基于VXI总线的超宽带线性调频信号源的设计

主要介绍了VXI总线C尺寸超宽带线性调频信号源的设计方法，重点描述了利用现场可编程逻辑器件FPAG和DSP设计VXI总线接口电路，以及数字波形存储直读技术在线性调频信号源中的应用。     

中低速率语音波形编码

提出了一种波形编码的新方法，阐述了其编码原理。该编码算法简单，恢复的语音质量较好。由于利用了矢量量化技术，所以该编码速率较低。     

Effect of strain waveform on creep-fatigue life for Sn–8Zn–3Bi solder

This paper describes the creep‐fatigue life of Sn–8Zn–3Bi under push–pull loading. Creep‐fatigue tests were carried out using Sn–8Zn–3Bi specimens in fast–fast, fast–slow, slow–fast, slow–slow and hold–time strain waveforms. Creep‐fatigue lives in the slow–slow and hold‐time waveforms showed a small reduction from the fast–fast lives but those in the slow–fast and fast–slow waveforms showed a significant reduction from the fast–fast lives. Conventional creep‐fatigue life prediction methods were applied to the experimental data and the applicability of the methods was discussed. Creep‐fatigue characteristics of Sn–8Zn–3Bi were compared with those of Sn–3.5Ag and Sn–37Pb.     

Inference and retrieval of facial images

Attempts have been made to extend SQL to work with multimedia databases. We are reserved on the representation ability of extended SQL to cope with the richness in content of multimedia data. In this paper we present an example of a multimedia database system, Computer Aided Facial Image Inference and Retrieval system (CAFIIR). The system stores and manages facial images and criminal records, providing necessary functions for crime identification. We would like to demonstrate some core techniques for multimedia database with CAFIIR system. Firstly, CAFIIR is a integrated system. Besides database management, there are image analysis, image composition, image aging, and report generation subsystems, providing means for problem solving. Secondly, the richness of multimedia data urges feature-based database for their management. CAFIIR is feature-based. A indexing mechanism,iconic index, has been proposed for indexing facial images using hierarchical self-organization neural network. The indexing method operates on complex feature measures and provides means for visual navigation. Thirdly, special retrieval methods for facial images have been developed, including visual browsing, similarity retrieval, free text retrieval and fuzzy retrieval.     

发射机脉冲调制器的探讨

针对雷达发射机调试实践中存在的调制器脉冲波形问题，对磁控管发射机常采用的刚性调制器脉冲波形影响雷达性能及发射机可靠性的情况进行了分析与探讨，并结合实际，提出了调制器脉冲波形的改善途径及解决办法。     

TBM地区低孔渗高产气储层预测

 本文从TBM地区目的层的地质和地球物理特征分析出发，以三维地震资料为基础，综合利用人工和神经网络波形分类等定性储层预测方法和利用反演及敏感地震属性分析，对TBM地区低孔渗砂岩分布区开展了砂体展布特征分析和天然气高产区预测研究。根据研究结果部署了10口钻井，已完钻的4口井中有3口获得高产气流（其中DK27井日产天然气36.8×10⁴m³）。值得指出的是，目前所用的预测方法还不能预测厚度小于6m的单砂层或砂层组构成的储层。     

波形测量技术的发展趋势--兼谈YOKOGAWADE的示波器发展

本文着重论述了波形测量技术的最新发展趋势。     

一种高性能超宽带线性调频信号源

介绍一种VHF／UHF频段高性能超宽带线性调频信号源的设计与实现。首先简要阐述了高性能超宽带线性调频信号源的设计思想，然后依据基带数字产生结合倍频扩展带宽的思路提出了一种超宽带线性调频信号产生方案，并进行了设计实现研究。测试结果表明：按照本文阐述的指导思想和实现方案所设计的超宽带线性调频信号源达到 了相当高的性能。     

光纤中的SBS反射率和波形研究

从理论和实验上研究了不同焦距下泵浦能量以及透镜与光纤间距对多模光纤中的SBS能量反射率和脉冲波形的影响。理论模拟采用一维瞬态SBS数值计算模型和边界噪声输入法，得到了SBS反射率和脉冲上升沿的变化规律。实验上采用1.06μm的YAG激光器和无掺杂多模阶跃石英光纤，测得了能量反射率和波形的变化规律，获得的最大反射率为69%，脉宽压缩比为3:1-2:1。计算结果与实验结果符合较好。     

用有限带宽反射波波形分析法进行储层横向预测

以正演地震模拟为基础的有限带宽反射波渡形分析法是一种新的储层横向预测方法。首先利用波形分解确定地震反射层的地质属性,找出能反映岩性变化的反射波波形特征参数;然后,采用多元数据聚类分析和灰色系统理论完成储层横向的预测。文中以预测江苏 J 凹陷 F 构造上阜二段生物灰岩分布及厚度横向变化为例,简述了反射波波形分析的全过程。预测结果已为钻探证实。