A melt-cast Duan-Zhang-Kim mesoscopic reaction rate model and experiment for shock initiation of melt-cast explosives

A melt-cast Duan-Zhang-Kim (DZK) mesoscopic reaction rate model is developed for the shock initiation of melt-cast explosives based on the pore collapse hot-spot ignition mechanism. A series of shock initiation experiments was performed for the Comp B melt-cast explosive to estimate effects of the loading pressure and the particle size of granular explosive component, and the mesoscopic model is validated against the experimental data. Further numerical simulations indicate that the initial density and formula proportion greatly affect the hot-spot ignition of melt-cast explosives.     

The effect of al particle size on thermal decomposition,mechanical strength and sensitivity of Al/ZrH2/PTFE composite

To study the thermal decomposition of Al/ZrH2/PTFE with different Al particle size as well as mechanical strength and impact sensitivity under medium and low strain rates, molding-vacuum sintering was adopted to prepare four groups of power materials and cylindrical specimens with different Al particle size. The active decomposition temperature of ZrH2 was obtained by TG-DSC, and the quasi-static me-chanics/reaction characteristics as well as the impact sensitivity of the specimen were studied respec-tively by quasi-static compression and drop-hammer test. The results show that the yield strength of the material decreased with the increase of the Al particle size, while the compressive strength, failure strain and toughness increased first and then decreased, which reached the maximum values of 116.61 MPa, 191％, and 119.9 MJ/m respectively when the Al particle size is 12—14μm because of particle size grading. The specimens with the highest strength and toughness formed circumferential open cracks and reacted partly when pressed. Those with developmental cracks formed inside did not react. It is considered that fracture of specimens first triggered initial reaction between Al and PTFE to release an amount of heat. Then ZrH2 was activated and decomposed, and participated in subsequent reaction to generate ZrC. The impact sensitivity of the specimens decreased with the increase of Al particle size.     

Partial penetration of annular grooved projectiles impacting ductile metal targets

Changing and optimizing the projectile nose shape is an important way to achieve specific ballistic performance. One special ballistic performance is the embedding effect, which can achieve a delayed high-explosive reaction on the target surface. This embedding effect includes a rebound phase that is significantly different from the traditional penetration process. To better study embedment behavior, this study proposed a novel nose shape called an annular grooved projectile and defined its interaction process with the ductile metal plate as partial penetration. Specifically, we conducted a series of low-velocity-ballistic tests in which these steel projectiles were used to strike 16-mm-thick target plates made with 2024-O aluminum alloy. We observed the dynamic evolution characteristics of this aluminum alloy near the impact craters and analyzed these characteristics by corresponding cross-sectional views and numerical simulations. The results indicated that the penetration resistance had a brief decrease that was influenced by its groove structure, but then it increased significantly-that is, the fluctuation of penetration resistance was affected by the irregular nose shape. Moreover, we visualized the distribution of the material in the groove and its inflow process through the rheology lines in microscopic tests and the highlighted mesh lines in simulations. The combination of these phenomena revealed the embed-ment mechanism of the annular grooved projectile and optimized the design of the groove shape to achieve a more firm embedment performance. The embedment was achieved primarily by the target material filled in the groove structure. Therefore, preventing the shear failure that occurred on the filling material was key to achieving this embedding effect.     

对军队党组织提高抓军事变革本领的理论思考

世界新军事变革的发展态势,既对我军建设提出了严峻挑战,同时也带来了难得的发展机遇,军队各级党组织必须把握趋势、揭示规律、采取措施、提高本领、积极应对,推进中国特色的军事变革。其中,观念革命是军事变革的先导;创新是军事变革的动力;培养大批高素质新型军事人才是军事变革的关键;科学筹划,正确处理变革中的各种关系是基础;善于抓住机遇,勇于解决关键性问题是推进军事变革和军队建设跨越式发展的必要条件。     

火力演进与陆军战术变革的回顾

自从火药发明并应用于军事领域之后,战争便逐渐步入热兵器时代。此后,陆军火力随着武器装备的发展不断发生变化,陆军战术因此在400余年的时间里经历了4次大的变革,分别是前装药滑膛火器时期的线式和纵队战术、后装药线膛火器时期的散兵线战术、机械化系列火器时期的诸兵种合同战术和信息促成火器融合时期的多军种联合战术。     

Optimal FCFS allocation rules for periodic‐review assemble‐to‐order systems

In Assemble‐To‐Order (ATO) systems, situations may arise in which customer demand must be backlogged due to a shortage of some components, leaving available stock of other components unused. Such unused component stock is called remnant stock. Remnant stock is a consequence of both component ordering decisions and decisions regarding allocation of components to end‐product demand. In this article, we examine periodic‐review ATO systems under linear holding and backlogging costs with a component installation stock policy and a First‐Come‐First‐Served (FCFS) allocation policy. We show that the FCFS allocation policy decouples the problem of optimal component allocation over time into deterministic period‐by‐period optimal component allocation problems. We denote the optimal allocation of components to end‐product demand as multimatching. We solve the multi‐matching problem by an iterative algorithm. In addition, an approximation scheme for the joint replenishment and allocation optimization problem with both upper and lower bounds is proposed. Numerical experiments for base‐stock component replenishment policies show that under optimal base‐stock policies and optimal allocation, remnant stock holding costs must be taken into account. Finally, joint optimization incorporating optimal FCFS component allocation is valuable because it provides a benchmark against which heuristic methods can be compared. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 158–169, 2015     

CARACaS无人自主框架及其感知、控制与协同技术综述

针对CARACaS(Control Architecture for Robotic Agent Command and Sensing)无人自主框架、核心组件、示范验证和应用发展情况进行综述.首先,简要描述了自主框架的组成及其软件架构的设计原则和思路,对行为、动态规划和感知三类引擎的技术特征进行分析,讨论了世界模型的...     

Defence expenditures and economic growth: The externality effect

In a series of articles published in the Fall 1990 issue of Defence Economics Alexander (1990), Atesoglu and Mueller (1990) and Huang and Mintz (1990) have all specified and empirically estimated defence‐growth models based on a neoclassical production function. We now isolate the externality component in our model, re‐estimate its coefficients using data on the U.S. economy 1952–88 and compare specifications and results with Atesoglu and Mueller (1990) and Alexander (1990).     

基于PEPA的目标选择方法

目标选择是军事作战领域的重要内容,而一体化联合作战更是要求目标选择从系统的角度出发,对指控系统进行破击目标选择。基于反映系统动态特性和消减主观因素的考虑,本文将过程代数的思想引入到指控系统破击目标选择领域中来。通过案例,对某防空指控系统进行简要分析,在硬杀伤和资源约束的条件下,进行目标方案选择的分析,过程简洁、结论客观、方案可行,证实了该方法的有效性,为指挥决策提供了借鉴和帮助。     

五冗余捷联惯组系统配置及优化

以五冗余陀螺惯组为平台,讨论了捷联惯性测量组合冗余设计方案,以系统导航精度最优为性能指标,引入了三种性能指标函数,并分析了这三种性能指标函数在使用过程中的等价性,最后研究了三正交两斜置结构的五轴冗余惯组系统的最优配置方法,并在考虑到量测精度对配置影响的条件下,通过理论分析和计算得到了最优配置的安装角,具有较强的工程实用性。