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991.
992.
假期中顾客以概率p进入的单重休假M/G/1排队 总被引:5,自引:1,他引:4
本文考虑单重休假M/G/1排队系统,其中在服务员休假中到达的顾客以概率p(0≤p≤1)进入系统,采用一种较简单的分析方法,得到了队长瞬态分布的拉普拉斯变换的递推表达式和稳态分布的递推表达式.另外,通过本文的研究直接导出了一些特殊情况下的相应结果. 相似文献
993.
Oleg I. Baskakov Eugen A. Alekseev Roman A. Motiyenko Jarmo Lohilahti Veli-Matti Horneman Seppo Alanko Brenda P. Winnewisser Ivan R. Medvedev Frank C. De Lucia 《Journal of Molecular Spectroscopy》2006,240(2):188-201
High resolution FTIR spectra of the two overlapping bands ν7 and ν9 of the 13C species of formic acid have been measured and analyzed. Rotational transitions in the millimeter wave region were measured and included in the analysis. As in the parent species, there is a strong Coriolis interaction between the 71 and 91 states. The corresponding IR bands of the parent species have been remeasured and new MMW transitions recorded. The analysis of the spectra for the two species provides an opportunity to consider a reduction of the Hamiltonian employed for the analysis of this type of interacting system of states. Parameters with low correlations could be obtained. Several interstellar features coincide with transitions predicted from these parameters. 相似文献
994.
对公路交通噪声预测模型进行了分析推导,指出美国联邦公路局FHWA模型为近似表达式,并给出了精确表达式。对FHWA模型与精确表达式在硬地面、软地面、混合地面几种条件下的值进行了比较分析。结果表明,两者在硬地面条件下的形式和计算结果相同;在混合地面,即公路的实际情况下,两者存在差异,差值等于10lg(r1/r0)α。在用于高速公路交通噪声预测计算时,当r0取15m,该差值较小,当r0取7.5m,该差值增大;在一般情况下,r0取15m时的差值为±0.3dB(A),r0取7.5m时的差值为1.2—1.8dB(A),后者约占交通噪声预测值的1.5-4%,是不应忽视的。说明我国在引用FHWA模型时,对参考点距离的更改,会造成用于高速公路交通噪声预测的误差增大。建议我国使用本文推导给出的修订模型。 相似文献
995.
JunLiangCAI YahPeiLIU 《数学学报(英文版)》2005,21(1):215-224
This paper provides some functional equations satisfied by the generating functions for enumerating general rooted planar maps with up to three parameters. Furthermore, the generating functions can be obtained explicitly by employing the Lagrangian inversion. This is also an answer to an open problem in 1989. 相似文献
996.
997.
V. A. Kosobukin A. V. Sel'kin 《Physica E: Low-dimensional Systems and Nanostructures》2003,18(4):452-468
A theory is developed for steady-state elastic scattering of light via quasi-2D excitons from a quantum well (QW) whose interfaces are randomly rough. The study is mainly focused on the angle dependences of radiation giving direct information about static disorder responsible for the elastic scattering. A nonlocal excitonic susceptibility is expressed in terms of random profile functions of QW interfaces. Treated is elastic scattering of light from a disordered QW in the following actual dielectric environments: (i) a uniform background, (ii) a Fabry–Perot film with rough boundaries, and (iii) a semiconductor microcavity. The cross-sections are derived analytically for scattering of linearly polarized light to the lowest (Born's) approximation with arbitrary roughness statistics. The spectral and angle dependencies of scattering intensity are analyzed numerically in the absolute-value scale with Gaussian correlation of interface roughness. The probability 10−2 was found for the exciton-mediated scattering of a photon from a QW interface roughness whose root-mean-square height is on the level of 2×10−1 nm. This probability is shown to exceed by two orders of magnitude that is typical of resonant scattering from either a single semiconductor surface or rough boundaries of a semiconductor Fabry–Perot film containing the QW. The scattering spectrum of a QW placed in a microcavity is predicted to have a doublet structure whose components are associated with the cavity exciton–polaritons. 相似文献
998.
考虑了存在温度梯度时,导体和半导体内传导电子的能量应视为温度的函数,从而给出了导体和半导体热导系数的更合理的推导过程及汤姆孙系数的更准确的量子统计表示。 相似文献
999.
1000.
Numan Hasan Dr. Zhimin Ma Jianwei Liu Zewei Li Chen Qian Yan Liu Dr. Mingxing Chen Prof. Hong Jiang Prof. Xinru Jia Prof. Zhiyong Ma 《Chemphyschem》2021,22(20):2093-2098
In this article, we report a newly designed D−A−D’ derivative (CNCzPTZ), which displays selective expression of chromophores. This enables CNCzPTZ with solvatochromism, rare dual-mode AIEE properties, solid-state dual-emissions with phosphorescence and distinctive mechanochromism.CNCzPTZ exhibits dual-mode AIEE properties, since the emission band abruptly shifts from 550 nm to 500 nm as the water fraction increases. In the crystalline state, CNCzPTZ demonstrated dual emission bands of 478 nm and 538 nm.CNCzPTZ shows distinctive mechanochromic property in the solid state due to the planarization. 相似文献