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.     

Disruption management in production planning

We study the problem of recovering a production plan after a disruption, where the disruption may be caused by incidents such as power failure, market change, machine breakdown, supply shortage, worker no‐show, and others. The new recovery plan we seek after has to not only suit the changed environment brought about by the disruption, but also be close to the initial plan so as not to cause too much customer unsatisfaction or inconvenience for current‐stage and downstream operations. For the general‐cost case, we propose a dynamic programming method for the problem. For the convex‐cost case, a general problem which involves both cost and demand disruptions can be solved by considering the cost disruption first and then the demand disruption. We find that a pure demand disruption is easy to handle; and for a pure cost disruption, we propose a greedy method which is provably efficient. Our computational studies also reveal insights that will be helpful to managing disruptions in production planning. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005.     

GNSS/SINS组合导航在地地导弹中的工程应用

介绍了基于Kalman滤波的GNSS/SINS组合导航技术在地地导弹中的应用,在发射点惯性坐标系中建立了便于工程应用的数学模型,针对某型号进行了位置速度仿真,并和目前在工程实际中应用的加权平均组合方法进行了比较。仿真结果表明,Kalman滤波技术可以应用于地地导弹工程实际中。     

基于Matlab/Simulink的内燃机凸轮挺柱磨损数值计算的仿真研究

建立了凸轮磨损计算的仿真模型,论证了模型的正确性以及利用Simulink进行凸轮机构的磨损数值计算仿真的有效性,并利用Matlab/Simulink对其进行仿真.仿真结果与实验结果较为吻合.     

面向提高分析效率的战场损伤分析（FMEA／DMEA）方法研究

战场损伤分析是战场抢修研究、准备和决策的基础。从装备战场损伤分析出发,针对目前战场损伤分析(FMEA/DMEA)中存在的过程复杂、内容较多和效率不高等问题,探讨了如何利用基础性损伤数据和已有分析案例为FMEA/DMEA提供数据支持,提高分析效率。     

Al2O3催化氧化脱除GB染毒空气的研究

以浸渍法制备的10%V／Al2O3为催化剂,研究对GB染毒空气的脱除效果,考察接触时间、温度、温度和浓度等因素对GB染毒空气脱除效果的影响,用GC-MS和LC-MS对尾气组分进行了检测分析．     

WSEIAC模型的中远程空空导弹武器系统效能分析

依据中远程空空导弹武器平台系统的战术指标,建立了中远程空空导弹武器平台系统的效能评价体系.对ADC扩展模型中的人为因素K进行了修正,在能力矩阵C中增加对载机生存能力和信息支持能力的体现.在此基础上给出了修正扩展模型下的系统效能,计算了在原始ADC模型下的系统效能,并对两种模型下的效能差异进行了比较.     

军用飞机综合效能/费用评估方法

军用飞机的效能与费用是两个相互制约的因素,对两者进行科学合理的综合评估,对于军用飞机的发展和使用有着很重要的意义。在分析综合效能/费用的基本评估指标基础上,提出了在军用飞机全寿命周期综合效能/费用评估指标,重点对作战使用阶段的最佳效能/费用进行评估分析,最后给出结论。     

Inside the Iraqi State Records: Saddam Hussein, ‘Irangate’, and the United States

This article uses captured Iraqi state records to examine Saddam Hussein's reaction to US arms to sales to Iran during the Iran–Iraq War (the Iran/Contra scandal). These records show that ‘Irangate’ marked a decisive departure in Saddam's relations with the United States. Irangate reinforced Saddam's preexisting suspicions of US policy, convincing him that Washington was a strategic enemy that could not be trusted. Saddam concealed his anger to preserve a working relationship with the Reagan administration, but this episode nevertheless cemented his negative views of the United States and forged a legacy of hostility and mistrust that would inform his strategic calculus for years to come.     

A queueing system with vacations after N services

This article is devoted to the study of an M/G/1 queue with a particular vacation discipline. The server is due to take a vacation as soon as it has served exactly N customers since the end of the previous vacation. N may be either a constant or a random variable. If the system becomes empty before the server has served N customers, then it stays idle until the next customer arrival. Such a vacation discipline arises, for example, in production systems and in order picking in warehouses. We determine the joint transform of the length of a visit period and the number of customers in the system at the end of that period. We also derive the generating function of the number of customers at a random instant, and the Laplace–Stieltjes transform of the delay of a customer. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 646–658, 2015