CRL与OCSP相结合的证书撤销方案

提出了一个基于CRL和OCSP策略的新的证书撤销方案。首先分析比较了CRL和OCSP协议的优缺点,然后结合两者的优点通过建立一个请求处理服务器提出了一个新的证书撤销方案,最后对改进方案的优劣做了分析总结。     

金属/Al2O3基纳米复合材料研究最新进展

金属／Al2O3纳米复合材料在保持原有金属的功能特性时，还可以获得 很好的力学性能，是有良好发展前景的一种纳米复合材料。本文回顾了近年来金属／Al2O3基纳米复合材料在制备工艺，微观结构和力学性能，增韧强化机理方面的最新进展，并指出了今后的研究方向。     

瞬态瑞利面波技术在地震勘探方面的应用研究

运用瞬态瑞利面小勘探方法可以在寻找激发岩性和提供静校正所需参数方面取得好的效果。     

碳纳米管(CNT)场发射显示器的关键技术的研究

对碳纳米管阴极的制备以及场发射显示器的真空封装技术进行了研究.利用一种新的碳纳米管生长工艺制备出了具有优良场发射性能的碳纳米管阴极.并将这种直接生长的碳纳米管薄膜作为阴极,结合一种弹性封装工艺,开发了一种具有简单字符显示功能的场发射显示器.该显示器在较低的工作电压下就可获得高亮度的显示效果,并且器件的亮度与驱动电压成较好的线性关系,这将有利于未来的碳纳米管场发射显示器实现高亮度和多级灰度显示.器件的持续工作寿命测试已经超过5500小时,充分验证了碳纳米管作为场发射阴极的应用潜力.     

Modulation and Equalisation Considerations for High Performance Radio LANs

The European Telecommunications Standards Institute (ETSI) has recently defined a European standard for a high performance radio LAN (known as HIPERLAN). To operate as wired LAN replacements, these systems will operate at 5.2 GHz and support instantaneous bit rates of just under 24 Mb/s. To counteract the time dispersive nature of the indoor radio channel, the use of adaptive equalisation is suggested. In this paper a number of possible modulation and equalisation techniques are presented and, in particular, the Bit Error Rate (BER) performance of quasi-coherent GMSK combined with Decision Feedback Equalisation is explored through computer simulation. The trade off between symbol spaced and fractionally spaced equalisation is considered together with the importance of feedfoward and feedback synchronisation to the channel's power delay profile. The paper also includes a comparison of the RLS and LMS based training algorithms and compares the modem developed under the ESPRIT III LAURA project with that specified in HIPERLAN.The application of dual antenna diversity is investigated and its impact on the number of received error free data packets obtained as a function of signal leval and rms delay spread. The use of such diversity is shown to greatly improve the BER performance of a HIPERLAN modem. The problem of frequency offset is considered and modifications are proposed to the HIPERLAN frame structure to improve the receiver's tolerance to such errors. Important practical issues such as frame and symbol synchronisation, frequency offset correction and hardware implementation are discussed from both the LAURA and HIPERLAN viewpoint.     

一种多晶硅高温压力传感器

制作压力传感器时，在二氧化硅层上淀积多晶硅膜，既可利用优良的机械特性，又可保证压敏电阻与衬底间具有良好的绝缘性，由此可大大提高器件的温度特性。介绍了一种多晶硅压力传感器的原理和设计。实验结果表明，这类传感器具有灵敏度好，精度高等特点，电路工作范围为０－２５０℃，且具有良好的温度稳定性。     

参数化图形库技术

本文论述了参数化图形库的实现原理，建立了以尺寸叠加算法为基础的参数化图形库开发工具，利用这种开发工具建立的图形数据可以由数据库管理，方便有效。     

超声波车辆车轴探头的研制与应用

提出了一种用于检测在役车辆车轴产生疲劳裂纹的超声波方法,设计了中心孔探头与斜角探头一起,完成了对车辆车轴的关键区域探伤。     

940nm高功率激光二极管及线阵

设计并制作出了940 nm无铝有源区高功率激光二极管和激光条.通过MOCVD法生长出应变量子阱材料,器件显示出极好的性能,100μm条宽的激光二极管最大输出功率达800mW(室温),填充因子为17%的激光二极管条发射功率达32 W.     

微型无阀泵参数化结构设计及测试

 从理论计算和试验两方面研究了用于微流控化学分析芯片的微型无阀泵流动特性，初步建立了微型无阀泵流道结构的数学模型，重点讨论了结构参数的选取原则及相应的流动阻尼系数的计算方法． 通过试验验证了数值计算的可靠性，为微型无阀泵参数化设计及优化提供了理论依据及经验曲线．