浅谈企业门户的架构与发展

本文就建立企业门户的必要性进行了探讨，并从信息门户、知识门户与应用门户三个方面简要介绍了企业门户的体系架构与发展。     

天基快速响应体系的虚拟演示系统

为了实时监测天基快速响应体系的工作过程,开发实现了一套基于 OSG平台的虚拟演示系统。首先,对组成天基快速响应体系的天基平台、轨道运载器和有效载荷进行三维可视化建模,并设计了定制在轨服务任务和管理天基平台的图形交互接口；其次,基于典型的轨道转移模型,介绍了执行任务的天基平台选定方法和流程；最后,通过典型的信息保障任务,展示了基于 OSG的天基快速响应体系的虚拟演示系统。     

辽沈地区航空航天信息资源共享平台设计与实现

航空航天信息资源共享平台利用先进技术和管理理念深度整合航空航天信息资源,提供一站式综合信息服务,深入数据挖掘,形成具有航空航天特色的文献信息资源中心,共享平台系统框架设计遵循代表数字资源管理发展趋势的数据开放技术和服务标准规范,通过资源加工子系统、资源管理子系统、数字图书馆门户系统、信息检索子系统和用户服务子系统加以实现,建设以航空航天文献数字化、传播服务网络化为目标的高效快捷的航空航天文献保障体系。     

民航事故调查信息平台框架设计

本文探讨了航空器事故调查信息平台的应用需求，设计了民航事故调查信息平台的总体框架。平台采用B／s系统开发模式，包括调查员管理、事故调查过程管理、事故和事故征候案例分析和事故调查信息资料共享管理等功能子系统。同时，针对平台的系统安全问题，设计构建基于网络安全设施和信息安全体系的平台整体安全体系结构，用于实现平台的安全性和可用性。平台的应用将为事故、事故征候和其他不安全事件的调查提供有效的分析工具，规范事故调查信息管理，辅助事故调查工作，提高我国民航事故调查信息化水平。     

Cocoon在3G业务管理平台门户的应用研究

随着Web应用的广泛普及,采用合适的Web门户开发框架,建立更加人性化的用户门户,满足用户对Web站点门户越来越高的要求就显得十分必要.Apache Cocoon是一个优秀的基于组件技术和XML的Web发布框架,文中简要介绍了Cocoon的基本特点和原理,并结合一个面向3G业务的用户门户的开发事例,分析了使用Cocoon这种框架的优点.     

BREW平台内部接口机制的探讨

BREW平台是一种新的移动应用开发平台,提供从服务端到客户端的全套解决方案。本文通过介绍BREW平台内部关键宏AEEINTERFACE和QINTERFACE的定义,分析了其内部接口机制及类COM特性；总结了BREW应用程序开发的特点；提出了一种通用的BREW平台应用程序的框架模型。     

在J2EE平台下进行多层分布式数据库系统开发的研究

J2EE是SUN公司提出的在分布式环境中的一种体系结构,EJB是基于J2EE(Java2平台企业版)开发基于Web企业应用程序的基础,EJB体系结构是生成业务应用程序的主要分布式组件模型。本文介绍了J2EE和EJB基本概念和特点,并列举了在J2EE平台下运用EJB技术开发多层分布式数据库系统的开发示例。     

基于虚拟设计制造技术的FL-9风洞模型架车开发

FL-9风洞是"十五"国家批准建设的大型航空科研基础设施,模型架车是其核心设备。以该风洞模型架车开发研制为背景,运用制造业信息化技术,构建了虚拟设计制造平台,此平台具备网络系统支持下的设备三维数字化设计、计算机辅助分析、工艺设计、可视化及三维交互等功能;并建立了设计制造信息化体系,实现了设计制造全过程信息分类代码的规范和统一。基于此平台开发的模型架车经2年的研制已全面建成并试车成功。     

我国CIO的生存之道

CIO的出现标志着信息技术已成为一个公司或企业的核心技术，标志着信息资源已成为一种等价于资本和人力的战略资源。文章分析了我国CIO发展过程中出现的一些问题，给出我国CIO发展的几点建议：建立健全法律政策体系；建立完整的管理和组织机构；加强学习，提高CIO自身的领导能力、沟通能力和协调能力；熟悉具体业务，保护和利用企业的信息资源；加大对CIO的宣传力度，推进CIO的成熟发展。     

