Gas mixture flow in nanoporous media in the presence of surface forces. The dusty-gas model

The dusty-gas model has been generalized to the case of gas mixture flow in nanoporous media under the conditions of the action of surface forces. A basic set of transport equations has been derived proceeding from kinetic equations for a gas mixture and dust particles. To take into account the surface forces, the interaction between a gas and dust particles has been represented as a sum of a long-range potential, which reflects the surface forces, and a short-range potential, which describes gas molecule scattering on the surface of pore walls. The contribution of the long-range component has been taken into account in the self-consistent approximation, while the short-range component has been considered in the standard manner. The surface forces have been shown to have a substantial effect on the transfer of mixed gases through porous bodies; in particular, it becomes possible to separate mixture components due to different potentials of the interaction of their molecules with pore surface.     

Higher Conditional Symmetry and Reduction of Initial Value Problems

We give the exposition of a generalized symmetry approach toreduction of initial value problems for nonlinear evolutionequations in one spatial variable. Using this approach we classifythe initial value problems for third-order evolution equationsthat admit reduction to Cauchy problems for systems of twoordinary differential equations. These reductions are shown tocorrespond to higher conditional symmetries admitted by thecorresponding nonlinear evolution equations.     

Some Features of a Turbulent Separated Flow and Heat Transfer Behind a Step and a Rib. 1. Flow Structure

The influence of the shape and size of the obstacle on separated flow and heat transfer is studied experimentally. Results of investigation and comparative analysis of the hydrodynamic structure of a separated flow behind a step and a rib are presented. A principally different character of transfer processes in the separated flow behind obstacles of these types is demonstrated. The flow structure in the secondary vortex region is considered.     

Electrical conductivity of a partially ionized gas mixture in a magnetic field

A considerable number of papers [1–5] has been devoted to determining the electrical conductivity of a partially ionized gas on the basis of kinetic theory. In so doing, a three-component plasma model (electrons, ions, neutrals) is generally employed. The general expressions for the electrical conductivity of a many-component system are fairly complicated [1], and the calculation of their determinants is most laborious.The case of a N-component gas mixture in which one of the components is partially ionized (N+2-component plasma) is considered below. A series of simplifications in the solution of the initial system of equations allows one to represent the expressions for the electrical conductivity of such a mixture in the same form as for the three-component plasma case, but with certain effective parameter values. The results obtained correspond to the second approximation of Cowling [1.6].     

Cross-Linked Polystyrene with Immobilized Glucopodand (Coronand) Fragments as a Polymeric Complexone for <Emphasis Type="Italic">s</Emphasis>-Metal Cations

Dicyclohexylideneglucose was grafted to Merrifield resin with the subsequent partial hydrolysis of the product and alkylation of the hydrolyzed substance with oligoethylene glycol tosylates. Only one of the products obtained exhibited the expected complexing power toward s metals. The possible structures of the immobilized polymers obtained are discussed.     

On the theory of the mechanical properties of the alkali and alkali-earth metals

The crystal lattice of an alkali or alkali-earth metal is studied under stresses which do not change the orthorhombic symmetry of the elementary body-centered cell. The results of the calculation make it possible to find the stress limit for destruction of the metal lattice.     

Spin-labeled organophosphorus cholinolytics

Conclusions An organophosphorus nitroxyl radical was synthesized for use as spin-probe.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2094–2097, September, 1984.The authors wish to express their gratitude to B. V. Rozynov for recording the high-resolution mass spectrum of radical (VI).     

The componentwise descent method

The problem of minimizing a function of several variables on a parallelepiped is considered. A method of componentwise descent, not requiring the computation of derivatives of the function being minimized, is suggested for its solution. Its convergence for smooth convex functions is proved.Translated from Matematicheskie Zametki, Vol. 22, No. 1, pp. 137–142, July, 1977.The author thanks F. P. Vasil'ev for assistance with the article.     

Ammonolysis and aminolysis of organochlorosilanes with the tricyclodecenyl radical at the silicon atom

Conclusions New organoaminosilanes and silazanes with tricyclodecenyl radicals at the Si atom were synthesized by the ammonolysis and aminolysis reactions of organochlorosilanes with tri-cyclodecenyl substituents at the Si atom, the co-ammonolysis of tricyclodecenylmethyldi-chlorosilane with trimethylchlorosilane, and the trans-silylation of tricyclodecenylmethyldi-chlorosilane with hexamethyldisilazane.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 663–665, March, 1988.