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71.
B. Nandi Ganguly V. S. Subrahmanyam P. K. Sarkar 《Journal of Radioanalytical and Nuclear Chemistry》1994,181(1):201-209
Interactions of positronium in aqueous solutions of Co2+ and Cu2+ ions have been investigated at room temperature (297 K) at varying concentrations using both lifetime and Doppler broadening of annihilation radiation techniques. In the case of Co2+, the results indicate spin conversion reaction alone. However, in the case of Cu2+, oxidation is predominant with a small contribution of spin conversion reaction. The corresponding rate constants have been evaluated. 相似文献
72.
K. Sai Prasad Rao G. Muralidhar S. Khajamasthan V. S. Subrahmanyam 《Reaction Kinetics and Catalysis Letters》1988,37(1):181-186
Low temperature oxygen chemisorption (LTOC) has been applied to characterize unpromoted and promoted tungsten sulfied catalysts supported on TiO2. LTOC, hydrodesulfurization and hydrogenation are found to correlate with the W loading.
() - TiO2 . , - W .相似文献
73.
Low temperature oxygen chemisorption (LTOC) has been applied to characterize a series of TiO2 and ZrO2 supported Mo-oxide catalysts. The monolayer coverage of the surface is completed when the Mo loading reaches 6% and 4% on the TiO2 and ZrO2 supports, respectively. The results are explained with the help of a Patch model of the Mo-oxide phase.
Mo- TiO2 ZrO2 . Mo TiO2 ZrO2 6% 4%, . Patch Mo- .相似文献
74.
J. Thimmasetty C. V. S. Subrahmanyam P. R. Sathesh Babu M. A. Maulik B. A. Viswanath 《Journal of solution chemistry》2008,37(10):1365-1378
The solubility behavior of pimozide in individual solvents ranging from nonpolar to highly polar was studied. For understanding
the solute-solvent interactions, the partial solubility parameters concept was utilized. Solutions containing excess drug
were shaken in a water bath for 72 hours at 25 °C. After the solutions attained equilibrium, they were filtered and analyzed
for drug content. A multiple regression method, using extended Hansen’s partial solubility parameters, was applied to verify
the solubilities of pimozide in pure polar and nonpolar solvents and to predict its solubility in untested solvents. The three-parameter
approach and the Flory-Huggins size correction term ‘B’ give predictions of solubilities with correlations up to 97%. The four-parameter approach involving proton-donor and proton-acceptor
parameters was also used in fitting the solubility data. The correlations are appreciable (94%). Further, the ‘B’ term coupled with four-parameter approach was examined in order to improve the data representation, and resulted in a 1%
improvement (98%) in the correlation when compared to the Flory-Huggins size-correction method. The solubility parameter obtained
by this method is 10.43 H which is closer to the values obtained by theoretical methods, such as Fedors’ and Hoy’s. The resulting
partial solubility parameters are δ
2d
=8.85 H, δ
2p
=2.17 H, δ
2a
=3.15 H, and δ
2b
=4.08 H, which give insights into the interaction capability of pimozide and are consistent with its chemical structure. Pimozide
is a Lewis base as its δ
2b
>δ
2a
. The total solubility parameter of pimozide is assigned at 10.43 H. This work demonstrates for the first time the validity
of the four-parameter approach coupled with the Flory-Huggins size-correction term and therefore the result is interesting. 相似文献
75.
Mannepalli Lakshmi Kantam Vura Bala Subrahmanyam Kota Balaji Shiva Kumar Gopaladasu T. Venkanna Bojja Sreedhar 《Helvetica chimica acta》2008,91(10):1947-1953
Rhodium fluoroapatite (RhFAP) is an efficient catalyst for conjugate addition of organoboron reagents to α,β‐unsaturated carbonyl compounds. A variety of arylboronic acids and α,β‐unsaturated carbonyl compounds were converted to the corresponding conjugate‐addition products, demonstrating the versatility of the reaction. The reaction is highly selective. RhFAP was recovered quantitatively by simple filtration, and reused for four cycles. 相似文献
76.
Catalytic decomposition of CH4 over Ni-Al2O3-SiO2 catalysts: Influence of pretreatment conditions for the production of H2
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Jangam Ashok Gangadhara Raju Padigapati Shiva Reddy Machiraju Subrahmanyam Akula Venugopal 《天然气化学杂志》2008,17(2):113-119
This article reports the production of COx free hydrogen and carbon nanofibers by the catalytic decomposition of methane over Ni-Al2O3-SiO2 catalysts. The influence of reaction temperature, pretreatment temperature, and effect of reductive pretreatment on the decomposition of methane activity is investigated. The physico-chemical characteristics of fresh and deactivated samples were characterized using BET-SA, XRD, TPR, SEM/TEM, CHNS analyses and correlated with the methane decomposition results obtained. The Ni-Al-Si (4 : 0.5 : 1.5) catalyst reduced with hydrazine hydrate produced better H2 yields of ca. 1815 mol H2/mol Ni than the catalyst reduced with 5% H2/N2. 相似文献
77.
78.
V. Antony Vijesh P.V. Subrahmanyam 《Journal of Mathematical Analysis and Applications》2008,342(1):361-370
This paper details an existence and uniqueness theorem for solving an operator equation of the form F(x)=0, where F is a Gateaux differentiable operator defined on an open convex subset of a Banach space proved. From the main theorem, an earlier theorem of Argyros follows as a consequence. Other corollaries constitute the semilocal versions of the theorems due to Ozban and Weerakoon and Fernando in a general Banach space. Our main theorem leads to the existence of solutions for a class of nonlinear Urysohn-type integral equations in the n-dimensional Euclidean space. 相似文献
79.
80.