Cyclotron dynamics of electron wave packets in topological insulators in an external magnetic field

The evolution of electron wave packets formed from surface states in topological insulators located in an external magnetic field is studied. The electron and spin densities of the wave packets under consideration are calculated analytically and are visualized. The influence of the main characteristics of the wave packets (the spin polarization) on the splitting and the change in their forms with time is considered.     

Peristaltic Motion of a Particle-Fluid Suspension in a Planar Channel

We analyze the mechanics of peristaltic pumpingof a particle-fluid suspension in a channel. Aperturbation series (to second order) in dimensionlesswave number of an infinite harmonic travelling wave is used to obtain an explicit form for thevelocities and a relation between the flow rate and thepressure gradient in terms of the Reynolds number,concentration of the particles, suspension parameters, and the occlusion. We discuss the effect of theconcentration of the particles, the Reynolds number, andthe wave number on the pressure rise, peristalticpumping, augmented pumping, and backward pumping. We also discuss the phenomenon oftrapping.     

Bromination of isoprene in acetic anhydride

Conclusions The reaction of bromine with isoprene in acetic anhydride as the medium proceeds as competing brominnation and bromoacetoxylation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1675–1677, July, 1977.     

Synthesis and structural consideration of 1‐chloro‐N,N′,N″‐tris(pentafluorophenyl)azagermatrane: Azagermatrane with the shortest intramolecular N → Ge bond

Two compounds of a novel‐type azagermatrane, N(CH₂CH₂NC₆F₅)₃Ge‐Hal: HalCl ( 1 ), Br ( 2 ), were prepared via a metathetical reaction of trilithium salt of tetramine, N[CH₂CH₂N(Li)C₆F₅]₃, with corresponding GeHal₄. A single crystal structure of 1 was determined by the X‐ray diffraction study: The compound shows the strongest transannular N_ax → Ge interaction (2.148(7) Å) among other studied azagermatranes. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:738–741, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20476     

Electrohydraulic effect in water-plant heterodisperse systems I. Compositions of the solid residue and the aqueous phase

The electrohydraulic (EH) treatment of water-plant heterodisperse systems leads to the partial degradation of the main components of the plant materials: lignin, cellulose, and carbohydrates. The presence of p-hydroxyphenyl and guaiacyl structures has been established on the basis of the results of the GLC analysis of the ether-extracted phenolic products of plant materials subjected to EH treatment. It has been shown that part of the carbohydrates passes into the aqueous phase in the form of free monosaccharides: pentoses and hexoses.Institute of Chemistry of Plant Substances of Uzbekistan Academy of Sciences, Tashkent. Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk. Siberian Institute of Terrestrial Magnetism, the Ionosphere, and the Propagation of Radio Waves, Siberian Branch, Russian Academy of Sciences, Irkutsk. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 707–711, November–December, 1992.     

Disproportionation of N-arylhydroxylamines in the presence of hydrogenation catalysts and sulfur compound additives

Conclusions The yield of N-arylhydroxylamines increases in the liquid-phase catalytic hydrogenation of aromatic nitro compounds due to a reduction in the rate of the secondary transformations of these products upon the introduction of thiophene, sulfolane, and other sulfur compound additives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 489–490, February, 1985.     

Conditions of supersonic flow around multiwedge bodies

An experimental study was made of some schemes for flow around multiwedge bodies at supersonic flow velocities. On the basis of data on the distribution of the pressure, on visualization of the flow, and on optical measurements, an analysis was made of the structure of the flow. Zones of breakaway of the flow were observed at the lateral surfaces of the lobes. In the nose part of a multiwedge body there is a three-dimensional configuration of attached plane shock waves, going over into a combined detached nonaxisymmetric wave directed toward the base of the body.     

A nonlocal problem for a mixed-type equation with a singular coefficient in an unbounded domain

In this paper we study a nonlocal problem for a mixed-type equation in a domain whose elliptic part is the first quadrant of the plane and the hyperbolic part is the characteristic triangle. With the help of the method of integral equations and the principle of extremum we prove the unique solvability of the considered problem.