扫描随机振动应用于电路板的高效应力筛选

随机振动试验是高效应力筛选中的二个重要试验之一。本文介绍用扫描随机振动试验来进行筛选的方法,根据有关资料和初步实践定出激振标准,并对产品的电路板做了试验。     

电子元器件二次筛选及质量控制探讨

某单位就近年来开展电子元器件二次筛选及筛选中遇到的问题,对二次筛选的发展方向及如何控制电子元器件质量等方面问题进行了论述.     

离心试验在产品可靠性检验中的应用

根据离心试验的特点,分析离心试验的失效机理,从而确定离心试验对于在实际使用中经受恒加速度环境的产品在实验室环境中进行考核的必要性。另外,由于离心试验的"无损"特性,认为离心试验作为一种工艺筛选手段对批量产品进行筛选从而在早期剔除存在某些工艺缺陷的产品是非常有效的,因此离心试验与环境应力筛选类似,也可以作为产品出厂可靠性检验的一种筛选方式。     

电子产品高加速应力筛选的应用探讨

本文论述了电子产品高加速应力筛选试验的流程和方法,包括高加速应力筛选试验剖面设计和筛选验证等,并将该试验方法在某机载惯导产品进行了应用。这一方法对于其他机载电子产品的高加速筛选工作有一定的指导意义。     

HAST试验对塑封器件分层的影响分析

选取三种具有一定代表性的塑封产品,严格按照军用级标准GJB 7400对塑封电路筛选、预处理后,进行HAST试验摸底,验证HAST环境试验对国产塑封器件的影响,并提出军用塑封器件在设计时的注意事项。     

高效强应力筛选方法(ESS)(上)

本文介绍了美国军标发展起来的对产品应用温度循环和随机振动的高效强应力筛选试验方法,可有效地消除产品的早期失效,提高使用的可靠性。对这种筛选试验方法的含义、发展过程、基本组成、基本参数及应用情况作了较详细的介绍,可供我国有关军标和民用标准制订者和使用者参考。     

面向航天产品批次试验的温度循环剪裁方法研究

根据航天产品的特点,参考QJ 3138提出了温度循环应力筛选度与试验完成率的数学模型,给出了温度范围65℃、85℃、105℃以及温变率3℃/min、5℃/min下不同试验完成率对应的筛选度、残余故障率和残余故障率曲线曲率。给出了基于残余故障率曲线曲率极值和航天产品特性的剪裁策略,建议剪裁仅针对一般件进行,并给出了剪裁方法算例。研究成果对提高航天产品批次试验的效率和效益有重要价值。     

国内外温度试验及其标准分析

温度试验几乎贯穿于产品的研制和生产的各个阶段。在元器件的可靠性筛选(寿命筛选和应力筛选)、定型试验、型式试验以及验收试验中,都要做各种适当的温度试验。本文探讨温度试验的目的和种类、试验条件、标准对温度箱的要求以及发展趋势。     

通过优化环境应力筛选提高电子产品可靠性

本文对国内环境应力筛选相关的标准进行了研究,通过理论计算和实际产品的试验验证两个维度对环境应力筛选进行了优化.结合我单位电路板的实际情况,研究了组件级别温度冲击中温度保持时间,温变率,温度循环次数等因素.通过对几组电路板组件温度冲击筛选度的计算,提出了最优温度循环次数的试验设计方法.通过两箱法对我公司的通信电子产品进行...     

一种油田注水缓蚀剂的合成与性能评价

以不同长链脂肪酸、四乙烯五胺为原料合成油田注水缓蚀剂,通过正交试验筛选了最优合成条件。采用静态挂片法评价了产品的缓蚀性能,并考察了用量、温度对其缓蚀性能的影响。结果表明,试验条件下此类缓释剂在用量800mg/L、相对低温的条件下缓蚀效果较好。     

电子产品环境试验概述

电子产品环境试验是将产品置于典型的自然或人工环境条件下,用以鉴定产品在运输、贮存和使用中的环境适应性。环境试验在产品研制和生产各个阶段得到了广泛的应用,了解环境试验对设计人员和试验人员有着重要的作用。文中着重介绍了环境试验的分类与试验项目、环境试验的顺序的选择、环境试验的实施及国内环境试验存在的问题与建议。     

A mechanical pre-treatment process for the valorization of useful fractions from spent batteries

In this paper the authors propose a full-scale plant aimed to pre-treat spent batteries in order to obtain cleaned useful fractions (magnetic and non-magnetic metals, paper, plastic, a fine-sized material made of a metal-carbon mixture). The treating process was designed after having analyzed and tested a representative sample coming from the whole amount of spent batteries collected in 1 month by the public service in and around Turin. The analyses performed on the sample allowed the authors to determine its in-percentage composition in term of type of batteries: 60-70% b.w. (by weight) alkaline, 25-30% b.w. Zn-C and 5-10% b.w. other types. For each type, the composition in term of size (AAA or LR03; AA or LR6; C or LR14; D or LR20; 9 V or 6F22A; 4.5 V or 3R12A) has also been determined.The treatment for the recovery of secondary raw materials foresees the following phases:

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separation of useful types/sizes of exhaust batteries to undergo further treatments by means of a first sieving process;

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liberation of the single components taking advantage of a crushing operation;

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separation of a fine-sized material (to subject to pyro or hydro metallurgic recovery) from a coarse-sized material (to send to secondary smelt foundries and incinerators) by means of a second sieving phase.

