基于CAN总线的条码扫描器管理系统

传统的数据采集系统一般采用485作为组网方式,485本身存在很大的局限性,总线效率低、系统的实时性差、通讯的可靠性低、后期维护成本高、网络工程调试复杂、传输距离不理想、单总线可挂节点少、应用不灵活等。基于CAN总线的数据采集系统解决了485网络的固有问题,CAN总线是国际上应用最广泛的现场总线之一。该系统采用Philips的基于ARM的带有CAN控制器的LPC2364作为主控制器,实现数据实时的采集。通过功能强大的数据管理软件,实现库存、生产、财务等多个生产过程信息化,方便信息管理、维护及查询。     

RS485总线时分复用实现地震数据并行同步采集

为解决数字垂直地震剖面(vertical seismic profilingr,VSP)系统中各采集节点间同步性差、布线复杂等问题,提出一种基于RS485总线时分复用技术实现地震数据并行同步采集的设计方案。方案中各采集节点均并行挂接在RS485总线上,选择RS485的通信B线作为同步信号线,将其与各采集节点的控制器中断口相连接。数据采集时,首先将同步采集指令通过通信B线以广播方式发送到各采集节点,实现各节点同时启动ADC转换,然后通过RS485总线将采集的数据传送到采集站,最后由采集站通过以太网将数据传送到上位机,实现地震数据的并行同步采集。实际应用表明:该方案不仅提高采集节点间的同步性,还提高系统的可靠性,同时也减少系统布线。     

基于PCI总线的LON网络适配器的设计

讨论了一种基于PCI总线的LON(local operating network)网络适配器的设计方法,实施了采用双口RAM实现Neuron与PC接口的技术,描述了LonWorks网络与PC通信所需的硬件设计电路和软件实现过程,提供了网络适配器的驱动程序开发方法．目前该网络适配器为PC与LonWorks网络之间的接口提供了有效支持。     

基于CAN总线的PLC与组态王通信的实现

为了完成基于CAN协议的可编程控制器与KingView的通讯,以高性能AVR单片机为处理器设计实现了CAN总线协议与MEWTOCOL-COM协议转换的数据适配卡.PC机通过CAN总线控制PIC,并将PLC采集到的状态信息送回PC上的组态王软件处理,完成状态监测.实验结果表明,该系统具有良好的实时性、可靠性和实用性.     

基于PROFIBUS的复烤能源数据采集管理系统设计

根据复烤能源数据采集与管理的特点及需求,采用PROFIBUS-DP/PA总线、PC-Base控制器WinAC、智能仪表构建了能耗采集系统.对生产班组的水、蒸汽、压缩空气累计能耗进行统计计算,并利用WinCC组态了生产能耗实时监控程序.在此基础上,开发的归档程序实现了能耗数据的长期存储,并利用C#开发了能耗报表自动生成系统.实现了分布式、多级能源采集与优化管理系统.     

基于W5100的网络化门禁管理系统设计

为实现分散式门禁控制器的集中管理,研制了一种基于W5100的网络化门禁管理系统．门禁控制器核心采用低功耗MSP430F149,与上位机的实时通信利用嵌入式以太网硬件协议栈W5100芯片实现．门禁管理软件采用VC++.NET设计开发,远程数据传输通过非对称式的客户端/服务器通信模式和面向连接的流式套接字来实现．该系统传输数据可靠,抗干扰性强,且支持电池供电,解决了市电故障带来的门禁锁死问题．     

基于can总线的温度采集与显示系统

介绍基于CAN总线的智能温度传感器DS10B20的设计。系统以单片机AT89S51作为处理器,DS10B20数字温度采集器采集温度数据。单片机接收并处理数据,LED数码管分时显示温度值。通过外扩的CAN总线控制器SJA1000和报文收发器PCA82C250,该控制器可直接作为CAN总线的一个从结点工作。     

基于PCI总线和CPLD的高速数据采集卡

为了实现对传感器信号的采集和数据分析,根据PCI总线的数据采集系统的设计思想,采集系统以PCI9054和CPLD相结合来实现信号的连续采集与数据传输的控制,PCI9054实现本地端与PCI端的桥接使用户接口设计简洁,CPLD实现数据缓存控制和读取控制,实验结果表明,该数据采集系统操作简单、实时性强、性能稳定,可实现对所需信号高速连续的数据采集.     

用VB6．0程序控制基于LonWorks总线的道岔融雪控制模块

在VB程序开发中,可以通过LonWorks总线的LNS技术,对基于Lonworks总线的关键芯片NeuronChip设计的控制模块进行编程以实现实时通讯控制,达到计算机程序对外部设备的控制和通信。本文通过这种方式可以充分进行对道岔融雪系统中融雪控制模块信息的传输与控制。     

基于PCI总线的激光粒度测量系统

本文设计了基于PCI总线的激光粒度测量系统,采用专用接口芯片S5933与CPLD相结合的方式实现PCI总线接口的设计,用CPLD开发了PCI数据采集的ADD-ON逻辑,通过DMA方式实现粒度测量系统数据由ADD-ON总线向PCI总线的传输,充分利用了PCI总线的高性能、高可靠性等特点,为激光粒度测量数据的实时采集、显示、处理提供了可靠的保证。     

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.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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.     

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.……     

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.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

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.……     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.