The X<Superscript>+</Superscript> trion in a system with spatial separation of the charge carriers

A system composed of two heavy holes located in a two-dimensional (2D) quantum well (QW) and bound via mediation of an electron in a neighboring 2D QW is considered. Using a simple qualitative trial wave function, the ground-state energy of this kind of X⁺ trion is determined in the infinite-hole-mass approximation as a function of the QW spacing. Coordinate dependence of the effective potential binding the holes to each other is calculated for different values of QW spacing. In the adiabatic approximation, a set of dependences describing the X⁺ trion binding energy as a function of the electron mass to the hole mass ratio is obtained. Several estimates for the trion binding energy in GaAs-and ZnSe-based double-QW heterostructures are given.     

The main task of the man-made fibre industry is to improve the quality of its products

The 10th Five-Year Plan — A Five-Year Plan For Product Quality And Production Efficiency

The main task of the man-made fibre industry is to improve the quality of its products     

The Study of Various Models of the Process of Thermal Treatment of Solid Waste

Methods for calculating and modeling individual processes that occur during the thermal treatment of solid waste in reactors with constant and variable temperatures of the medium have been considered. Studies of the influence of various mathematical models of the heating of dispersed material on the results of kinetic analysis of the pyrolysis of wood waste have been carried out. The influence of the type of the mathematical model and its parameters on process characteristics have been shown. For the model of material heating that takes into account the change in the local temperature both with time and with coordinate, the dependences of the average nondimensional temperature of material of spherical and cylindrical form on nondimensional time have been proposed for different values of the Biot number.     

Experimental Investigation and Mathematical Modeling of a Coaxial Tubular Apparatus for Steam Methane Conversion

A tubular steam methane conversion apparatus containing a coaxial insert coated with a nickel–chromium catalyst by thermal gas deposition was experimentally studied and mathematically modeled. By solving the inverse problem, the parameters of the kinetic function of the steam–methane reaction were found. The efficiency of the coaxial tubular apparatus was shown to considerably exceed the efficiencies of its modern industrial analogs, namely, the PPR-600 and PPR-1360 furnaces and the Kellog tubular reactor.     

Carrier photoexcitation from levels in quantum dots to states of the continuum in lasing

Carrier photoexcitation from levels in quantum dots to continuous-spectrum states during lasing is analyzed theoretically. The simplest approach is used to provide upper estimates of the absorption coefficient and the photoexcitation cross section. Light absorption in carrier photoexcitation is shown to be essential for quantum dot laser operation only at very low total losses, e.g., in the case of long cavities.     

A mathematical model of the oxidative degradation of alkali cellulose in pre-ripening chambers

Conclusions A theoretical study of the oxidative degradation of alkali cellulose in pre-ripening chambers has been conducted.A mathematical model of the process has been constructed which reflects the change in mean degree of polymerization and temperature of the alkali cellulose along the length of the chamber, with consideration of heat-exchange and hydrodynamic processes.The values of the kinetic and thermal constants of the mathematical model have been refined on the basis of experimental data, and its adequacy for the object has been established.Translated from Khimicheskie Volokna, No. 2, pp. 14–16, March–April, 1985.