Development of On—Line Perturbed Angular Correlation

The on-line time differential perturbed angular correlation technique has been developed for the first time.The quadrupole interaction of ^19F in Cd was measured.     

A Compact Vircator with Feedback Annulus Operated in Quasi—Single TM01 Mode Within the C Band

An axially extracted virtual cathode oscillator(vircator)with a feedback annulus is proposed and configured through particle-in-cell simulation.This compact device needs no guiding magnetic field.Its experimentally radiated microwave is measured to be of quasi-single TM01 mode with a frequency range of 4.41-4.69GHz and a power level of above 300MW,when the diode voltage ranges between 400-480kV and the beam current 20-25kA;this confirms the simulation results.     

嵌入式系统功率逻辑器件在嵌入式系统中的应用

本文简要介绍了嵌入式可编程控制器及其I／O模块，结合功率逻辑器件TPIC6B273的特点，对传统的输出模块进行了改进，实验证明其简捷有效。     

Polarons with Spatially Dependent Mass in a Finite Parabolic Quantum Well

We study the energy levels of an electron (or hole) polaron in a parabolic quantum well structure,including the spatial dependence of the effective mass.We also consider the two-mode behaviour of longitudinal optical phonon modes of the ternary mixed crystals in the structure,in the calculation of the effect of the electron phonon interaction.We calculate the ground state,the first excited state and the transition energy of an electron (or hole) in the GaAs/AlxGa1-xAs parabolic quantum well structure.The numerical results show that the electron-phonon interaction obviously affects the energy levels of the electron (or hole),which are in agreement with experimental results.     

谐和随机噪声联合作用下Van der PolDuffing振子的参数主共振

研究了Van der Pol－Duffing振子在谐和与随机噪声联合激励下的参数主共振响应和稳定性问题。用多尺度法分离了系统的快变项，并求出了系统的最大Liapunov指数和稳态概率密度函数，还分析了失稳、分 叉和跳跃现象，讨论了系统的阻尼项、非线性项、随机项和确定性参激强度等参数对系统响应的影响。数值模拟表明所提出的方法是有效的。     

Spatial Interference Effect of Two—Photon in Femtosecond—Pules Pumped Spontaneous Parametric Down—Conversion

We have used the transverse correlated properties of the entangled photon pairs generated in the process of spontaneous parametric down-conversion,which is pumped by a femtosecond pulse laser,to perform Young‘s interference experiment.Unlike the case of a continuous wave laser pump,a broadband pulse laser pump can submerge an interference pattern.In order to obtain a high visibility interference pattern,we used a lens with a tunable focal length and two interference filters to eliminate the effects of the broadband pump laser.It is proven that the process of two-photon direct interference is a post-selection process.     

谈硫酸盐光亮镀铜的磷铜阳极

在装饰性和PCB电镀中，酸性光亮镀铜的阳极的最佳含磷量为0.035-0.075%，磷化铜（Cu3P）黑膜的生成对阳极性能、工艺的稳定及镀层质量有显作用。     

移动互联网的关键技术——IPv6

移动互联网是因特网发展的一种趋势。IPv4已不能满足互联网发展的需要，而新一代的IPv6为移动互联网提供了故障。本在分析了移动IP的基本原理后，具体论述了IPv6对移动性的支持。并通过与IPv4的比较，突出IPv6的特点和优势。     

特征点匹配法实现汽车牌照的快速识别

本文在模板匹配法的基础上，根据汽车牌照本身的特性，提出了特征点匹配识别的方法，选取能够区分各字符的若干特征点，进面最值得到各字符的编码、通过判断达到识别汽车牌照的目的。本方法减少了冗余信息，大大提高了识别速度。