极性晶体外表面电子的量子像势及其极化子的基态能量

本从与真空接触的存在二支声子的半无限极性晶体表面附近极化子的哈密顿算符入手，应用二支模型理论，分别对GaAs和ZnO两种材料计算了外表面电子的量子像势及其极化子的基态能量，计算结果表明，利用二支模型理论求出的外表面极化子的基态能量与利用一支模型理论求出的外表在面极化子的基态能量相差较大，对GaAs，误差约为31.1%, 对ZnO，误差约为14.8%。     

激光二极管端面抽运的棒状Yb：YAG激光器

分析了影响激光二极管抽运Yb：YAG激光器调Q效率的参量，推导了激光二极管端面脉冲抽运Yb：YAG晶体的速率方程，解出了双程抽运情况下的净抽运量子产率。利用数值计算方法，模拟了净抽运量子产率与晶体长度，抽运光脉冲宽度等关系，得出晶体长度的优化可以提高Yb：YAG激光器输出效率。计算了词Q Yb：YAG激光器的最大增益、最大储能，分析了放大自发辐射对于Yb：YAG能量存储的影响。同时给出了激光二极管端面抽运调Q Yb：YAG优化设计方法。这些分析和计算为实际器件的研制提供参考。     

Quark Virtuality and QCD Vacuum Condensates

Based on the Dyson-Schwinger equations (DSEs) in the ‘rainbow‘ approximation, we investigate the quark virtuality in the vacuum state and quantum-chromodynamics (QCD) vacuum condensates. In particular, we calculate the local quark vacuum condensate and quark-gluon mixed condensates, and then the virtuality of quark. The calculated quark virtualities are λu,d^2 0.7 GeV^2 for u, d quarks, and λs^2=1.6 GeV^2 for s quark. Our theoretical predictions are consistent with empirical values used in QCD sum rules, and also fit to lattice QCD predictions.     

非奇异单圈图的刻划

边数等于顶点个数的连通图称为单圈图.本文修正了文献[1]中关于奇异单圈图的充要条件,并且利用该条件证明了文献[2]中一个关于非奇异单圈图的猜想.     

Evolution of Shower Parton Distributions in a Jet from Quark Recombination Model

The evolution of shower parton distributions in a jet is investigated in the framework of a quark recombination model. The distributions are parameterized and the Q^2 dependence of the parameters is given by polynomials of In Q^2 for a wide range of Q^2     

Raman spectroscopic study of ceramic Sr2Bi4Ti5O18

Raman spectra of ceramic Sr2Bi4Ti5O18 （SBTi5） are reported to consist of four different Raman bands. Temperature-dependent spectra reveal the relationship between the lattice vibration and the material＇s structure. There appears a relatively large change in structure of the material at about 273K, The anharmonic potential of the material has a great influence on its phonon mode full width at half maximum （FWHM）, which can be expressed by a function of temperature. Theoretical fittings of the FWHMs for the two modes at around 312 cm^-1 and 464cm^-1 indicate that the latter phonon mode is more anharmonic than the former one.     

基于CPLD的DSP数据采集系统

介绍一个基于CPLD的DSP高速数据采集系统的设计方案，重点讨论了CPLD在系统中的设计和工作过程，包括数据通信接口设计，采样脉冲信号合成等，系统电路简单，易于实现，由于使用CPLD器件，因而硬件设计灵活，并可利用ISP特点改善系统设计。     

Cntinuity of Some Classes of Functions Related to Degenerate Parabolic Equations and Its Applications

We study some classes of functions satisfying the assumptions similar to but weaker than those for the classical B2 function classes used in the research of quasi-linear parabolic equations as well as the ones used in the research of degenerate parabolic equations including porous medium equationsl.Comsequently,we prove that a function in such a class is continuous.As an application,we obtain the estimate for the continuous modulus of the solutions of a few degenerate parabolic equations in divergence form,including the anisotropic porous equations.