Firm embedding behavior of annular grooved projectiles impacting ductile metal targets

Annular grooved projectiles (AGPs) have drawn ongoing concerns as an advanced penetrator for their excellent anti-rebound capability in impacting metal plates. They could become embedded solidly in the target surface during low-velocity impact. In this investigation, the firm embedding behavior of AGP was observed by impact experiments. Corresponding numerical simulations provided a better understanding of this process. Experimental and numerical results indicated that the firm embedding behavior of AGP was mainly due to the filling-material in the groove rather than the friction between the projectile and target, unlike traditional shape such as conical projectile. According to observation, firm embedding process can generally be subdivided into four stages: initial-cratering stage, groove-filling stage, filling-material failure stage and rebound vibration stage. Moreover, the damage mechanics of target material around crater was obtained through microscopic tests. A comparison of the cross-sectional figures between the experiment and simulation proved that the analysis and the proposed method were reasonable and feasible, which further demonstrated that the firm embedding behavior has application potential in new concept warheads.     

无人舰艇技术及军事应用研究

随着无人飞机的大量研发和广泛应用,无人化智能武器越来越受到世界各国的重视。在海洋争端愈演愈烈的今天,世界军事强国又纷纷把目光投向海上无人作战舰艇,无人舰艇技术得到突飞猛进的发展。近期,美国高调宣布将在中国南海打造以"无人飞机"和"无人舰艇"为骨干的"无人军团",以期全面遏制我海军的行动,加强无人舰艇技术研究已迫在眉睫。从世界无人舰艇发展历程出发,详细阐述了无人舰艇的技术特点和应用前景,重点分析了我军无人舰艇发展应用对策。研究表明,无人舰艇作为未来海航作战中不可忽视的力量,必将走俏未来战场,深度改变战争格局。     

红外成像水面靶标的设计与实现

水面靶标为反舰武器海上飞行试验提供水面模拟舰船目标。介绍了红外成像靶的功能和技术指标,详细给出了舰船红外成像模拟实现的总体设计方案、硬件和软件实现方式。海上测试结果表明,这种靶标能够较好地实现舰船红外热像模拟,在海上试验的实际应用中取得了预期效果。     

论当今国际维和行动发展和趋势

本文从当今国际维和行动现状出发,分析了国际维和行动的特点,剖析了国际维和行动面临的挑战问题,最后对国际维和行动的发展提出几点思考,并系统阐述了维和行动的相关问题。     

话务女兵业务训练周期的心理特点

针对空军某基地通信站女兵连话务女兵的业务训练周期逐渐变长的情况进行研究,将话务专业的"训练周期"划分为基础业务训练阶段、上机跟班训练阶段、考核冲刺阶段、单放后适应阶段及业务熟练阶段5个阶段。从心理学的角度入手进行原因及对策分析,建立"兴奋期-适应期-疲劳期-调整期-实现期"的心理周期模型。以此为框架分析女新兵在各个训练阶段的心理特点,分别以"培养和提高自信""注意集中和正确归因""焦虑情绪和心境状态的调节"及"目标设置"为重点制定阶段性对策,并着眼训练全过程,从帮助新兵持续保持适当的动机水平的角度提出应对办法。     

Analysis of sliding electric contact characteristics in augmented railgun based on the combination of contact resistance and sliding friction coefficient

The contact resistance between the armature and rails is an important indicator of the contact characteristics in electromagnetic launches. As the contact resistance depends not only on the contact state but also on the contact stress and temperature, there are some limitations in analyzing the contact characteristics using only the contact resistance. In this paper, the contact characteristics of the augmented railgun are analyzed by the combination of contact resistance and sliding friction coefficient. Firstly, the theoretical calculation model of the contact resistance and friction coefficient of the augmented electromagnetic railgun is established. Then the contact resistance and friction coefficient are calculated by the measured values of the muzzle voltage, rail current and armature displacement. Finally, the contact characteristics are analyzed according to the features of the waveforms of the contact resistance and the friction coefficient, and the analysis conclusions are verified by experimental rail images. The results showed that: the aluminum melt film gradually formed on the contact surface reduces the contact resistance and the friction coefficient; the wear and erosion of the armature cause deterioration of the contact state; after the transition, the reliability of the sliding contact between the armature and rails decreases, resulting in an increase in contact resistance.     

大学生的心理特点与创新潜力的挖掘

当代大学生在社会认知、社会情感、意志品质等心理因素上存在着这一阶段的普遍特点 ,这些特点为挖掘大学生的创造潜能提供了得天独厚的条件 ,高校应抓住这些特点有的放矢地对学生进行创新引导     

复波速在挠性胶管动态特性研究中的应用

针对挠性胶管管壁的粘弹性,提出了复波速的概念,并将其应用于挠性胶管现有的动态特性理论中,分别建立了挠性胶管瞬态响应和频率响应的模型,说明了挠性胶管衰减管中液体介质压力脉动和流量脉动的原理并解释了现有的现象,得出了一些新的结论.此外,还指出了该方法目前存在的不足及今后的研究方向.     

清代边塞诗的时代特征及其个案论析

作为中国边塞诗史上继盛唐之后的第二个高峰期,清代边塞诗在反映地域、创作主体、表现内容等许多方面都有着明显的新变与深化,从而形成了其独有的时代特征,即反映地域的扩大化、创作取向的学者化和表现内容的民俗化。     

基于BP神经网络的柴油机调速特性和外特性统一建模

对比分析了柴油机调速系统常用的两种建模方法的优缺点,采用BP神经网络方法建立了柴油机调速特性和外特性统一模型,并给出了仿真结果。