Determination of the parameters of semiconductor quantum dots in glassy matrices from the absorption and luminescence spectra and from saturation of the optical absorption

Optical methods are described for determining the parameters of semiconducting quantum dots synthesized in a glassy borosilicate matrix. The limitations of these methods and the magnitudes of their errors are analyzed. The parameters of CdS_xSe_1−x nanocrystals in the commercial glasses KS-10, OS-12, Corning 2–61, and other experimental samples are determined. Fiz. Tverd. Tela (St. Petersburg) 39, 1865–1870 (October 1997)     

Semicontinuity and Quasiconvex Functions

Criteria are derived for quasiconvex functions under lower semicontinuity and upper semicontinuity conditions. The results thus obtained generalize earlier results for convex functions. We also give new conditions under which a given function is r-convex in the sense given by Avriel.     

Stereochemical aspects of the formation of toxisterols A

Mechanisms for the formation of toxisterol A are suggested. The connection between the conformation of the initial previtamin and the stereochemistry of the reaction products is discussed.Lensoviet Leningrad Technological Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 225–229, March–April, 1989.     

Multiphonon renormalization of the spectrum of two-dimensional excitons in a magnetic field

The renormalization of the dispersion law for two-dimensional excitons in a magnetic field is studied by the Green's-function method taking into account multiphonon processes.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 3–7, April, 1987.     

Thermoelastic contact interaction of bodies in the presence of surface thermophysical irregularities

We study the thermoelastic contact interaction (in the absence of friction) of half-spaces under conditions of planar deformation in the presence of thin surface thermophysical irregularities that are taken into account by means of generalized conditions of thermal contact with one another. The problem is reduced to solving a system of singular integrodifferential equations with respect to the jumps of temperature and heat flow on the boundary of a section. We analyze the influence of a nonuniform thermal resistance distributed periodically along the surface or localized in one region of it on the distribution of temperature and stresses in the bodies and on their boundary. Four figures.Translated fromMatematicheskie Metody i Fiziko-Mekhanicheskie Polya, Issue 27, 1988, pp. 23–28.