美国AIAA风洞试验管理标准与从业者标准浅析

本文归纳了风洞试验发展的历史背景,简述了美国AIAA风洞试验管理标准和从业者标准制定的过程和内容,重点阐述了标准中风洞试验的理念、管理和推荐的风洞试验具体做法,分析了标准中映射出的美国风洞试验技术的先进点,探讨了标准对改进国内风洞试验通常做法的启示。     

天然气流量量值溯源

天然气流量量值溯源是天然气流量计量准确和量值统一的关键环节。文章结合实际分析了天然气流量量值溯源所具有的特殊性,介绍了天然气流量量值溯源的重要组成部分,其中对国际上具有代表性的MT法、HPPP法和PVTt法天然气流量原级标准装置的工作原理、不确定度范围及应用进行了重点介绍,提出了增加核查标准装置和积极参加天然气量值国际比对活动对提高我国天然气流量量值溯源工作的重要意义,总结了天然气流量鼙值溯源的发展。     

制订军用瓦楞纸箱和瓦楞纸板国军标的认识和体会

介绍了军用瓦楞纸箱和瓦楞纸板国家军用标准（以下简称《标准》）制订的必要性和基本原则，详述了《标准》制订要求，简述了《标准》实施情况，提出了贯彻《标准》的建议措施。     

我国协会和联盟的标准化发展研究

本文正面提出了我国的民间组织制定民间标准的合法性问题,并进行了一定的探讨;对标准化界和我国学术界所作的讨论和基本观点作了简单回顾,对改革开放之后国内的协会和联盟标准化发展进行了梳理.作者认为,我国开始了从完全政府组织制定标准向政府和民间标准化共存的转型.这对我国市场经济转型的突破,提高产业竞争力具有非常重要的意义.     

标准数字化转型中标准标签集发展与应用分析

本文聚焦标准数字化转型中标准标签集这一关键技术,系统回顾了标准标签集从ISOSTS演变到NISOSTS的发展历程,并分析了两者的区别。随后围绕NISOSTS的组成,明确了标准标签集中元素和属性的特征及用法,并分析了和两种根元素结构。最后结合标准标签集在国内外的应用情况,分别介绍了相关典型案例,并指出NISO STS需要进一步引入语义更丰富的元素,从而增强标准的机器可读能力。     

浅谈“计量标准命名”（试行）

本文以在具体实施计量标准现场考核和复查工作和贯彻“计量标准命名”技术规范中，遇到的一些具体问题，就某些计量标准项目的名称命名，提出了一些见解。     

质检人员如何正确选择检测标准

本文主要介绍了标准的分类及检测人员如何选择正确的检测标准。     

国外标准中文版转化探讨及建议——以API标准为例

随着我国石油天然气工业和石油企业的国际化发展,对国外标准中文版的需求不断提升。本文探讨了在国外标准中文版转化工作中遇到的问题,通过总结和梳理,进一步提出了可改进建议。为后续我国国家标准采标国际标准及探索团体标准采用国外先进标准提供了切实可行的解决方案,也可以为中国标准外文版的质量提升提供经验和借鉴。     

标准情报专题服务

本文探讨了标准情报专题服务的基本方法、服务形式。     

认真落实《深化标准化工作改革方案》 努力开启标准化事业发展新征程——访质检总局党组成员、国家标准委主任田世宏

3月26日,国务院发布《深化标准化工作改革方案》(以下简称《改革方案》),强调了深化标准化工作改革的重大意义,明确了改革的指导思想、基本原则和总体目标,提出了一系列重大改革举措和政策措施,记者近日就相关问题采访了质检总局党组成员、国家标准委主任田世宏同志。问:国务院出台的《改革方案》是我国标准化事业发展进程中的一件大事,请您谈谈制定《改革方案》的重大意义。答:党中央、国务院高度重视标准化工作。2001年成立国家标准化管理委员会,加强标准化     

GLONASS时间频率传递研究

分析了基于GNSS的时间频率传递方法的发展趋势和GLONASS发展现状及趋势。对GLONASS时间频率传递进行了研究,就其原理实现、误差补偿及数据处理进行了阐述,实现了GLONASS时间频率传递的基本方法,实施了GLONASS和GPS时间频率传递实验。将两种时间频率传递结果进行了对比,对GLONASS时间频率传递自身性能进行了分析,结果显示:GLONASS时间频率传递已达到了可与GPS时间频率传递相比较的水平。     

Analysis of powder steel material,laser sintering technology and machining on surface parameters and fatigue

The technology of selective laser melting (SLM) is booming in all engineering applications today and tends to expand production of statically and dynamically loaded parts, not only for the prototypes but also for direct metal end–use parts. However, apart from design and type of loading, there still is a number of real material and technological parameters that contribute to the final quality of the produced parts and affect or improve the surface integrity and life of the parts. This paper expands the results and conclusions made in some previous works and presents all data from the tests expressed in their technological relations. The main conclusion is that a suitable machining process did not affect the surface integrity and fatigue of the tested samples, and the key role in assessments were the material structure, its homogeneity and defects.     

