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31.
Wet oxidation of BPL porous carbon by H2O2 and HNO3 changes the pore structure and also increases the concentration of surface oxides. KOH uptake is increased by oxidation and is seen to be dependent on KOH concentration and to a lesser extent on inert electrolyte concentration. Enthalpy of immersion measurements have allowed the estimation of the enthalpy of hydration of the surface oxides and the enthalpy of neutralization of the easily accessible acid oxides. 相似文献
32.
33.
Orlik S. N. Ostapyuk V. A. Alekseenko L. M. 《Theoretical and Experimental Chemistry》2002,38(3):195-198
The possibility of making products of partial oxidation, alcohols and acids in particular, by the reaction of C3-C4 alkanes with nitrogen monoxide over oxide and zeolite catalysts is demonstrated. The most effective catalysts are CeO2 and Fe-TsVK. The dependence of the rate and selectivity of the process on the reaction conditions has been established. 相似文献
34.
Yu. E. Roginskaya F. Kh. Chibirova T. L. Kulova A. M. Skundin 《Russian Journal of Electrochemistry》2006,42(4):355-362
Products of lithium interaction with thin-film nanostructured SnO2-TiO2 (ST) oxides are studied with the aid of x-ray diffraction analysis and Moessbauer spectroscopy on the 119Sn nuclei. Electrochemical properties of a series of the ST electrodes with different concentrations of TiO2 varied from 0 to 20 mol % are also examined. It is concluded that the specific feature of the charge-discharge mechanism of the ST electrodes is a significant participation of oxygen in reversible reactions during insertion and extraction of lithium as compared with an alloying mechanism of operation of tin-containing anodes. The leading role in this is played by titanium oxide. Remaining stable towards reduction by lithium, it facilitates the holding of the neighboring layers of SnO2 in a nanodisperse state and in an oxidized state. The effect of a decrease in the capacity degradation in modified TiO2 electrodes, which is discovered in this work, is attributed to the hampering of the growth of nanocrystallites of β-Sn by interlayers of tin and titanium oxides mentioned above. 相似文献
35.
O. I. Artyushin E. V. Sharova I. L. Odinets S. V. Lenevich V. P. Morgalyuk I. G. Tananaev G. V. Pribylova G. V. Myasoedova T. A. Mastryukova B. F. Myasoedov 《Russian Chemical Bulletin》2004,53(11):2499-2507
An efficient method for the synthesis of secondary alkylamides of phosphorylacetic acids (APA) was proposed. The method involves amidation of ethyl phosphorylacetates with primary aliphatic amines. The scope of reaction was determined. Reactions with ethylenediamine and 1,4-diaminobutane yield the corresponding bisamides; in the case of 1,3-diaminopropane, N-(3-aminopropyl)diphenylphosphorylacetamide or N,N-propylenebis(diphenylphosphorylacetamide) was obtained, depending on the reaction conditions. The extraction of americium(III) complexes and the sorption of uranium(VI) by sorbents with physically sorbed APA from nitric acid solutions were studied. There is no correlation between the partition coefficient of americium(III) and the structure of APA; in the sorption of uranium(VI), the degree of extraction depends on the complexone structure.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2394–2402, November, 2004. 相似文献
36.
LIN Jun-Fan YAN Ya-XieDepartment of ChemistryInstitute of Chemistry Chemical EngineeringNanjing UniversityNanjing Jiangsu 《天然气化学杂志》1995,(2)
A series of perovskite type oxides La_(1-x)A_(x)MnO_3(x=0.1 for A=Li,Na,K;x=0.1~0.5 for A=Li)have been prepared by impregnation.Experimental results showed that the substitution of La~(3 ) by Li~ inLaMnO_(3 ?) greatly increased the selectivity to ethane and ethylene for theoxidative coupling of methane.Temperature-programmed desorption of oxygenproved the presence of oxygen vacancies in the oxide lattice.The higher Mn~(4 )/Mn_t ratio in oxide made the formation of oxygen vacancies easier on the oxidesurface.The general formula of the oxides is La_(1-x)Li_(x)Mn'V'_(y)O_(3-y),V=vacancy. 相似文献
37.
