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991.
992.
Zhi‐zhong Sun Lei Zhao Fu‐Le Li 《Numerical Methods for Partial Differential Equations》2007,23(1):1-37
In this article, we study a sequence of finite difference approximate solutions to a parabolic system, which models two dissimilar rods that each rod is fixed at one end and is free to expand or contact at the other end. A finite difference scheme is derived by the method of reduction of order on nonuniform mesh. The unique solvability, unconditional stability, and convergence of the difference scheme are proved. The convergence order is of order two in both time and space. The convergence of iterative algorithm for the difference scheme are also discussed. A numerical example is presented to demonstrate the theoretical results. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007 相似文献
993.
M. Guillot A. Marchand F. Tchéou P. Feldmann H. Le Gall 《Zeitschrift für Physik B Condensed Matter》1981,44(1-2):41-52
The magnetic properties of single crystals of erbium iron garnet (ErIG) were studied in applied fields up to 150kOe between 1.4 and 300K. At low temperature, the macroscopic easy direction of the bulk magnetization is [100]; below the compensation temperature (80±2K), the magnetization presents non-linear field evolution. On the assumption of an isolated ground doublet, the anisotropy constantsK
i
(i=1,2) of ErIG are given byK
i
(Er)+K
i
(YIG); theK
i
are calculated as a function of theG andg tensor components. It is worthwhile noting that theK
i
(Er) are strongly temperature dependent; so at low temperature the anisotropy of the garnet is determined by the rare earth ions, while in the 50 K regionK
1(Er) becomes comparable toK
1(YIG) with the opposite sign which results in a very weak anisotropy of the garnet. Above 50 K,K
1(YIG) is predominant and the Fe3+ ions determine the garnet anisotropy. 相似文献
994.
A saturation-spectroscopy experiment is performed in a three-level system in Xe I, and shows that a narrow dip occurs in the
power-broadened Lorentzian response. It is due to the Zeeman splitting of common level by the earth magnetic field. Other
splittings, typically larger than 0.2 the natural width, can be observed using this saturation effect. Interpretation is made
on the basis of simple realistic assumptions.
Associé à l'Université Paris-Sud 相似文献
995.
996.
Classical and quantum theories of radiation damping in ferromagnetic and antiferromagnetic resonance
Both classical and quantum theories of radiation damping in ferromagnetic and antiferromagnetic resonance relaxation are given. Effects of demagnetization and anisotropy, that is, of elliptical classical precession, are included. In the classical theory a phenomenological approach to ferromagnetic resonance relaxation by means of the Landau-Lifshitz equation is also presented. In the quantum theory, the magnon-photon interaction Hamiltonian is derived, and the radiation-damped linewidth is obtained by computing the transition matrix element and also the one-magnon self energy. As noted long ago by Einstein, each photon is emitted in a random but specific direction, and only on average does the quantum radiation pattern reproduce the classical. To first order, however, this reproduction is shown to be exact, correcting a recent calculation by Shrivastava. 相似文献
997.
B. Roussière F. Le Blanc J. Pinard L. Cabaret J. Crawford H. T. Duong J. Genevey G. Huber F. Ibrahim M. Krieg J. K. P. Lee J. Obert J. Oms J. C. Putaux C. Richard-Serre J. Sauvage V. Sebastian 《Acta Physica Hungarica A》1998,7(1):97-100
Isotope shift and hyperfine structure measurements have been performed on the short lived184Au nucleus using the COMPLIS apparatus installed at ISOLDE. The charge radius change and the magnetic and quadrupole moments of both isomeric and ground states have been deduced. The184Au ground state appears to be slightly more deformed than the isomeric state. 相似文献
998.
999.
1000.
MCVD preforms with a doped core are known to have a central index depression which can have a noticeable influence on the fiber transmission properties. The magnitude of the dip can be reduced by carrying out an etching treatment with a fluorine compound during the collapse preliminary steps. 相似文献