对我国B2B的一些思考

从B2B的现状入手,指出中国非常需要B2B;从B2B企业的内部环境对B2B出现的问题加以分析,并提出了相关对策,最后对B2B给予了展望。     

算子李代数的性质

经典群论的概念已经有一部分推广到了李代数的抽象理论之中,群论中的算子群理论也已经被推广,本文将结合李代数与算子群理论引入算子李代数,并给出算子李代数的一些相关概念,探讨算子李代数的性质。     

多输出函数的一些密码学性质

首先对处理布尔函数的Ｗａｌｓｈ变换进行了修改，使其能应用于多输出函数ｆ（ｘ），：ＧＦ（２）＾ｎ→ＧＦ（２）＾ｍ，（１＜ｍ＜ｎ）；其次对多输出函数的退化性、线性结构、非线性性和相关免疫性等密码学性质进行了讨论。     

银纳米材料的光吸收特性理论研究

本文采用时域有限差分的方法(FiniteDifference Time Domain,FDTD)模拟贵金属纳米结构的光学性质,对照实验结果探索实验条件对光学性质的影响,合理解释模拟结果,为进一步探索纳米结构光吸收的影响因素提供了理论依据。     

复等角紧框架的性质

研究Hilbert空间上复等角紧框架的性质.首先,建立复等角紧框架的一些必要条件;其次,实等角紧框架的一些结果被拓广到复等角紧框架上.     

简单液体CS2多波段非线性光学性质研究

采用双4f相位成像技术,在皮秒时域内分别测量了CS2在532nm和745nm两个波长光学非线性系数的变化。通过数值模拟确定了CS2在这两个波长的光物理参数。实验结果表明,在非共振区内,随着波长的增加,CS2没有双光子吸收,三阶非线性折射率保持不变。     

Some properties of a class of biased regression estimators

For the linear statistical model y = Xb + e, X of full column rank estimates of b of the form (C + X′X)⁺X′y are studied, where C commutes with X′X and Q⁺ is the Moore-Penrose inverse of Q. Such estimators may have smaller mean square error, component by component than does the least squares estimator. It is shown that this class of estimators is equivalent to two apparently different classes considered by other authors. It is also shown that there is no C such that (C + X′X)⁺X′Y = My, in which My has the smallest mean square error, component by component. Two criteria, other than tmse, are suggested for selecting C. Each leads to an estimator independent of the unknown b and σ². Subsequently, comparisons are made between estimators in which the C matrices are functions of a parameter k. Finally, it is shown for the no intercept model that standardizing, using a biased estimate for the transformed parameter vector, and retransforming to the original units yields an estimator with larger tmse than the least squares estimator.     

Hybrid neural control systems: Some stability properties

Nonlinear control with feedforward neural networks is usually designed by means of model based control strategies, which make explicit use of (direct or inverse) models of the controlled system. In this framework, a typical control problem consists in reducing the effects of the inevitable errors introduced by neural network approximation. In a non-adaptive setting, modeling errors can be compensated by hybrid control schemes, where the approximate neural controller is complemented with an integral type regulator connected in parallel. However, in this way, the model based control paradigm is partially lost and stability properties of the control system may be degraded. In this paper a stability analysis of such hybrid schemes is performed, which shows that control system stability can be achieved provided each of the two control blocks obeys a specific condition. Furthermore, a modified hybrid scheme is proposed to enhance the cooperation between the two control blocks: a nonlinear static filter is employed to modulate the integral action so that it becomes significant only when the neural controller has approached the equilibrium. Stability analysis is extended to this case. The hybrid scheme where the two control blocks are connected hierarchically in cascade is finally discussed.     

闪锌矿型CdTe电子结构和光学性质的第一性原理

采用基于密度泛函理论(DFT)框架下广义梯度近似平面波超软赝势法,计算了闪锌矿型CdTe的能带结构、态密度和光学性质.计算表明,闪锌矿型CdTe为直接带隙半导体,禁带宽度为0.671eV.计算并分析了闪锌矿型CdTe的复折射率、复介电函数、吸收系数、光电导率、损失函数和反射率,其折射率为2.69,静态介电常数为7.23.计算结果与其他文献结果吻合较好,为闪锌矿型CdTe的应用提供了理论依据.     

纳木措湖中黄色物质（Yellow Substance）光吸收特性初步研究

对纳木措湖泊水样中黄色物质的吸收特性进行了初步研究,结果表明该黄色物质的吸收系数随着波长的增加呈指数型减小,在短波部分具有强烈的吸收特性.该黄色物质在波长310nm处的吸收系数a(310nm)值从1.24m-1变化到3.19m-1,黄色物质吸收光谱曲线的指数斜率S值的变化范围为0.015～0.026nm-1.     

Basics of videodisc and optical disk technology.

This article outlines basic videodisc and optical disk technology. Both optical and capacitance videodisc technology are described. Optical disk technology as a mass digital image and data storage device is defined and briefly compared with other established information storage media including magnetic tape and microforms. The article includes a look into the future of videodisc and optical disk.