中国未来的中西部门户枢纽机场——关于西安咸阳国际机场战略定位问题的思考

2004年我国完成航空运输总周转量240.76亿吨公里,跃居世界第三位,标志着我国朝着建设“民航强国”的目标迈进了一大步。在此背景下,如何进一步完善我国民航机场体系,充分发挥门户枢纽机场的重要作用,日益引起各界的广泛关注。笔者从我国航空运输的整体背景出发,立足于满足国家及区域经济、社会和航空运输发展的战略需要,结合西安咸阳国际机场的现状,提出将咸阳机场定位为我国中西部门户枢纽机场的目标。必要性分析“西部大开发”是我国的基本国策和长期战略。西安作为西部大开发的桥头堡,在我国西北五省的中心城市中排名第1位,是国务院确定…     

The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow

This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig.Measurements of heat transfer from the discs and tangential velocities are presented.The test rig is a 70% full scale version of a high pressure compressor stack of an axial gas turbine engine.Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air.Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows(Re up to 5×106 and Rez up to 2×105).Two different builds have been tested.The most significant difference between these two build configurations is the size of the annular gap between the(non-rotating) drive shaft and the bores of the discs.The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method.The velocity measurements were made using a two component,LDA system.The heat transfer results from the discs show differences between the two builds.This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity.There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig.For the narrow annular gap,there is an increase of non-dimensional tangential velocity V/Ωr with radial location to solid body rotation V/Ωr=1.For the wider annular gap,the non-dimensional velocities show a decrease with radial location to solid body rotation.      

Research on Auto-detection for Remainder Particles of Aerospace Relay Based on Wavelet Analysis

Aerospace relay is one kind of electronic components which is used widely in national defense system and aerospace system. The existence of remainder particles induces the reliability declining, which has become a severe problem in the development of aerospace relay. Traditional particle impact noise detection (PIND) method for remainder detection is ineffective for small particles, due to its low precision and involvement of subjective factors. An auto-detection method for PIND output signals is proposed in this paper, which is based on direct wavelet de-noising (DWD), cross-correlation analysis (CCA) and homo-filtering (HF), the method enhances the affectiv-ity of PIND test about the small particles. In the end, some practical PIND output signals are analysed, and the validity of this new method is proved.     

Preparation of Highly Dispersed Antimony-doped Tin Oxide Nano-powder via Ion-exchange Hydrolysis of SnCl4 and SbCl3 and Azeotropic Drying

Antimony-doped tin hydroxide colloid precipitates have been synthesized by hydrolysis of SnCl4 and SbCl3 using: (1) an ion-exchange hydrolysis to remove chlorine ions, and (2) isoamyl acetate as an azeotropic solvent to obviate water. The obtained dried powder is of high dispersivity without any need for further grinding. The size and dispersivity of the final particles are investigated with the aid of TG-DTA, BET, XRD and TEM. After having calcined, the antimony-doped tin oxide nanopowder possesses a tetragonal rutile structure with high dispersivity, uniform particles and low hard agglomeration.     

Effects of Mo on the Microstructure and Hydrogen Sorption Properties of Ti-Mo Getters

The effects of Mo on the microstructure evolution, porosity and hydrogen sorption properties of Ti-Mo getters are investigated in this work. The results show that the addition of Mo prolongs the densification process of Ti-Mo getters and results in a significant amount of sintered pores. With the Mo content increasing, the porosity of getters firstly increases reaching the maximum value as it at- tains about 7.5wt.%, and then drops. At the room temperature, the hydrogen sorption property of getters increases progressively with the Mo content increasing, but the tendency is not very clear before its content lies below 2.5wt.%. When the Mo content achieves about 7.5wt.%, the hydrogen sorption property proves to be the best. The discussion is made about the above mentioned phenomena inclusive of hydrogen sorption properties of getters under different activation conditions (from 500-750 ℃).     

