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11.
The effect of intrinsic degrees of freedom on tunneling through a potential barrier is discussed using a BKW-like approximation. In the present work intrinsic degrees of freedom are represented by a single harmonic oscillator. The theory leads to a formula for the effect of the coupling on the decay width Γ of a metastable state. When the frequency ω of the intrinsic degree of freedom is large, then Γ → Γad where Γad is the decay width calculated with the adiabatic barrier. An inequality Γ ≤ Γad is proved for any form of the coupling hamitonian. Corrections are discussed and are shown to be of order where M is the mass of the tunneling coordinate. An application to fission is considered. The generalization of our formula for Γ to the case of many intrinsic degrees of freedom is given explicitly. 相似文献
12.
Recently determined Coriolis coupling constants for H2 and D2 Ketene, centrifugal distortion constants for H2, HD, and D2 Ketene have enabled 16 of the 19 parameters in the general force field of Ketene to be determined with significance, the ambiguity between the choice of two sets of A1 and B1 species force constants being removed. The r0 structure has been redetermined using the latest values of the rotational constants of H2, HD, and D2 Ketene and an rz structure has been determined for the first time. 相似文献
13.
El Kettani SE Escudié J Couret C Ranaivonjatovo H Lazraq M Soufiaoui M Gornitzka H Nemes GC 《Chemical communications (Cambridge, England)》2003,(14):1662-1663
The first alpha-germyl-substituted alpha-amino ester and alpha-germyl-substituted alpha-aminophosphonic ester have been synthesized by a one-pot reaction between the germene Mes2Ge=CR2 (CR2 = fluorenylidene) and the iminoester or iminophosphonate Ph(H)C=NCH2-Y (Y = COOMe, P(O)(OEt)2). 相似文献
14.
In the present contribution we show that the introduction of a conserved axial current in electrodynamics can explain the quantization of electric charge, inducing at the same time a dynamical quantization of spacetime. 相似文献
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16.
We derive the tunneling rate for paramagnetic molecules in the context of a collective spin model. By means of path integral methods, an analytical expression is derived. Given the very large spins in question (s3000), the observation of magnetization changes due to pure unitary tunnel effects is unlikely. 相似文献
17.
A concise synthetic pathway towards 5-substituted indolizidines 总被引:1,自引:0,他引:1
The total synthesis of 5-(2′-hydroxyethyl)indolizidine via 5-thioindolizidinone is described. The key step is the transformation of 5-thioindolizidinone via Eschenmoser’s sulfide contraction. The racemic mixture of 5R,9R- and 5S,9S-5-(2′-hydroxyethyl)indolizidine was obtained in seven steps in 17% overall yield from 2-allyl cyclopentanone. 相似文献
18.
Marcos Sampaio A. P. Baêta Scarpelli J. E. Ottoni M. C. Nemes 《International Journal of Theoretical Physics》2006,45(2):436-457
We apply the Implicit Regularization (IR) technique in a non-abelian gauge theory. We show that IR preserves gauge symmetry as encoded in relations between the renormalization constants required by the Slavnov–Taylor identities at the one-loop level of QCD. Moreover, we show that the technique handles divergencies in massive and massless QFT on equal footing. 相似文献
19.
L. Rosenthaler P. Krumholz J. Vasquez Sanchez F. Feigl A. S. Komarowsky N. S. Poluektoff J. V. Dubský J. Trtilek A. Oká G. Hellsing K. Heumann F. Emich Olga S. Fedorova Georges Glomaud J. Trtílek VI. Stanék T. Nemes Carl Urbach R. Baril und J. H. Yoe 《Fresenius' Journal of Analytical Chemistry》1935,102(7-8):280-289
Ohne Zusammenfassung 相似文献
20.