On the basis of the results obtained from the crushing/sieving laboratory tests and the chemical characterization, a full-scale plant able to treat about 76,000 t/y of spent batteries has been designed. The cost analysis performed on the proposed treatment plant has given back a unit pre-treatment cost equal to 3€ per ton of processed spent batteries.     

Reusing pretreated desulfurization slag to improve clinkerization and clinker grindability for energy conservation in cement manufacture

The purpose of this study was to combine the physical pretreatments of grinding, sieving, and magnetic-separation processes to reclaim iron-rich materials from the desulfurization slag, and to use the remainder for cement clinker production. The iron-rich materials can be separated out efficiently by grinding for 30 min and sieving with a 0.3 mm mesh. The non-magnetic fraction of the particles smaller than 0.3 mm was in the majority, and proved to be suitable for use as a cement raw material. The raw mixes prepared with a pretreated desulfurization slag had a relatively high reactivity, and the temperature at which alite forms was significantly reduced during the clinkerization process. The clinkers produced with 10% desulfurization slag had a high level of alite and good grindability. Generally, the improvements in clinkerization and clinker grindability are beneficial to energy conservation in cement manufacture.     

Preparation and characterization of carbon-enriched coal fly ash

Carbon-enriched fractions have been obtained from two coal fly ash (FA) samples. The FA came from two pulverized-coal fired power stations (Lada and Escucha, Spain) and were collected from baghouse filters. Sieving was used to obtain carbon-enriched fractions, which were further subjected to two beneficiation processes: acid demineralization using HCl and HF, and oil agglomeration using soya oil-water. Yield in weight after sieving, unburned carbon content, and several physicochemical characteristics of the obtained fractions were used to compare the performance of the beneficiation methods. Low carbon concentration was obtained by sieving, particularly in the case of Escucha FA. However, after acid demineralization or oil agglomeration, fractions containing unburned carbon in a range of 63% to 68% were obtained. These fractions showed differences in mineral phase composition and distribution depending on the FA and on the beneficiation method used. The textural properties of the obtained fractions varied as a function of their carbon content and the beneficiation method used. However, no significant differences in morphology of the carbonaceous particles were found.     

电工设备高原环境适应性与标准体系建设研究

介绍了电工设备高原环境适应性研究与标准制定的进展,提出高原环境条件下的模拟试验仍然是检测高原电工产品性能的有效手段.建立地方标准和企业标准体系,是发展高原特色电工产品的重要内容.     

电工电子产品抗霉性能分析与评价

简要概括了霉菌对电工电子产品的作用机理与影响,指出了现行霉菌试验标准和产品技术文件中关于产品抗霉性能评价存在的问题,并从长霉等级评定方法和产品合格判据两方面就如何正确、合理地评价产品的抗霉性能提出了自己的看法.     

HALT试验技术的研究

高加速寿命应力试验（HALT）,是一种通过施加阶梯强化应力于试品,达到快速发现产品潜在缺陷,操作设计边际及结构强度极限的试验方法,主要应用于产品研发设计阶段。由于该方法效果明显,目前已越来越多的电子电气产品制造商认可并推广使用,成为研发设计工程师提高产品可靠性的重要试验手段。本文简要介绍HALT试验的目的,并结合实际,探讨了HALT试验设备的关键性能指标。另外,基于日常实践经验,重点分析和讨论了HALT试验过程中应该关注的一些技术处置措施,从而帮助测试人员正确执行HALT。     

The influence of iron flow on iron resource efficiency in the steel manufacturing process

An iron resource efficiency is proposed to define a measure of the natural iron resources saved in the steel manufacturing process. A simplified iron flow diagram is presented for the steel manufacturing process. The influences of various deviations in iron flow from the simplified iron flow diagram on iron resource efficiency are analyzed. The relationships between iron resource efficiency of unit processes and the final product are also discussed. As an example, data from a steel plant are used to analyze the influence of iron flow on its iron resource efficiency of finial product in the steel manufacturing process, the influence of iron resource efficiency of unit process on iron resource efficiency of the final product, and give some measures to improve the iron resource efficiency of the steel manufacturing process.     

Super—CM利水净处理生活污水的试验研究

Ｓｕｐｅｒ－ＣＭ利水净是利用ＭＡＢ技术研究成功的一种用于治理水污染的新产品。本文介绍了Ｓｕｐｅｒ－ＣＭ利水净结合活性污泥法处理生活污水的一则现场试验案例。试验结果表明,在活性污泥法中加入Ｓｕｐｅｒ－ＣＭ利水净能够有效的提高污水处理能力,在试验后期进水增加３０％的情况下,ＣＯＤ、ＳＳ的平均去除率仍然分别提高了８．７％、４．１％。     

油田污水过滤罐含油污染滤料再生技术

大庆油田污水处理系统产生的含油污染滤料,经过含油污染滤料再生工艺化学清洗、烘干、分筛、磁浮选等程序处理后,各种再生滤料重复使用于油田污水处理系统,清洗过程中产生的污水经自然沉降、旋流除砂、重力式过滤、杀菌和有机物降解处理后循环使用。减少油田含油污染滤料带来的环境污染,为油田节约了新滤料采购费用、废旧滤料集中堆放和处置费用。