多量子阱半导体激光器的交叉增益调制波长转换特性

实验利用光注入多量子陆半导体激光器产生的载流子消耗和带间载流子吸收产生的交叉增益调制效,实现波长转换，转换光的光强变化幅度与偏置电流有关。通过调节偏置电流的大小，能使转换光与注入信号光在同向和反向间进行切换。     

Evaluating alternative system configurations using simulation: A nonparametric approach

The real utility of simulation lies in comparing different alternatives that might represent competing system designs. Conventional statistical techniques are not directly applicable to the analysis of simulation output data in the evaluation of competing alternatives since the usual assumptions of normality and common variance are difficult to justify in simulation experiments. This paper revisits a known nonparametric test whose application has recently become feasible due to considerable increases in computing power:randomization tests assess the significance of the observed value of the test statistic by evaluating different permutations of the data. The procedure only requires invariance of the data under all permutations.     

关于位势井及其对强阻尼非线性波动方程的应用

本文研究强阻尼非线性波动方程的初边值问题其中f(u)u≥0.首先用新的方法再次得到了位势井深度d的值,并首次得到了位势井内外结构.而后用位势井方法得到了问题的整体弱解,整体强解的存在性.最后证明了位势井W及井外集合V在问题(1)-(3)的流之下的不变性.     

Combinatorial data analysis: Confirmatory comparisons between sets of matrices

The task of assessing the similarity of pattern between the entries of two square matrices has been discussed extensively over the last decade, as a unifying strategy for approaching a variety of seemingly disparate statistical problems. As typically defined, the comparison depends on a measure of matrix correspondence, usually a normalized cross-product measure of some form, that is evaluated for relative size by the use of a reference distribution constructed through an equally likely permutation hypothesis defined at the level of the objects corresponding to the rows and columns of the two matrices. The extreme generality provided by this very simple framework subsumes a variety of different statistical problems, ranging from the study of spatial autocorrelation for variables observed over a set of geographic locations, to the topics of analysis of variance, the measurement of rank correlation, and confirmation techniques concerned with various conjectures of combinatorial structure that might be posited for an empirically determined measure of relationship between pairs of a given set of objects. The comparison strategies extant always assume that both matrices are fixed, and in those cases where one of the matrices codifies a given theoretical structure to be evaluated according to a second, this assumption can lead to substantial arbitrariness in how matrix similarity might be indexed, and thus, in how the comparison is implemented. As developed in this paper, exactly the same principles appropriate for use in the fixed comparison context can be extended to include matrices constructed through optimally weighted linear combinations of other sets of matrices. This generalization provides one mechanism for developing comparison strategies that allow assessment against very broad classes of matrices, which in turn serve to represent very general conjectures of possible combinatorial structure. This paper reviews some of these extensions in detail, with a particular emphasis on categorical and ordered categorical variables and whether they may reflect an empirically generated measure of object relationship.     

Photoluminescence of n-doped double quantum well—electron subbands under influence of in-plane magnetic fields

We report on photoluminescence (PL) measurements of a GaAs/AlGaAs double quantum well (DQW) in high magnetic fields. Measurements were carried out on a selectively contacted symmetric p-δn-DQW-δn-p structure, which allows a variation of the electron density in DQW by a p–n bias and simultaneously a tilting of DQW, when a p–p bias is applied. Attention was paid to phenomena in in-plane magnetic fields, theoretically studied by Huang and Lyo (HL), [Phys. Rev. B 59, (1999) 7600]. In this paper, we compare our results for both symmetric and asymmetric DQWs with the theoretical model made by HL. Whereas the spectra from a symmetric DQW fully confirmed the theoretical predictions, the results gained from DQW with an electric-field-induced asymmetry did not allow a proper study of anticipated effects. The reasons for that are discussed.     

Electronic states in a step quantum well in a magnetic field

The quantum states and energy spectrum of an electron in a rectangular step quantum well in a magnetic field parallel to the plane of two-dimensional electronic gas are investigated. It is shown that the joint effect of a magnetic field and confining potential of quantum well results in radical change of the electron energy spectrum. The energy dependencies on the parameters of the quantum well and magnetic field induction are investigated. Numerical calculations are carried out for an AlAs/ GaAlAs/ GaAs/ AlAs step quantum well.     

孔隙地层井壁上的声波首波及其诱导电磁场的原因

声波测井时孔隙地层中的声波首波平行于井轴沿井壁传播，它既有轴向位移分量，又有垂直于井壁的位移分量.这种以快纵波速度传播的波, 不仅含有由快、慢纵波势给出的梯度场,而且还含有由横波势给出的旋度场.慢纵波势的梯度是渗流位移首波的主要构成成分, 也是声电效应测井响应中存在伴随声波首波电场的主要原因.首波包含有旋度位移场，是存在伴随声波首波磁场的原因. 关键词： 孔隙介质 声波首波 诱导电磁场 测井     

Testing Hypotheses About the Power Law Process Under Failure Truncation Using Intrinsic Bayes Factors

Conventional Bayes factors for hypotheses testing cannot typically accommodate the use of standard noninformative priors, as such priors are defined only up to arbitrary constants which affect the values of the Bayes factors. To circumvent this problem, Berger and Pericchi (1996, J. Amer. Statist. Assoc., 19, 109-122) introduced a new criterion called the Intrinsic Bayes Factor (IBF). In this paper, we use their methodology to test several hypotheses regarding the shape parameter of the power law process. Assuming that we have data from the process according to the failure-truncation sampling scheme, we derive the arithmetic and geometric IBF's using the reference priors. We deduce a set of intrinsic priors that correspond to these IBF's, as the observed number of failures tends to infinity. We then use these results to analyze an actual data set on the failures of an aircraft generator.     

LOCAL EXISTENCE THEOREM FOR FIRST ORDER SEMILINEAR HYPERBOLIC SYSTEMS IN SEVERAL SPACE DIMENSIONS

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Some test statistics for the structural coefficients of the multivariate linear functional relationship model

Summary For the testing problem concerning the coefficients of the multivariate linear functional relationship model, the distribution of a statistic previously proposed by A. P. Basu depends on the unknown covariance matrixV of errors, so limiting its applicability. This article proposes new test statistics with sampling distributions which are independent of the unknown parameters for the cases whereV is either unknown or known only up to a proportionality factor. The exact distributions of the test statistics are also discussed.