Complex salts trans-[Rh(β-Pic)4Cl2]X (X = Cl?, ReO 4? , and ClO 4? ): Synthesis, crystal structures, and thermal properties

Three novel complex salts containing the cation trans-[Rh(β-Pic)₄Cl₂]⁺ with the anions Cl⁻ (I), ReO₄⁻ (II), and ClO₄⁻ (III) were obtained and characterized by elemental analysis, X-ray diffraction, NMR spectroscopy, and IR spectroscopy. The complex trans-[Rh(β-Pic)₄Cl₂]ReO₄ crystallizes from DMF as a solvate in which solvent molecules fill the channels formed by the cations and anions. The thermal properties of complexes I, II, and II · DMF were examined by DTA. Final and some intermediate products of the thermolysis were isolated and characterized by physicochemical methods.     

An efficient synthesis of cholesterol formate

Russian Chemical Bulletin -     

Oxidation of Sn(II) in methanesulfonate electrolytes in presence of antioxidants

The influence of copper(II) ions and some aromatic organic compounds on the oxidation of Sn²⁺ ions in the methanesulfonate electrolyte was studied.     

Models of anisotropically polarizable suspensions with irreversible processes: Anisotropy relaxation,dielectrophoresis, and electroviscous flows

We consider media consisting of an anisotropically polarizable particle of a disperse phase and a nonconducting liquid carrier phase. The particles exhibit easy axis or easy plane anisotropy. A complete electrohydrodynamic model describing the motion of the medium in an electric field is constructed with allowance for irreversible processes. The laws determining the polarization of the medium, dielectrophoresis of particles, and anisotropy relaxation are determined. Expressions are derived for the kinetic coefficients appearing in these laws and the expression for the free energy of the medium. The dependence of the effective viscosity on the electric field strength is determined for a flow in narrow channels.     

Detection equipment for investigating dp elastic scattering at internal target of nuclotron in the framework of DSS project

A complex of detection equipment based on scintillation detectors for investigating dp elastic scattering at the internal target of the Nuclotron developed in the framework of the Deuteron Spin Structure (DSS) project is presented. The results of optimizing scintillation detectors and the results of test measurements of a deuteron beam of the Nuclotron are given.     

Boundary Distortion Estimates for Holomorphic Maps

We establish some estimates of the angular derivatives from below for holomorphic self-maps of the unit disk ${\mathbb {D}}$ at one and two fixed points of the unit circle provided there is no fixed point inside ${\mathbb {D}}$ . The results complement Cowen–Pommerenke and Anderson–Vasil’ev type estimates in the case of univalent functions. We use the method of extremal length and a semigroup approach to deriving inequalities for holomorphic self-maps of the disk which are not necessarily univalent using known inequalities for univalent functions. This approach allowed us to obtain a new Ossermans type estimate as well as inequalities for holomorphic self-maps which images do not separate the origin and the boundary.     

Gasoline- and oil-proof rubbers based on cyclic α-oxides for heavy-duty rubber technical goods

The physicomechanical properties of oil- and gasoline-proof rubbers based on cyclic α-oxides (epichlorohydrin, propylene oxide) and hydrocarbon rubbers (butadiene-nitrile, chloroprene) are described. It is shown that epichlorohydrin rubbers (EKhGKs) have some advantages over butadiene-nitrile and chloroprene rubbers, particularly for operation in extreme conditions in oil drilling and gas equipment for environments with a high content of hydrogen sulfide. Examples of the application of low-molecular EKhGKs as adhesives and sealants are given.     

Structural and electrical properties of metamorphic nanoheterostructures with a high InAs content (37–100%) grown on GaAs and InP substrates

A complex study of the structural and electrical properties of nanoheterostructures containing a metamorphic barrier with a high InAs content (37–100%) in the active region have been performed by the Van der Pauw and X-ray diffraction methods. All peaks observed in the rocking curves for the samples studied (throughout the entire structure) have been revealed and identified. It is shown that, having properly chosen the design of the metamorphic buffer and the compositional gradient in it, one can obtain mobilities and concentrations of the 2D electron gas in the In _x Ga_1−x As quantum well in the heterostructures formed on GaAs substrates that are comparable with the corresponding values for the nanoheterostructures grown on InP substrates. It is established that the mobility and concentration of 2D electron gas depend both on the metamorphic barrier design and on the structural quality of heterostructure as a whole.     

Effect of the microwave signal power on the controllability of a ferroelectric phase shifter

We consider a microwave phase shifter based on thin-film ferroelectric parallel-plate capacitors operating as a part of a phased array at an elevated microwave power level and for a limited power in the control circuits. To eliminate capacitance modulation in parallel-plate capacitors by an ac field, we propose the separation of the effects of the dc control voltage and the ac voltage based on the symmetry of the capacitance-voltage characteristic of the unit including two capacitors parallel-connected in the ac voltage U _ac and series-connected in dc voltage U _dc. The experiment shows that for U _dc > U _ac, the phase of the wave passing through the phase shifter weakly depends on the microwave signal power. The reflection phase shifter is tested for a pulsed power of the microwave signal up to 6 W and a power in the control circuit on the order of 10 μW.