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931.
932.
A. S. Saidov Sh. N. Usmonov M. U. Kalanov A. N. Kurmantayev A. N. Bahtybayev 《Physics of the Solid State》2013,55(1):45-53
Films of the solid solutions Si1 ? x Sn x (0 ≤ x ≤ 0.04) on Si substrates have been grown by liquid phase epitaxy. The structural features of the films have been investigated using X-ray diffraction. The temperature behavior of current-voltage characteristics and the spectral dependence of the photocurrent for the heterostructures p-Si-n-Si1 ? x Sn x (0 ≤ x ≤ 0.04) have been analyzed. The grown epitaxial films of the solid solutions Si1 ? x Sn x (0 ≤ x ≤ 0.04) have a perfect single-crystal structure with a (111) orientation and a subgrain size of 60 nm. In the epitaxial films at the Si-SiO2 interfaces between silicon subgrains and SiO2 nanocrystals, where there are many sites with a high potential, the Sn ions with a high probability substitute for the Si ions and encourage the formation of Sn nanocrystals with different orientations and, as follows from the analysis of the X-ray diffraction patterns, with different sizes: 8 nm (for the (101) orientation) and 12 nm (for the (200) orientation). The current-voltage characteristics of the heterostructures p-Si-n-Si1 ? x Sn x (0 ≤ x ≤ 0.04) are described by the exponential law J = J 0exp(qV/ckT) at low voltages (V < 0.2 V) and the square law J = (9qμ p τ p μ n N d /8d 3)V 2 at high voltages (V > 1 V). These results have been explained by the drift mechanism of charge carrier transport in the electrical resistance relaxation mode. 相似文献
933.
Optimum conditions for the formation and extraction of a slightly soluble ion associate of diphenhydramine with the anionic complex molibydenum–gallein were determined. The ternary complex was extracted with butanol at pH 4–7. In the presence of diphenhydramine, the color strength became stronger, which was manifested in the absorption spectra as hypsochromic and bathochromic shifts. Some physicochemical characteristics of the complex were determined, the specificity of the reaction with respect to diphenhydramine was studied, and the probable complexation scheme was proposed. It was found that the molybdenum–gallein–diphenhydramine complex forms at a component ratio of 1: 2: 2. A procedure for the extraction–photometric determination of diphenhydramine in injection solutions and tablets was developed (RSD = 15–20%). The linearity range of the calibration graph was 0.02–0.20 mg/mL. 相似文献
934.
S. B. Hosseini T. Beno S. Johansson U. Klement J. Kaminski K. Ryttberg 《Experimental Mechanics》2014,54(3):369-377
In this investigation, the applicability of the two-color pyrometer technique for temperature measurements in dry hard turning of AISI 52100 steel was studied, where both machined surfaces as well as cutting tools were considered. The impacts of differing hard turned surface topography on the two-color pyrometer readings was studied by conducting temperature measurements on reference samples created using cutting tools with different degrees of tool flank wear. In order to conduct measurements in a controlled environment, a specially designed furnace was developed in which the samples were heated step-wise up to 1,000 °C in a protective atmosphere. At each testing temperature, the temperatures measured by the two-color pyrometer were compared with temperatures recorded by thermocouples. For all materials and surfaces as studied here, the two-color pyrometer generally recorded significantly lower temperatures than the thermocouples; for the hard turned surfaces, depending on the surface topography, the temperatures were as much as ~20 % lower and for the CBN cutting tools, ~13 % lower. To be able to use the two-color pyrometer technique for temperature measurements in hard turning of AISI 52100 steel, a linear approximation function was determined resulting in three unique equations, one for each of the studied materials and surfaces. By using the developed approximation function, the measured cutting temperatures can be adjusted to compensate for differing materials or surface topographies for comparable machining conditions. Even though the proposed equations are unique for the hard turning conditions as studied here, the proposed methodology can be applied to determine the temperature compensation required for other surface topographies, as well as other materials. 相似文献
935.
