On the polarization interaction between two closely spaced conducting spheres in a uniform electrostatic field

An electrostatic interaction between two separate, grounded, uncharged, perfectly conducting spheres of different radii in a uniform electrostatic field is investigated. It is shown that at a small center-to-center distance of the spheres, the force of the polarization interaction between the spheres depends appreciably more weakly on that distance in comparison to the force of the electrostatic interaction of two elementary dipoles as it should be in view of the interaction between two like polarization charges.     

Fast and Slow Diffusion of Channelized Particles in Transverse Energy Space

The Fokker–Planck-type kinetic equation is constructed with the help of the evolution equation for the transverse energy of channelized particles, which in its turn is derived beyond the framework of perturbation theory proceeding from the condition of nonconcervation of the adiabatic invariant.     

Spontaneous formation of a system of highly ordered germanium nanoislands upon epitaxial deposition on profiled (111) silicon substrates under electromigration conditions

Atomic-force microscopy was used to study the surface topography of SiGe structures grown by epitaxial deposition of Ge on profiled Si(111) substrates under electromigration conditions. Systems of highly ordered germanium nanosized islands with dimensions of 10–20 nm and a density of 6×10¹⁰ cm^?2 were obtained. It is shown that the geometrical parameters of self-organizing nanoislands can be controlled by a proper choice of the growth and postgrowth annealing conditions for these structures.     

Synthesis and structures of nitroxyalkyl methylphosphonates

The reactions of ethylene glycol mononitrate and glycerol 1,3-dinitrate with methylphosphonic dichloride afforded new nitroxyalkyl methylphosphonates.     

Synthesis of N-substituted xanthines (review)

The literature on the synthesis of N-substituted xanthines by cyclization, recyclization, and N-substitution is reviewed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 3–27, January, 1991.     

Calculation of regression functions in problems of rejections of gaussian random fields

We study the asymptotics of some regression functions which occur in the study of high rejections of homogeneous Gaussian random fields.Translated from Statisticheskie Metody Otsenivaniya i Proverki Gipotez, pp. 143–148, 1988.     

Dominant structures in jet streams

A Hamiltonian version has been formulated for the model of axisymmetric equally rotating jet streams with a free boundary. In the framework of this approach, dominant structures, i.e., structure elements appearing in strongly disturbed jet streams at the preturbulent stage of their decay, are studied. It has been shown that compactons, i.e., solution with a compact support, can be such dominant structures. Analysis of the mechanism of the instability of compactons shows the possibility of collapse, which occurs almost without deformation of their shape but leads to the intensification of the vortex sheet at the boundary according to the law (t ₀ ? t)^?1, where t ₀ is the collapse time.     

Characterization of surface deformation around Vickers indentations in InGaAsP epilayers on InP substrate

The deformation surrounding Vickers indentations on InGaAsP/InP epilayers have been studied in detail. The surface topography was characterized by using atomic force microscopy (AFM). The material pile-up and sink-in regions around the indentation impression was observed for the quaternary InGaAsP/InP epilayers. The sectional analysis mode of the AFM shows the depth profile at the indented region. Microindentation studies were carried out for different atomic fraction of the quaternary InGaAsP/InP compound semiconductor alloys. The microhardness values of InGaAsP/InP epilayers were found to be in the range of 5.08 and 5.73 GPa. These results show that the hardness value of the quaternary alloy drastically increases as the composition of As was increased by 0.01 atomic fraction and when the phosphorous concentration decreases from 0.4 to 0.38. The reason may be that the increase in As concentration hardens the lattice when phosphorous concentration was less and hardness decreases when phosphorous was increased.     

Fermi surface and thermoelectric power of (Bi1−x Sbx)2Te3<Ag, Sn> mixed crystals

The Fermi surface anisotropy of (Bi_1?x Sb_x)₂Te₃ single crystals (0.25 ≤ x ≤ 1) was studied by analyzing the angular dependence of the frequency of Shubnikov-de Haas oscillations and the effect of tin and silver doping on the thermoelectric power in these crystals in the temperature range 77 ≤ T ≤ 300 K. It was shown that silver doping of (Bi_1?x Sb_x)₂Te₃ mixed crystals produces acceptors, while silver in Bi₂Te₃ acts as a donor. Tin also exhibits acceptor properties. Both tin and silver doping of p-(Bi_1?x Sb_x)₂Te₃ mixed crystals decrease the thermoelectric power due to an increase in the hole concentration.