Heterojunctions based on II-IV-V2 and III–V compounds

Conclusion Only preliminary steps have been taken in creation and study of heterojunctions based on (II-IV-V₂)-(III–V) compounds. They have shown that the technical difficultues of creating heterostructures based on such multicomponent systems are completely surmountable. Meanwhile, the most interesting property of such heterostructures, distinguishing them from III–V heterostructures, is their sensitivity to radiation polarization. This property can be used in certain optoelectronic systems. The task of creating effective radiating structures is a completely practical one.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 112–121, August, 1986.     

Quantum Damped Oscillator in Probability Representation

The probability distribution describing quantum states of the damped oscillator in the framework of the Caldirola-Kanai model is introduced. The probability distributions for coherent states and Fock states of the damped oscillator are found explicitly. The transition probability for the damped oscillator is expressed in terms of distributions describing initial and final states.     

Crytal and molecular structure of hydrido(trichlorostannyl)bis-cyclopentadienyl molybdenum(η5-C5H5)2Mo(H)SnCl3

On the basis of X-ray analysis the crystal and molecular structures of (η₅-C₅H₅)₂Mo(H)SnCl₃ have been determined. The compound crystallizes in the monoclinic system with parameters: a = 8.313(3), b = 13.109(4), c = 6.384(2) Å, β = 106.52(2)°, space group P2₁/m, R = 0.028. The conformation occurring in Cp₂Mo(H)SnCl₃ is that with the maximum repulsion between the chloride atoms and the cyclopentadienyl rings. The hydride H atom is shielded by the cyclopentadienyl groups and chlorine atoms, which accounts for the compound's stability to oxygen and hydrolysis.     

The abstract cauchy-kovalevskaya theorem in a weighted banach space

A scale of Banach spaces is considered as a single weighted Banach space. A variant of the Cauchy-Kovalevskaya theorem is proved, including the results of Nirenberg and Nishida for the abstract nonlinear Cauchy problem. ©1995 John Wiley & Sons, Inc.     

Dynamic Characteristic of an Electrochemical Cell with Gauze Electrodes in Convective Diffusion Conditions

A frequency dependence of the transfer function of an electrochemical cell is studied experimentally in the frequency span 0.02 to 40 Hz under conditions of controlled convective diffusion. Above the diffusion frequency, experimental data nicely conform to theoretical calculations, but below it the function's decay cannot be explained within existing theoretical notions.     

Modeling the Relaxation of Surface Layers on Renewable Electrodes Made of Alloys of the Solid Solution Type

A model is suggested for describing the kinetics of a diffusion exit of atoms of the surface-active component of binary alloys of the solid solution type into a surface layer. An impedance method is used to study the dependences of the differential capacitance of the electrical double layer on the potential on renewable-by-mechanical-cut electrodes made of alloys of the system Ag–Sn (1 and 3 at. % Sn) in solutions of NaF. It is established that with increasing duration of contact of a renewed surface of electrodes with a solution of an electrolyte there takes place a very rapid process of predominant exit of tin atoms into a surface layer. It is shown that the observed temporal effects are quite satisfactorily described by the model suggested. Additionally, direct data about the accumulation of tin atoms in a surface layer of alloys studied are obtained by an XPS method.     

A new reverse mode light shutter from silica-dispersed liquid crystals

Nanoparticle dispersions in liquid crystalline materials at low concentrations allow both investigating the formation of defects in liquid crystal (LC) and enhancing the light-scattering properties of LC optical devices. Reverse mode LC dispersions are LC devices, which look like transparent in their OFF state, when no electric field is applied, and opaque in their ON state. In this paper, a new reverse mode device, formed by a dispersion of a LC mixture in a silica nanoparticle crosslinked network, is presented. The morphology and the electro-optical properties of these silica nanoparticle/LC composites were investigated for two different LC mixtures with a negative dielectric anisotropy. The observed transmittances and relaxation times were found to depend strongly on the silica amount and chemical–physical properties of LC used in the sample preparation.     

Energy-efficient dehydrogenation of methanol in a membrane reactor: a mathematical modeling

A two-dimensional non-isothermal stationary mathematical model of the catalytic membrane reactor for the process of methanol dehydrogenation is described. Copper supported on the carbonaceous support was considered as a catalyst. The reaction of methanol dehydrogenation was thermodynamically conjugated with a reaction of hydrogen oxidation taking place in a shell side of the membrane reactor. The effects of various parameters on the methanol conversion and the methyl formate yield have been calculated with the developed model and discussed. Two different types of heating the gas flow were considered and compared. In the case of conjugated dehydrogenation process, the methyl formate yield reaches 77%, when the reactor outer wall was heated up to 150 °C. When the inlet gas flows in the tube and shell sides were heated up to 100 and 83 °C, correspondingly, the yield was 72%.