单光子时间分辨在线谱仪系统中的接口电路

本文介绍单光子时间分辨在线谱仪系统中的多道分析器与IBM PC/XT微型计算机接口的工作原理及控制程序。     

Boundary-integral equation analysis of twisted internally cracked axisymmetric bimaterial elastic solids

 Green's function is obtained for the infinite bimaterial elastic solid, containing an internal circular interface crack, loaded by a unit tangential co-axial circular source. An axisymmetric direct boundary integral equation (BIE) is used for the analysis of a finite bimaterial axisymmetric body containing an internal circular interface crack and a finite homogeneous cracked cylinder, both under torsional loading. Using the proposed technique, no discretization of the crack surface is necessary. Numerical results for both examples as obtained by the proposed method are presented and discussed. Received: 29 October 2001 / Accepted: 29 May 2002     

基于XML和N层VSM的Web信息检索

基于XML文档格式良好、层次清晰，可以方便地操纵、分析其结构的特点。文中在将Web上的HTML文档转化为XML文档的基础上，通过Java中的DOM树，分析文档的层次结构。把文档分为层次化的文本段，对传统的VSM算法进行改进，把每个文本段转换为空间向量，实现了N层VSM算法，通过试验证明，改进后算法的查全率和查准率都要优于传统的VSM算法。     

HCl氧化物MOS结构质子辐照诱导的界面陷阱效应

用微分电容法研究质子辐照HCl氧化物铝栅MOS结构诱导的界面陷阱,栅氧化层在1 160℃很干燥的、含0～10％HCl的气氛中热生长而成,质子辐照能量为120～300keV,注入总剂量范围为8×10~(13)～1×10~(16)p/cm~2。结果表明,辐照诱导的界面陷阱能级密度随质子能量、剂量增加而增加。然而,氧化层中掺入6％HCl时,辐照诱导的界面陷阱明显减少。这样,已能有效地改变MOS器件的抗辐照性能。实验结果可用H~+二级过程解释。     

The Michigan benchmark: towards XML query performance diagnostics

We propose a micro-benchmark for XML data management to aid engineers in designing improved XML processing engines. This benchmark is inherently different from application-level benchmarks, which are designed to help users choose between alternative products. We primarily attempt to capture the rich variety of data structures and distributions possible in XML, and to isolate their effects, without imitating any particular application. The benchmark specifies a single data set against which carefully specified queries can be used to evaluate system performance for XML data with various characteristics.     

综合联机指令系统及其应用

介绍了综合联机指令系统的业务功能、处理流程和软件架构,并举例说明了该系统的应用。     

Damage mechanisms and failure modes in cross-ply laminates under monotonic tensile loading: The influence of fiber sizing

In this study, the effect of fiber-matrix interphase on the damage modes and failure mechanisms in (0, 90₃), cross-ply graphite-toughened epoxy laminates is investigated. Two material systems (designated as 810 A and 810 O) with the same fiber and same matrix, but with different fiber sizings, were used to study the effect of the interphase. The system designated as 810 A contained an unreacted Bisphenol-A (epoxy) sizing, while a thermoplastic polyvinylpyrrolidone (PVP) sizing was used in the 810 O system. Damage accumulation in the cross-ply laminates under monotonic tensile loading was monitored using edge replication, x-ray radiography, acoustic emission, optical and scanning electron microscopy. Results indicate that the fiber-matrix bond strength is lower in the 810 O system compared to the 810 A system. Transverse matrix cracking initiates at a significantly lower stress level in the 810 O laminate. The 810 O laminates also exhibit longitudinal splitting, while the stronger bonding suppress this damage mode in the 810 A laminates. Numerous local delamination occur on the 0/90 interface at the intersection of 0 and 90 degree ply cracks, in the 810 O laminates. These are absent in the 810 A laminates. The failure modes are also different in the two material systems used in this study. The 810 A laminate exhibits a brittle failure, controlled by the local stress concentration effects near broken fibers. In the 810 O laminates, the presence of longitudinal splits result in the reduction of stress concentration effects near fibe fractures. This results in a global strain controlled failure in the 810 O system. It is concluded that the presence of different fiber sizings result in different damage modes and failure mechanisms in the cross-ply laminates used in this study.Research Associate, Research Assistant, Alexander Giacco Professor and Professor respectively.     

带FPGA的PCI接口应用

文章介绍了一种带FPGA的PCI接口的应用及设计方法。该方法将PCI接口和PCI用户逻辑集成在一片FPGA里，可以对整个逻辑进行仿真测试，大大缩短了开发周期，提高了系统集成度和性能。文章重点叙述了Quicklogic公司提供的32wug TARGET接口芯片QL5030的原理和结构，分析了时序设计要点，给出了典型应用的逻辑框图和注意事项。     

12864-12 LCD模块与射频SoC nRF9E5的串行接口设计

本文首先介绍一种具有2位或3位串行、4位或8位并行多种接口方式，内部含有国标一级、二级简体中文字库的图形点阵液晶显示模块12864-12，以及该模块的技术特性、串行接口方式和操作指令。然后介绍射频片上系统nRF9E5的片内微控制器结构与其接口资源，给出在无线数据传输系统中12864-12与nRF9E5串行连接的硬件电路和部分程序。最后，论述了该方案的优点。