核动力冷却剂主泵控制的模拟实践

冷却剂主泵是核动力装置系统中的重要设备之一,为模拟核动力系统,对冷却剂主泵切换控制采用电气模拟的方法。实践证明,这既节省经费,结构简单,同时逼真性好,工作性能可靠。     

高炮人-机跟踪系统建模及动态特性分析

本文以某高炮人-机系统为对象,以人的最优控制模型为基础,建立该人-机跟踪系统部分的数学模型,利用计算机求解——即模型预测方法,研究操作者(炮手)在跟踪沿不同航路飞行的空中目标时系统的跟踪误差和动态性能;与此同时研制一套模拟原高炮人-机系统的仿真试验装置,以获取的试验数据做为检验上述模型预测结果和进行全系统性能分析的依据。     

一高精度随动系统的分析研究

本文对某坦克火控系统的瞄准线控制机构进行了分析、仿真,并对改进其性能提出了初步设想。     

硫磷钼极压剂的研究

用新方法合成了含 S,P,Mo 三种活性元素的油溶性有机化合物,并在四球机、Falex 试验机上作了摩擦磨损试验。结果表明:添加0.5%的该化合物到46~#汽轮机油中就能显示很好的减摩、抗极压作用,在油中、空气中均较稳定。理化性能试验表明:加入该添加剂后,基础油的理化性能均合格。用 X—射线光电子能谱(XPS)对摩擦副的表面进行了测试,初步探讨了其极压抗磨机理。     

人体静电极端值的分析研究

本文在讨论人体静电定义的基础上,分析各国报导人体静电极端值差异的原因,经理论分析和实验验证,给出人体静电电位的取值范围:10~(-2)～10~5V,并证明人体静电极端值60kV 是可信的.     

Expected time delay in multi‐item inventory systems with correlated demands

This paper considers multi‐item inventory systems where a customer order may require several different items (i.e., demands are correlated across items) and customer satisfaction is measured by the time delays seen by the customers. Most inventory models on time delay in the literature assume each demand only requires one item (i.e., demands are not correlated across items or are independent). In this paper, we derive an exact expression for the expected total time delay. We show that when items are actually correlated, assuming items are independent leads to an overestimate of the total time delay. However, (1) it is extremely difficult in practice to obtain the demand information for all demand types (especially in a system with tens of thousands of part numbers), and (2) the problem becomes too complicated to be of practical interest when the correlation is considered. We then explore the possibility of including the demand information partially and develop bounds for the time delays. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 671–688, 1999     

The impact of inventory information distortion due to customer order cancellations

In this paper we study the impact of cancellations of customer orders on an inventory system. We develop a periodic review (s, S) inventory model with Poisson demands, deterministic demand leadtimes and supply leadtimes. When no set up cost is present for replenishment, the behavior of the system cost can be studied analytically. For the case with a fixed set up cost, we derive the operating characteristics of the model via an embedded Markov chain analysis. Based on this, we formulate the total cost function and suggest a two‐phase approach to optimization. Our model can be used to compute cancellation fees and to evaluate the impacts of various conditions of cancellation. We find that cancellations, as major sources of inventory information distortion, increase total system costs, and the magnitude of the cost impact depends on the probability of cancellation and the expected cancellation time. Other relevant lessons and insights are also discussed. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 213–231, 1999     

卫星通信抗干扰综合运用模式

从历史战例归纳通信干扰作战样式,从技术角度分析卫星通信潜在干扰威胁,立足当前卫星通信抗干扰能力,针对通信干扰作战样式设计卫星通信抗干扰综合运用模式,并提出后续研究工作。     

俄罗斯应对导航战举措

卫星导航系统作为重要的战场传感器,已经成为现代战争不可或缺的重要组成部分,围绕卫星导航系统的攻防博弈由此兴起。针对美国首先提出的导航战概念,俄罗斯为进一步提升导航战作战实力,有针对性地采取了应对举措。文章介绍了导航战概念及相关作战案例,具体分析了俄罗斯应对导航战威胁的主要举措,并结合美俄围绕导航战开展的攻防博弈,得出掌握现代战争制导航权的改进方向。     

多点喷射空气酒精燃气发生器试验验证

为有效解决现有燃气引射气源存在的诸多缺点,适应一种引射系统大流量、小型化的需要,在综合分析各燃气引射气源方案的基础上,研制了一种以空气、酒精作为推进剂的多点喷射结构的燃气发生器,并开展了多种工况下的试验研究。结果表明:采用的多点喷射方案大大提高了空间利用率,有效满足了引射系统小型化的要求;喷雾性能好,喷雾锥角及粒径优于设计指标要求;点火可靠性高,解决了领域内现有燃气发生器点火可靠性低的缺点;点火迅速,燃烧平稳,可实现较为均匀的出口温度场;燃气发生器工作范围较宽,能在余气系数2.52～4.34范围内稳定燃烧;高效的火焰筒内壁空气冷却方式有效保证了燃气发生器长时间工作运行。