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651.
直升机专用检测设备直接应用于直升机机载设备的性能校验,关系直升机的飞行安全和任务完成。基于直升机专用检测设备及其计量保障现状分析,对做好直升机专用检测设备的计量技术保障工作进行了探索和实践,为军用装备计量覆盖率和计量受检率的提升提供了借鉴和参考。  相似文献   
652.
计量保障是武器装备试验数据准确和试验质量可靠的重要保证,是考核与评价装备战术技术指标的关键环节,在武器装备的发展建设中发挥着不可替代的基础作用。本文结合目前武器装备试验计量保障工作的现状,从计量管理的法制化、试验计量保障能力建设、试验装备的强制检定和装备计量保障信息数据库等若干方面深入阐述了试验需求和法律法规要求,探讨了做好试验计量保障工作应采取的改进措施。  相似文献   
653.
付翔  付斌  赵亮 《国防科技》2020,41(6):8-15
自2017年8月DARPA公布“马赛克战”作战概念以来,世界各国都高度关注这一新型作战概念,学者们对“马赛克战”的研究也逐渐走向深入。本文首先从国际形势、美军装备特点、人工智能技术等方面分析了“马赛克战”的提出背景,回顾了其发展历程,剖析了其概念内涵,并从三个角度分析了其主要特点。接着着眼未来,从革新理念、鼓励创新、形成质变等视角探讨了“马赛克战”对装备体系试验鉴定领域未来发展方向的启示,重点论述了装备体系试验鉴定要向全智能作战体系试验鉴定方向发展的观点。最后聚焦当下,阐述了现阶段试验鉴定工作应重点关注动态互联互通性测试、互操作能力验证、新型仿真试验技术、系统自主能力等级评估及决策可解释性评估等五个方面的内容。  相似文献   
654.
How do states use nuclear weapons to achieve their goals in international politics? Nuclear weapons can influence state decisions about a range of strategic choices relating to military aggression, the scope of foreign policy objectives, and relations with allies. The article offers a theory to explain why emerging nuclear powers use nuclear weapons to facilitate different foreign policies: becoming more or less aggressive; providing additional support to allies or proxies, seeking independence from allies; or expanding the state’s goals in international politics. I argue that a state’s choices depend on the presence of severe territorial threats or an ongoing war, the presence of allies that provide for the state’s security, and whether the state is increasing in relative power. The conclusion discusses implications of the argument for our understanding of nuclear weapons and the history of proliferation, and nonproliferation policy today.  相似文献   
655.
The nuclear weapons taboo is considered one of the strongest norms in international politics. A prohibition against using nuclear weapons has seemingly shaped state behavior for nearly seven decades and, according to some observers, made nuclear use ‘unthinkable’ today or in the future. Although scholars have shown that nuclear aversion has affected decision-making behavior, important questions about the nuclear taboo remain unanswered. This article seeks to answer a basic question: How durable is the taboo? We develop different predictions about norm durability depending on whether the taboo is based primarily on moral logic or strategic logic. We use the comparable case of the norm against strategic bombing in the 20th century to evaluate these hypotheses. The logic and evidence presented in this paper suggest that the norm of nuclear non-use is much more fragile than most analysts understand.  相似文献   
656.
为准确、快速地预测橡胶的贮存寿命,在步进高温应力加速老化试验的基础上,对不同加速温度下的加速系数进行计算,获得加速因子和绝对温度倒数的曲线,发现橡胶老化过程表现出非Arrhenius特性。针对非Arrhenius特性,引入幂指数因子,采用一种改进的Arrhenius模型对加速系数进行拟合。由对数反应速率与绝对温度倒数曲线的斜率,计算了改进Arrhenius模型在不同温度下的等效线性活化能,结果表明低温下活化能减小。建立低温下的老化寿命模型,对胶料在10℃,20℃和30℃下的老化寿命进行评估。评估结果表明,该模型可为相关高分子材料腐蚀过程中呈现的非Arrhenius特性的分析及寿命预测提供参考。  相似文献   
657.
《防务技术》2019,15(3):295-299
The use of asbestos material is being avoided to manufacture the brake pads as it is harmful and toxic in nature. Further it leads to various health issues like asbestosis, mesothelioma and lung cancers. These brake pads can be replaced by natural fibers like Palm kernel (0–50%), Nile roses (0–15%) and Wheat (0–10%) with additives like aluminum oxide (5%–20%) and graphite powder (10%–35%). Phenolic resin of 35% is utilized as a binder. Particulated Nile roses are used to increase the friction coefficient and wheat powder is used to reduce the wear rate. Aluminum oxide and graphite are abrasive in nature. This helps to make brake pads with high friction co-efficient and less wear rate with low noise pollution. The wear of the proposed composites have been investigated at different speeds. Various tests like wear on pin-on-disc apparatus, hardness on the Rockwell hardness apparatus and oil absorption test have been conducted. Phenolic resin produces good bonding nature to fiber. Thus, Fibers found to have performed palatably among all commercial brake pads. The objective of the research indicates that Palm kernal shell could be a conceivable alternative for asbestos in friction coating materials.  相似文献   
658.
《防务技术》2019,15(5):690-697
Influence of multiple structural parameters on the performance of a gun launch system driven by high-pressure reactive gases is important for structural design and performance adjustment. A coupled lumped parameter model was utilized to predict the propellant combustion, and a dynamic finite element method was applied to approximate the mechanical interactions between the projectile and the barrel. The combustion and the mechanical interactions were coupled through a user subroutine interface in ABAQUS. The correctness and the capability of the finite element approximations in capturing small structural changes were validated by comparing predicted resistance with experiments. Based on the coupled model, the influence of structural parameters of a medium-caliber gun on the system performance was investigated. In order to reduce the research costs, orthogonal tests were designed to investigate the comprehensive effects of the parameters. According to statistical analysis, the important order of the structural parameters on the launching process was obtained. The results indicate that the influence of the width of the rotating band stands out among the studied parameters in the gun. The work provides a method to investigate the influence of multiple parameters on system performance and gives guidance for controlling the system performance.  相似文献   
659.
众所周知,美军的装备试验鉴定技术一直处于世界领先地位,对其进行深入研究有利于试验鉴定的发展。本文主要对美军试验鉴定的管理部门、类型、发展历程以及技术领域进行详细研究,系统梳理美军试验鉴定的整个过程,在此基础上,结合我试验鉴定的发展现状,取其精华,去其糟粕,为试验鉴定的发展提出了几点思考和建议。  相似文献   
660.
滚动轴承加速寿命试验技术研究   总被引:1,自引:0,他引:1       下载免费PDF全文
为了有效地获取滚动轴承具有可比性的加速寿命试验数据,利用已有加速寿命试验相关标准,结合实际滚动轴承加速寿命试验设计和实施中积累的经验,深入分析滚动轴承加速寿命试验过程中遇到的各种问题,提出一套完整的滚动轴承加速寿命试验方法。该方法对相关标准没有涉及的试验前检查、试验条件一致性分析和试验数据的处理方法进行了补充并对加速寿命试验进行深入分析,形成完整的滚动轴承加速寿命试验解决方案,可以有效地指导滚动轴承加速寿命试验的设计和实施。  相似文献   
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