Sintering and Electronic Conducting Properties of Lao.7Ca0.3CrO3 Perovskite Synthesized by a Glycine-nitrate Process

La0.7 Ca0.3 CrO3 powder consisting of superfine and uniform particles （ 100-200 nm ） were synthesized using a glycine-nitrate process （ GNP ）. The sintering and electronic conducting properties of La0.7 Ca0.3 CrO3 were invetigated in the sintering temperature range of 1 200-1 450 ℃. The desired morphology of the powder significantly improved its sinterability. La0.7 Ca0.3 CrO3 ceramics sintered at 1 250-1 450 ℃ show high relative densities above 95 % . The ceramics sintered at 1 250-1 400 ℃ have very similar electronic conduct- ing properties, providing electronic conductivities around 55 Ω^-1 cm^-1 at a measuring temperature of 800 ℃ . Further increasing the sintering temperature to 1450 ℃ led to an apparent degradation of electronic conducting properties. This research demonstrates the advantage of the GNP in producing La0.7 Ca0.3 CrO3 with respect to the enhanced sintering properties and superior electronic conducting properties.     

基于IC设计的验证技术

验证是Soc设计最重要的阶段.在将设计交付给生产厂家之前,要想能够找出体系结构上、功能上或者物理实现上的错误只是通过验证.对于众多团队设计而言,验证占到了设计流程的50%至80%.本文主要介绍了功能仿真、静态时序仿真、形式仿真等相关验证技术.     

Performance of an HTS Generator Field Coil Under System Fault Conditions

High-temperature superconducting (HTS) coils are generally stable against transient thermal disturbances. Protection against spontaneous quenches is not a main design issue for an HTS coil. However, HTS coils used in many electric devices such as motors, generators, transformers, and current limiters will operate under over-current fault conditions, which may result in a coil quench and thermal runaway. Those electric devices should be able to ride through some grid fault conditions and remain functional. This requires a certain over-current capability of the HTS coils. This paper discusses the over-current requirements from grid faults and the thermal transient responses of a BSCCO coil. It presents the analysis results of the coil subjected to over-current pulses at different operating conditions. The study also investigates the thermal runaway current and its relationship with the over-current pulse     

U型竖埋管地源热泵-辐射地板联合运行冬季启动特性实验研究

对U型竖埋管地源热泵-辐射地板联合运行实验冬季运行启动特性进行分析，研究启动阶段U型竖埋管进出水温的变化规律，得出平均每米井深的换热量。研究启动阶段辐射地板供暖的进出水温的变化规律，为地源热泵及辐射地板在长江中下游地区的工程设计与应用推广提供参考。     

一种嵌入式系统通信中间件的设计

基于嵌入式系统的跨平台实现互通、互连、互操作及通用性的特殊要求,我们根据中间件的设计思想研制开发了一种基于嵌入式技术的各通信设备之间进行网络互连的通信中间件XCOM。本文对通信中间件XCOM的设计思想、设计过程以及通信流程进行了介绍。     

基于单片机的电脑弹簧机按键板的设计与实现

电脑弹簧机是用来生产弹簧的专用设备,按键板则是实现对弹簧机控制的一个人机交互的操作界面。本文介绍了电脑弹簧机按键板的设计及实现方法。该按键板采用薄膜面板开关的形式,用PS/2协议作为按键板和主机的通信手段,以单片机AT89S51作为处理芯片,设计灵活,使用方便可靠,具有锁键的功能,很好地满足了工业现场需求。它具有的通用性使得其能广泛应用于以PC机为主机的控制系统中。     

DSP程序地址总线低功耗分段Gray编码方法

地址总线的功耗是DSP功耗的重要来源。降低地址总线上的翻转率可以有效降低整个系统的功耗。文章在分析CMOS电路功耗基础上,提出了一种改进的Gray编码。结果表明,采用此种编码可以有效地降低DSP程序地址总线功耗。     

带修正函数的模糊控制器在硅钼炉控制中的应用

硅钼棒的电阻随温度的上升呈非线性正变化，以硅钼棒作为发热元件的硅钼炉具有大容量、非线性、大滞后、热惯性时变的特点。本文介绍了一种带修正函数的模糊控制器，通过引入瞬态输出值△U提高控制器对系统参数变化的适应能力，最终达到提高系统响应速度与控制精度的目的。     

基于DirectShow的视频图像处理系统设计与实现

文章对DirectShow技术作了概括介绍，并给出了一种通用的视频图像处理系统的DirectShow应用软件实现过程。     

多工位烧结炉智能温度控制系统的设计与应用

针对传统的多工位烧结炉的温度控制精度、生产工艺控制能力等较低的现状，提出了一种多工位烧结炉的智能温度控制系统。该系统以可编程逻辑控制器（PLC）为核心，以模糊PID算法为控制器。在该系统的控制下，可有效地实现对三工位烧结炉温度工艺曲线和辅助工艺的控制，并可在线自整定PID参数，实现了烧结炉生产过程的自动化，提高了温度控制精度以及工作效率。应用结果表明，该温控系统具有良好的自适应性和鲁棒性。