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991.
Daniel C Mattis 《Annals of Physics》1975,89(1):45-67
We study an impurity atom, on which two-body forces are important, dissolved in a metal, where they are negligible. With the aid of the well-known boson excitation spectrum of the electronic Fermi sea, we predict the low-energy effects of one- and two-body potentials on the impurity, in the nonmagnetic regime. We obtain for the first time exact expressions for the cutoff independent contributions to the specific heat and paramagnetic susceptibility, the spectral amplitudes or one-electron density of states on the impurity, and the scattering cross-section. The entire spectrum of manybody eigenstates is explicitly obtained. The onset of a local magnetic moment appears as a sudden breakdown of the model Hamiltonian, and occurs when the two-body potential exceeds a critical value Uc which is O(EF) in magnitude. A study of the renormalization of the interaction parameters terminates the paper. 相似文献
992.
The competitive reactions between 2-trifluoromethylpropene (TMP) and OCS for O(3P) atoms were studied between 300° and 523°K, using the mercury-senstitized photolysis of N2O as a source of O(3P). From the known value for the rate constant of the O(3P) + TMP reaction, k3 was found to be 1.6 × 10?11 exp (?4500/RT) cm3/particle-sec, where reaction (3) is Mixtures of O3 and OCS were photolyzed at 197°, 228°, 273°, and 299°K with radiation above 4300 Å to produce O(3P) from the photolysis of O3, and thus study the competition between reaction (3) and From the above value of k3, k1 could be computed. When combined with all the previous data, the best espression for k1 is k1 = 1.2 × 10?11 exp (?4300/RT) cm3/particle-sec. 相似文献
993.
994.
A facile method for preparing 2-(2-X-vinyl)-5-nitrothiophene has been established by the reaction of (Z)-2-(2-bromovinyl)-5-nitrothiophene with O, S and N nucleophiles. 相似文献
995.
A random walk with variable step size, depending on the location of the particle, is considered. Two cases are discussed: one with two absorbing boundaries, and another when one boundary is absorbing while the other cannot be reached. Generalization of the uniquess problem of a functional equation for the expected duration is proved. Also the optimal policy, i.e. step size for each location minimizing the expected duration, is discussed. The natural solution of the problem in case of two absorbing boundaries is verified, while for the case of one boundary a necessary and sufficient condition for the existence of optimal solution is developed, while specific policy still remains open. 相似文献
996.
997.
P.J. Bussey C. Raine J.G. Rutherglen P.S.L. Booth L.J. Carroll G.R. Court P.R. Daniel A.W. Edwards R. Gamet C.J. Hardwick P.J. Hayman J.R. Holt J.N. Jackson W.H. Range F.H. Combley W. Galbraith V.H. Rajaratnam C. Sutton 《Nuclear Physics B》1979,154(3):492-502
The polarisation parameters Σ, P and T have been measured for the process γp→π0p in the photon energy range 1300–2100 MeV and c.m. angles between 30° and 110°, in an experiment with a polarised beam and polarised target. The results are compared with a recent theoretical analysis which fits data from threshold to 16 GeV. The new data are in general agreement with the analysis, but with some significant discrepancies in detail. 相似文献
998.
999.
With a high pressure gas target muonic F and S X-ray intensities in SF6 and H2+SF6 have been measured. It was found that the distribution of muons between sulphur and fluorine is not at all equal to the ratio of the atomic numbers Z. 相似文献
1000.