A novel environmental control system based on membrane dehumidification

This paper conducts a simulation study of a novel aircraft environmental control system based on membrane dehumidification(MD-ECS),and compares the system with the up-to-date four-wheel high pressure de-water system(4WHPDW-ECS).Mathematical models for the two systems are established,and a system simulation using a numerical technique is performed to analyze and compare the cooling performance of the two systems.Simulation results show that the cooling capacity of MD-ECS is much higher than that of 4WHPDW-ECS under the same working conditions,indicating that the novel system is theoretically feasible and promising.The effects of the sweep ratio of the membrane dehumidifier on the dehumidification and cooling performance of the system is also investigated.     

低成本IMU／GPS组合导航系统研究

ＧＰＳ／ＩＮＳ组合导航系统已在一定领域得到应用，而ＩＮＳ昂贵的价格限制了它的广泛应用，本文采用低成本惯性测量组件（ＩＭＵ）设计了低成本ＩＭＵ／ＧＰＳ组合系统的硬件和相应的软件，进行了静态实验和数据处理，系统的俯仰角和横滚角误差均小于０．２°，实验结果表明，低成本组合系统的性能较好，而其性能价格比更高。     

股份合作制下的委托代理分析

指出股份合作制的一个重要特征是委托人内化，即企业员工互为委托人及代理人．通过一个简单的企业模型，将股份合作制的这一特征纳入委托代理理论的分析框架，研究表明，在股份合作制下，尽管股权结构对员工积极性的发挥有重要的影响，但它并不能很好地解决员工“搭便车”（ｆｒｅｅｒｉｄｅｒ）问题，而一些在一般企业里行之有效的激励措施，在股份合作制企业里却可能失效     

超声电火花复合加工的研究进展

概括了目前国内外超声电火花复合加工技术的最新进展，介绍了其结构和工作原理，并指出了其发展趋势。     

航空领域嵌入式测控系统自动生成平台

基于ARM-Linux的试验平台能够满足航电测控中绝大部分要求,并可以按照用户的实际需求进行软硬件功能的裁剪,增强了平台的适应性,同时也体现了嵌入式系统的快速定制性与特定功能的自由选择相结合的新型设计思想.     

一种用于出舱活动的相变储热／辐射器式热沉

首先讨论了出舱活动中的各种散热方案；然后介绍了一种相变储热／辐射器式热沉。给出了闭式散热系统设计的性能要求及相变材料的选取标准和计算方法。     

大飞机部件数字化柔性装配若干关键技术

随着CAD/CAM/CAE/PDM/CAPP技术的不断发展,装备制造业制造水平的不断提升,以及大飞机研制计划提供的良好平台,我们有理由相信在今后的几年内,依靠各部门的团结协作,大飞机部件数字化柔性装配技术一定能取得突出的成果,为我国其他装备制造技术提供基础.     

偏转弹头导弹控制系统设计与仿真

根据弹头的可偏转特性,利用无根多刚体系统动力学方法建立了偏转弹头导弹的动力学模型,并对通道间的耦合特性及弹头偏转对弹体运动的影响进行了分析。在此基础上,将通道间的耦合及弹头偏转对弹体运动的影响作为干扰项处理,将气动参数的非线性变化等效为标称参数的摄动,利用变结构控制理论设计了偏转弹头导弹的控制器。仿真结果表明,所设计的变结构控制器能够有效地减小和消除俯仰、偏航通道对滚转通道的耦合作用以及弹头偏转对弹体运动的影响,较好地抑制了导弹气动参数的摄动,具有较高的稳态精度和良好的动态性能。     

安徽省生产性服务业和制造业融合发展研究

产业融合是现代产业发展的必然结果,利用2002-2007年安徽省投入产出表相关数据,结合中间投入率和中间需求率,对安徽省生产性服务业和制造业间的融合度进行测算,探究安徽省产业融合特点和规律,旨在为安徽省产业结构调整和转型升级提供科学依据。研究表明:整体制造业和生产性服务业相互依赖,融合程度在不断加深,生产性服务业的投入主要集中在劳动和资源密集型产业,对技术密集型产业的投入较低,不同生产性服务业对整体制造业的投入结构存在明显差异。     

Design for aircraft engine multi-objective controllers with switching characteristics

The aircraft engine multi-loop control system is described and the switching control theory is introduced to solve the regulating and protecting control problems in this paper. The aircraft engine multi-loop control system is firstly described and the control problems are formulated. Secondly, the theory of the smooth switching control is devoted and a new extended scheme for the smooth switching of a switched control system is introduced. Then, for the key technologies of aero-engines switching control, a design algorithm is presented which can determine which candidate controller should be put in feedback with the plant to achieve a desired performance and the procedure to design the aircraft engine multi-loop control system is detailed. The switching performance objectives and the switching scheme are given and a family of PID controllers and compensators is designed. The simulation shows that using the switching control design method can not only improve the dynamic performance of the aircraft engine control system and reduce the switching times, but also guarantee the stability in some peculiar occasions.