基于FPGA+DSP的GPIB接口设计

简要介绍GPIB的接口规范,阐述GPIB专用芯片NAT7210APD的基本原理和功能,给出基于FPGA+DSP的GPIB接口的硬件设计方案和基本软件控制流程。     

一种温湿度综合试验系统的研究与设计

研究与设计了一种采用GPIB总线技术和虚拟仪器技术的温湿度综合试验系统，给出了硬件设计原理和软件设计方法。     

基于GPIB接口的时钟测试仪内部晶振频率自动测试系统

介绍时钟测试仪,给出了基于GPIB接口的时钟测试仪内部晶振频率自动测试系统的硬件平台构建和自动测试实现方法,并详细讨论了实现过程中仪器控制、数据采集、数据处理和输出实现,最后给出了性能分析。     

3330B恒压／恒流源的GPIB标准接口

本文介绍了用单片微计算机芯片和GPIB专用接口芯片为Fluke 3330B恒压/恒流源实现GPIB标准接口的方法。它同时也为类似的不具有GPIB标准接口的可编程仪器设计GPIB标准接口提出了一种可供参考的方法。     

用VB开发基于GPIB接口技术的测控程序

文章以设计YS87B多功能可程控标准源虚拟面板为例 ,介绍了在WINDOWS操作系统环境下 ,用VB开发基于GPIB接口技术测控程序的方法 ,并给出了部分源代码     

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.     

一种基于PXI/GPIB混合总线的无人机自动检测系统

本文介绍了一种基于PXI／GPIB混合总线的无人机地面自动检测系统，给出了系统的硬件和软件结构以及工作流程。该系统可显著提高无人机综合检测的测试精度和效率，具有良好的使用性能和价值。     

USB-GPIB控制器的VISA设计与实现

本文阐述了基于USB总线的GPIB仪器控制器的设计思想，提出系统的整体构架和实现方案。目前很多采用GPIB接口的测试测量产品都可以让用户调用VISA函数来编制自己的软件程序，本文重点介绍了该控制器的软件部分的VISA设计，VISA函数的基本结构，概述了VISA函数的总体设计思想，即PC机对该控制器的驱动程序、VISA调用、动态链接库以及应用程序的编写过程，并给出了实现方法。     

试述GPIB总线虚拟仪器的系统设计

文章结合作者实际工作,简要介绍了GPIB技术及GPIB总线虚拟仪器,在此基础上,结合案例阐述了实验软件编程的操作过程,得出结论:通过编程把适当的GPIB命令通过两个Ⅵ发送给仪器或者接收仪器返回信息。最终确定为使用GPIB总线的虚拟仪器在使用中比较方便。     

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     

Reflections on the fable of the caliph,the ten architects and the philosopher

This paper discusses whar are the proper criteria for decision-making in planning and design. A parable introduces three principles by which to justify decisions: the principle of indifference or chance, the principle of absolute truth and the principle of idoneity, where the idoneus is ‘that which is proper to, and conforms with, the ends and intentions’.     

Letter to the editor: Revisiting the h-index and the p-index

Scientometrics - In this Letter to the Editor we revisit the h-index, which is a heuristic construction and the mock h-index (also known as the p-index) which is derived from analytical...     

History of cryogenics: the epoch of the pioneers from the beginning to the year 1911

The invention of the thermometer by Galileo in 1592 may be considered as the start of the science of thermodynamics. Guillaume Amontons predicted for the first time the existence of an absolute zero in 1702, which marks the beginning of the science of low temperatures. Around 1780, the liquefaction of a gas was achieved for the first time. It took almost another 100 years before a so-called “permanent” gas, i.e. oxygen, was successfully liquefied. Thereafter Linde and Claude founded the cryogenic industry, which today has annual sales of more than 30 billion US $. Kamerlingh Onnes and his Cryogenic Laboratory in Leiden worked in the field of low temperature physics, which contributed to the experimental proof of the quantum theory.     

UNEP assesment of the Montreal protocol: Refrigeration within the framework of the technology review

In order to provide a scientific and technological basis for adjustments and amendments to the Montreal Protocol (which was conceived and adopted in 1987), a large number of reports were made by international experts in 1989. These reports are used in the assessment procedure which takes place in the period June 1989–June 1990, after which period final decisions will be made by the Contracting Parties in the so-called ‘Second Meeting of the Parties’. In this contribution the assessment process and the time schedule of the whole procedure is described. One of the Panel Reports centres on a Review of the Technology; conclusions from this report are presented. In its turn, information in this report is based on sector reports, one of which is the Options Report ‘Refrigeration, AC and Heat Pumps’. Specific topics dealt with in this sector report are presented here. Some concluding remarks on the findings presented in the reports and on possible future reassessments are given.     

染机换热器管板裂纹成因分析及控制

本文从实际例证入手,通过对管板材料成分、设备使用介质等项目的检测结果,分析得到了染机不锈钢换热器管板裂纹产生的原因,并提出了避免裂纹产生的控制措施。     

一种检测平晶和透镜面形的方法

介绍了数字式激光平面干涉仪的测量优势,阐述了利用其进行平面和球面面形的测量方法,弥补了传统平面等厚干涉仪只能测量平面平晶的不足。同时分析了影响测量结果的几个因素,并利用ZEMAX软件模拟平晶位置,观察干涉条纹。     

Aberrations of Spectrographs with the Correction of the Schmidt Camera Effected in the Collimator

Of the different ways to introduce the Schmidt correction of the camera in a spectrograph, the case was studied in which it is effected in the collimator. Equations which describe the form of the wave-front at one side of the grating as function of the form at the other side were found. The sixth-order terms in the correction to compensate for the deformation of the wave-front in the path from the collimator to the grating and to the mirror were also found. The aberrations for a correction which is symmetrical around the collimator axis were calculated. The limit of camera aperture for which these aberrations are tolerable is between F/D=4 and F/D=3 according to the size and number of lines of the grating.     

疏水性白炭黑在硅橡胶海绵中的应用研究

研究了表面疏水处理对白炭黑在硅橡胶及其海绵材料中的分散效果及其增强作用的影响.研究表明:表面疏水处理改善了白炭黑在硅橡胶中的分散均匀性,提高了胶料的可塑性,有利于胶料发泡,使硅橡胶海绵的表现密度降低;而表观密度降低导致硅橡胶海绵的硬度、拉伸强度、延伸率、压缩应力松弛减小.     

Materials science education in the USA and the UK: the industrial influence

Abstract

A short account is given of educational developments in materials science in the USA which have led to the introduction of more broadly based courses, interdisciplinary studies, and stronger links with industry. The objectives of Materials Research Laboratories, which do not themselves seek industrial funding, is contrasted with the new Materials Research Centers which actively seek industrial participation and finance. Such developments have features in common with the Interdisciplinary Research Centres currently being established in the UK. Finally, a tribute is paid to the many contributions made by Sir Alan Cottrell to education in the materials field.

MST/1312     

用考虑置信区间长度影响的最小二乘法拟合S－N曲线

S－N曲线是用名义应力法预测结构疲劳寿命的基础。基于试验疲劳寿命分散的物理机制,提出了一个S－N曲线试验数据处理的加权最小二乘法,此方法中每组数据的权重与该组数据的置信区间成反比。计算结果表明用考虑置信区间长度影响的最小二乘法拟合得到的S－N曲线比用一般最小二乘法得到的S－N曲线具有更高的可靠度,给出的寿命预测结果也更安全。