聚能射流形成过程的理论建模与分析

分析了聚能射流的形成过程,并对其中的各阶段进行了详细建模。在模型中考虑了炸药爆轰、金属的驱动、药型罩压垮以及射流和杵体的形成过程。采用该模型对某一聚能装药结构进行了计算,计算结果表明:药型罩顶部和底部微元的压垮速度较小,在射流头部形成反向速度梯度,与试验数据吻合较好。该模型对于多级侵彻战斗部的工程设计与侵彻参数的计算具有一定的参考价值。     

强爆轰驱动超高速碎片发射装置设计因素分析

为了得到发射装置设计因素和超高速碎片性能间的关系,考虑了药型罩的材料、炸药种类、装药长径比、药型罩的锥角、药型罩的厚度、药型罩顶部靠近装药侧的曲率半径等设计因素,采用AUTODYNTM,结合正交试验,对超高速碎片的发射过程进行数值模拟。结果表明,3种发射装置结构分别可以提供质量为1. 533 g的紫铜碎片、速度为11. 649 km/s的铝碎片、动能为85. 6 k J的铝碎片; 2种发射装置结构均可以提供质量大于1 g、速度高于11 km/s的密实结构圆柱状碎片。验证了仿真方法的可信性,对影响碎片性能的设计因素进行了分析、排序,并得到了这些设计因素与碎片质量、速度、动能的关系。     

A stochastic model for burn‐in procedures in accelerated environment

Burn‐in procedure is a manufacturing technique that is intended to eliminate early failures of system or product. Burning‐in a component or system means to subject it to a period of use prior to being used in field. Generally, burn‐in is considered expensive and so the length of burn‐in is typically limited. Thus, burn‐in is most often accomplished in an accelerated environment in order to shorten the burn‐in process. A new failure rate model for an accelerated burn‐in procedure, which incorporates the accelerated ageing process induced by the accelerated environmental stress, is proposed. Under a more general assumption on the shape of failure rate function of products, which includes the traditional bathtub‐shaped failure rate function as a special case, upper bounds for optimal burn‐in time will be derived. A numerical example will also be given for illustration. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006     

模糊非单调推理系统的实现方法

本文首先分析了非单调推理系统的两个主要过程——正确性维持过程和面向从属关系的回溯过程,讨论了模糊非单调推理系统的独特性,然后对模糊非单调推理系统的实现方法进行了探讨,并给出了模糊非单调推理系统与问题求解程序一起工作的计算机程序。     

Optimal burn‐in procedure for periodically inspected systems

Burn‐in is a widely used method to improve the quality of products or systems after they have been produced. In this paper, we study burn‐in procedure for a system that is maintained under periodic inspection and perfect repair policy. Assuming that the underlying lifetime distribution of a system has an initially decreasing and/or eventually increasing failure rate function, we derive upper and lower bounds for the optimal burn‐in time, which maximizes the system availability. Furthermore, adopting an age replacement policy, we derive upper and lower bounds for the optimal age parameter of the replacement policy for each fixed burn‐in time and a uniform upper bound for the optimal burn‐in time given the age replacement policy. These results can be used to reduce the numerical work for determining both optimal burn‐in time and optimal replacement policy. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

理、情、意、行——思想政治工作的四要素

我国思想政治工作者在实践中总结出来的"晓之以理、动之以情、持之以恒、导之以行"的十六字方针,是对思想政治工作规律的反映,其中的"理"、"情"、"意"、"行"是做好思想政治工作的四个基本因素,它们在思想政治工作中起着各自不可替代的作用.     

东突恐怖主义成因分析

突厥文化和泛突厥主义的泛滥、伊斯兰复兴运动和泛伊斯兰主义的传播、新疆周边国家各种恐怖势力的影响、国际敌对势力的怂恿、改革开放以来国际交流的加强以及新疆特殊的地理位置 ,是我国新疆地区“东突”恐怖主义形成的重要条件 ,并对“东突”恐怖主义的泛滥起到了催化作用     

多孔材料药型罩聚能射流的形成条件

依据Herrmann状态方程和斜冲击波关系估算了多孔材料药型罩压垮之前的冲击温升,求解了经过冲击压缩卸载后材料的声速。给出了多孔材料药型罩聚能射流的形成条件。初始冲击温升会使材料的声速和强度降低,从而使多孔材料聚能射流形成射流的高速和低速条件降低。     

火灾事故调查认定结论的可诉性研究

火灾事故调查是公安消防机构为了确定火灾事故的原因和性质,依法对事故责任者提出处理意见,同时为研究火灾规律、预防和扑救火灾提供实际依据的一种行为。火灾事故调查认定结论中的火灾原因认定和火灾损失统计在法理上不能提起行政诉讼,在司法实践中法院也不应受理,应在立法上和火灾调查工作中予以明确。     

聚能射流侵彻下舰船钢与均质钢的等效关系

基于剩余穿深理论,依据聚能射流对钢靶板侵彻毁伤作用机理,推导出2种等效模型,并结合数值模拟建立了聚能射流侵彻下某舰船装甲钢与603钢靶板的等效关系。结果表明:当舰船钢厚度较小时,舰船钢与603装甲钢的等效厚度比约为1;当舰船钢厚度较大时,两者等效厚度比约为1.13。由此等效关系可给出用于战斗部考核性穿靶试验中相应均质靶板的确定厚度,从而为用603装甲钢靶代替该舰船钢进行聚能射流威力考核试验提供依据,达到了简化、经济、方便、有效的目的。