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81.
本文用系统工程的方法,对航空母舰(简称航母)装甲-结构防护系统的约束、组成要素和目标进行了较深入的分析和概括,并对航母装甲-结构防护系统的设计方法提出了探索性意见。 相似文献
82.
朱锡 《海军工程大学学报》1991,(2)
本文采用较为先进的实验技术——高应变率下材料的分段式Hopkinson拉杆实验(分段式—维杆拉伸实验)研究了“921A”钢在高应变速率情况下的动态屈服性能,获得了很有理论和实用价值的应变率ε—功屈服应力σ_d变化曲线。同时本文简要介绍了分段式Hopkinson拉杆实验技术的基本原理和实验方法。 相似文献
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综合后勤保障是美军武器系统研制与采办过程的一项重要活动,本文阐述了这一活动的基本概念、实质内容、发展动态以及对我军的启示。 相似文献
85.
朱永清 《军队政工理论研究》2005,6(4):9-11
战斗精神具有政治性、实践性、团队性、系统性特征.培育战斗精神,要把握其特征,以坚定信念、铸牢军魂为首要任务,以任务摔打、日常养成为基本途径,以发扬传统、体现特色为重要内容,以健全机制、形成合力为有效保证. 相似文献
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Zeng Liu Cheng-lei Fan Zhu Ming Chao Chen Ang Liu Chun-li Yang San-bao Lin Lang-ping Wang 《防务技术》2021,17(3):923-931
High nitrogen stainless steel with nitrogen content of 0.75%was welded by gas metal arc welding with Ar—N2-O2 ternary shielding gas. The effect of the ternary shielding gas on the retention and improvement of nitrogen content in the weld was identified. Surfacing test was conducted first to compare the ability of O2 and CO2 in prompting nitrogen dissolution. The nitrogen content of the surfacing metal with O2 is slightly higher than CO2. And then Ar—N2-O2 shielding gas was applied to weld high nitrogen stainless steel. After using N2-containing shielding gas, the nitrogen content of the weld was improved by 0.1 wt%. As N2 continued to increase, the increment of nitrogen content was not obvious, but the ferrite decreased from the top to the bottom. When the proportion of N2 reached 20%, a full austenitic weld was obtained and the tensile strength was improved by 8.7%. Combined with the results of surfacing test and welding test, it is concluded that the main effect of N2 is to inhibit the escape of nitrogen and suppress the ni-trogen diffusion from bottom to the top in the molten pool. 相似文献
89.
Zhi Yang Ke Wang Peng Zhu Peng Liu Qiu Zhang Cong Xu Hao-tian Jian Rui-qi Shen 《防务技术》2021,17(4):1572-1578
Triggered spark-gap switch is a popular discharge switch for pulse power systems. Previous studies have focused on planarizing this switch using thin film techniques in order to meet the requirements of compact size in the systems. Such switches are one-shot due to electrodes being too thin to sufficiently resist spark-erosion. Additionally, these switches did not employ any structures in securing internal gas composition, resulting in inconsistent performance under harsh atmospheres. In this work, a novel planar triggered spark-gap switch (PTS) with a hermetically sealed cavity was batched-prepared with printed circuit board (PCB) technology, to achieve reusability with low cost. The proposed PTS was inspected by micro-computed tomography to ensure PCB techniques meet the requirements of machining precision. The results from electrical experiments demonstrated that PCB PTS were consistent and reusable with lifespan over 20 times. The calculated switch voltage and circuit current were consistent with those derived from real-world measurements. Finally, PCB PTS was used to introduce hexanitrostilbene (HNS) pellets in a pulse power system to verify its performance. 相似文献
90.
Min Zhu Sheng-ao Wang Huang Huang Gui Huang Fei Wu Shao-hua Sun Biao Li Zi-jian Xu 《防务技术》2021,17(4):1444-1452
The response characteristics of the warhead under thermal stimuli conditions are important to the safety improvement. The goal of this study is to obtain data on the warhead in the fast cook-off process. In this paper, a numerical calculation method is proposed, whose reliability is supported by comparison with experimental results. Through the numerical calculation, the temperature distribution, temperature change, and ignition time are acquired. The numerical results show that the ignition time is 76 s after the warhead started to burn and that the maximum temperature of the explosive's outer surface is 238.3 C at the ignition time. The fast cook-off experiment of the warhead is implemented so as to get the flame temperature and reaction grades that are not available through numerical calculation. The experimental results show that the overpressure fails to reach the preset minimum value which is equivalent to 6 kg of TNT and that the reaction grade is deflagration. The research results have reference value for the design of the warhead and the reduction of detonation risks. 相似文献