The reaction of different mercapto substituted heterocycles with o,o-dialkyl chlorphosphate or thiophosphates, gave the corresponding S- and N- alkylated derivatives instead of the expected phosphorylated products. 相似文献
936.
V. Sankara Sastry S. Kalavathy B. K. Guha R. Baskaran U. De J. Janaki 《Phase Transitions》2013,86(1-2):97-105
Electrical resistance measurements at low temperatures and high quasihydrostatic pressures on superconducting and non-superconducting varieties of Y0.8Ba1.2Cu2O5 (obtained by annealing in oxygen and air respectively) show striking anomalies in the vicinity of 100K and 40K. Arguments are presented to show that these anomalies as also the occurrence of T 's in the oxide superconductors either in the vicinity of 100K or of 40K are connected with their layered structure containing planes of Cu-O otahedral complexes. 相似文献
937.
U.P. Verma Sonu Sharma Nisha Devi P. Rajaram 《Journal of magnetism and magnetic materials》2012,324(19):3017-3023
We have investigated the structural, electronic, magnetic and optical properties of Hg1?xMnxTe in the zinc-blende phase for 0≤x≤1. The calculations were performed by using the full potential linearized augmented plane wave plus local orbitals method within the framework of the density functional theory. The lattice constants of Hg1?xMnxTe at different Mn concentrations exhibit Vegard's law perfectly. For spin-up channel the Mn 3d bands are occupied and mixed with the Te 5p bands whereas for spin-down channel the Mn 3d bands are unoccupied. The values of the p–d exchange splitting energy, ?x(pd) as produced by the Mn 3d states are given. The contribution of the valence band and the conduction band in the process of exchange and splitting is described by the exchange coupling constants N0α and N0β. Due to p–d hybridization the magnetic moment of the Mn atom reduces, which results in small local magnetic moments on the non-magnetic Hg and Te sites. The potential applications of Hg1?xMnxTe in infrared device have been discussed on the basis of its optical properties. 相似文献
938.
A distance based measure of dependence is proposed for stable distributions that completely characterizes independence for a bivariate stable distribution. Properties of this measure are analyzed, and contrasted with the covariation and co-difference. A sample analog of the measure is defined and demonstrated on simulated and real data, including time series and distributions in the domain of attraction of a stable law. 相似文献
939.
E. Werner P. Roth U. Heinrichs A. Giussani M. C. Cantone Th. Zilker 《Isotopes in environmental and health studies》2013,49(2):123-132
Abstract Although molybdenum is considered to be an essential trace metal for humans, the knowledge about its metabolism is rather limited. The present study was aimed at the assessment of biokinetics following intravenous injection of trace amounts of 95Mo or 96Mo into five healthy volunteers. In a total of 11 investigations, the plasma clearance up to eight hours and the urinary excretion for at least three days after the injection were evaluated. The tracer concentrations were determined by proton nuclear activation analysis in blood plasma and by thermal ionization mass spectrometry in urine samples respectively. In all subjects, the plasma clearance is much faster than expected from the literature. The data obtained for the plasma clearance of the tracer can reasonably be fitted by a two exponential equation. The half times of the fast component range between 4 and 70 minutes and for the slow component between 3 and 30 hours. The urinary excretion of the injected tracer seems also to be faster than expected and the fractions lost are higher for larger doses administered. For the smallest dose given, 34% of the injected tracer were excreted within one day whereas for the four times larger dose about 60% were lost. These findings on urinary excretion are in agreement with recently published results. 相似文献
940.
Bharat Kumar Ruth L. Viboh Margel C. Bonifacio William B. Thompson Jonathan C. Buttrick Babe C. Westlake Min‐Soo Kim Robert W. Zoellner Sergey A. Varganov Philipp Mrschel Jaroslav Teteruk Martin U. Schmidt Benjamin T. King 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2012,124(51):13071-13071