基于S3C2440A的分布式温度监控系统的设计

介绍一种通过CAN现场总线进行分布式温度监控的嵌入式系统的设计与实现.该系统采用S3C2440A为主处理器,MCP2515作为外接CAN控制器与基于CAN的工业现场总线相连,PIC18F2580为现场智能采集点微控器,18b20进行现场分布式温度采集.简要的简绍硬件系统、接口电路、温度采集模块,重点介绍Linux下CAN驱动设计.     

基于ARM的直放站远程监控仪的设计

为了解决移动通信网络覆盖中直放站的监控分散、实时性差等问题,采用PHILIPS公司生产的ARM微处理器LPC2214与μC/OS-Ⅱ操作系统设计了直放站远程监控仪.系统主要由ARM监控平台和通信模块两大部分组成.根据直放站的远程监控要求,重点讨论了系统的硬件设计,通过SP3232E实现RS232本地通信,LAN91C11实现了以太网远程通信的技术实现方法.通过实验测量表明,系统实现了对直放站运行参数的采集、标定与配置等远程监控工作,且数据量大、实时性好、工作可靠,具有广阔的应用前景.     

嵌入式设备电源控制系统的CAN通信软硬件设计

为解决电源监控系统中存在的数字化程度低、实时性差、准确度和可靠性低等问题,在研究CAN协议的原理及应用技术的基础上,采用外挂Microchip MCP2515 CAN控制器的设计思想,完成基于AVR单片机的CAN通信软硬件设计,满足电源控制系统策略的需要。该文给出CAN总线的整体结构及控制器、收发器等组成部分硬件及软件的设计与实现,并对系统进行网络负载分析及实时性分析。实际运行表明:该系统可实现报文的发送、接收等功能,可靠性强、通信实时性好。另外,电气隔离电路的设计,进一步提高系统的抗干扰能力;同时,软件设计部分采用自顶向下的模块化设计方法,增强系统的可移植性。     

基于物联网技术的通信动力环境监控系统设计

随着通信技术的不断发展,通信系统及其配套设备数量都日益增多,通信机房已成为电信网络的重要组成部分。机房内的动力、环境设备必须时时刻刻为通信系统提供正常的运行环境,一旦机房环境设备出现故障,就会影响通信网络运行,后果不堪设想。为了保证通信系统安全可靠工作,对机房里面动力、环境设备进行自动监视和有机管理是极其必要的一通信机房动力环境集中监控对机房电源、环境、空调、消防、门禁、图像进行全面监控和管理,实现实时监测、实时记录、实时报警的监控目的,同时系统对所采集的各类数据进行存储备份并作自动分析,为通信设备的有效运行提供充分的决策支持。文章结合工程实例论述了基于物联网技术的通信动力设备及环境监控系统的构造设计。     

基于DSP的温度监控系统研究

本文采用了数字信号处理器（DSP）设计了一种远程温度监控系统,介绍了系统关键硬件电路的具体设计。本系统采用TMS320LF2407芯片为核心．使用CAN总线技术实施通信,实现了对多个节点远程的多路温度检测功能。     

基于CAN总线的电梯远程监控系统设计

分析了CAN总线技术的优点,提出了基于CAN总线组建电梯远程监控系统的方法,并通过对系统的数据采集,适配器软硬件设计,监控软件设计等方面论述了系统的实现.同时也讨论了使用USB2.0对系统扩展能力的影响.该系统运行稳定高效,大大缩短电梯故障维修的反应时间,人机界面友好,具有良好的可扩展性.     

基于CAN总线的高精度温湿度监控系统

本文介绍了一种高精度温湿度自动监控系统的设计原理和实现方法。通过采用CAN总线网络及高精度温湿度传感器,并进行相应的软、硬件设计,实现了对分布式网络的温湿度采集节点的数据采集与传输。实验结果表明,该系统克服了传统温湿度监控系统传输效率低和实时性差的缺点,提高了数据采集准确度,符合日益严格的温湿度环境条件监控需求。     

基于CAN总线的实时数据传输系统的设计与实现

介绍基于CAN总线的实时数据传输系统的CAN固件设备、通信协议、以及应用程序的设计与具体实现;其中详细介绍了独立CAN总线控制器SJA1000的特点、内部结构以及SJA1000的寄存器结构及地址分配,并给出它的典型应用电路.     

CAN总线综述及其应用实例

本文介绍了CAN总线的基本知识,对其技术指标进行了叙述,并介绍了一个基于CAN总线的应用．采用VB语言编程,利用CAN现场总线技术以及华控RSM智能模块搭建分布式监控系统的逻辑结构,采用CAN2．0通讯协议实现上位机与模块的数据通信。详细介绍了RSM04隔离型脉冲输入计数器模块与上位计算机的连接与通讯实现。在实验过程中模拟了信号发生源,其发出的信号经模块采集后送至上位机．执行计数值程序后,可以读取计数结果。     

基于Modbus和GPRS的配电房监控系统

针对目前配电监控网络数据传输速率低、监控手段单一、系统通用性低等问题,对配电房中数据采集技术、RS485通信技术和远程通信技术进行研究,提出了一种基于嵌入式系统的配电房监控系统.利用ARM为控制核心的嵌入式操作平台,对配电房中电参数和环境参数进行采集,实现基于Modbus通信协议的现场监控与基于GPRS的远程监控.研究结果表明,该系统能够实现快速、稳定的数据传输,对配电房进行现场和远程的实时监控,其人机终端操作简单、界面美观、通用性强.经实际应用,该系统满足了配电监控的要求.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.