Voronezh State University

About: Voronezh State University is a education organization based out in Voronezh, Russia. It is known for research contribution in the topics: Silicon & Boundary value problem. The organization has 5166 authors who have published 6097 publications receiving 31680 citations. The organization is also known as: VSU & Voronezh University.

Singular Cauchy problem for the general Euler-Poisson-Darboux equation

Abstract: Abstract In this paper we obtain the solution of the singular Cauchy problem for the Euler-Poisson-Darboux equation when differential Bessel operator acts by each variable.

Electronic structure and polarizability of quantum metallic wires

Abstract: The electronic structure and the linear response to an external electric field of simple metal wires with a quantum-size cross-section have been studied within the density-functional theory and the “jellium” model. It is found that an increase in the wire radius leads to a nonmonotonic change in the work function and static polarizability of the wire. The photoabsorption spectra of Na wires with different cross-sections are obtained. The effect of a dielectric environment on the properties of metallic wires is investigated. An increase in the permittivity of a medium brings about a decrease in the static polarizability of metallic wires. It is demonstrated that the surface plasma resonance in the photoabsorption cross-section for Na wires placed in a dielectric matrix is shifted from the continuous spectrum toward the range somewhat below the ionization threshold.

XANES, USXES and XPS investigations of electron energy and atomic structure peculiarities of the silicon suboxide thin film surface layers containing Si nanocrystals †

Abstract: Films obtained using molecular-beam deposition of SiO powder on c-Si (111) substrates for the purpose of SiO2 system formation with silicon nanocrystals were investigated before and after 900–1100 °C annealing by photoluminescence, ultrasoft X-ray emission spectroscopy, X-ray photoelectron spectroscopy, X-ray absorption near edge structure spectroscopy and X-ray diffraction. The appearance of (111) oriented luminescent silicon nanoclusters in considerable amounts on annealing at 1000–1100 °C is established in the investigated films. An anomalous phenomenon of the X-ray absorption quantum yield intensity inversing for the L2, 3 elementary silicon edge is detected. Models for this phenomenon are suggested. Copyright © 2010 John Wiley & Sons, Ltd.

On steady motion of viscoelastic fluid of Oldroyd type

Abstract: We consider a mathematical model describing the steady motion of a viscoelastic medium of Oldroyd type under the Navier slip condition at the boundary. In the rheological relation, we use the objective regularized Jaumann derivative. We prove the solubility of the corresponding boundary-value problem in the weak setting. We obtain an estimate for the norm of a solution in terms of the data of the problem. We show that the solution set is sequentially weakly closed. Furthermore, we give an analytic solution of the boundary-value problem describing the flow of a viscoelastic fluid in a flat channel under a slip condition at the walls. Bibliography: 13 titles.

Optimal Feedback Control in the Mathematical Model of Low Concentrated Aqueous Polymer Solutions

Abstract: We consider the feedback control problem in the model of motion of low concentrated aqueous polymer solutions. We demonstrate the solvability of an approximating problem, using some a priori estimates and the topological degree theory. Then the convergence (in some generalized sense) of solutions of approximating problems to a solution of the given problem is proved. Moreover, we show the existence of a solution minimizing a given convex, lower semicontinuous functional.