Multiple-value inductance coils for working standards

The circuit and construction of new multiple-value toroidal inductance coils of 1 μH to 1 H for first- and second-class working inductance standards are described. Optimal relations between the dimensions of toroidal coils with different cross-section geometries providing the best Q factor for a given inductance and external coil diameter have been obtained. The results of experimental investigations are presented. Translated from Izmeritel'naya Tekhnika, No. 10, pp. 21–24, October, 1997.     

Kinetics of thermochemical reaction of TBP solutions in HCBD with nitric acid in two-phase systems

The kinetics of thermochemical reaction of 30% TBP in hexachlorobutadiene (HCBD) saturated with HNO₃ (1.35 M HNO₃) in two-phase systems with 12 M HNO₃ at temperatures from 90 to 115°C was studied. The kinetic parameters of thermolysis of organic solutions of TBP in HCBD, contacting with HNO₃ in open and closed vessels, were determined experimentally for the subsequent estimation of the explosion hazard of these systems under conditions of extraction recovery of high-level radioactive materials. It was shown that, in two-phase systems, solutions of TBP in HCBD exhibit increased resistance to thermochemical oxidation with nitric acid in comparison with hydrocarbon solutions of the extractant in the entire temperature range.     

Structure and properties of welded blanks for tools of new high-speed steels

Conclusions In a broad range of values of various factors (pressure during heating and forging, heating and forging time, relative speed of rotation) the torsional strength of welded samples of steels R12+45, R9K5+45, R6M5K5+45, R8M3K6S+45, and R9M4K8F+45 is constant with a confidence coefficient of 0.95 and meets the requirements. Within this region it is necessary to select friction welding conditions in conformity with the optima technicoeconomic parameters.S. M. Kirov Tomsk Polytechnic Institute. Tomsk Institute of Automatic Control Systems and Radioelectronics. Tomsk Factory of Cutting Tools. Translated from Metallovedenie i termicheskaya Obrabotka Metallov, No. 11, pp. 22–26, November, 1976.     

Insights into carrier recombination processes in 1.3 μmGaInNAs-based semiconductor lasers attained using high pressure

The threshold current of 1.3 μm GaInNAs lasers increases by ~30%, up to a pressure of 1 GPa compared with a decrease of ~15% for Auger-dominated InGaAsP devices, indicating that direct band-to-band Anger recombination is not important in these materials. The lasing energy varies sub-linearly with pressure, indicative of the increasing interaction of the N-level with the conduction band     

Anisotropy of the spatial distribution of In(Ga)As quantum dots in In(Ga)As-GaAs multilayer heterostructures studied by X-ray and synchrotron diffraction and transmission electron microscopy

High-resolution X-ray and synchrotron (crystal truncation rods) diffraction methods and transmission electron microscopy have been employed to study MBE-grown multilayer In(Ga)As-GaAs heterostructures with arrays of vertically coupled In(Ga)As quantum dots (QDs) in a GaAs matrix. Additional (vertical and lateral) spatial ordering of QDs in perfect crystalline structures, giving rise to undulations of the crystalline planes and quasi-periodic elastic strain, was shown to be essentially anisotropic with respect to crystallographic directions of the [110] type. The anisotropy of the QD formational system of can be accounted for by assuming that the spatial ordering of the QDs and the corrugation of the crystal planes are the initial stages of relaxation of the elastic strain introduced into the system by the QDs. The anisotropic relief of the crystal planes (corrugated growth surface) results from the formation of a system of spatially ordered quantum quasi-wires uniformly filled with QDs. In a multilayer heterostructure with high crystal perfection, the anisotropic relief of the crystal planes is inherited by overlying layers and its amplitude decreases gradually with increasing distance from the source of elastic strain—the superstructure containing In(Ga)As QDs in the given case.