再论标准和标准化的基本概念

本文是作者再次对标准和标准化的概念进行讨论。首先讨论的是标准化的目的、主体和对象。作者认为标准化的目的是控制、有序化和统一化;标准化的主体是人/机构;标准化对象可以是具体的或抽象的事物,也可以是它们的组合;任何事物都可以抽象地表达为实体(entity)。第二,作者讨论了标准和标准化的本质以及它们的作用;认为从内容角度看,标准是匹配问题解决方案,也是为标准化对象规定需要满足的要求;从实施角度看,标准是规则;标准化则是制定、实施、传播标准的过程;标准的作用是能够创建并组织现实世界,并能够为相关方建立互相交流和共同理解的基础;标准化的作用是对创新方案进行选择和简化,阻止现实世界过度无序化发展,形成复杂化和简化之间的平衡。第三,作者讨论了标准的记录形式、自愿/强制属性和时空范围,认为标准的记录形式有文件、样品、图形符号、物理表达等多种形式;标准具有选择的自愿性和实施的强制性;标准在时空范围内是有限的。文章的结尾给出了理解标准化概念的框架。     

Dielectric properties of Na<Subscript>1-<Emphasis Type="Italic">x</Emphasis></Subscript>K<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>NbO<Subscript>3</Subscript> in orthorhombic phase

Pellets of ceramic Na_1−xK_xNbO₃ (x = 0, 0.2 and 0.5), were prepared by conventional solid-state reaction method. Prepared samples were characterized using XRD and SEM. The frequency and temperature variation of dielectric constant, loss tangent and dielectric conductivity of prepared samples were measured in the frequency range from 10 KHz-1 MHz, and in the temperature range from 50–250°C for x = 0.2 and 0.5, and between 50 and 480°C for x = 0 compositions. It was observed that the dielectric constant and loss tangent decrease, and conductivity increases with increasing frequency. Near the transition temperature the material shows anomalous behaviour for the observed properties, and the peaks of dielectric constant and loss tangent were observed shifting towards lower temperature with increasing frequency.     

Technik und Potenziale des Verschleißschutzes mittels thermisch gespritzter Beschichtungen

Technology and Potential of Wear Resistant Thermal Spray Coatings Thermal spray technologies are used for coating of component parts with a large variety of materials, e. g. for protection against wear and corrosion. During the last 20 years, the comparatively novel processes in thermal spraying have been established in surface technologies and will increasingly develop their market. Continuous equipment developments as well as new technologies for thermal spraying guarantee increasing importance of this technology, and will have a sustainable effect on industries with typical wear and corrosion‐caused problems. Therefore, thermal spray coated components possess an outstanding suitability and a high application potential for the construction of stone machining machines / plants and the mining industry (as well as associated vehicle and equipment technology), which still has hardly been developed in the area of mining industry and stone machining. A short introduction of thermal spray technology and processes and an overview is given for typical applications and already established coating solutions besides some recent examples from the area of stone machining and mining. This article shows the potential of thermally sprayed coatings as solutions for the stone machining and mining industry.     

Strength, Durability, and Safety of Engineering Systems

The evolution of approaches to the solution of machine dynamics and strength problems on the basis of determining static and dynamic nominal and local stresses of the operating load is discussed. It is shown how the material strength and plasticity characteristics, the cyclic strength characteristics in the high-cycle and low-cycle fatigue regions, the high-temperature long-term strength and creep characteristics, and the linear and nonlinear characteristics of fracture mechanics were sequentially used as the basic criterial parameters of the deformability and strength of structural materials. Particular emphasis was given to the results of studies on machine safety and catastrophe mechanics. Integrated approaches to the solution of strength and safety problems of potentially dangerous facilities (nuclear power stations, spacecraft complexes, aircraft, chemical plants, etc.) by analysis of all stages of their life cycle, including design, manufacture, testing, and operation, are discussed.     

