The Squeezing Effect in a Mesoscopic RLC Circuit

Using the path integral method we derive quantum wave function and quantum fluctuations of charge andcurrent in the mesoscopic RLC circuit. We find that the quantum fluctuation of charge decreases with time, oppositely,the quantum fluctuation of current increases with time monotonously. Therefore there is a squeezing effect in the circuit.If some more charge devices are used in the mesoscopic-damped circuit, the quantum noise can be reduced. We also findthat uncertainty relation of charge and current periodically varies with the period π/2 in the under-damped case.     

聚乳酸类医用生物降解材料的研究进展

聚乳酸由于其突出的优点如生物相容性好、降解产物对人体无毒而倍受重视,并且在生物医学领域的应用中获得了很好的效果。本文对聚乳酸的合成及在医学方面的应用作了总结和评述,并对其在生物医学领域的应用前景作了进一步展望。     

同时估计回归函数零点及噪声参数

对未知的回归函数以 ARMA 型的误差得到量测时,本文以随机逼近型算法搜索回归函数的零点,同时以参数辨识算法估计噪声模型中的未知系数阵.本文证明了两种算法以概率1的收敛性.     

Spectral Representation Theory for Dielectric Behavior of Nonspherical Cell Suspensions

Recent experiments revealed that the dielectric dispersion spectrum of fission yeast cells in a suspension was mainly composed of two sub-dispersions. The low-frequency sub-dispersion depended on the cell length, while the high-frequency one was independent of it. The cell shape effect was simulated by an ellipsoidal cell model but the comparison between theory and experiment was far from being satisfactory. Prompted by the discrepancy, we proposed the use of spectral representation to analyze more realistic cell models. We adopted a shell-spheroidal model to analyze the effects of the cell membrane. It is found that the dielectric property of the cell membrane has only a minor effect on the dispersion magnitude ratio and the characteristic frequency ratio. We further included the effect of rotation of dipole induced by an external electric field, and solved the dipole-rotation spheroidal model in the spectral representation.Good agreement between theory and experiment has been obtained.     

BEPCⅡ高频发射机和环流器的调整和测试

北京正负电子对撞机升级改造工程(BEPCⅡ)将采用的频率500MHz、输出功率250kW的高频发射机和环流器已安装、调整、测试和验收完毕,这是国内建立的第一套500MHz/250kW发射机系统.本文将详细介绍机器的调测试的原理和各项测量内容及结果, 并比较设计指标和要求,来阐述此发射机的实际技术指标和测试性能.     

声流现象的研究及其应用

本文从声流产生的机理出发，综合了影响声流的诸因素，介绍了声流现象的检测方法及声流效应的应用。     

60keV质子辐照对TiNi记忆合金薄膜马氏体相变的影响

 利用磁控溅射的方法在氧化后的单晶Si基片上制备了TiNi形状记忆合金薄膜，利用示差扫描量热法和原位X射线衍射研究了薄膜的马氏体相变特征。通过60keV质子注入（辐照）薄膜样品研究了H+离子对合金薄膜马氏体相变特征的影响，结果表明氢离子注入后引起了马氏体相变开始Ms和结束点Mf以及逆马氏体相变开始As和结束温度Af的下降，而对R相变开始Rs和结束温度Rf影响不大。掠入射X射线衍射表明H+离子注入后有氢化物形成。H⁺离子注入形成的氢化物是引起相变点的变化的主要因素。     

硫化锌掺钴对电子结构和光学性质的影响

根据密度泛函理论对钴掺硫化锌周围的品格进行了结构优化,计算得到了钴杂质周围的晶体结构、电子态密度分布和吸收光谱.计算结果表明,由于Co原子掺入ZnS晶格常数减小,导致晶格畸变;带隙变窄;吸收峰展宽至更长波长区域.     

铜基催化剂的结构、物性及其对混合碳四选择加氢反应的催化性能

 用XRD，XPS，SEM和H2－TPR等手段研究了铜基负载型催化剂的结\r\n构和物性及其对混合碳四加氢脱炔的催化性能．结果表明，在负载铜催\r\n化剂中加入一定量的Co可提高催化剂的加氢脱炔活性，而Co含量较少时\r\n加入少量的Ce也能提高催化剂的活性和选择性．Cu和Co之间存在着相互\r\n协同作用，使得活性组分在催化剂表面偏析，CuO在催化剂表面呈非晶\r\n相分散状态，催化剂颗粒粒径变小，催化剂更容易被还原，从而改善了\r\n催化剂的催化性能．