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Oxidative coupling of methane over Bi2O3–P2O5–K2O/Sm2O3 takes place giving more C2H4 as compared to C2H6. Sm2O3 supported Bi–P–K is a more active and selective catalyst, than TiO2, -Al2O3, SiO2 and MgO supported catalysts.
Bi2O3–P2O5–K2O/Sm2O3 , . Bi–P–K, Sm2O3, , TiO2, -Al2O3, SiO2, MgO.相似文献
75.
A Mg/Fe hydrotalcite-like-compound (HTlc) was prepared and its affinity toward the removal of SeO(3)(2-) from an aqueous medium was studied as a function of pH, time, temperature, particle dose, and SeO(3)(2-) concentration. The fraction of SeO(3)(2-) removal increases with decrease in both pH and temperature. The adsorption data are fitted to the Langmuir adsorption isotherm in the temperature range 303-333 K, and the thermodynamic parameters viz. standard Gibbs' free energy change (DeltaG degrees ), enthalpy change (DeltaH degrees ), and entropy change (DeltaS degrees ) are calculated. The negative value of DeltaH degrees indicates that the adsorption process is exothermic. The apparent equilibrium constants (K(a)) are also calculated and found to decrease with increase in temperature. 相似文献
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Geetanjali Parida 《Phase Transitions》2013,86(5):452-459
In this study, Bi4Ti3O12–SrBi4Ti4O15 (BIT–SBTi) intergrowth ferroelectric ceramics was synthesized by a modified oxalate route. The phase formation behaviour, structure, morphology and electrical properties of the intergrowth ceramics were also investigated. The phase formation takes place through intermediate phases like SrBi2O4 and Bi12TiO20. The precursor mostly changes to Bi4Ti3O12 at 600°C and to BIT–SBTi intergrowth at 800°C. Rietveld analysis of the X-ray diffraction pattern showed that the structure of the intergrowth compound was orthorhombic with lattice parameters a = 5.4408(3), b = 5.4505(1) and c = 74.0851(4) Å. The intergrowth ferroelectrics showed a phase transition at 610°C and a frequency-stable permittivity and dielectric loss behaviour. The intergrowth ferroelectrics also showed a larger 2Pr than their constituents BIT and SBTi. 相似文献
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Sushanta Kumar Parida Sudhir Kumar Hota Raushan Kumar Dr. Sandip Murarka 《化学:亚洲杂志》2021,16(8):879-889
Synthetic methods enabling late-stage modification of heterocycles hold tremendous importance in the pharmaceutical and agrochemical industry and drug discovery. Accordingly, efficient, functional group tolerant and selective late-stage alkylation of valuable molecular entities is of enormous significance and well-acknowledged in medicinal chemistry. Radical alkylation of heteroarenes employing carboxylic acids as the alkyl radical precursor represents one of the most direct ways of C−H functionalizations of heterocycles. Recently, the field has undergone a revolutionary development especially with regard to the generation of alkyl radicals under much milder conditions. In this regard N-(acyloxy)phthalimides (NHPI esters) have emerged as a suitable precursor of a diverse set of alkyl radicals allowing formal C−H alkylation of not only N-heteroarenes but a diverse set of non-aromatic heterocycles under visible light photocatalysis or electrochemical conditions. This review delineates all these discoveries and provides readers a comprehensive overview of this rapidly expanding field. 相似文献
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Sandhya Choubey D. Indumathi S. Agarwalla A. Bandyopadhyay G. Bhattacharyya E. J. Chun B. Dasgupta A. Dighe P. Ghoshal A. K. Giri S. Goswami M. Hirsch T. Kajita M. Kaplinghat H. S. Mani R. Mohanta M. V. N. Murthy S. Pakvasa M. K. Parida G. Rajasekaran S. Ray W. Rodejohann P. Roy S. Uma Sankar T. Schwetz N. Sinha 《Pramana》2009,72(1):269-275
This is the report of the neutrino physics working group at WHEPP-X. We summarize the problems selected and discussed at the
workshop and the papers which have resulted subsequently.
相似文献
80.
证明了随机浮点数矩阵非奇异的概率接近于1,从而表明在求具有秩亏损的有理浮点数矩阵的秩时,没有一种数值算法是有效的. 相似文献