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1.
2.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 54, No. 6, pp. 965–969, June, 1991. 相似文献
3.
A procedure is proposed for the voltammetric determination of selenium as selenosulfate (SO3Se2?) ions at a mercury-film electrode (MFE). Selenosulfate ions are determined in the range from 2 × 10?4 to 1.0 × 10?3 M without analyte accumulation, using peak current at ?0.92 ± 0.02 V and in the range from 1 × 10?7 to 2 × 10?4 M after analyte accumulation with the open circuit, using peak current at ?1.18 ± 0.03 V as the analytical signal. The mechanisms of SO3Se2? reduction at an MFE under the conditions of direct voltammetry and stripping voltammetry with accumulation are proposed and discussed. 相似文献
4.
I. Ya. Zaitseva I. S. Kovaleva V. A. Fedorov 《Russian Journal of Inorganic Chemistry》2007,52(6):940-944
Several vertical sections are investigated in the HgBr2-PbBr2-CsBr system by the methods of physicochemical analysis. Six compounds, namely, CsHg2Br5, CsHgBr3, Cs2HgBr4, CsPb2Br5, CsPbBr3, and Cs4PbBr6, are formed in the bordering binaries of the ternary system. By the results of investigation, the projection of the liquidus surface of the HgBr2-PbBr2-CsBr system on the composition triangle is constructed, and the fields of primary crystallization of nine phases are plotted, namely, HgBr2, PbBr2, CsBr, CsHg2Br5, CsHgBr3, Cs2HgBr4, CsPb2Br5, CsPbBr3, and Cs4PbBr6. An immiscibility region is found in the system. This region occupies a considerable part of the primary crystallization field of PbBr2. The coordinates of invariant points are determined, and isotherms are plotted. 相似文献
5.
6.
The reactions of aliphatic β-amino-β-trifluoromethylvinyl ketones with an excess of ethylenediamine at room temperature afforded
the corresponding 2,3-dihydro-1H-1,4-diazepines or substituted 2-acetonyl-2-trifluoromethylimidazolidines (the latter were obtained when the approach to the
carbonyl group was sterically hindered).
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2305–2308, November, 1998. 相似文献
7.
Kovaleva E. G. Molochnikov L. S. Kharchuk V. G. Kuznetsova O. V. Shishmakov A. B. Yanchenko M. Yu. Buldakova L. Yu. Zhdanov I. N. Mikushina Yu. V. Petrov L. A. 《Kinetics and Catalysis》2004,45(5):752-758
The distribution of Cu2+ ions in ZrO2 and sulfated ZrO2 hydrogel phases was studied by EPR spectroscopy and voltammetry. The formation of the following three types of copper structures was observed: mononuclear Cu2+ complexes (A), magnetic associates (B), and Cu2+ compounds (C) that gave no EPR signals under the conditions used in the spectroscopic measurements. The specific catalytic activity of various Cu2+ compounds in the liquid-phase reaction of 2,3,5-trimethyl-1,4-hydroquinone oxidation was determined. The copper complexes C were found to exhibit the highest catalytic activity. 相似文献
8.
L. A. Novokshonova N. Yu. Kovaleva T. M. Ushakova I. N. Meshkova V. G. Krasheninnikov T. A. Ladygina I. O. Leipunskii A. N. Zhigach M. L. Kuskov 《Kinetics and Catalysis》2005,46(6):853-860
The heterogenized reaction products of the partial hydrolysis of the organoaluminum compounds AlMe3 and Al(i-Bu)3 with water as a constituent of highly hydrated supports, zeolite (ZSM-5-H2O) and montmorillonite (MMT-H2O), have been synthesized. The thermal degradation of the resulting heterogenized methylalumoxane compound and methylalumoxane (MAO) in a solid state is studied by temperature-programmed desorption with the mass-spectrometric analysis of liberated gaseous products, and the structural identity of the above compounds is found. Alkylalumoxanes prepared immediately on the surface of a support form heterogenized complexes with the metallocenes Cp2ZrCl2 and Et(Ind)2ZrCl2. These heterogenized complexes exhibit high activity in the reactions of ethylene and propylene polymerization. For this reason, MAO can be replaced by AlMe3 or Al(i-Bu)3 and the additional introduction of MAO or another alkylaluminum for zirconocene activation is unnecessary. It has been found that, upon the immobilization of commercial MAO on dehydrated SiO2, the MAO molecule loses a portion of its most reactive methyl groups and, as a result of this, becomes incapable of activating metallocenes. 相似文献
9.
G. S. Zakharova L. Yu. Buldakova V. L. Volkov L. S. Molochnikov E. G. Kovaleva 《Russian Journal of Electrochemistry》2006,42(1):53-58
Complex vanadium and titanium oxides modified by copper ions are studied by the electrochemical and ESR methods. Oxides Cu x V2?y Ti y O5?δ·nH2O (0<y<1.33) have a layered structure and oxides Cu x Ti1?y V y O5+δ·nH2O (0<y<0.25), an anatase structure. The intercalation of cations Cu2+ into the hydrates leads to oxidation of V4+. According to ESR data, V4+ exists in the oxides in the form of VO2+ and an octahedral surround of oxygen (V4+?O6), respectively. The electroreduction of ions of d-elements and chemisorbed oxygen in the oxides is analyzed. The intercalation of cations Cu2+ alters the content of V4+ and the chemisorption ability of the oxides. Possible reasons for this phenomenon are discussed. 相似文献
10.
R. M. Khomutov E. S. Severin G. K. Kovaleva N. V. Gnuchev 《Russian Chemical Bulletin》1967,16(8):1743-1745
Conclusions Various O-substituted hydroxylamines were synthesized by the method proposed by us.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1820–1823, August, 1967. 相似文献