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911.
Maiorova N. A. Khazova O. A. Tarasevich M. R. 《Russian Journal of Electrochemistry》2004,40(10):1060-1065
The kinetics of the hydrogen oxidation and the CO adsorption on a Pt (ultra)microelectrode is studied in a 0.5 M H2SO4 solution saturated with a mixture of gaseous H2 and CO at partial CO pressures p
CO = 10–500 ppm. The balance between rates of diffusion and adsorption of CO at different adsorption times is studied. Studied is the effect of CO impurities in H2 on steady-state polarization curves for the hydrogen ionization and nonsteady-state curves of the oxidation current decay with time at 0.02–0.05 V. Conditions under which in a certain time interval and at a certain CO concentration the slope of an I vs. t curve is proportional to p
CO are determined. The obtained dependence may be used when designing a technique for monitoring CO impurities in technical hydrogen. 相似文献
912.
V. A. Krylov O. Yu. Chernova Yu. M. Salganskii L. S. Malygina A. P. Kotkov 《Journal of Analytical Chemistry》2003,58(8):750-755
It is shown that the results of determining methane in high-purity arsine by reaction gas chromatography can be overestimated by more than two orders of magnitude. This overestimation is caused by the formation of methane as a side product of the reaction. Cryogenic preconcentration at the injection stage is proposed to improve the accuracy of determination of methane, and the cryofocusing of impurity hydrocarbons is proposed to improve separation. Detection limits of (3–10) × 10–6 vol % are achieved for C1–C5 hydrocarbons. 相似文献
913.
A. S. Rybak E. V. Grinyuk T. G. Klimets A. P. Polikarpov M. M. Brazhnikov O. I. Shadyro L. P. Krul' 《High Energy Chemistry》2003,37(4):224-227
The effect of concentration of an acrylamide–sodium acrylate copolymer in an aqueous solution on the crosslinking of macromolecules by the action of ionizing radiation was studied. It was shown that the efficiency of radiation crosslinking of the copolymer increased with an increase in the concentration of solution subject to irradiation, which was tentatively explained in terms of the existence of fluctuative entanglement network ensuring the approaching of macroradical sites and, thus, facilitating the combination reactions of macroradicals. 相似文献
914.
Talismanova M. O. Sidorov A. A. Aleksandrov G. G. Oprunenko Yu. F. Eremenko I. L. Moiseev I. I. 《Russian Chemical Bulletin》2004,53(7):1507-1510
The new dinuclear palladium complex Pd2(-S,N-SC7H5N2)4 with a Chinese-lantern structure was synthesized by the reaction of K2PdCl4 with 2-mercaptobenzimidazole and structurally characterized by X-ray diffraction analysis. 相似文献
915.
One-Pot Synthesis of Phenytoin Analogs 总被引:1,自引:0,他引:1
A series of phenytoin analogs (5,5-diphenylimidazolidine-2,4-dione or 5,5-diphenyl-hydantoin) were synthesized in 65–75% yield from the corresponding substituted benzils. The same products were also obtained directly from -hydroxy ketones via one-pot procedure. 相似文献
916.
917.
Teleshev A. T. Vasil"eva L. N. Nifant"ev E. E. Tsodikov M. V. Bukhtenko O. V. Zhdanova T. N. 《Russian Chemical Bulletin》2003,52(9):2083-2085
The reactivities of cyclophosphite precursors in alkoxo syntheses involving titanium(iv) tetra(n-butoxide) were studied by 31P NMR and IR spectroscopy. 2-Diethylamido-4-methyl-1,3,2-dioxaphosphinane and 4-ethyl-2,6,7-trioxaphosphabicyclo[2.2.2]octane in benzene are inert toward Ti(OBu)4. Gelation is accompanied by hydrolysis 2-diethylamido-4-methyl-1,3,2-dioxaphosphinane to give the corresponding hydrophosphoryl compound, while 4-ethyl-2,6,7-trioxaphosphabicyclo[2.2.2]octane remains intact during gelation. 相似文献
918.
V. P. Borovik I. Yu. Bagryanskaya Yu. V. Gatilov O. P. Shkurko 《Journal of Structural Chemistry》2003,44(4):650-654
The crystal structures of 2-amino-4-phenyl-9H-pyrimido[4,5-b]indole and its nitrate were determined by XRD analysis. 13C NMR, XRD, and quantum-chemical data indicate that the acid proton is predominantly localized at the N(3) atom of the pyrimidine ring in both isolated nitrate molecules and in molecules in crystal and solution. 相似文献
919.
M. G. Koroleva O. V. Dyablo A. F. Pozharskii Z. A. Starikova 《Chemistry of Heterocyclic Compounds》2003,39(9):1161-1171
The previously unknown 1-amino- and 3-aminonaphtho[1,2-d]imidazoles, 1-aminonaphtho[2,3-d]imidazole, 1-aminophenanthro[9,10-d]imidazole and the N-amino-N'-methylimidazolium picrates corresponding to them have been obtained by direct amination of a series of condensed imidazoles with O-picrylhydroxylamine. An X-ray structural investigation of 1-amino-3-methylnaphtho[1,2-d]imidazolium picrate showed that, in difference to 1-aminobenzimidazolium salts, a conformation exists in it in which the hydrogen atoms of the N-NH2 group are directed to the side of the meso carbon atom. 相似文献
920.
Krylov I. O. Lugovskaya I. G. Anufrieva S. I. Krylova A. V. 《Russian Journal of Applied Chemistry》2003,76(8):1234-1237
The chemical composition, specific surface area, and pore structure of a schungite sorbent were studied as influenced by the conditions of thermal treatment. 相似文献