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.

Synchrotron investigations of the specific features in the electron energy spectrum of silicon nanostructures

Abstract: The Si L 2, 3 x-ray absorption near-edge structure (XANES) spectra of porous silicon nanomaterials and nanostructures with epitaxial silicon layers doped by erbium or containing germanium quantum dots are measured using synchrotron radiation for the first time. A model of photoluminescence in porous silicon is proposed on the basis of the results obtained. According to this model, the photoluminescence is caused by interband transitions between the energy levels of the crystalline phase and oxide phases covering silicon nanocrystals. The stresses generated in surface silicon nanolayers by Ge quantum dots or clusters with incorporated Er atoms are responsible for the fine structure of the spectra in the energy range of the conduction band edge and can stimulate luminescence in these nanostructures.

High-order harmonic generation using quasi-phase matching and two-color pump in the plasmas containing molecular and alloyed metal sulfide quantum dots

Abstract: As high-order harmonic emitters, quantum dots are produced through laser-induced plasmas. Subsequently, we generate high-order harmonics with 800-nm and 30-fs pulses from laser-produced plasmas containing quantum dots of different metal sulfides (Ag2S, CdS, and Cd0.5Zn0.5S). The high-order harmonic generation is analyzed using different approaches, including two-color (800 nm + 400 nm) pump, application of alloyed quantum dots, and quasiphase matching of interacting waves. We discuss the self-phase modulation induced splitting of harmonics, the difference in the application of thick and thin crystals for second harmonic (400 nm) emission during two-color pumping of the quantum dot plasma, the spatial modulation of the quantum dot plasma for quasiphase matching, and the comparison of harmonic yields from monomer and quantum dot plasmas. This study allows us to determine the mechanisms of coherent extreme ultraviolet radiation generation using a few nanometer-sized emitters as well as optimal methods for further enhancing the high-order harmonic generation efficiency.

Phase Composition of Copper Sulfide Films Produced from Copper Salt–Thiourea Complexes

Abstract: Copper sulfide films were deposited by spray pyrolysis using aqueous solutions of copper salt–thiourea complexes. The phase composition of the deposits was shown to depend on the nature of the precursor complex, which is governed by the anion of the copper salt and, accordingly, the redox reactions in the starting solution.

A new species of Tingidae (Insecta: Hemiptera: Heteroptera) from the Lower Cretaceous of Transbaikalia

Abstract: A new species of lace-bug Sinaldocader ponomarenkoi sp. nov. (Tingidae: Phatnomatini) is described from the Lower Cretaceous Transbaikalian locality Baissa. The new species differs from the type spe- cies S. drakei Popov, 1989 from the Lower Cretaceous of Mongolia in the well-developed lateral carinae of pronotal disc and in the details of hemelytral venation.

The Solution Set to BVP for Some Functional Differential Inclusions

Abstract: We consider a multivalued BVP x'(t)∈ A(t)x(α(t))+λ F(t,x(β(t))), Lx=θ . Under appropriate assumptions on A, L and F, we prove that for sufficiently small λ the set of solutions to this problem is a nonempty infinite dimensional AR-space (Theorem 4).