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.

Disjointly strictly-singular inclusions between rearrangement invariant spaces

Abstract: A linear operator between two Banach spaces X and Y is strictly-singular (or Kato) if it fails to be an isomorphism on any infinite dimensional subspace. A weaker notion for Banach lattices introduced in [8] is the following one: an operator T from a Banach lattice X to a Banach space Y is said to be disjointly strictly-singular if there is no disjoint sequence of non-null vectors (xn)n∈N in X such that the restriction of T to the subspace [(xn)∞n=1] spanned by the vectors (xn)n∈N is an isomorphism. Clearly every strictly-singular operator is disjointly strictly-singular but the converse is not true in general (consider for example the canonic inclusion Lq[0, 1]↪Lp[0, 1] for 1≤p

Effect of a pulsed magnetic field on the real solid-solution structure in the Sb-As system

Abstract: A first study of the effect of weak pulsed magnetic fields (PMFs) on Sb1−x Asx solid solution crystals is reported An effect of long-time (months) redistribution of the solid solution components at room temperature after a short (seconds) exposure to a PMF was revealed The effect includes stages of enrichment of the crystal surface in antimony with the formation of clusters, antimony cluster breakup, and a decrease in surface antimony content, which is accompanied by a substantial improvement in solid-solution homogeneity The PMF-induced component redistribution entails a decrease in the crystal melting temperature Rupture of stressed chemical bonds in arsenic vacancy complexes, which is induced by a change in their multiplicity under PMF exposure, is considered as a possible trigger mechanism

Higher-order Stark effect on an excited helium atom

Abstract: Degenerate perturbation theory is used to study dipole susceptibilities of an excited helium atom in an external electric field. The dependence of the perturbed energy of levels in atoms on fine-structure effects and on the higher-order Stark effect is investigated. Numerical results have been obtained for the (1s3p) P0 and (1s3p) P2 states of helium. The magnitude of the electric field and the energy separation at the 0 30 anticrossing are calculated. Calculations of polarizabilities and hyperpolarizabilities are carried out using sums of oscillator strengths and, alternatively, with the excited electron Green function. An estimate is given based on the model potential method for the contribution of an infinite series over the bound states, including the integral over the continuum, for secondand higher-order matrix elements. The relativistic approach for evaluating reduced dipole matrix elements based on the relativistic no-pair Hamiltonian and including both the Coulomb and Breit interactions ~configuration-interaction method! is analyzed. @S1050-2947~99!06108-9#

Harmonic and spectral analysis of power bounded operators and bounded semigroups of operators on Banach spaces

Abstract: Asymptotic representations of power bounded operators and bounded semigroups of linear operators acting in Banach spaces are obtained under the assumptions that the spectrum of bounded operators on the unit circle and the spectrum of the semigroup generator on the imaginary axis are countable. The methods of abstract harmonic analysis and the spectral theory of operators were used.