排序方式: 共有19条查询结果,搜索用时 15 毫秒
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Sialons as a new class of supports for oxidation catalysts 总被引:1,自引:0,他引:1
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V. G. Grebinnik V. N. Duginov V. A. Zhukov S. Kapusta A. B. Lazarev V. G. Olshevsky V. Y. Pomjakushin S. N. Shilov D. T. Bezhitadze I. I. Gurevich B. F. Kirillov E. P. Krasnoperov B. A. Nikolsky A. V. Pirogov A. N. Ponomarev V. A. Suetin G. F. Tavadze I. P. Borovinskaya M. D. Nersesyan A. G. Peresada Y. F. Eltzev V. R. Karasik O. E. Omelyanovsky 《Hyperfine Interactions》1990,61(1-4):1093-1096
We report the results of μSR investigations of the ceramic samples La2-xSrxCuO4-σ (x=0.1, 0.15, 0.25) and ReBa2Cu3O7-σ (Re=Er, Ho, Y0.5Ho0.5) in the external magnetic field 0–800 Oe. The measurements were performed by the ZFC and FC methods. The irreversibility effects were studied at several temperatures by measuring the mean value and the width of the magnetic field distribution on the muon in the step by step procedure of increasing and subsequent decreasing of the external field. The temperature dependences of the magnetic penetration depth perpendicular to the basal plane λ⊥ were obtained. For the lanthanum sample with 0.15 of Sr its value at the zero temperature is λ⊥ (0)=2400 Å, for Er-Ba-Cu-O λ⊥ (0)=1600 Å. 相似文献
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V. G. Grebinnik V. N. Duginov V. A. Zhukov S. Kapusta A. B. Lazarev V. G. Olshevsky V. Y. Pomjakushin S. N. Shilov I. I. Gurevich B. F. Kirillov B. A. Nikolsky A. V. Pirogov A. N. Ponomarev V. A. Suetin I. P. Borovinskaya M. D. Nersesyan A. G. Persada Y. F. Eltzev V. R. Kapasik O. E. Omelyanovski 《Hyperfine Interactions》1990,61(1-4):1085-1088
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T. A. Bazhenova N. V. Bardina G. N. Petrova M. A. Borovinskaya 《Russian Chemical Bulletin》2004,53(8):1646-1654
The effect of potential value and chemical properties of an external electron donor on C2H2 reduction catalyzed by nitrogenase active center (cluster [(6-N)Fe7MoS9·homocitrate] FeMoco isolated from the enzyme) has been investigated in the presence of proton donors of different acidity. The temperature—reaction rate dependences of these reactions have been studied. It has been shown that the rate-limiting steps of the reactions differ depending on the proton donor used. When thiophenol or water are used as proton donors, and electrochemical step — the electron transfer from cathode to adsorbed catalytic cluster — has been found to be a rate-limiting one. The effective activation energy of ethane formation as a product of four-electron C2H2 reduction is found to be 1.5 times lower than that of ethylene, namely, 13 kcal mol–1. When stronger acid, pentafluorothiophenol, is used as a proton donor, the chemical step of intramolecular rearrangement of the catalyst—substrate complex taking place in solution becomes a rate-limiting one. The effective activation energies of both ethylene and ethane become equal to 32 kcal mol–1.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1583–1591, August, 2004. 相似文献
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Microstructure reactors (microreactors) in recent decades became one of the most actively studied subjects of the reaction
equipment aimed at intensification of chemical processes and increase in their safety. It is not surprising because due to
miniature dimensions of microstructures which do not exceed 2 mm microreactors contribute to minimization of the material
at their production as well as raw material and energy in the process of exploitation. Moreover, due to acceleration of heat
and mass transfer the productivity of equipment with microreactors in a range of cases is significantly higher than classical
batch reactors applied in industry. The brief overview of the modern development and achievements of microreactor technology
is given in this article by an example of heterogeneous reaction systems which are different by their nature and occur in
different types of microreactors: phase-transfer catalysis, biocatalysis, and synthesis of nanoparticles. A special attention
in the article is paid to the aspects of intensification of the considered processes because exactly the possibility of intensification
makes microreactor technology attractive for the industry. 相似文献
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V. M. Uvarov E. S. Borovinskaya D. A. de Vekki V. P. Reshetilovskii 《Russian Journal of General Chemistry》2010,80(11):2263-2273
The hydrosilylation of acetophenone with diphenylsilane in a microreactor in the presence of complexes [Rh(cod)Cl]2 and [Rh(CO)2(μ-Cl)]2 and (R)-(-)-cis-mirtanyl- and (R)-(+)-bornylamine in situ was studied, the kinetics simulation of the process was performed, and the multicriteria optimization
of the process was carried out. The influence of the micro-mixing effect on the reaction rate was revealed. Best results in
the microreactor were obtained for the [Rh(cod)Cl]2-BornylNH2 catalytic system. It was established that the formation of 1-phenylethanol and related enol silyl ethers are simultaneous
competing reactions. 相似文献
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