N2O/C7H8单喷嘴燃气发生器试验研究

以基于N2O/C7H8的燃烧驱动混合型气动CO2激光器点火试验为研究背景,设计了液态N2O供应系统及N2O/C7H8单喷嘴燃气发生器.对液态N2O供应系统、N2O/C7H8的点火及燃烧性能进行了研究.试验结果表明:设计的N2O供应系统能够实现液态N2O的稳定供应;在设定的时序下,两个设计工况(余氧系数分别为0.3和0....     

A componentwise index of service measurement in multi‐component systems

In this paper we present a componentwise delay measure for estimating and improving the expected delays experienced by customers in a multi‐component inventory/assembly system. We show that this measure is easily computed. Further, in an environment where the performance of each of the item delays could be improved with investment, we present a solution that aims to minimize this measure and, in effect, minimizes the average waiting time experienced by customers. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 50: 2003     

具有适应能力的微小系统——芯片级系统工程学研究领域的一场革命

当前，在电子工程技术类刊物上，经常会看到有关集成式微小系统及其技术发展现状方面的研究报道。本文立足于此技术发展的前沿，集中论述了当今世界高新技术领头雁美国的一些最新的设计范例，其设计思想和技术发展概念远远超出了当前所有基于静态元件的先进系统。文章首先提出了具有适应能力的微小系统概念，概述了实现这种片上系统所面临的技术难题和适用途径；讨论了美国国防高级研究计划局（DARPA）在推动这种未来元件和未来系统的研究中所起的作用；介绍了DARPA为促进这种系统的研究和生产所做的努力，并着重讨论了DARPA下属的微小系统技术办公室（MTO）目前正在实施的多个研究项目，其中包括新颖的电路体系结构（3DIC）、具有适应能力的成像与感觉判断装置（AFPA，VISA，MONTAGE，A—to—I），以及可重组的RF／微波装置（SMART、TFAST和IRFFE）等。     

无人机地面控制系统操作员控制台设计与仿真

设计的无人作战飞机地面控制系统操作员控制台是为进行未来无人机编队作战需求,通过仿真手段进行验证的某大型无人机作战演示系统的一个子系统,采用了二维、三维图形显示技术、TCP/IP网络技术、数据库技术,完成了实时无人机状态监控平台、无人机多机任务监控平台、无人机信息监控平台、三维虚拟环境仿真平台、网络数据传输与管理、飞行数据处理、无人机平台等模块的编制工作.从软件工程的角度分别对各个开发阶段的工作及其功能实现做了具体的阐述.最后,对本系统进行了仿真测试,获得了较好的效果,为实际应用提供了有力依据.     

Minimizing weighted earliness and tardiness penalties in single‐machine scheduling with idle time permitted

In this paper, a single‐machine scheduling problem with weighted earliness and tardiness penalties is considered. Idle time between two adjacent jobs is permitted and due dates of jobs could be unequal. The dominance rules are utilized to develop a relationship matrix, which allows a branch‐and‐bound algorithm to eliminate a high percentage of infeasible solutions. After combining this matrix with a branching strategy, a procedure to solve the problem is proposed. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 760–780, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10039     

新体制导航信号下I/Q幅相不一致对接收机测距零值的影响分析

随着现代化导航信号带宽的增大，由于可以大幅降低采样率，复信号采样的优势日趋明显。由于存在I/Q幅相误差，复信号采样对导航接收机伪距测量造成了一定影响。改进了信道非理想与I/Q幅相误差共同影响BPSK/QPSK信号零值测量的分析模型；在该模型基础上，推导得到了任意I/Q误差和信道非理想特性影响BOC信号伪距零值的模型；探讨了二者在频域抗干扰应用场景下引起的零值变化；理论分析与软件接收机仿真结果高度吻合，误差在1.5×10^-4码片内，证明了分析模型的精确性。该分析方法可用于对高性能导航接收机信道特性进行事先约束及筛选，以确保干扰场景下的零值变化满足要求。     

反电动势对无扰载荷航天器精确定向的影响

无扰载荷航天器中非接触式作动器反电动势会引起有效载荷模块与支持模块之间的耦合，影响有效载荷模块的精确定向性能。通过建立无扰载荷航天器的耦合动力学模型，分析非接触式作动器反电动势对有效载荷模块精确定向性能的影响。考虑六支杆立方构型无扰载荷接口，结合拉格朗日方程和牛顿欧拉方法建立有效载荷模块平台动力学模型。推导非接触式作动器的输出力模型，并引入有效载荷模块平台动力学模型，给出考虑非接触式作动器反电动势的耦合动力学模型。将支持模块上飞轮动静不平衡引起的谐振作为干扰力矩，建立了无扰载荷航天器在轨定向状态的Simulink仿真模型。仿真结果表明，反电动势系数越大，干扰力矩对有效载荷模块的影响越大，有效载荷模块精确定向精度越低。     

准陶瓷Cf/SiC复合材料的制备

采用热重-差热(TG-DTA)、红外(IR)等分析测试手段,研究了聚碳硅烷(PCS)的裂解及化学转化过程,从理论上验证了先驱体聚碳硅烷(PCS)600℃裂解产物的准陶瓷特性.先驱体聚碳硅烷在600℃呈现一种半有机、半无机状态,其产物具有准陶瓷的特征,在大约750℃出现无机化转变高峰,固称其为准陶瓷.以碳布、准三维编织体、三维编织体为增强体,采用先驱体浸渍裂解(PIP)工艺在600℃制备了碳纤维增强碳化硅(Cf/SiC)准陶瓷基复合材料.结果表明,以三维编织体增强的准陶瓷Cf/SiC复合材料获得了较理想的结构、性能,所制备3D-Cf/SiC复合材料密度仅有1.27g/cm3,弯曲强度达到193.69MPa,室温拉伸强度为197.69MPa,600℃拉伸强度为167.33MPa.复合材料断口形貌分析表明,在低温600℃制备的准陶瓷Cf/SiC复合材料呈现明显的韧性断裂特征.     

STK/Connect模块在GPS仿真演示系统中的应用

卫星工具软件STK(Satellite Tool Kit)是航天领域中进行卫星系统分析和仿真的有效工具,其重要模块之一STK/Connect可提供用户在客户机/服务器环境下与STK连接的功能.在深入研究STK/Connect模块的核心技术的基础上,详细说明了第三方应用程序与STK进行通信的方法,并将其应用于GPS应用仿真演示系统,同时进行了编程实现,取得了较好的效果.     

Capacitated warehouse location model with risk pooling

In this article, we introduce the capacitated warehouse location model with risk pooling (CLMRP), which captures the interdependence between capacity issues and the inventory management at the warehouses. The CLMRP models a logistics system in which a single plant ships one type of product to a set of retailers, each with an uncertain demand. Warehouses serve as the direct intermediary between the plant and the retailers for the shipment of the product and also retain safety stock to provide appropriate service levels to the retailers. The CLMRP minimizes the sum of the fixed facility location, transportation, and inventory carrying costs. The model simultaneously determines warehouse locations, shipment sizes from the plant to the warehouses, the working inventory, and safety stock levels at the warehouses and the assignment of retailers to the warehouses. The costs at each warehouse exhibit initially economies of scale and then an exponential increase due to the capacity limitations. We show that this problem can be formulated as a nonlinear integer program in which the objective function is neither concave nor convex. A Lagrangian relaxation solution algorithm is proposed. The Lagrangian subproblem is also a nonlinear integer program. An efficient algorithm is developed for the linear relaxation of this subproblem. The Lagrangian relaxation algorithm provides near‐optimal solutions with reasonable computational requirements for large problem instances. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008