江澳两地高校文创设计的协同研究与商业实践

目的 探索江门世遗文化的传承、发展和转化的新思路,践行国家在《粤港澳大湾区发展规划》纲要中要求江门承担与港澳地区文化创意合作与开发任务的分工。方法 与澳门高校紧密合作,开展专业培训课程,以开平碉楼为例,从人文视角开展设计研究,梳理开平碉楼的文化脉络,把世遗文化的元素和其背后的文化融入文创产品中,提升文创产品的附加值,推动当地文创产业结构的变革。结果 两地高校构建了稳定的科研团队,开设长期有效的设计培训课程,与景区建立了研究协作关系,帮助景区构建了一套产销研的商业模式。结论 以跨区域高校合作为平台,以文创产品为抓手,依托江澳两地的资源优势,可以构建江门世遗文化全新的品牌形象,最终推动开平世遗文化的活化。     

Entwicklung des Reibnietens als neues Fügeverfahren für Kunststoff und Leichtbaulegierungen

Development of FricRiveting as a new joining technique for polymer and lightweight alloys The increasing demand on environmental consciousness, cost savings and high performance end products has been guiding scientists and engineers to a constant development of new materials and technologies. This class of lightweight structures are specially used in industrial fields such as transportation and modern civil engineering. Currently available joining methods for polymer‐metal structures (adhesive bonding and mechanical fastening) are usually application‐specific, presenting high operational costs, limited mechanical performance or are not environmental friendly. A new Friction Riveting technique for polymeric‐metallic joints was developed, demonstrated and characterized in this work, as an alternative, reliable, environmental compatible and economically viable spot joining process. In the simplest process variant a rotating cylindrical metallic rivet is inserted in one or more thermoplastic base plates. The high rotation speed and pressure increase friction and heat is generated. When the preset time is achieved the temperature highly increases and the rivet tip plasticizes. At this point rotation is decelerated and the axial pressure increased, so the plasticized rivet tip becomes deformed; after cooling it becomes anchored in the polymeric base plate. In this work case‐study joints on commercially available polyetherimide (PEI) and aluminium 2024‐T351 (Al‐Cu‐Mg alloy) were chosen for demonstrating proposed theories and mechanisms of FricRiveting. Sound friction riveted point‐on‐plate and single‐rivet overlap joints with elevated joint efficiencies in terms of base materials strength were obtained (tensile joint efficiencies of about 97 % of the rivet strength and shear joint efficiencies of about 70 % of the polymer strength) through tensile and lap shear testing at room temperature. Finally, the microstructural changes and properties were described for this case‐study joint. The feasibility of FricRiveting was demonstrated in this work by the presented technical and scientific results. From this work it can be suggested that FricRiveting has the potential to be established as a reliable, simple, cost effective and environmental friendly joining technique for polymer‐metal components.     

A novel special distributed method for dynamic refrigeration system simulation

A novel dynamic mathematical model based on spatially distributed approach has been developed and validated in this paper. This model gives good agreement in predicting the system COP and other parameters. The validated model has been used to enhance the prediction of the micro variations of superheat and sub-cooling. The novel spatial distributed model for the condenser and evaporator in refrigeration system, calculates the two-phase region in gas and liquid field separately since the gas and liquid in the two-phase region have different velocities. Previous researchers have used a pre-defined function of the void fraction in their spatially distributed model, based on experimental results. This approach results in the separate solution of the mass and energy equations, and less calculation is required. However, it is recognized that the mass and energy equations should be coupled during solving for more accurate solution. Based on the energy and mass balance, the spatial distribution model constructed here solves the velocity, pressure, refrigerant temperature, and wall temperature functions in heat exchangers simultaneously. A novel iteration method is developed and reduces the intensive calculations required. Furthermore, the condenser and evaporator models have shown a parametric distribution along the heat exchanger surface, therefore, the spatial distribution parameters in the two heat exchangers can be visualised numerically with a two-phase moving interface clearly shown.     

Influence of Processing Temperatures on Mechanical Properties and Microstructure of Squeeze Cast Aluminum Alloy Composites

The paper deals with the influence of melt and die temperatures on the squeeze cast silicon carbide particulate reinforced aluminum alloy composites. Samples were produced at the following constant melt and die temperatures: melt—750, 800, 850, and 900°C; die—250, 300, 350, and 400°C. During the specimen fabrication, pressure was maintained at 100 MPa. The results reveal significant influence of both melt and die temperatures on the mechanical properties. The optimum melt and die temperatures for the preparation of the composite are 850°C and 350 °C, respectively. Tensile and impact strengths, and hardness of composite samples prepared at this temperature combination are found to be better than those of samples prepared at other temperatures. Additionally, microstructures of samples prepared at this temperature combination display a relatively fine grain structure and the smallest degree of particle agglomeration which explain the dependence of mechanical properties on the melt and die temperatures.