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161.
本文研究了在两个耦合的量子点和腔QED系统中的双模激子的压缩性质.讨论了不同的初始光场对双模激子的正常压缩与和压缩的影响.计算表明,当初始态光场制备在相干态时,双模激子既不存在正常压缩,也不存在和压缩,这说明双模激子振辐的两个正交分量具有相同的量子涨落;然而,当初始腔场处于压缩真空态时,无论是正常压缩还是和压缩,双模激子振辐的两个正交分量总有一个存在压缩.这意味着量子噪声能被有效的得到抑制.此外,两种情形下的最大压缩都由初始腔场的压缩因子r决定.经过比较,我们还发现双模激子的正常压缩比和压缩大. 相似文献
162.
V. M. Andrianov 《Journal of Applied Spectroscopy》2007,74(1):1-12
A theoretical conformational analysis has been carried out for the side substituents of a fragment of the molecule for 2,6-carboxymethyl
cellulose (a water-soluble cellulose ether), and the frequencies and the potential energy distribution of the normal vibrations
have been calculated for the most stable conformers of the ether groups of this fragment in the approximation of the molecular
mechanics method. It has been shown that the most stable conformers are those that have the conformations gg, t, g−, g−, g−-for the groups of atoms on the bonds C5-C6, C6-O6, C13-O6, C10-C13, C10-O9 and the conformations g+g−, g+, g−, g−; g+g−, g−, g−, g−; g+g−, g−, g+, t for the groups of atoms on the bonds C2-O2, C11-O2, C7-C11, C7-O8. Comparative analysis of the calculated frequencies
and the potential energy distribution of the normal vibrations for 13 of the most stable conformers showed, as in the case
of the 2,6-hydroxyethyl cellulose molecule, that the frequencies and modes of the normal vibrations are highly sensitive to
conformational transitions in the analyzed spectral region (800–1500 cm−1). The characteristic patterns for the change in the frequencies and modes of the normal vibrations have been established
in connection with conformational transitions within both side substituents. The observed conformational lability of the bulky
substituents in the cellulose ether molecules and its manifestations in the vibrational spectrum provide a basis for hypothesizing
that one of the major mechanisms for the process of their thermal gelation in aqueous solutions is conformational transitions
within these substituents.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 5–15, January–February, 2007. 相似文献
163.
《Journal of computational and graphical statistics》2013,22(2):281-294
By introducing auxiliary variables, the traditional Markov chain Monte Carlo method can be improved in certain cases by implementing a “slice sampler.” In the current literature, this sampling technique is used to sample from multivariate distributions with both single and multiple auxiliary variables. When the latter is employed, it generally updates one component at a time. In this article, we propose two variations of a new multivariate normal slice sampling method that uses multiple auxiliary variables to perform multivariate updating. These methods are flexible enough to allow for truncation to a rectangular region and/or exclusion of any n-dimensional hyper-quadrant. We present results of our methods and existing state-of-the-art slice samplers by comparing efficiency and accuracy. We find that we can generate approximately iid samples at a rate that is more efficient than other methods that update all dimensions at once. Supplemental materials are available online. 相似文献
164.
《Journal of computational and graphical statistics》2013,22(3):731-752
This article describes a reduction formula for the computation of multivariate normal probabilities first developed by Plackett. The method is recursive and, despite very promising results, seems not to have been implemented before. Extensive numerical results are given to compare the effectiveness of the approach to other methods from the literature. 相似文献
165.
Scanning deflectometric profilers based on an f–gθ system are typical optical tools used to measure mirror profiles at many synchrotron facilities. Unlike these profilers, which are based on a pencil beam, here a secondary light source and a pinhole are used to construct a system that automatically selects a beam that will always pass through the pinhole and propagate along the normal direction of the measured area on the surface under test. By measuring the angle variation of the selected beam, slope variations of the surface under test can be measured. Systematic errors introduced by manufacturing defects or aberrations of an optical element, which greatly degrade the performance of traditional profilers, could be minimized by using the developed method. Simulation values of the proposed method and a conventional method are compared. 相似文献
166.
This paper is about how to compute the Hermite normal form of a random integer matrix in practice. We propose significant improvements to the algorithm by Micciancio and Warinschi, and extend these techniques to the computation of the saturation of a matrix. We describe the fastest implementation for computing Hermite normal form for large matrices with large entries. 相似文献
167.
Maria Elena Valcher 《Linear algebra and its applications》2010,432(4):980-1006
The aim of this paper is that of investigating the asymptotic exponential cone of a single Metzler matrix, introduced in [23], and of defining and analysing the new concept of asymptotic exponential cone of a family of Metzler matrices (along a certain direction). These results will provide necessary and/or sufficient conditions for the solvability of an interesting algebraic problem that arises in the context of continuous-time positive switched systems and, specifically, in the investigation of the reachability property [21,22,25]. 相似文献
168.
weyl群的定义关系及其应用 总被引:1,自引:0,他引:1
首 先深化 R. Steinberg 关于 W eyl 群定义 关系的一个定 理,作为应 用,对 Bl , Cl 型 W eyl群分别构造了一 个指数为2的正 规子群 相似文献
169.
Let F be a family of mermorphic functions in a domain D, and let a, b, c be complex numbers, a ≠ b. If for each f ∈ F, the zeros of f-c are of multiplicity ≥ k + 1, and -↑Ef(k)(a) belong to -↑Ef (a), -↑Ef(k)(b)belong to -↑Ef (b), then F is normal in D. 相似文献
170.
CAO Zhen-Bin DUAN Yi-Shi 《理论物理通讯》2009,51(1):110-114
Generally, open string boundary conditions play a nontrivial role in string theory. For example, in the presence of an antisymmetric tensor background field, they will lead the spacetime coordinates noncommutative. In this paper, we mainly discuss how to build up a generalized Dirichlet normal ordered product of open bosonic string embedding operators that satisfies both the equations of motion and the generalized Dirichlet boundary conditions at the quantum level in the presence of an antisymmetric background field, as the generalized Neumann case has already been discussed in the literature. Further, we also give a brief check of the consistency of the theory under the newly introduced normal ordering. 相似文献