三相异步电动机运行指标的分析

利用电机学理论分析了影响电机起动转矩、起动电流、最大转矩和最小转矩的因素。     

Interaction of optical radiation with GaAs nanowhisker arrays

We have studied the reflectivity spectra of doped GaAs nanowhiskers (NWs) with various morphologies, which were grown by molecular-beam epitaxy. It is established that the character of the reflectivity spectra of NWs is determined by the shape of nanocrystals. NWs with droplike and pointlike vertices differently interact with electromagnetic radiation. Laser radiation produces a spectraly selective action on the NW array, which leads to a change in the NW height and induces “caking” of their vertices, thus modifying the reflectivity of the sample. This phenomenon can be used for the creation of local microstructures with preset characteristics in large NW arrays.     

On the prospects of developing high-efficiency piezocomposites based on crystals of solid solutions of ferroelectric relaxors

Electromechanical properties of the 0-0-2-2 type composite based on platelike crystals of solid solutions of ferroelectric relaxors of the Pb(A_1/3Nb_2/3)O₃-PbTiO₃ system (A = Zn, Mg) have been studied for the first time. Factors accounting for the record values of some effective parameters of this composite are considered. The relationship between the components of the elastic compliance tensor of the layered structures forming the composite and the positions of maxima of the effective hydrostatic parameters is established.     

Threshold sensitivity of anti-Stokes frequency converter

Expressions describing the threshold sensitivity of a quantum converter of IR radiation into visible light are obtained for two schemes of energy levels in the active atoms. Based on these expressions, practical criteria for the creation of such devices are formulated.     

脉冲电镀最佳参数之探索和优化

本文利用正交实验法对脉冲电镀各控制参数进行试验,对影响分散能力、镀层可靠性及外观质量的各种因素进行探讨,寻找影响外观质量的显著因子并加以控制,同时进一步优化脉冲电镀的工艺参数。     

Nanoscale Crystallization in the Amorphous Alloy Fe79P14.2Si4.4Mn2.2V0.2 upon Pulsed Photon Annealing

The effect of pulsed photon annealing with energy densities from 1.4 to 42 J/cm² for various lengths of time on the structure of the amorphous alloy Fe₇₉P_14.2Si_4.4Mn_2.2V_0.2 was studied by x-ray diffraction, differential scanning calorimetry, and transmission electron microscopy. The results demonstrate that short-term irradiation with low energy densities leads to surface relaxation of the amorphous alloy, increases the strength of the surface layer, and reduces the internal-friction peak. Longer term photon annealing leads to crystallization of the alloy throughout the sample thickness.     

Integrated magnetic full wave converter with flexible output inductor

A new integrated magnetic full wave DC/DC power converter that provides flexible transformer design by incorporating an independent output inductor winding is introduced. The transformer is implemented on a traditional three-leg magnetic core. The inductor winding can be separately designed to control the output current ripple. The cross-sectional area of the inductor core leg can be reduced dramatically. The operation and performance of the proposed circuit are verified on a 100 W prototype converter.     

Comparative Assessment of the Effect of Chemical and Radiation Factors on Workers and the General Public Resulting from the Salvaging of Nuclear-Powered Submarines

The results of observations performed over many years are used to make an assessment of the degree to which the concentration of chemical and radioactive substances escaping into the environment during salvaging of nuclear-powered submarines exceeds the admissable norms for workers at the main ship-repair facilities in Russia and for the general public in the surrounding territories. It is shown that the chemical substances are a determining factor in environmental contamination. Their content in the atmosphere and sea water exceeds the admissable norms near sources, on the territory of the enterprises, and (for individual indicators) at populated points. Under these conditions, the concentration of technogenic radionuclides does not exceed the admissable norms and its damaging effect on man is hundreds and thousands of times less than that of chemicals.