时域多分辨率法分析二维光子带隙结构的色散特性

采用时域多分辨率法分析计算了在TM波情形下二维介质光子带隙结构的色散曲线．分别在介质柱的相对介电常数εr＝10．2，20．2的算例中选取较粗网格(约为细网格的3倍)，其计算结果在精度上与采用细网格的时域有限差分法相同，但均明显地节省了计算内存和时间。     

弹流拖动力试验系统关键技术的研究

介绍了弹流拖动力试验系统中的几个关键技术及实施．     

基于中间件的企业应用集成

在企业的信息化发展过程中，形成的信息孤岛已成为现代企业信息共享的一个制约因素。笔者对当前企业应用集成的现状、方法及存在的问题进行了分析和讨论，通过结合中间件技术和Web技术特点，探讨了一个基于中间件技术的企业应用集成框架。该集成框架以中间件系统为核心构建分布式应用平台，克服了传统应用集成方法的不足，有效地解决了企业内部的跨平台应用间的集成问题，并为企业发展电子商务提供支持。     

Efficient expression of human factor Ⅸ cDNA in liver mediated by hydrodynamics-based plasmid administration

The transfection of plasmid DNA into mammalian cells is an indispensable tool in the study of gene transfer and gene function. Since the original report in 1990 on the successful expression of a reporter gene in muscle[1], plasmid DNA injection has been widely used to mediate gene transfer study. As a gene transfer vector, naked DNA has many obvious advantages. It is easy and cheap to be prepared and more safe after transfection. But the plasmid mediated gene expression is low because of t…     

机床高速主轴系统的动力学特性

基于Riccatti传递矩阵法，对正在研制的MK2120A型内圆磨床的高速主轴系统进行了动力特性分析，不同规格砂轮对主轴系统的固有频率影响可忽略不计，而不同规格的皮带轮对多统的高阶固有频率影响很大；经过结构动态设计，使主轴临界转速与额定转速之间呈合理布置，确保主轴系统具有优良的动力学品质。研究表明：此方法计算简单，精度较高，计算主轴系统回转效应快捷有效。     

Design and application of 60mer oligonucleotide microarray in SARS coronavirus detection

In April 2003, a novel coronavirus[1,2] which was associated with cases of Severe Acute Respiratory Syn-drome (SARS) was first isolated and sequenced in Canada. The genome of SARS coronavirus (SARS-CoV) is 29727[3] nucleotides in length and has 11 known open reading frames (ORFs). Although the genome organiza-tion of this virus is similar to that of other coronaviruses, phylogenetic analyses and sequence alignment show that SARS-CoV is not closely related to any of the previously ch…     

Temperature variations on the Tibetan Plateau over the last two millennia

The paleoclimate data recovered from ice cores,tree rings and lake sediments indicate regional features of cfimatic change on the Tibeta n Plateau (TP) during the last 2000 years. The composite temperature reconstructions in-dicate that several main climatic episodes, such as the “LittleIce Age“ between 1400 and 1900, the “Medieval Warm Pe-riod“ in 1150-1400, a less warm period in 800-1100, and an earlier cold period between the 3rd and 5th centuries,occurred in the TP. In addition, temperature varied from region to region. The period from AD 800 to 1100, which waswarm in northeastern TP, was contemporaneous with cool-ing in the western and southern TP. The southern TP ex-perienced warming between 1150 and 1400. For western TP,the δ^18O records of the Guliya ice core indicate that the pe-Hod 1250-1500 witnessed a clear warming. Large-scaletrends in the temperature history from northeastern TP aremore similar to those in eastern China than are the trendsfrom the Guliya ice cap far to the west and southern TP. The most prominent similarities between the temperature varia-tions of the TP and eastern China are such cold phases as 1100-1150, 1500-1550, 1650-1700 and 1800-1850, andthe latter three cold events match with three widespreadg lacial advances which occurred on the TP during the Little Ice A2e.     

多媒质区域介质子网格时域有限差分法

介绍了应用于多媒质区域电磁问题的介质子网格时域有限差分法．该方法在保证精度的前提下，节省了大量计算时间及计算机内存，尤其在处理多媒质界面方面具有很大的优势．     

基于小波包联合AR功率谱理论的滚动轴承故障诊断

提出了小波包联合自回归功率谱理论的故障诊断方法.对采集的轴承振动信号采用高、低正交共轭镜面滤波器组,将信号划分到不同频道上.滤波器每作用一次,数据点减半,采样的时间增至两倍.选取轴承缺陷所在频段的数据插零,将其他频带补零重构提高缺陷信号的时频分辨率;然后通过AR功率谱分析轴承运行状态,诊断出轴承对应的故障.对207滚动轴承的早期缺陷作了实际诊断,诊断结果与实际较为符合.证明该方法是一种有效的弱信号缺陷提取与诊断方法.     

纳米TiO2的制备及光催化性能

采用RF-PCVD法，以TiCl4 O2为反应体系，制备出了球状纳米级TiO2粉体。经TEM，XRD，BET测试表明，粉体为锐钛型金红石型的混晶体，粒径范围为20-60nm，平均粒径45nm。苯酚降解实验表明，TiO2粉体具有明显的光催化活性，并就光催化效率与德国产TiO2进行了比较。