diffraction modes with different selectivity of interaction of light and sound.
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