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161.
报道了一种HBF4水溶液中的全铅液流电池,正、负电极电解液均采用Pb(BF4)2的HBF4水溶液.在酸性的四氟硼酸铅电解液中考察了石墨电极和玻碳电极作为工作电极的循环伏安性能,石墨电极较适于用作全铅液流电池的正、负电极.采用石墨电极作为电池的正、负电极并在四氟硼酸铅酸性电解液中进行充放电实验,其中Pb(BF4)2浓度分别为0.5、1.0和1.5 mol·L-1,且保持游离的HBF4浓度为1.0 mol·L-1.该电池为单液流电池,不需要隔膜分隔正、负极的电解液,电流密度为10、20和40 mA.cm-2,当限定充电容量为7.0 mAh.cm-2,放电电压截止到1.0 V时,平均库仑效率大于87%,平均能量效率大于68%;当电解液采用1.0或1.5 mol·L-1 Pb(BF4)2+1.0 mol·L-1HBF4水溶液时,在10及20 mA.cm-2电流下的能量效率最高可超过74%. 相似文献
162.
163.
E. M. Chervyakovsky D. A. Bolibrukh D. L. Kurovskii A. A. Gilep T. M. Vlasova V. P. Kurchenko S. A. Usanov 《Chemistry of Natural Compounds》2008,44(4):427-431
Some of the main oxidation products of quercetin were shown to be compounds formed by oligomerization of the starting flavonoid.
Conditions for the preparative synthesis of these compounds were developed. Their structures were established using HPLC-MS
and NMR methods. Quercetin oligomers in the natural sample, outer leaves of modified runners of Allium cepa L., were found using chromatographic procedures. The use of quercetin oligomers as indicators of its oxidation was proposed.
Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 344–347, July–August, 2008. 相似文献
164.
《Journal of Coordination Chemistry》2012,65(1-3):1-16
Kinetic and mechanistic studies of the oxidation of olefins, sulfides, and sulfoxides by [RuIV(bpy)2(O)- (PR3)](ClO4)2 (bpy = 2,2′-bipyridine; R = ethyl or phenyl) complexes have been conducted in both methylene chloride and acetonitrile. In all cases, the rate law shows a first-order dependence on both the concentration of (oxo)ruthenium(IV) species and the target substrate. In addition, product distributions of substrate oxidation exhibit a strong dependence on both the particular phosphine ligand and the solvent utilized in the experiment. On the basis of labelling experimcnts and kinetic evidence, a mechanism is proposed involving a two-electron, oxygen atom insertion into the target substrate. Notably, an (oxidized substrate)ruthenium(II) complex has been isolated and characterized for the oxidation of styrene by the (oxo)(triethylphosphine)ruthenium(IV) complex, where a cyclic voltammogram of this complex displays one quasi-reversible Ru(III)/Ru(II) couple with an E1/2 = 1.24 V vs SSCE. Kinetic analysis of styrene oxidation indicates that the formation of benzaldehyde from styrene does not occur simply by two sequential two-electron steps. In this regard, alternative mechanisms are discussed. 相似文献
165.
166.
L. N. Bochkarev T. A. Zheleznova A. V. Safronova M. S. Drozdov S. F. Zhil'tsov L. N. Zakharov G. K. Fukin S. Ya. Khorshev 《Russian Chemical Bulletin》1998,47(1):165-168
Triphenyl[tris(tetrahydrofuran)]ytterbium, Ph3Yb(THF)3 (1), was synthesized in high yields by the reaction of Yb with an excess of Ph2Hg or Ph3Bi in the presence of catalytic amounts of YbI2(THF)4 as well as by the reaction of Ph2Yb(THF)2 (2) with Ph2Hg or Ph3Bi. The crystal structure of complex1 was studied by X-ray structural analysis.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 163–166, January, 1998. 相似文献
167.
168.
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170.