A review of the existing performance verification infrastructure for micro-CMMs

The performance verification of micro-CMMs is now of intense interest because of their capability to perform length measurements in three dimensions to high accuracy with low uncertainties. Currently, verification of micro-CMMs is completed in the spirit of existing specification standards, because strict adherence to these standards is often difficult. This review aims to present and discuss verification techniques available for micro-CMMs: specification standards, existing calibrated test lengths and traceability routes that can be associated with micro-CMMs. Three specification standards used in the testing of CMMs will be considered. In addition, a wide range of calibrated test lengths are reported, and any advantages and disadvantages associated with their use are discussed. It is concluded that micro-CMMs cannot yet be verified in accordance with existing specification standards. Suggestions are made for future standardisation work required to rectify these issues.     

结冰风洞校准标准研究

本文按结冰风洞制冷方式、试验对象、用途性质和试验段尺寸归纳总结了结冰风洞的类型,指出校准标准主要针对的结冰风洞类型;阐述结冰风洞空气动力流场校准可以依据的3个国内外标准;介绍SAE结冰风洞校准标准中云雾场校准的主要内容;分析研究相关标准的特点和存在的不足;提出未来我国制定结冰风洞校准标准的建议。     

一次性使用医用手套标准解读

一次性医用手套是能够防止人们交叉感染的常用防护用品。随着新冠肺炎疫情在全球范围的迅速蔓延,疫情防控一线以及广大普通民众对一次性医用手套的需求与日俱增,其标准也受到广泛关注。本文对中国国家标准涉及一次性使用医用手套的4项产品标准进行了解读,并分析它们与国外同种产品标准间的对应关系以及重点指标的差异。     

澳大利亚“基于能力本位的评估”模式及对我国高职教育 质量评估的启 示

澳大利亚职业教育在全球享有较高的声誉,这与其坚持严格的"基于能力本位的评估"(competency based assessment, CBA)密不可分。介绍了澳大利亚CBA的内涵特征,并详细描述"准备评估、开发评估工具、开展评估、对评估结果进行评估"的CBA运作过程,关注评估工具的开发和后续常规系统性检查及完善,以期对我国的高等职业教育质量评估起到启示和借鉴作用。     

汽车计算平台工程国外相关标准概述

结合我国汽车计算平台工程,分析了国外相关的标准现状和基本框架,并为今后工作的开展提出了建议.     

有线电视系统工程的招标

针对有线电视系统工程建设的特点，依照《招标投标法》的规定和程序，对有线电视系统工程招标的种类、招标方式、招标工程必备的条件、标底的编制及审定、开标、评标和中标的原则进行详细介绍，对招标文件的编制进行具体说明。     

Display reflectance: Basics,measurement, and rating

Abstract— In this paper, methods and instruments for measurement and evaluation of reflection characteristics are reviewed as needed for research and development of electronic displays and for material and surface modeling with ray‐tracing and rendering software packages. Contrast under ambient illumination and recognizability under daylight illumination are prime development targets in the electronic‐display field, while computation and synthesis of realistic scenes and objects are pushing the need for physical data in computer graphics applications. Three categories of instruments are available for detailed reflection analysis. They are based on (1) gonioscopic (mechanical) and conoscopic (optical) directional scanning, (2) imaging approaches, and (3) on arrangements with variable source or receiver aperture. The capabilities, advantages, and limitations of these methods are introduced and discussed in order to facilitate appropriate selection of methods and instruments. For illustration purposes we present typical results obtained from commercial electronic display screens. A basis for continued widespread implementation and standardization of reflection metrology as required for objective rating and comparison of electronic‐display screen performance under ambient illumination is provided.     

Study of liquid injection impact on the performance of new refrigerant mixtures

In this paper, the test results of liquid injection impact on the performance of new alternative refrigerant mixtures such as: R-410A, R-507, R-407C and R-404A are discussed, analysed and presented. The test results were obtained using an air-source heat pump set-up with enhanced surface tubing under various liquid injection ratios. Performance tests were conducted according to the ARI/ASHRAE standards. The performance data demonstrated that as liquid injection ratio increases, compressor head pressure and discharge temperature decrease. This has a positive effect in protecting the compressor. The effect of liquid injection on mixture behaviour varies from one mixture to another depending upon the mixture's composition. Furthermore, liquid injection appears to have a significant influence on R-410A behaviour compared to the other mixtures in question. Copyright © 2002 John Wiley & Sons, Ltd.     

对单位工程竣工验收资料核查要点的探讨

针对竣工资料核查工作中遇到的一些常见和普遍存在的问题进行了分析、探讨，指出单位工程竣工资料的核查应以核查基建程序资料、综合管理资料及质量保证资料为重点。