Effect of metal powders on explosion of fuel-air explosives with delayed secondary igniters

In order to improve the energy level of fuel air explosive(FAE) with delayed secondary igniters, high energetic metal powders were added to liquid fuels mainly composed of ether and isopropyl nitrate. Metal powders' explosive properties and reaction mechanisms in FAE were studied by high-speed video, pressure test system, and infrared thermal imager. The results show that compared with pure liquid fuels, the shock wave overpressure, maximum surface fireball temperature and high temperature duration of the mixture were significantly increased after adding high energetic metal powder. The overpressure values of the liquid-solid mixture at all measuring points were higher than that of the pure liquid fuels. And the maximum temperature of the fireball was up to 1700 ℃, which was higher than that of the pure liquid fuels. After replacing 30％of aluminum powder with boron or magnesium hydride, the shock wave pressure of the mixture was further increased. The high heat of combustion of boron and the hydrogen released by magnesium hydride could effectively increase the blast effect of the mixture. The improvement of the explosion performance of boron was better than magnesium hydride. It shows that adding high energetic metal powder to liquid fuels can effectively improve the explosion performance of FAE.     

抗美援朝战争中志愿军空军培育战斗精神的历史经验

抗美援朝战争中,志愿军空军在敌强我弱的情况下,既发挥高技术武器装备的作用,又重视战斗精神培育,取得了空战的胜利。他们在培育战斗精神中的“五个结合”,即:把思想教育与技术准备、继承传统与空战实践、单独作战与协同作战、学习苏军与军事民主、立功运动与服务保证结合起来的经验,对当前我军战斗精神的培育具有重要的借鉴意义。     

纳米结构炭材料的储放氢性能研究

主要对多种纳米结构炭材料（超级活性炭、多壁碳纳米管,纳米碳纤堆,纳米石墨纤堆、纳米石墨球等）在常温、10-13MPa的氢气压力下的储放氢量进行了测定（其中包括经过一系列物化处理的样品）,井对其结构和比表面积分别采用SEM、TEM、HRTEM、ASAP2010吸附测试仪（BET）进行了分析．实验结果表明：经过处理的纳米碳样品的储放氢量有所提高,但没有一种样品在温和的实验每件下的储放氢量超过1．0wt％,离DOE目标（6．5wt%）相距甚远。     

Exploiting symmetry in the reliability analysis of coherent systems

Components in a complex system are usually not structurally identical. However, in many cases we may find components that are structurally symmetric, and one should make use of this additional information to simplify reliability analysis. The main purpose of this article is to define and study one such class of systems, namely, those having symmetric components, and to derive some reliability-related properties. © 1996 John Wiley & Sons, Inc.     

Supply management in assembly systems

We consider the case when n components are needed to assemble a given product. Components are provided by suppliers, and the period between the order time and the time a component is available (i.e., the lead time) is a random variable with a known distribution. The due date for the assembled product is also known. The costs to be taken into account are the inventory costs of the components and the backlogging cost of the assembled product. We propose an iterative algorithm which leads to the optimal order instants of the components. © 1993 John Wiley & Sons, Inc.     

二部图的(g,f)匹配

本文证明了二部图存在(g,f)匹配和f 因子的充要条件以及有关的几个结果,并且给出了求二部图的最大(g,f)匹配、最小(g,f)匹配和最小权最大f 匹配、最小权(g,f)匹配、最大权(g,f)匹配的算法。     

任意信号FFT频谱显示误差及消除方法

分析了任意信号FFT、变换频谱在计算机显示中产生误差的原因,介绍了频率轴坐标标定和显示引起的误差对高精度频谱图的影响,指出了无误差显示应满足的条件,并给出了相应的无误差频谱显示程序。     

超精密金刚石车床伺服进给数学模型

首先分析了车床进给系统各环节的传递函数,在此基础上采用频域估计建模和时域建模方法建立了车床伺服进给系统的Ｓ域和Ｚ域模型     

基于神经网络的超精密机床伺服进给非线性模型辨识

以双轴Ｔ型结构的超精密金刚石车床的伺服进给系统为研究对象,采用自构造神经网络技术,建立了系统的非线性动态数学模型,为系统非线性控制与补偿提供参考模型     

赛船自动固定启航装置的研制

设计了一种新型赛船固定启航装置。该装置主要由浮台、尾固定器和侧固定器组成。整个系统为全飘浮式,不需要水下作业,因而可用于多种竞赛水域,可快速转移赛程。第一届世界龙舟锦标赛应用实践证明,该装置结构简单,使用方便可靠。该装置已获中华人民共和国国家专利