LabVIEW环境下的GPIB总线虚拟仪器开发

LabVIEW是当今最流行的虚拟仪器开发平台 ,文中介绍了用LabVIEW开发基于GPIB总线的虚拟仪器的全过程及其硬件和软件要求 ,并给出了一个开发实例。实例为用LabVIEW虚拟仪器开发平台对一台带有GPIB接口磁测量仪进行二次开发 ,构建自己的虚拟仪器。与台式仪器相比 ,该虚拟仪器最突出的优点是不需要其它数据采集卡便可完成磁场的实时采集测量 ,并将采集结果保存到文件 ,以供后续分析使用 ,从而大大扩展了原有台式仪器的功能     

在LabVIEW环境中实现频谱分析仪计算机控制

本文介绍了运用GPIB接口和虚拟仪器开发平台LabVIEW设计开发的HP8563E频谱分析仪的计算机控制软件,实现了HP8563E频谱分析仪的计算机控制,扩展了HP8563E的功能.     

虚拟仪器在电学校准计量平台中的应用初探

虚拟仪器技术是利用PC机软件和相应的硬件板卡、传感器实现传统仪器功能的技术,文章基于美国NI公司的LabVIEW虚拟仪器技术,使用LabVIEW软件和相对应的PCI—6024E数据采集板卡对虚拟仪器在电学计量中的应用进行了初步的设计和研究。     

一种增强虚拟仪器软件数据共享性的方法

在介绍虚拟仪器及其开发环境LabVIEW的特点的基础上,分析了LabVIEW与外部程序代码接口的途径,并着重实现了将LabVIEW与外部代码进行连接的高级技术之一——动态链接库机制。实践表明,此机制高效、易行,是增强LabVIEW与其它Windows应用程序之间数据共享能力的一条很好的途径。     

abVIEW外部代码接口技术的研究与应用

LabVIEW是一种功能强大的图形化虚拟仪器编程软件,广泛应用于仿真、数据采集、仪器控制、测量分析等嵌入式应用系统的开发。然而,在需要进行大量数据运算处理和数据采集时,LabVIEW显得有些力不从心。为此,本文研究了LabVIEW外部接口技术,提出了LabVIEW与其他软件之间接口的方法。并且通过举例验证了各种方法的可行性,从而有效的解决了问题。     

基于LabVIEW的高速DA转换系统

针对高速DA转换系统设计难度高、工作量大的状况,根据虚拟仪器设计思想,设计实现了基于LabVIEW的高速DA转换系统.该系统利用USB接口从PC接收波形数据包,在主控制器FPGA解析数据后,从高速DA芯片产生优质模拟信号.实际使用情况表明,该系统满足绝大部分科研、教学的要求,并且只需修改LabVIEW软件.就可以实现诸如信号发生器、雷达模拟器等不同功能.     

LabVIEW外部代码接口技术的研究与应用

LabVIEW是一种功能强大的图形化虚拟仪器编程软件,广泛应用于仿真、数据采集、仪器控制、测量分析等嵌入式应用系统的开发.然而,在需要进行大量数据运算处理和数据采集时,LabVIEW显得有些力不从心.为此,本文研究了LabVIEW外部接口技术,提出了LabVIEW与其他软件之间接口的方法,并且通过举例验证了各种方法的可行性,从而有效的解决了同题.     

基于LabVIEW的气体微流量测量虚拟仪器的开发

运用LabVIEW6．1开发了用于气体微流量测量的虚拟仪器，阐明了该虚拟仪器的硬件结构、软件设计思想和具体实现，结合实验数据对不确定度进行了分析。该系统具有测量精度高、界面友好、运行稳定可靠、功能便于扩展等特点。     

HP3458A数字万用表的计算机控制

为实现对HP3458A数字万用表的计算机控制，利用了虚拟仪器开发平台LabVIEW和GPIB接口，设计了基于GPIB、VISA和IVI的三种编程方法。试验表明，这些方法简单实用。     

如何运用LabVIEW设计汽车油罐车液位监测装置

正本文依据JJG133-2005《汽车油罐车容量检定规程》,介绍如何运用虚拟仪器软件LabVIEW设计开发汽车油罐车液位监测装置的控制系统。系统为利用计算机通过USB接口与准确度高的磁致式伸缩液位计进行数据通信,通过编程在计算机上实现实时显示测量结果,使用LabVIEW进行数据存储和打印的自动检测装置。     

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.     

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.……     

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 ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.