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从研究开发HALT试验的背景出发,介绍了进行HALT试验的基本原理及其意义,并说明了该试验设备的各组成部分。同时指出了HALT试验可分为四个分段试验过程,对其分别进行了阐述,最后对HALT试验的实施步骤进行了分析,认为该试验是一个重复试验-失效-失效分析-改进并维修-再试验的过程。开展HALT试验技术及其应用的研究与工程实践,可在产品设计阶段快速消除设计缺陷,缩短研发时间和成本,迅速提供产品的质量和固有可靠性。 相似文献
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本文提出“产品可靠也是试验出来”的新观念,这就把可靠性环境试验提高到与产品的设计、加工、使用维护同等地位,这一观念的提出,对试验技术的研究发展不无好处.作者还将十种试验进行分析比较,将试验分为对产品固有可靠度无直接贡献的评值性试验和对产品可靠性有着很大贡献的可靠性增长、可靠性恢复的试验,支持其论点 相似文献
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利用氧化诱导期法(OIT)探讨在相同试验温度,不同试验条件下对HDPE的氧化诱导时间的影响,研究总结了样品厚度,样品形状,试验气流,坩埚是否加盖对其试验结果的影响。以方便测试时选择适当的测试条件,即能提高测试方法效率又能使测试结果尽可能真实反映材料本身的抗氧化能力。 相似文献
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为了研究功率三极管在热带海洋-寒冷环境时序影响效应,采用热带海洋环境和寒冷环境时序试验的方法,将试验件放置于棚下机箱内模拟其使用环境,开展自然环境试验工作。试验过程中,定期对样品分析其外观及功能性能变化情况,样品在完成5个月寒冷大气和5个月热带海洋环境试验后,出现致使ICBO和ICEO参数超差现象,通过失效分析发现,导致功率三级管失效的原因为CI离子引起管壳局部腐蚀,生成氧化产物,导致引脚间漏电,上述试验结果可为其热带海洋-寒冷环境适应性设计改进提供技术支撑。 相似文献
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本文简述运输环境和试验条件的制订对模拟运输试验的各种方法作了简单评述,尤其是对利用电子--液压振动台对大型整体产品在悬臂梁状态的试验作了介绍。最后说明一种能模拟带有高峰值随机振动的试验技术,以改进现有数控设备的不足。 相似文献
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用数控电子─液压振动台模拟整体大件产品的公路运输试验 总被引:1,自引:0,他引:1
本文简述运输环境和试验条件的制订。对模拟运输试验的各种方法作了简单评述 ,尤其是对利用电子─液压振动台对大型整体产品在悬臂梁状态的试验作了介绍。最后说明一种能模拟带有高峰值随机振动的试验技术 ,以改进现有数控设备的不足。 相似文献
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制定室内模拟运输试验条件的一种方法 总被引:2,自引:0,他引:2
介绍了制定室内模拟运输试验条件的一种技术方法。以运输距离、运输速度及路面等级给出的运输环境条件可以采用空间频率功率谱密度(PSD)描述,进而获得以时间频率PSD描述的室内模拟运输试验条件。文中还分析了确定的路面等级的空间频率PSD的波动以及运输速度对于室内模拟运输试验条件量级的影响,结果表明:相同的运输环境条件,其室内模拟运输试验条件振动量级可以具有的波动范围;相同的路面等级,运输速度与试验条件振动量级成正比。工程应用中可以针对不同产品的设计要求来剪裁使用。 相似文献
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Janie M. Chermak 《Resources Policy》1998,24(4):207-216
An intent of the U.S. Federal Regulatory Commission's Order 636, promulgated in April 1992, was to promote competition and efficiency in the transportation sector of the natural gas industry. Additionally, the Order altered the roles of the traditional players in the industry by increasing not only their options for purchase and sale of natural gas, but also their risks. Increased options have the potential of increasing competition and efficiency, not only in the transportation sector, but also in the distribution sector. This paper examines impacts of Order 636. Using annual, aggregate, U.S. price data, a Wilcox rank sum test is employed to test for statistically significant differences between the pre- and post-636 eras. Results indicate median revenues attributable to the transportation sector have declined since the implementation of Order 636.1 Although there are naturally a number of factors that may affect transportation revenues, the decline in median price can be attributed, at least in part, to increased competition, increased efficiency, or both. At this level of aggregation the effects can not be segregated. Results also indicate that although decreased costs of transportation have at least partially been passed on to final consumers, local distribution companies have not significantly altered their business practices when dealing with customers. 相似文献
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U. Oses E. Rojí I. Gurrutxaga M. Larrauri 《Journal of Environmental Planning and Management》2017,60(11):1891-1922
The management of urban transportation systems represents one of the most formidable challenges for local government that generates several problems related to the well-being and the comfort of the public that commute and travel in their daily life. Improvements to various policies and practical measures can move us closer to the ideal of sustainable urban areas with sustainable urban transportation systems. Nevertheless, these aspirations in no way ensure unanimity over the most effective actions to take and the extent of their benefits. In response, a mathematical model has been developed for decision-taking purposes using multi-criteria analysis adapted to urban transportation systems. This model not only takes account of environmental parameters, but also examines economic, social and urban models, the characteristics and condition of the transport fleet and freight distribution vehicles, in order to generate a sustainability index value for the transportation system of urban areas. 相似文献