D. V. Tsyganov A. P. Yakubov L. D. Konyushkin S. I. Firgang V. V. Semenov 《Russian Chemical Bulletin》2007,56(12):2460-2465
A series of analogs of the natural mitostatic agent combretastatin were synthesized by the reaction of nitrile oxides with
natural allylbenzenes, such as myristicin, apiol, and dillapiol. The 1,3-dipolar cycloaddition reactions in allylic systems
proceed regiospecifically. The reactions with trans isomers of propenylbenzenes, viz., isomyristicin, isoapiol, and isodillapiol, as dipolarophiles produce regioisomers.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2375–2380, December, 2007. 相似文献
38.
IntroductionSupportedPt-Sncatalystsareimpo~inthepdrileumandpthechendcalindustricsbecauseoftheirsuperiorcatalyticperformances.Forexample,Pt-Snsupportedonaneutralsupporthasbeenreportedtoexhibithighdehydrogenationselectivityanddebilitythansupportedplatinumca… 相似文献
39.
Qiong Yu Lai Ji Zheng LuXiao Bo Su Xiao Yang Ji 《Journal of solid state chemistry》2002,165(2):312-316
Spinel compound LiNi1−xMnxVO4 (0≤x≤0.4) had been prepared by using the moist chemical method. X-ray diffraction spectra showed that the lattice constant increased with x in the LiNi1−xMnxVO4, XPS spectra indicating that Li1s had a chemical shift towards lesser binding energy, and manganese in LiNi1−xMnxVO4 existing as the mixed valence of Mn2+ and Mn3+. The electrochemical charge and discharge testing at a current density of 0.1 mA/cm2 between the potentials of 4.0 and 3.0 V vs Li/Li+ in 1 mol/dm3 LiPF6/EC+DEC (1:1 by volume) at 25°C showed that LiNi1−xMnxVO4 cell has a better rechargeability, but a lower cell voltage of 4.0 V vs Li/Li+ than that without the doping sample, and the capacity and the cycle efficiency of the Li/LiNi1−xMnxVO4 cells increased with x in the LiNi1−xMnxVO4. 相似文献
40.
M. Karppinen Y. Morita I. Grigoraviciute R.S. Liu 《Journal of solid state chemistry》2005,178(11):3464-3470
Superconductivity characteristics have been systematically evaluated for a two-CuO2-plane copper oxide system, (Cu,Mo)-12s2, upon increasing the number of fluorite-structured layers, s, between the two CuO2 planes. Essentially single-phase samples of (Cu0.75Mo0.25)Sr2YCu2O7+δ (s=1), (Cu0.75Mo0.25)Sr2(Ce0.45Y0.55)2Cu2O9+δ (s=2) and (Cu0.75Mo0.25)Sr2(Ce0.67Y0.33)3Cu2O11+δ (s=3) were synthesized through a conventional solid-state route in air. To make the samples superconductive an additional high-pressure oxygenation (HPO) treatment was required. Such treatment (carried out at 5 GPa and 500 °C in the presence of 75 mol% Ag2O2 as an oxygen source to maximize the Tc) compressed the crystal lattice for the three members of the (Cu0.75Mo0.25)-12s2 series equally, i.e., by 0.01 Å for the a parameter and by 0.07 Å for the c parameter per formula unit. From both Cu L-edge and O K-edge XANES spectra the s=1 sample was found to possess the highest overall hole-doping level among the HPO samples. Accordingly it exhibited the best superconductivity characteristics. With increasing s, both the Tc (s=1: 88 K, s=2: 61 K, s=3: 53 K) and Hirr values got depressed, being well explained by the trend of decreasing CuO2-plane hole concentration with increasing s as revealed from O K-edge XANES spectra for the same samples. Hence, the present results do not suggest any significant (negative) impact on the superconductivity characteristics from the gradually thickened fluorite-structured block itself. 相似文献