Understanding the impact properties of polymeric sandwich structures used for motorcyclists' back protectors

Conventional back protectors are comprised of two main parts: elastomeric foams to absorb the impact energy; and thermoplastic polymers to distribute the impact force on a wider area before the absorption process. Thermal comfort is usually maintained by vent holes within the structure. In the present work, the impact behavior of a number of samples made of materials commonly used for manufacturing such protectors was studied. Nitrile butadiene rubber as the soft layer and polyethylene thermoplastic as the hard layer were considered. The variables for the analyses were the thickness of the layers, the sample temperature and the distribution of the vent holes in the sample. The key findings are: the force distribution capability of the hard part and the stability of the impact properties with respect to temperature variations are fairly dependent on the thickness of the soft part; and a reasonable distance between two consecutive vent holes is required for achieving optimal impact protection.     

MT-1型真空摩擦磨损试验机的研制

MT-1型真空摩擦磨损试验机可以提供从大气到6.7×10~(-3)Pa的压力环境,其可测载荷和速度的可调范围以及温度和振动特性等的变化范围都比较大,并且采用微机系统进行数据采集和处理,测量参数多,重复性和精确度都比较好,因而是航天工业、真空工业和摩擦学基础研究中一种有用的工具。     

高压脉冲放电技术在金属裂纹止裂中的应用

如何产生高强度脉冲电流是应用电磁热效应遏制金属裂纹研究的一个关键问题。本文介绍了高压脉冲放电装置的工作原理;从理论上分析了充电电压、回路参数与放电电流幅值、放电周期之间的关系。在此基础上,自主设计、开发了一套高压脉冲放电装置。采用它对金属模具钢中裂纹进行了脉冲放电止裂实验。放电时裂纹尖端熔化形成堆焊和高压应力区,使裂纹尖端钝化,达到了止裂的目的。由于脉冲放电快速加热和冷却,在裂纹尖端处实现了冲击淬火,得到了超细化的隐晶马氏体和细粒碳化物等微观组织,提高了裂纹尖端处的硬度、强韧性和耐磨性,试验结果验证了该装置的有效性,本文的成果为采用电磁热效应对金属模具裂纹止裂提供了实验技术基础。     

激光侦察装备综合作战效能评估模型

根据激光侦察装备的工作原理,分析了影响其作战效能的主要因素,用系统分析的方法,通过对系统的可用度向量A、可信度矩阵D和能力向量C的建模,建立了定量评价激光侦察装备综合作战效能的数学模型,并通过算例对模型进行了验证.     

军用光电设备红外窗口技术及发展

论述军用光电设备红外窗口的性能要求，叙述红外窗口材料，镀膜及结构设计的考虑，提出今后的发展方向。     

Perfluoroelastomer and fluoroelastomer seals for semiconductor wafer processing equipment

Parts made from fluorinated elastomers, e.g., Kalrez^® perfluoroelastomer parts, parts made from Viton^® fluoroelastomer, are widely used as seals on semiconductor wafer processing equipment. Many of these seals are required to function in harsh chemical environments and at process temperatures ranging from 25 to 300 °C. Fluoroelastomers, including those of the perfluoroelastomer type, have extraordinary resistance to chemicals and heat, enabling them to withstand virtually any process media, including reactive plasmas, at temperatures as high as 316 °C.This paper is a review of perfluoroelastomers and fluoroelastomers used in semiconductor wafer processing. These seals offer cleanliness and lack of contamination while maintaining sealing functionality in aggressive media. Applications requiring resistance to both “wet” and “dry” process chemistry include etching, ashing, stripping, copper plating and chemical vapor deposition. Applications requiring thermal resistance include LPCVD, diffusion furnace and rapid thermal processing (RTP). A relative comparison of the various types of perfluoroelastomers used as well as a comparison to other elastomeric materials will also be discussed.     

Fibre bundle scanner for laser photocoagulation treatment

Wide-angle irradiation is achieved in laser photocoagulation treatment by means of a fibre bundle. The laser transmission system consists of multiple quartz fibres, the input ends of which are aligned and driven by a stepper motor across a high-power laser beam. The output ends are arranged in a hexagonal close-packed array from which the diverging laser beam successively irradiates different parts of a lesion without the use of a mechanical scan over the lesion. This fibre bundle scanner is useful for the treatment of widely spread skin lesions such as port wine stains.     

电子回旋共振微波等离子体技术及应用

 电子回旋共振微波等离子体技术(ECR-MP)在表面处理、等离子体刻蚀和薄膜制备，尤其是高品质的激光惯性约束聚变薄膜靶的制备中有着重要的应用。综述了ECR-MP的基本原理、反应装置、实验研究、理论研究和应用情况的发展现状，同时分析了其今后可能的发展趋势。     

通用测试设备验证评估系统设计

部队现有通用测试设备均按照相关标准研制设计,贯标的程度对检测结果产生很大影响,为验证通用测试设备执行标准的规范程度,设计了一套验证评估系统,该评估系统具备体积小、资源广、易操作等特点,可以从仪器级、系统级、软件级三个层次对通用测试设备进行评估验证。应用结果表明,该评估系统很好的对测试设备的贯标程度进行了量化评价,在部队测试设备的标准化程度检验上具有一定的实用性和推广性。     

基于成熟度评估的武器装备体系集成性能试验方法研究

单装试验到体系试验需要架设集成试验这座桥梁,论文借鉴技术集成成熟度评估方法提出了集成成熟度试验的思路,并建立了基于集成成熟度试验评估的装备体系集成性能试验方法,实现了体系集成性能的试验与评价,并通过示例对所提出的方法进行了演示验证,证明了方法的可行性。