程控仪器设备在自动测试系统中的应用

随着计算机技术和智能化仪器的不断发展,具有程控功能的仪器设备在测试过程中被广泛地组成自动测试系统,本文介绍了具有GPIB、RS-232、RS-422/RS-485、GPIB/USB等接口仪器的自动测试系统的组成以及系统的特点,同时,还介绍了软件设计时应当考虑的问题。     

RS485／RS232智能型转换器的设计

提出了一种解决通用微机对由MCS－51系列单片机组成的主从式通讯网络进行远程信息查询和控制的方案，并设计了一种RS485／RS232智能型转换器。     

家用电磁灶能效测量自动控制系统

基于GB21456—2008《家用电磁灶能效限定值及能源效率等级》试验方法的要求,采用面向对象分析设计方法和UML规范,本文阐述了构建家用电磁灶能效测量自动控制系统的思路,提高了电磁灶能效测量准确性、稳定性、可靠性和工作效率,并给出了基于GPIB接口的功率计和RS232接口稳压电源的系统实例。     

用SCPI语言实现HP34401数字多用表的远程控制

应用SCPI语言通过RS232串口和GPIB接口实现对HP34401数字多用表的远程控制,分析了实现自动测试的设置步骤和实现方法。经实验测试,该方法大大提高了测量效率,实现了仪表的自动检测。     

VB编程实现对GPIB仪器控制及文档处理

一、GPIB系统设计 1.硬件构成 带有GPIB接口的数字仪器与装有GPIB接口卡的控制计算机通过24芯的GPIB电缆连接起来,设备间的连接方式有线型连接和星型连接,或者是两种连接的组合.一般情况下,一个GPIB系统最多可连接15个GPIB设备(包括控制计算机),通常是由一个控制器(一般是配置有GPIB板卡的计算机)和多个受控设备(各种带有GPIB接口的仪器)组成,实现综合测控.     

恒温箱类温度试验设备自动检测系统的设计

本介绍了用带RS－232接口的高精度数字繁用表、程控扫描器及笔记本电脑组成的恒温箱自动检测系统,并具体论述了系统的组建、工作原理、软硬件设计及设计中遇到的实际问题的解决方案。     

数控微波组件的工程测试方法

以数控衰减器为例,介绍了一种采用C builder编写控制程序,利用GPIB控制矢量网络分析仪对数控微波组件进行自动测试的方法。测试软件向基于RS232的通讯控制板发送控制码,通过GPIB总线接口从测试仪器获取测试数据,使用Matlab对数据处理后,对数据进行在线下载,实现对数控组件的自动化数据采集和自动化测试。该方法可提高组件的测试效率,提高测量结果的准确度,对工程应用有重要的现实意义。     

脉冲信号发生器自动检定/校准系统

脉冲信号发生器被广泛应用在电子测量和数据通信领域。利用Visual Basic高级语言，开发基于GPIB接口的脉；中信号发生器自动检定／校准系统。该系统能够完成对脉冲信号发生器的自动检定／校准，测量数据自动保存在数据库，实现检定／校准证书自动生成，利用网络打印检定／校准证书。     

谈对通信方案设计的探讨

文章介绍了目前最先进的C6000系列DSP与多路RS232、RS485／422设备通信的设计方案，并给出了软硬件实现实例。     

解析媒体矩阵（MediaMatrix）（五十一） NWare软件应用（13）——Python编程基础（续7）

（续“14系统备份的脚本任务”）上期讨论了两台主机是如何通过IP网络端口进行的备份,这是最常见的应用情况。但是在另外一些工程项目中,因为种种原因并没有安装以太网,或者用户觉得网络不安全。这种情况的解决方案就是利用NION主机的串口（RS232）间通信完成备份功能。基本原理就是任意一台NION主机都有两个串口（RS232和RS422／485端口）,     

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.……     

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.     

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...     

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.……     

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.     

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.     

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.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...