MSP4000型多业务处理器在软交换终端设备中的应用

MSP4000是PMC-Sierra公司生产的多业务处理器,内部集成了语音编解码用DSP、MIPS内核、VPN安全引擎和MAC控制器等,使用这种处理器可完成软交换系统中IAD设备的设计.介绍MSP4000的系统结构及各个模块的功能,并给出根据MSP4000设计的IAD设备的硬件方案和软件流程.     

基于ISP芯片的任意编码波形发生器设计

介绍了一种可程控编码波形发生器的设计,利用可预置计数器和并入串出移位寄存器阵列,通过微机控制,可形成多位的任意组合的编码脉冲波形,实现码元宽度、重复周期、编码脉冲个数(512位以内)任意可变.阐述了Lattice公司的设计工具以及设计流程,并用ispMACH4000器件实现该波形发生器.在ISP器件的开发过程中,采用自顶向下的设计方法,用VHDL语言作为设计输入并利用电子设计自动化(EDA)工具Synplify Pro和ModelSim SE分别进行综合与仿真.在此基础上,讨论了系统资源的占用情况和相应的系统优化.该编码波形发生器的最大码元位数也可根据实际情况简单地通过修改程序进行相应的改动.     

Dawning4000A high performance computer

Dawning4000A is an AMD Opteron-based Linux Cluster with 11.2Tflops peak performance and 8.06Tflops Linpack performance. It was developed for the Shanghai Supercomputer Center (SSC) as one of the computing power stations of the China National Grid (CNGrid) project. The Massively Cluster Computer (MCC) architecture is proposed to put added-value on the industry standard system. Several grid-enabling components are developed to support the running environment of the CNGrid. It is an achievement for a high performance computer with the low-cost approach.     

DirectDraw在实时显示中的应用

ＤｉｒｅｃｔＤｒａｗ是Ｍｉｃｒｏｓｏｆｔ公司发行的软件开发工具包,由于它能产生快速、平稳图形,而被广泛地应用于游戏软件的开发制作中,同样,我们利用其显示速度的优越性,扩展ＤｉｒｅｃｔＤｒａｗ在其他领域的应用。文章介绍了ＤｉｒｅｃｔＤｒａｗ软件开发工具包在ＧＹＺ４０００型遥测仪微震监视模块中的应用。利用ＤｉｒｅｃｔＤｒａｗ,实现了野外地震数据的无闪烁、平稳、高速显示。     

Testing a multiprogramming system

A central problem in program design is to structure a large program such that it can be tested systematically by the simplest possible techniques. This paper describes the method used to test the RC 4000 multiprogramming system. During testing, the system records all transitions of processes and messages between various queues. The test mechanism consists of fifty machine instructions centralized in two procedures. By using this mechanism in a series of carefully selected test cases, the system was made virtually error free within a few weeks. The test procedure is illustrated by examples.     

Thermal Conductivity Measurements on UO2+x from 300 to 1,400 K

In order to evaluate the thermal conductivity of oxidized fuel pellets of leaker fuel rods, UO_2+x samples with x between 0.00 and 0.20 were prepared by an oxidation or a sintering method. Sample thermal diffusivities were measured by using a laser flash method from 300 to 1,400 K and their thermal conductivities were evaluated from multiplying the thermal diffusivities by the sample densities and the specific heat capacities derived from the literature. The thermal conductivities of UO_2+x were decreased with increasing hyperstoichiometry and they were expressed as a function of their hyperstoichiometry using the concentration of U⁵⁺ formed with the excess interstitial oxygen atoms.     

微波快速消解仪提取侧柏叶总黄酮的工艺研究

用WX-4000微波快速消解系统提取侧柏叶中黄酮类物质。通过料液比、乙醇浓度、微波时间、微波功率等单因素实验与正交实验确定侧柏叶黄酮提取的最佳条件为:乙醇的浓度为40%,微波时间为60s,料液比为1∶20(g/mL),微波功率为480 W。在此条件下,黄酮的提取率为1.43%。紫外可见光谱及红外光谱表明侧柏叶中的黄酮主要为黄酮醇类。     

伺服电机及系统特性性能测试系统设计

介绍了用于伺服电机及系统特性性能试验的测试系统。该系统采用能量回馈的方式进行对拖加载试验,能够满足0.75~110 k W伺服电机及控制器的交/直流伺服电机系统的性能测试。     

PT4000改善涤纶织物喷墨印花应用性能研究

探讨了PT4000在不同的处理条件下对提高涤纶喷墨印花质量的影响．实验发现,使用PT4000可以改善喷墨印花的效果,印制的织物图案清晰,颜色鲜艳．较好的处理条件是室温处理30min,PT4000用量为3％．     

表面活性剂对磁流体稳定性及外层包覆结构的影响

采用化学共沉淀法制备粒径分布均匀的纳米Fe3O4颗粒,用油酸钠和聚乙二醇4000(PEG4000)对纳米Fe3O4颗粒进行表面修饰,制得分散稳定的纳米Fe3O4磁流体,通过电动电位(Zeta电位)、粒径测试、离心沉淀、红外光谱分析(FT-IR)和热分析(TG)对修饰后的纳米Fe3O4颗粒进行了稳定性能评价与结构表征。结果表明,油酸钠与纳米Fe3O4颗粒存在两种不同类型的化学键作用;增大油酸钠加入量不会改变Fe3O4颗粒表面包覆结构,但是,其在纳米Fe3O4颗粒表面的吸附量呈先增加后降低的趋势;PEG4000物理吸附于油酸钠包覆的纳米Fe3O4颗粒表面,PEG4000的加入会进一步提高磁流体的稳定性。