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排序方式: 共有170条查询结果,搜索用时 31 毫秒
1.
N. P. Venediktov M. Yu. Glyavin V. E. Zapevalov A. N. Kuftin A. S. Postnikova M. V. Yulpatova 《Radiophysics and Quantum Electronics》1997,40(4):336-342
A scheme for automated study of current-voltage characteristics of gyroresonance devices is developed. The effective emission
spread at the cathodes of powerful gyrotrons is studied by analysis of current-voltage characteristics. Experimental data
on the effective emission spread parameter for different modes are given. The permissible emission spread at the cathodes
of powerful gyrotrons is estimated, and the dependence of the electron beam parameters on the cathode emission spread is presented.
A complex measurement technique showing the contribution of different physical mechanisms to the cathode emission spread is
proposed.
Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh
Zavedenii, Radiofizika, Vol. 40, No. 4, pp. 506–516, April, 1997. 相似文献
2.
V. N. Odinoko V. R. Akhmetova R. G. Savchenko A. A. Fatykhov A. Ya. Zapevalov 《Russian Chemical Bulletin》1994,43(6):1084-1085
Perfluoro-1-octene was used as a model for developing a method for the preparative ozonolysis of perfluoro-1-alkenes to the corresponding perfluoro-nor-alkenals. Perfluoroheptanal was synthesized.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1146–1147, June, 1994. 相似文献
3.
V. A. Flyagin V. I. Khizhnyak V. N. Manuilov M. A. Moiseev A. B. Pavelyev V. E. Zapevalov N. A. Zavolsky 《International Journal of Infrared and Millimeter Waves》2003,24(1):1-17
Main results of experimental testing of the 140 GHz/1.5 MW coaxial gyrotron are summarized. High selective properties of the coaxial cavities and a possibility to increase considerably the efficiency of a coaxial gyrotron only by applying independently an appropriate voltage on its electrodes (without any design modification) have been confirmed. Successful uses of the two-potential connection scheme for the frequency step tuning and output power modulation in a coaxial gyrotron has been also demonstrated. 相似文献
4.
E. V. Gavryushin T. I. Gorbunova A. Ya. Zapevalov V. I. Saloutin 《Russian Journal of Applied Chemistry》2006,79(5):861-864
Wetting angles and limits of thermal stability of esters derived from pentaerythritol and perfluoro-, ω-chloropolyfluoro-, and perfluoropolyethercarboxylic acids were studied. 相似文献
5.
N. A. Zavolsky V. E. Zapevalov M. A. Moiseev 《Radiophysics and Quantum Electronics》2006,49(2):108-119
We study theoretically the influence of the spread of initial energies and velocities in the electron beam on the starting
conditions and efficiency of a gyrotron. We compare various analytical and numerical models and the results of experimental
studies of gyrotrons in which the interaction takes place at the first and second harmonics of the cyclotron frequency. The
aftercavity interaction of the electron beam with the high-frequency field in the output waveguide transition is taken into
account. The influence of the energy spread on the recuperation efficiency is estimated. Permissible spreads of the initial
energies and electron velocities are determined.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 49, No. 2, pp. 121–133, February 2006. 相似文献
6.
Lyudmila V Saloutina Aleksandr Ya Zapevalov Konstantin A Lyssenko Victor I Saloutin 《Journal of fluorine chemistry》2003,120(1):41-47
The reaction of oxides of internal trans- and cis-perfluoroolefins with (1S, 4S)- or racemic camphor thiosemicarbazone leads to the formation of trans- and cis-isomers of (1S, 4S)- or racemic camphor 5′-fluoro-4′-hydroxy-4′,5′-di(perfluoroalkyl)-1′,3′-thiazolinyl-2′-hydrazones, respectively. Unsymmetrical dodecafluoro-2,3-epoxyhexane yields a mixture of regioisomeric hydrazones. The molecular structure of the trans-isomer of (1S, 4S)-camphor 5′-fluoro-4′-hydroxy-4′,5′-bis(trifluoromethyl)-1′,3′-thiazolinyl-2′-hydrazone has been established by X-ray crystallography. The quite rare example of cocrystallization of two diastereomers of the latter in homochiral crystal (sp. group P21) has been revealed. 相似文献
7.
8.
V. Yu. Korotaev Yu. A. Skorik A. Yu. Barkov M. I. Kodess A. Ya. Zapevalov 《Russian Chemical Bulletin》2005,54(11):2545-2549
3,3,3-Trifluoro-N′-(3-trifluoromethylphenyl)-1,2-propanediamine (5) was synthesized by the reaction of 2-diazo-1,1,1-trifluoro-3-nitropropane or 3,3,3-trifluoro-1-nitropropene with 3-aminobenzotrifluoride
followed by the reduction of the nitro group. The Michael 1,4-addition of diamine 5 to acrylic acid occurs only at the N(1) atom and affords N-mono-or N,N-dicarboxyethyl derivatives 6 and 7, depending on the reactant ratio. Protolytic equilibria 5–7 in aqueous solutions were studied by pH-potentiometry and UV spectroscopy. Only the aliphatic amino group can be protonated
in an aqueous solution, while the aromatic amino group remains unprotonated even in 12 M HCl. The stability constants of transition metal (Cu2+, Ni2+, Zn2+) complexes with ligands 5–7 were determined by pH-potentiometric titration. The stability of the complexes and selectivity of the ligands toward Cu2+ ions increase with an increase in the number of N-carboxyethyl groups.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2465–2469, November, 2005. 相似文献
9.
D. N. Bazhin T. I. Gorbunova A. Ya. Zapevalov V. I. Saloutin 《Russian Journal of Applied Chemistry》2005,78(10):1646-1650
Procedures for preparing polyfluorinated ethers H(CF2CF2) n CH2OR by alkylation of the corresponding telomeric alcohols H(CF2CF2) n CH2OH (n = 1–3) with alkyl halides and alkyl tosylates were examined. 相似文献
10.
T. I. Filyakova A. Ya. Zapevalov M. I. Kodess P. A. Slepukhin V. I. Saloutin 《Russian Journal of Organic Chemistry》2014,50(6):854-857
Perfluoro(1,2-epoxycyclohexane) readily reacts with bifunctional nucleophiles (urea, thiourea, and benzene-1,2-diamine) via opening of the oxirane ring and subsequent heterocyclization to give fluorinated benzimidazole, 1,3-benzothiazole, and phenazine derivatives, respectively. 相似文献