Mechanical behavior and failure mechanism of polyurea nanocomposites under quasi-static and dynamic compressive loading

Polyurea is an elastomeric material that can be applied to enhance the protection ability of structures under blast and impact loading.In order to study the compressive mechanical properties of SiC/polyurea nanocomposites under quasi-static and dynamic loading,a universal testing machine and split Hop-kinson pressure bar(SHPB)apparatus were used respectively.The stress-strain curves were obtained on polyurea and its composites at strain rates of 0.001-8000 s-1.The results of the experiment suggested that increase in the strain rates led to the rise of the flow stress,compressive strength,strain rate sensitivity and strain energy.This indicates that all of the presented materials were dependent on strain rate.Moreover,these mechanical characters were enhanced by incorporating a small amount of SiC into polyurea matrix.The relation between yield stress and strain rates were established using the power law functions.Finally,in order to investigate the fracture surfaces and inside information of failed specimens,scanning electron microscopy(SEM)and micro X-ray computed tomography(micro-CT)were used respectively.Multiple voids,crazes,micro-cracks and cracking were observed in fracture surfaces.On the other hand,the cracking propagation was found in the micro-CT slice images.It is essential to understand the deformation and failure mechanisms in all the polyurea materials.     

A method to determine the shell layout scheme for equipment battlefield damage tests under artillery fire

In this paper,a new method for determining the shell layout scheme is proposed,which can make the equipment damage data by the battlefield damage test resemble as close as possible the actual combat data.This method is based on the analysis of the impact point distribution and effective damage area of equipment.In order to obtain the position of the impact points,an impact point distribution model under artillery fire was established.Similarly,in order to obtain the effective damage area of equipment,the concepts of generalized damage area and task-based equipment functional damage probability were demonstrated,and the corresponding calculation model was established.Through case analysis,the shell layout scheme was effectively obtained,verifying the correctness of the proposed method.     

基于BP神经网络的防空C3I人机交互性能评估

阐述了BP神经网络的相关原理,建立了防空武器指挥自动化系统人机交互性能评估的指标体系,对应用人工神经网络解决防空武器指挥自动化系统人机交互性能评估的方法问题进行了探讨,并且给出了神经网络的评估模型及算法.通过实例证明该方法是可行的.     

唐生智与1937年南京保卫战

1937年12月爆发的南京保卫战,是抗战初期的重要战役之一。国民政府蒋介石任命唐生智为南京卫戍司令长官,具体负保卫南京之责。他将10余万卫戍军部署在外围阵地及复廓阵地上,以抗击来犯的约8个师团的日本侵略军。保卫战于12月5日正式打响,经过近10天的殊死战斗,消灭敌人大批有生力量,但以种种原因,国民政府首都南京于12月13日陷于敌手。凶残成性的日本侵略者制造了骇人听闻的南京大屠杀,我被杀害的军民同胞达30万人,为世界所罕见。中国军民在战斗中表现出来的高度爱国主义精神,令人钦敬;保卫战的经验教训及其历史地位,永远载入中国抗战史册。     

孙吴益州战略论析

益州战略是孙吴建国初期即定下的图取天下的基本战略。赤壁之战后,孙吴着手实施益州战略,由于复杂的三国政治、军事、外交以及地理形势等因素的作用,刘备集团占据益州,孙吴最终无法实现益州战略。基于现实,孙吴修正了益州战略,以略取、经营益州为主变为防御、联合益州为主,从而与蜀汉形成矛盾统一的关系。益州战略贯穿孙吴历史,深刻影响三国政局。     

西方传统武德文化中的德性之维

西方文明虽有崇尚战争、赞美胜利的倾向,但这并不影响其传统武德文化放射注重战争正义和军人德性的光芒。西方传统武德文化的“正义必胜”战略思想、以“爱国主义”为核心的道德规范体系、“注重自然法和重视精神力量作用”的传统在当代军人武德建设中仍有积极意义。     

第二次世界大战与战后局部战争刍议

本文阐述了世界大战与局部战争两类战争形态的区别与联系,二战以后两类战争因素的消长;重点考察了二战后局部战争的高技术性、局部性、立体性、快节奏、强化空战和空战形式创新之特点及其发展趋势。     

古代军人利益观述评

本文对古代中外一些国家不同时代的军人利益观进行了梳理,并作了简要的评论,指出了这些军队的军人利益观之阶级特点、民族特征,且与我军军人利益观作了粗浅的比较。希冀此文能起到抛砖引玉的作用,引发对军人利益观问题的深入研究。     

一种新型直流电网短路限流装置的设计与分析

针对直流电网短路故障时迅速产生的短路电流,利用IGBT器件为核心,设计出一种新型的直流短路电网限流装置并阐述了其工作原理.在分析了该装置的各种工作状态后,给出了对应的数学解析模型,为直流电网短路限流装置各参数的设计提供了理论依据.研制出小功率实验样机,并经过实验验证了解析模型的正确性和所设计的限流装置工作的快速有效性.