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91.
Riemannian nilmanifolds attached to Clifford modules 总被引:6,自引:0,他引:6
Aroldo Kaplan 《Geometriae Dedicata》1981,11(2):127-136
92.
The possibility of excitation of the 238U shape-isomer by the atomic cascade of a negative muon has been investigated by a search for back-decay γ-rays. No candidates for such γ-rays have been found with yields greater than 1% per stopping muon, indicating that the probability of the isomer excitation by muons is less than 3%. The lifetime of a μ? bound to 238U has been determined from capture γ-rays to be 79.1 ± 0.5 ns, which also set the upper limit of this probability to 7–15%. 相似文献
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The possibility of orbital magnetism and structural phase transitions in crystals with “orbital exchange” and vibronically coupled Jahn-Teller ions are examined. 相似文献
96.
C. M. Stevens Louis Kaplan Robert Gorse Susan Durkee Michael Compton Sidney Cohen Karen Bielling 《国际化学动力学杂志》1980,12(12):935-948
The kinetic isotope effect (KIE) for carbon and oxygen in the reaction CO + OH has been measured over a range of pressures of air and at 0.2 and 1.0 atm of oxygen, argon, and helium. The reaction was carried out with 21–86% conversion under static conditions, utilizing the photolysis of H2O2 as a source of OH radicals. The value of the KIE for carbon varies with pressure and the kind of ambient gas; for air the ratio of the reaction rates 12k/13k has the value 1.007 at 1.00 atm and decreases to 0.997 at 0.2 atm; for oxygen and argon over the same pressure range the values are 1.002–0.994 and 1.000–0.991, respectively. The value of the KIE for the CO oxygen atom is 16k/18k = 0.990 over the pressure range 0.2–1.0 atm and is independent of the kind of ambient gas. No exchange of the oxygen atoms in the activated complex, followed by decomposition to the starting molecules, was observed. From the mechanistic standpoint the normal KIE observed for carbon at the high pressure is attributed to the initial formation of the activated HOCO radical, whereas the inverse KIE observed at low pressures is a result of the KIE for the reverse reaction HOCO? → CO + OH being greater than that for the forward reaction HOCO? → CO2 + H. The derived isotopic equilibrium constant for HOCO ?CO favors the enrichment of 13C in the more strongly bound HOCO. 相似文献
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We study the behaviour of σppT at ISR energies in the Reggeon calculus with a bare triple Pomeron coupling non vanishing at q2 = 0. The parameters are determined from elastic and inclusive data. A sizable increase of σT with s can only be obtained when the bare Pomeron intercept is such that the renormalized Pomeron singularity is above one, in the forward direction. 相似文献
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