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1.
It is demonstrated that the diffraction of a plane light wave by an acoustic wave of fundamental frequency in the Raman-Nath
mode with admixture of the second acoustic harmonic may be accompanied by a considerable change in the higher diffraction
orders with numbers ±2, ±3, etc. Conditions for the selective suppression of the orders are obtained in the weak and strong
interaction modes. Results of a numerical simulation are presented. 相似文献
2.
Zaitseva N. A. Molchanov V. V. Chesnokov V. V. Buyanov R. A. Zaikovskii V. I. 《Kinetics and Catalysis》2003,44(1):129-134
The particle morphology and surface structure of nickel metal in metal–filamentous carbon catalysts were found to depend on the nature of coke-forming species used in the synthesis of catalysts. Metal carbonization with hydrocarbons that are characterized by high thermodynamic stability results in the formation of well-cut metal particles the surface of which is formed by (110) facets. Selective hydrogenation reactions of diene and acetylene hydrocarbons to olefins are typical of these catalysts. In the catalytic decomposition of hydrocarbons with relatively low thermodynamic stability, metal particles become irregular in shape, and their surface is formed by (111) facets. In this case, the reactions of full hydrogenation of olefin, diene, and acetylene hydrocarbons to corresponding alkanes take place. These data are consistent with the found dependence of the catalytic properties of catalysts on the character of the exterior faceting of active metal particles. 相似文献
3.
N. A. Prokudina E. A. Paukshtis R. A. Buyanov V. V. Chesnokov T. A. Konovalova 《Reaction Kinetics and Catalysis Letters》1996,59(1):187-192
The role of carbonate-carboxylate species on alumina surface has been studied during alumina coking. The species are intermediates poisoning the active sites. Little O2 added to the hydrocarbon feedstock causes further oxidation of the species and promotion of the active sites. 相似文献
4.
A. I. Mikhalev V. P. Chesnokov M. E. Konshin 《Chemistry of Heterocyclic Compounds》1979,15(6):652-653
10-Alkylaminobenzo[b]-1,8-naphthyridines were synthesized by cyclization of 2-arylaminonicotinic acid alkylamides by means of phosphorus oxychloride. The pKal values of the 10-alkylaminobenzo[b]-1,8-naphthyridines, which range from 8.74 to 8.50, were determined by potentiometric titration in anhydrous ethanol.See [1] for communication 9.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 799–801, June, 1979. 相似文献
5.
M. P. Shurygina S. A. Chesnokov M. A. Lopatin V. K. Cherkasov G. A. Abakumov 《Russian Chemical Bulletin》2004,53(11):2485-2489
A study of the kinetics of photoreduction of 9,10-phenanthrenequinone in the presence of hydrogen donors (para-substituted N,N-dimethylanilines and polymethylbenzenes) showed that plots of the quantum yield of photoreduction (H) and apparent reaction rate constant (k
H) vs. oxidation potential of hydrogen donors are extreme. In the presence of amines, k
H and H increase, as a whole, whereas they decrease in the presence of polymethylbenzenes. In coordinates H-G
e (G
e is the change in the free energy of electron transfer) for pairs quinone-H donor, H increases with G
e approaching to zero. For the amine series, this effect is mainly in the exothermic region of G
e (G
e < 0). For the series of polymethylbenzenes, this increase is observed in the endothermic region (G
e > 0).__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2381–2385, November, 2004. 相似文献
6.
The kinetics of methane steam reforming and pyrolysis on Ru/Al2O3(T= 650–750°C,
= 0.001–0.030 MPa) is studied. The values of the rates and activation energies are compared with the kinetic parameters for nickel catalysts. It was shown that steam reforming can occur on the ruthenium catalyst both heterogeneously and heterogeneously–homogeneously depending on the reaction conditions. Comparative activities of the Ru/Al2O3and Ni–Al2O3catalysts are discussed under the conditions of purely heterogeneous and heterogeneous–homogeneous steam reforming. 相似文献
7.
Observation that rates of dehydrobromination of trans-β-bromostyrene (1) and the Hofmann degradation of tetrabutyl ammonium cation depend on strength of base in different ways and that treatment of 1 with base results in fast abstraction of the β-proton imply the possibility that the dehydrobromination of 1 could proceed via α-elimination and Ph migration. In order to clarify this question, β-13C-labeled 1 was obtained and subjected to PTC dehydrobromination which proceeds without migration of Ph. The obtained results are consistent with an irreversible E1cB mechanism. 相似文献
8.
9.
Chesnokov S. A. Cherkasov V. K. Abakumov G. A. Kurskii Yu. A. Shurygina M. P. Mamysheva O. N. Shavyrin A. S. 《Russian Chemical Bulletin》2003,52(3):718-724
Photoreduction of o-benzoquinones in the presence of p-bromo-N,N-dimethylaniline under irradiation ( > 500 nm) affords the corresponding pyrocatechols and hydroxyphenyl ethers. The latter are unstable and, in turn, decompose in the dark reaction to pyrocatechols. The ratio between pyrocatechol and hydroxyphenyl ether formed upon the photoreaction is determined by the structure of o-quinone, namely, the presence and bulk of substituents in positions 3 and 6 of the ring. The yield of pyrocatechol is maximal (60—65%) if the substituents are the same (H and H, But and But) or insignificantly differ (Pri and But), regardless of its bulk. 相似文献
10.
A. R. Suzdorf L. I. Kuznetsova V. G. Chumakov N. V. Chesnokov B. N. Kuznetsov 《Reaction Kinetics and Catalysis Letters》1984,26(1-2):183-188
Studies of the properties of precipitated Fe–Mn catalysts in CO hydrogenation have revealed that samples precipitated from iron and manganese nitrates by sodium carbonate are more selective to olefins than those precipitated by ammonia. Difference in the catalytic properties is due to the different phase compositions of the catalysts.
CO , . , , , , . .相似文献