CSUT—88弹性合金的应力松弛特性EI

一、前言 应力松弛是材料在高温条件下长期使用过程中经常出现的现象,即具有恒定总变形的材料随时间的延长,其应力自行降低。作为导电弹性材料,应力松弛特性已日益引起人们的关注。众所周知,电连接器的可靠性是系统、整机可靠性的基础。随着航空航天事业和计算机技术的发展以及核能的开发,系统的工作条件对所有元件的要求,特别是对一些长期在中温和高温下使用的导电弹性材料的稳定性和可靠性的要求越来越苛刻。象导弹。     

压电元件驱动的功能梯度弹性薄板的屈曲

考虑功能梯度薄板,其上下表面嵌有压电执行元件.根据逆压电效应将电压转换成作用于板上的等效电载荷.假设梯度材料的弹性参数为板厚度方向坐标的幂函数,基于经典板理论,导出了功能梯度弹性薄板小挠度屈曲平衡微分方程.利用双三角级数展开法,得到了四边简支具有压电元件的功能梯度矩形板的临界屈曲载荷,在此基础上通过数值例子讨论了弹性板的几何尺寸、材料梯度指数的变化对临界电压(载荷)的影响.研究结果表明,材料的梯度指数对临界电压有重要影响,并且通过调整作用于执行元件上的电压的大小和方向,可实现对结构稳定性的有效控制.     

仪表弹性敏感元件稳定化处理方法的研究

仪表弹性敏感元件的时间稳定性取决于以下三个基本要素: 第一,弹性敏感元件用合金的弹性极限与在使用过程中该元件产生的最大应力的关系;第二,弹性敏感元件用合金的抗蠕变性能和组织状态的稳定性,这两种因素能保证合金在弹性敏感元件的使用过程中体积、弹性模量和弹性极限不发生变化或者变化甚微;第三,弹性敏感元件残余应力的大小。所以,旨在获得弹性敏感元件最低不稳     

γ-Al2O3基纳米陶瓷气敏元件稳定性研究

报道对采用纳米粉料制作的γ-Al2O3基气敏元件的稳定性的研究结果。分别采用纳米粉料和微米级粉料制备了γ-Al2O3基气敏元件,该气敏元件对碳氢化合物还原性气体敏感;连续17个月测定了这些气敏元件对甲烷的气敏特性;通过XPS等技术分别在3个阶段对这两种元件的表面化学元素含量进行了表征。结果表明,元件失效的原因之一是由于在气敏反应过程中由于部分反应产物在表面沉积造成表面活性位减少,并导致吸附能力下降所致;而元件失效或不稳定与使用过程中元件表面有沉积物有关。通过以上研究工作,找出了利用纳米粉料制备气敏元件失效快和长期工作稳定性差的部分原因,为该类材料的进一步发展提供实验依据。     

精密级锗霍耳元件的设计与制造(英文)

锗霍耳元件是比较老并逐渐被人们所忽视的元件,但它比化合物半导体元件具有更好的稳定性,经过精心设计可以制成性能良好的元件。本文通过对锗性能的分析,给出选择材料和晶体切割方向以及封装工艺,以制造精密级锗霍耳元件的方法。我们利用这种元件制成了大电流测量装置,获得如下结果:线性度—0.1%;稳定度—0.1%/年;温度系数稳定性—0.01%/℃。     

聚合物弹性印章的制作工艺

为了解决软光亥4技术中核心元件弹性印章的制备技术,对SU-8胶印模和聚合物弹性印章进行了工艺研究．通过多次实验和测量,获得了制作SU-8胶印模和聚合物弹性印章的稳定工艺参数,得到了表面形貌好、线条控制精确的SU-8胶印模和聚合物弹性印章样品,弹性印章特征线条尺寸在长宽高方向上为70mm×50μm×42μm,完全可满足软光刻技术要求,这为软刻蚀技术的进一步开发打下了良好的基础．     

CSUT—88弹性合金的应力松弛特性

一、前言 应力松弛是材料在高温条件下长期使用过程中经常出现的现象,即具有恒定总变形的材料随时间的延长,其应力自行降低。作为导电弹性材料,应力松弛特性已日益引起人们的关注。众所周知,电连接器的可靠性是系统、整机可靠性的基础。随着航空航天事业和计算机技术的发展以及核能的开发,系统的工作条件对所有元件的要求,特别是对一些长期在中温和高温下使用的导电弹性材料的稳定性和可靠性的要求越来越苛刻。象导弹、地缆和同步卫星等现代电子系统中的电连接件要求无故障工作时间一般     

弹性石墨体的开发

炭材料具有重量轻、耐热性等其它材料所不具备的特性。因此在许多领域作为工业材料使用。最近正在开发新的制造方法,控制产品的物性及具有新结构和功能的材料,也在开发新的用途。本文介绍炭材料中具有尚未被明确认识的所谓弹性的粒状石墨,即弹性石墨体的制造和性状。     

丝材剪切模量、剪切模量温度系数、内耗测试装置及性能试验

一、前言仪器仪表中的金属弹性元件在工作中处于扭转受力状态时,了解其在扭转变形的弹性和滞弹性性能是十分重要的,这些性能是选材和元件设计的依据。例如,高精度张丝电表的设计和相应的材料研究,要求张丝元件和张丝材料的弹性性能对温度的稳定性好,从而降低电表的测量误差。金属及合金的滞弹性性能对组织结构十分敏感。尤其是内耗能反映材料中许多物理过程的本质。采用一种适当的方法和仪器可以较方便和较精确地测定内耗。丝材的剪切模量及其温度系数、内耗的测量绝大多数都采用扭摆法。检测方式有用     

超弹性材料过盈配合的轴对称平面应力解答

主要讨论了一种采用超弹性材料轴对称过盈配合的橡胶减震元件,推导了橡胶材料过盈配合平面应力的大变形解析解,并应用 ABAQUS 有限元软件进行数值模拟,分析和对比了解析解和数值解的结果,定量分析材料泊松比和体积刚度对问题的影响。     

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.……     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

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.