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121.
Thomas Moore und Edgar F. Smith 《Fresenius' Journal of Analytical Chemistry》1892,31(1):201-206
Ohne Zusammenfassung 相似文献
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Andrea Rodriguez Loriett Cartaya Alexis Maldonado Edgar Marquez José R. Mora Tania Cordova 《Molecular physics》2017,115(14):1624-1632
The study on the mechanism of the gas-phase elimination or thermal decomposition kinetics of 2, 2-dimethyl-3-butenal has been carried out by using theoretical calculation at MP2, combined ab initio CBSQB3 and DFT (B3LYP, B3PW91, MPW1PW91, PBEPBE, PBE1PBE, CAMB3LYP, M06, B97d) levels of theory. A good reasonable agreement between experimental and calculated parameters was obtained by using CAMB3LYP/6-311G(d,pd) calculations. The contrasted calculated parameters against experimental values suggested decarbonylation reaction to proceed through a concerted five-membered cyclic transition state type of mechanism, involving the hydrogen transfer from the carbonyl carbon to the gamma carbon, consistent with observed kinetic isotope effect. The breaking of alpha carbon–carbonyl carbon bond to produce carbon monoxide is 50% advanced in the transition state. The reaction mechanism may be described as a concerted moderately non-synchronous process. Examination of the Atoms in Molecules (AIM) analysis of electron density supports the suggested mechanism. 相似文献
125.
Barrett PA Boix T Puche M Olson DH Jordan E Koller H Camblor MA 《Chemical communications (Cambridge, England)》2003,(17):2114-2115
The new synthetic form of microporous crystalline silica, denoted as ITQ-12, shows a high potential for the separation of propane and propene from its mixtures. 相似文献
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Jonathan P Wisor Bruce F O'Hara Akira Terao Chris P Selby Thomas S Kilduff Aziz Sancar Dale M Edgar Paul Franken 《BMC neuroscience》2002,3(1):20-14
Background
The cryptochrome 1 and 2 genes (cry1 and cry2) are necessary for the generation of circadian rhythms, as mice lacking both of these genes (cry1,2 -/-) lack circadian rhythms. We studied sleep in cry1,2 -/- mice under baseline conditions as well as under conditions of constant darkness and enforced wakefulness to determine whether cryptochromes influence sleep regulatory processes. 相似文献128.
Edgar Reich 《Proceedings of the American Mathematical Society》1997,125(5):1479-1481
The possibility that the extremal dilatation of quasiconformal extensions from the circle is determined by quadrilaterals with vertices on the circle is related to an approximation question for holomorphic functions. This allows an alternative demonstration of a result of Anderson and Hinkkanen.
129.
Edgar Heilbronner 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》1995,107(22):2773-2774
130.
The compacted spin coefficient (ghp) formalism is clearly more concise and efficient than the older Newman-Penrose formalism. Yet few people use it when integration of the field equations is involved, Held being the notable exception. However, to most workers in the field, Held's approach seems far removed from the usual Newman-Unti (nu) type integration procedure. This paper and a subsequent one are concerned with integration within theghp formalism. In this first paper we develop aghp
coordinate-style integration procedure modelled closely on thenu procedure whereas in the second paper we present aghp
operator-style integration procedure along the lines suggested by Held. For simplicity of illustration we restrict the discussion to algebraically special vacuum spacetimes. We show clearly the similarities and differences between the two approaches, and compare their respective efficiencies. To deal with a concrete example, we illustrate the two methods by once more considering the problem of twisting typeN vacuum solutions to Einstein's field equations. TheGhp approach enables us to have a comprehensive overview of this much discussed problem and gain new insight into the relationship between various results derived in a number of different formalisms. 相似文献