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排序方式: 共有3779条查询结果,搜索用时 15 毫秒
1.
Theoretical Foundations of Chemical Engineering - A set of measures to establish the technology for manufacturing highly active sources of γ radiation with an active part from... 相似文献
2.
V. I. Zubkov O. V. Kucherova I. N. Yakovlev A. V. Solomonov 《Russian Microelectronics》2015,44(3):203-209
An automated system for integrated electrophysical and optical studies of semiconductor nanoheterostructures, which operates in a wide temperature range from 15 to 475 K, is designed. The setup is intended to measure the temperature and frequency admittance and electroluminescence spectra of light-emitting diode and laser chips formed on substrates of diameter up to 50.2 mm, and the distribution of parameters over the wafer. The setup includes the closed-cycle helium cryogenic station, LCR meter, and temperature controller. The characterization results of nanoheterostructures with InGaN/GaN multiple quantum wells, which are used for creating highly efficient white and blue light-emitting diodes, are presented. 相似文献
3.
Tseluikin V. N. Yakovlev A. V. 《Protection of Metals and Physical Chemistry of Surfaces》2020,56(2):374-378
Protection of Metals and Physical Chemistry of Surfaces - Nickel-based composite electrochemical coatings (CECs) modified with graphite nitrate have been obtained. Their microstructure and... 相似文献
4.
High-efficiency LEDs of 1.6–2.4 µm spectral range for medical diagnostics and environment monitoring
N. D. Stoyanov B. E. Zhurtanov A. P. Astakhova A. N. Imenkov Yu. P. Yakovlev 《Semiconductors》2003,37(8):971-984
High efficient LED structures covering the spectral range of 1.6–2.4 μm have been developed on the basis of GaSb and its solid
solutions. The electroluminescent characteristics and their temperature and current dependences have been studied. The radiative
and nonradiative recombination mechanisms and their effect on the quantum efficiency have been investigated. A quantum efficiency
of 40–60% has been obtained in the quasi-steady mode at room temperature. A short-pulse optical power of 170 mW was reached.
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Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 37, No. 8, 2003, pp. 996–1009.
Original Russian Text Copyright ? 2003 by Stoyanov, Zhurtanov, Astakhova, Imenkov, Yakovlev. 相似文献
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KJ Shon M Grilley R Jacobsen GE Cartier C Hopkins WR Gray M Watkins DR Hillyard J Rivier J Torres D Yoshikami BM Olivera 《Canadian Metallurgical Quarterly》1997,36(31):9581-9587
A paralytic peptide, psi-conotoxin Piiie has been purified and characterized from Conus purpurascens venom. Electrophysiological studies indicate that the peptide inhibits the nicotinic acetylcholine receptor (nAChR). However, the peptide does not block the binding of alpha-bungarotoxin, a competitive nAChR antagonist. Thus, psi-conotoxin Piiie appears to inhibit the receptor at a site other than the acetylcholine-binding site. As ascertained by sequence analysis, mass spectrometry, and chemical synthesis, the peptide has the following covalent structure: HOOCCLYGKCRRYOGCSSASCCQR* (O = 4-trans hydroxyproline; * indicates an amidated C-terminus). The disulfide connectivity of the toxin is unrelated to the alpha- or the alphaA-conotoxins, the Conus peptide families that are competitive inhibitors of the nAChR, but shows homology to the mu-conotoxins (which are Na+ channel blockers). 相似文献
8.
T. I. Voronina T. S. Lagunova M. P. Mikhailova K. D. Moiseev M. A. Sipovskaya Yu. P. Yakovlev 《Semiconductors》1997,31(8):763-767
Galvanomagnetic phenomena and photoconductivity in broken-gap type-II GaInAsSb/p-InAs heterojunctions with different levels of doping of the solid solution with donor (Te) or acceptor (Zn) impurities have
been investigated. It has been determined that in such structures an electronic channel, which determines the galvanomagnetic
effects in a wide range of doping levels, is present at the heterojunction. A sharp decrease of the Hall mobility was observed
in the experimental heterostructures with a high level of doping of the epitaxial layer with an acceptor impurity. The observed
effect is due to exhaustion of the electronic channel as a result of carrier localization in potential wells at the heterojunction.
Fiz. Tekh. Poluprovodn. 31, 897–901 (August 1997) 相似文献
9.
JM Rumsey BC Donohue DR Brady K Nace JN Giedd P Andreason 《Canadian Metallurgical Quarterly》1997,54(12):1481-1489
The influence of ionic strength and composition on the binding and inhibition of human leukocyte elastase by glycosaminoglycans with variable degree and position of sulfation was investigated. The kinetic mechanism of inhibition had a hyperbolic, mixed-type character with a competitive component that was promoted by low ionic strength, reduced by phosphate ions, and which also depended on the substrate and glycosaminoglycan structure. Enzyme binding was a cooperative phenomenon that varied with ionic strength and composition. The inhibition patterns correlated with the cationic character of elastase and with the distribution of arginines on its molecular surface, most notably with residues located in the vicinity of the substrate binding region. The order of affinity for elastase binding was chondroitin 4-sulfate < chondroitin 6-sulfate < dermatan sulfate, iduronate-containing derivatives being superior with respect to the glucuronate-containing counterparts. Additional sulfation at both the 4- and 6- positions or at the N- and 4-positions of the N-acetylgalactosamine moiety decidedly improved the inhibitory efficiency. The results highlight a fundamental physiological role of enzyme-glycosaminoglycan interactions. In the azurophil granule of the human polymorphonuclear neutrophil, elastase and other enzymes are bound to a matrix of chondroitin 4-sulfate because this is the only glycosaminoglycan that simultaneously offers good binding for enzyme compartmentalization together with prompt release from the bound state at the onset of phagocytosis. 相似文献
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