马科维兹资产组合选择模型的旋转算法

提出线性不等式组的一种旋转算法，并用其求解马科维兹资产组合选择模型，此算法每次迭代约需n^2次乘法和加法，其中n是模型中变量的数目，在微机上运行Delphi程序的实验结果表明，从上海和深圳股市1072支股票70期周末收盘价计算出20个最优投资组合仅需314次迭代和45s。     

THE COUPLING OF NATURAL BOUNDARY ELEMENT AND FINITE ELEMENT METHOD FOR 2D HYPERBOLIC EQUATIONS

In this paper, we investigate the coupling of natural boundary element and finite element methods of exterior initial boundary value problems for hyperbolic equations. The governing equation is first discretized in time, leading to a time-step scheme, where an exterior elliptic problem has to be solved in each time step. Second, a circular artificial boundary FR consisting of a circle of radius R is introduced, the original problem in an unbounded domain is transformed into the nonlocal boundary value problem in abounded subdomain. And the natural integral equation and the Poisson integral formula are obtained in the infinite domainΩ2 outside circle of radius R. The coupled variational formulation is given. Only the function itself, not its normal derivative at artificial boundary ΓR, appears in the variational equation, so that the unknown numbers are reducedand the boundary element stiffness matrix has a few different elements. Such a coupled method is superior to the one based on direct boundary element method. This paper discusses finite element discretization for variational problem and its corresponding numerical technique, and the convergence for the numerical solutions. Finally, the numerical example is presented to illustrate feasibility and efficiency of this method.     

数字全息技术的原理和应用

数字全息是随着现代计算机和CCD技术发展而产生的一种新的全息成像技术．文章主要介绍数字全息技术的基本原理，数字全息重建中的主要方法以及数字全息技术以其独特的优点在各个领域中的应用．     

绿色荧光粉YAGG∶Tb,Gd用于FED的尝试

FED器件的发展迫切需要具有化学和热稳定性 ,高亮度 ,长寿命的新型荧光材料。本文合成了Gd3 +离子共掺杂的YAGG∶Tb获得了YAGG∶Tb ,Gd ,并将其用于 0～ 30 0 0V低压范围 ,对其在不同电压和电流密度下的发光特性进行了测试。结果表明 ,该种材料特性优于ZnO∶Zn并且不存在电压与电流饱和     

Photoluminescence Characterization of Silicon Nanoparticles Hybridized Europium Complex

A europium complex Eu (DBM)3 TPPO (Eu tris(benzoylmethide)-(triphenylphosphine oxide)) and silicon nanoparticles have been hybridized.The hybridization can evidently change the photoluminescence (PL) characteristics of the Eu complex in the following aspects:under an excitation of 390nm,the intensity of the PL peak at 611nm due to the ^5Du-^7F2 transition of the Eu^3 ions has been increased by 30%,and thc integrated PL intensity in the visible range has been increased by nearly 3 times;the PL excitation efficiency beyond 440nm has been improved cvidently;the peak in the PL excitation spectrum shifts from 408nm to 388nm,and the PL decay time decreases from 2.07 to 0.96μs,The experimental results indicatde that in the PL process,the photoexcited energy may transfer from the silicon nanoparticlcs to the Eu^3 ions.     

非因子化方法研究D~+→ ■~0K~+衰变(英文)

在领头阶和αs 修正阶 ,用QCD因子化方法 ,并对它的软胶子效应用光锥QCD求和规则分析D+ → K0 K+ 衰变过程 ,我们分析发现朴素因子化方法的结果远离实验结果 ,QCD因子化方法结果靠近实验结果 ,但是 ,在QCD因子化方法中 ,若考虑软胶子效应 ,其结果与实验结果相一致 .另外 ,计算发现 ,软胶子效应在该衰变道中有相当大的贡献 ,因此不能被忽略     

A New Pathway to Synthesize Cyclomercurated Ferrocenylimines Containing Heterocyclic Ring

The cyclomercurated ferrocenylimines containing heterocyclic ring were prepared by the condensation of cyclomercuration of acylferrocene with the appropriate heterocyclic amine.This procedure provides an efficient method for the synthesis of cyclomerucurated ferrocenylimines containing heterocyclic ring which are difficultly synthesized by the conventional method.The reaction mechanism is proposed.     

全息透镜在车辆中的两种应用

通过把全息透镜嵌入挡风玻璃，实现全息透镜在车辆中的两种应用，即将具有颜色选择性的窄带全息透镜用于车辆的平视显示，将具有角度选择性的宽带全息透镜用于车辆的阳光防护。     

关于含非凸约束的变化问题

本文分别讨论泛函Ｉｐ（ｕ）＝∫Ω｛「α＾αβ（ｘ，ｕ）ｇｉｊ（ｘ，ｕ）Ｄαｕ＾ｉＤβｕ＾ｉＤβｕ＾ｊ」＾ｐ／２＋Ｐ（ｘ，ｕ）｝ｄｘ，在一般的非凸几何约束Ｆ１＝｛ｕ∈Ｈ＾１，ｐ（Ω，Ｒ＾Ｎ）；ｕ∈Ｍａ．ｅ．于Ω，ｕ│δΩ＝ｕ０｝和非凸图约束下的极小化问题，其中Ｍ为Ｒ＾Ｎ中的任一光滑开子集或Ｒ＾Ｎ的一个开子流形。