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991.
J.C. Pickering V. Zilio 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,13(2):181-185
High resolution spectra of neutral silver have been recorded by Fourier Transform Spectrometry in the region 2 000-8 280 ?(50
000-12 000 cm-1) with silver-neon and silver-argon hollow cathode lamps as sources. This work represents order-of-magnitude improvements,
compared to previous work on Ag I, in accuracy of transition wavelengths and wavenumbers, and energy level values. 35 classified
Ag I transitions are given, and the wavenumber uncertainty for the strongest lines is less than 0.002 cm-1. Improved values for 28 energy levels are presented.
Received 31 January 2000 and Received in final form 13 June 2000 相似文献
992.
993.
Xiao Huang Xizhang Luo Xun Zhang 《International Journal of Infrared and Millimeter Waves》2001,22(1):31-39
By means of solving the density matrix equations, base on the mechanism model of buffer gas, the output intensity of FIR and the FIR signal gain coefficient Gs and IR pumping signal absorption coefficient Gp were calculated, energy exchanged process of superradiant OPFIRL with buffer gas was analyzed. It was found that after adding buffer gas into the laser medium, the FIR output could be increased, and the active region of a FIR laser was lengthened. 相似文献
994.
Xun Zhang Xiao Huang Xizhang Luo Ping Zhang Jiayin Qin 《International Journal of Infrared and Millimeter Waves》2001,22(4):509-519
Multi-Raman effect in optically NH3 pumped superradiant two-longitudinal-mode CO2-9R(30) laser was theoretically studied. And with different pumping power, operating gas pressure and length of laser tube, the rule of multi-Raman interaction and its effect to THz laser spectral characteristics were discussed. 相似文献
995.
WANG Wen-Fu 《理论物理通讯》2001,36(1):122-124
Taking the cosmological expansion rate directly as a function of field φ, H=H(φ), we present a new exact solution to Einstein's equations that describe the evolution of cosmological chaotic inflation model. The inflation is driven by the evolution of scalar field with inflation potential V(φ)=(λ/8)(φ2-υ2)2. The spectral indices of the scalar density ns and gravitational wave fluctuations
ng are computed.
The value of ns lies well inside the limits set by the cosmic
background explorer satellite. 相似文献
996.
WANG Wen-Ge 《理论物理通讯》2001,35(2):143-150
The Wigner band random matrix model is studied by making use of a generalization of Brillouin-Wigner perturbation theory. Energy eigenfunctions are shown to be divided into perturbative and nonperturbative parts. A relation between the average shape of eigenstates and that of the so-called local spectral density of states (LDOS) is derived by making use of some properties of energy eigenfunctions drawn from numerical results.
Several perturbation strengths predicted by the perturbation theory
are found to play important roles in the variation of the shape of the LDOS with perturbation strength. 相似文献
997.
We derive a functional central limit theorem for quasi-Gaussian processes. In particular, we prove that the limit of the Mandelbrot–Weierstrass process is a complex fractional Brownian motion. 相似文献
998.
金属酞菁配合物结构研究的一些谱学方法 总被引:30,自引:0,他引:30
本文介绍了近年来在研究金属酞菁配合物结构方面的一些谱学方法及其结果,首先简要概述了金属酞菁配合物的红外、紫外可见光谱性质,着重讨论了配合物中环周边取代基的类型、位置、数目以及配合物在溶液中处于不同聚集态时,对紫外可见光谱的影响。另外还对四取代金属酞菁配合物的异构体的NMR谱表征作了简介。 相似文献
999.
This paper deals with the optimal exponential convergence rate β to the equilibrium state in Boltzmann-Shannon entropy for
general Markov semigroups. We prove a variational formula of β, and then discuss the relation among β, spectral gap λ and
logarithmic Sobolev constant α, which is read as λ≥β≥α. 相似文献
1000.
Our objective in this article is to present some numerical schemes for the approximation of the 2‐D Navier–Stokes equations with periodic boundary conditions, and to study the stability and convergence of the schemes. Spatial discretization can be performed by either the spectral Galerkin method or the optimum spectral non‐linear Galerkin method; time discretization is done by the Euler scheme and a two‐step scheme. Our results show that under the same convergence rate the optimum spectral non‐linear Galerkin method is superior to the usual Galerkin methods. Finally, numerical example is provided and supports our results. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献