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The effect of hydrogen on the photoluminescence and planar conductivity of GaAs/InGaAs quantum-well heterostructures with an island Pd layer at the anodically oxidized surface was studied. Unlike continuous deposited Pd layers, island layers do not cause the formation of defects in the GaAs surface region and yet the Pd layer maintains high catalytic activity with respect to hydrogen. It is found that the thermal treatment of such a structure in a hydrogen atmosphere causes atomic-hydrogen passivation of the defects in quantum wells. Studies of the characteristics of planar photoresistors with an island Pd layer acting as hydrogen sensors show that their hydrogen detectivity is approximately two orders of magnitude higher than that of diode structures with continuous Pd layers. 相似文献
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The surface of hydrogen-sensitive GaAs Schottky diodes is modified by nonpolishing etching and by producing quantum wells and quantum dots in the space-charge region of the semiconductor. The sensitivity to hydrogen is found to increase by a factor of 8–37 after the etching and by two or three orders of magnitude after the introduction of quantum wells and dots. It is shown that the increased sensitivity is associated with the lowering of the barrier at the Pd/GaAs interface, the retardation of hydrogen diffusion into GaAs due to the presence of strained quantum-size layers, and an increase in the recombination current. The presence of the recombination component is supported by luminescence from the quantum wells and quantum dots, as well as from the GaAs substrate. The etch composition is shown to be a decisive factor in raising the sensitivity. 相似文献
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M. S. Tikhov 《Journal of Mathematical Sciences》1991,53(6):607-614
Limiting distributions are constructed for the log likelihood ratio of close hypotheses and for estimators from censored samples.Translated from Statisticheskie Metody Otsenivaniya i Proverki Gipotez, pp. 95–104, 1986. 相似文献
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A. E. Kuz'min Yu. N. Dyatlova S. F. Tikhov V. I. Kurkin V. A. Sadykov E. V. Slivinskii E. I. Bogolepova S. V. Tsybulya V. B. Fenelonov V. P. Mordovin G. S. Litvak A. N. Salanov 《Kinetics and Catalysis》2005,46(5):743-751
ZrFe and ZrFe2 intermetallides in an Al2O3/Al cermet matrix are reported as catalysts for the fixed-bed Fischer-Tropsch synthesis, and the effects of some preparation conditions on their texture, structural, mechanical, and catalytic properties are discussed. A nonmonotonic dependence of their catalytic activity on the size of interametallide particles is observed. The selectivity, activity, and mechanical strength of the composites depend on the calcination temperature and on the place of the hydriding step in the catalyst preparation procedure. In terms of volumetric efficiency, the catalysts prepared are comparable with bulk, unencapsulated intermetallides and are among the most efficient iron-containing catalysts known to date. 相似文献
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M. S. Tikhov 《Journal of Mathematical Sciences》1984,25(3):1219-1230
One investigates the asymptotic behavior of the Bayes estimates tn of the parameter from censored samples of type II, under certain conditions on the behavior of the densities. One finds the limit distributions for (n)(tn–), where (n) is a normalizing factor.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 108, pp. 170–187, 1981.In conclusion, the author expresses his gratitude to I. A. Ibragimov and L. B. Klebanov for their interest in the paper and for their support. 相似文献
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G. N. Kryukova V. I. Zaikovskii V. A. Sadykov S. F. Tikhov V. V. Popovskii N. N. Bulgakov 《Reaction Kinetics and Catalysis Letters》1986,32(1):111-115
For the first time, using high-resolution electron microscopy, extended defects (twins, screw dislocations and microdistortions) of disperse CuO have been found. Their structure is described.
CuO -, .相似文献
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S. V. Tikhov V. I. Danilov I. A. Karpovich V. V. Martynov 《Russian Physics Journal》1982,25(9):848-851
The properties of metal (Al, Au)-anodic oxide-CdSnAs2 monocrystal structures are studied. It is established that MOS-structures using undoped CdSnAs2 crystals show a high positive fixed charge in the anodic oxide (NS 5·1012 cm–2) and high surface state density on the oxide-CdSnAs2 boundary surface (NSS 2·1013 cm–2·eV–1). In MOS-structures using diffusion-doped (copper) crystals the sign of the fixed charge is negative (NS 1011 cm–2, NSS 2·1012 cm–2·eV–1). The latter structures show a definite photosensitivity and photomemory. The possibility of effective control of the fixed charge value within the oxide by illumination is shown. The surface state distribution over energy, time constant, and capture section is determined.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 90–93, September, 1982. 相似文献
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We describe Novikov-Poisson algebras in which a Novikov algebra is not simple while its corresponding associative commutative
derivation algebra is differentially simple. In particular, it is proved that a Novikov algebra is simple over a field of
characteristic not 2 iff its associative commutative derivation algebra is differentially simple. The relationship is established
between Novikov-Poisson algebras and Jordan superalgebras.
Supported by RFBR (grant No. 05-01-00230), by SB RAS (Integration project No. 1.9), and by the Council for Grants (under RF
President) and State Aid of Leading Scientific Schools (project NSh-344.2008.1).
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Translated from Algebra i Logika, Vol. 47, No. 2, pp. 186–202, March–April, 2008. 相似文献