Tetrahalotetraazafulvalenes — New strong electron acceptors

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, p. 1421, October, 1989.     

Mackey–Ahrens Theorem for Spatial Scales

The Mackey–Ahrens theorem on topologies which are congruent in duality is extended to the duality of inductive scales of spaces.     

Formation of derivatives of 1,2,4-triazoloquinazolines in the reactions of 3-amino-1,2,4-triazoles with cyclohexanone

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 999–1000, July, 1990.     

The influence of a transverse magnetic field on a subnormal glow discharge in air

In subnormal glow discharge under d.c. excitation at different pressure in a varying transverse magnetic field (0 to 30 G) some measurements have been carried out for various initial average tube currents. The voltage across the discharge increases and average tube current and residual current decreases in the magnetic field. With the help of Beckman’s expression [4] for the axial field and the electron density distribution in a transverse magnetic field the observed variation of current and voltage can be satisfactorily explained. The variation of axial electric field with transverse magnetic field can be represented to a fair degree of accuracy by the derived equation. The behaviour of residual current with magnetic field has been observed in these oscillations.     

Study of Properties of Structural Materials of Powerful Pulsed Plasma Facilities under Extreme Loads

Physics of Atomic Nuclei - The effect of high-current relativistic electron beams on samples made of polycrystalline tungsten (Goodfellow) and corrosion-resistant ferrite-martensitic steel EK-181...     

Ammonolysis of magnesiothermic tantalum powders

Tantalum nitrides are synthesized by ammonolysis of a mesoporous magnesiothermic tantalum powders. The effect of specific surface area of the powders and synthesis temperature on product composition is shown. Nitrogen content in the ammonolysis product of tantalum powder with a specific surface area of 56 m² g^–1 corresponds to oxynitride TaON exposed to 600°C for 1 h. The specific surface area of the oxynitride is 35 m² g^–1.     

Integral equation formulation for buoyancy-driven convection problems

An integral equation formulation for buoyancy-driven convection problems is developed and illustrated. Buoyancy-driven convection in a bounded cylindrical geometry with a free surface is studied for a range of aspect ratios and Nusselt numbers. The critical Rayleigh number, the nature of the cellular motion, and the heat transfer enhancement are computed using linear theory. Green's functions are used to convert the linear problem into linear Fredholm integral equations. Theorems are proved which establish the properties of the eigenvalues and eigenfunctions of the linear integral operator which appears in these equations.     

A quantum-mechanical study of inductive and steric effects in isoalkanes

The method of “quantum mechanics of atoms in molecules” was used to find the parameters of functional groups in isopropylalkanes. The relation between such concepts of the classic theory of the structure of molecules as inductive and steric effects and electron density distribution was shown. Branching could cause deformation of the shape of an atom in a molecule accompanied by changes in volume and energy with charge conservation. The degree of damping of intramolecular steric and inductive effects was substantiated and described. An analysis of transferability of groups and the corresponding parameters was performed to obtain procedures for calculating properties by additive methods.     

Shear viscosity of dispersions of particles with liquid shells

Shear viscosity of the dispersions of particles with a liquid shell is calculated on the basis of cell method. The problem of choosing an optimal radius of the cell is considered. Exact expression for the shear viscosity of dispersion, which is suitable at the arbitrary volume fraction of dispersed phase, is derived.