超声速燃烧数值模拟中的湍流与化学反应相互作用模型

高精度数值模拟有助于理解超声速湍流燃烧中湍流与化学反应的相互作用,可为发动机燃烧室等工程应用设计提供可靠的预测模型。除直接数值模拟外,目前在湍流燃烧应用中使用的大涡模拟和雷诺平均Navier-Stokes模拟均需要借助模型模化发生在湍流小尺度上的流动与化学反应过程对湍流大尺度运动的影响。现有的湍流与化学反应相互作用模型大致可分为:火焰面类模型和概率密度函数类模型,2类模型在不同的应用中各自具有优势和局限性。此外,现有模型大都基于低马赫数燃烧,而超声速燃烧中通常会伴随快速混合、局部熄火和再着火以及激波等复杂过程,这为发展其中的湍流与化学反应相互作用模型提出了更多的挑战。     

适于低轨卫星IP网络的单核共享树组播算法(英文)

为了解决低轨卫星IP网络中现有典型源组播算法的信道资源浪费问题,本文提出了一套单核共享树组播算法,即核心群合并共享树(CCST)和加权核心群合并共享树(w-CCST)算法。CCST 算法包括动态近似中心(DAC)选核方法和核心群合并组播路径构建方法。DAC方法专为周期、规律运动的低轨卫星网络提出,不需要复杂的星上计算。在核心群合并方法中,以核节点作为初始核心群,通过核心群和剩余组成员的最短路径方法逐步扩展直至整棵组播树构建完成,从而使得组播树的树代价最小,大大提高了网络的带宽利用率和组播传输效率。w-CCST 算法中所提出的加权因子可以调整树代价和端到端传播时延之间的折衷程度,因此,可以通过调整加权因子来适度增大树代价、降低端到端传播时延以支持某些端到端时延要求苛刻的实时组播业务。最后,与低轨卫星 IP 网络中典型算法进行了性能比较,仿真结果说明,CCST 算法的平均树代价比其它算法显著降低,w-CCST 算法的平均端到端传播时延小于 CCST 算法。     

Jet Vectoring Control Using a Novel Synthetic Jet Actuator

A primary air jet vectoring control system with a novel synthetic jet actuator (SJA) is presented and simulated numerically. The results show that, in comparison with an existing traditional synthetic jet actuator, which is able to perform the duty of either “push” or “pull”, one novel synthetic jet actuator can fulfill both “push” and “pull” functions to vector the primary jet by shifting a slide block inside it. Therefore, because the new actuator possesses greater efficiency, it has potentiality to replace the existing one in various appli- cations, such as thrust vectoring and the reduction of thermal signature. Moreover, as the novel actuator can fulfill those functions that the existing one can not, it may well be expected to popularize it into more flow control systems.     

Nonlinear Adaptive Slewing Motion Control of Spacecraft Truss Driven by Synchronous V-gimbaled CMG Precession

The slewing motion control of a truss arm driven by a V-gimbaled control-moment-gyro (CMG) is a nonlinear control problem. The V-gimbaled CMG consists of a pair of gyros that must precess synchronously. The moment of inertia of the system, the angular momentum of the gyros and the external disturbances are not exactly known. With the help of feedback linearization and recursive Lyapunov design method, an adaptive nonlinear controller is designed to deal with the unknown items. Performance of the proposed controller is verified by simulation.     

An SOR Implicit Time-accurate Scheme in Calculating Unsteady Flows

A new time-accurate marching scheme for unsteady flow calculations is proposed in the present work. This method is the combination of classical Successive Over-Relaxation (SOR) iteration method and Jacobian matrix diagonally dominant splitting method of LUSGS. One advantage of this algorithm is the second-order accuracy because of no factorization error. Another advantage is the low computational cost because the Jacobian matrices and fluxes are only calculated once in each physical time step. And, the SOR algorithm has better convergence property than Gauss-Seidel. To investigate its accuracy and convergency, several unsteady flow computa- tional tests are carried out by using the proposed SOR algorithm. Roe’s FDS scheme is used to discritize the inviscid flux terms. Un- steady computational results of SOR are compared with the experiment results and those of Gauss-Seidel. Results reveal that the numerical results agree well with the experimental data and the second-order accuracy can be obtained as the Gauss-Seidel for unsteady flow computations. The impact of SOR factor is investigated for unsteady computations by using different SOR factors in this algorithm to simulate each computational test. Different numbers of inner iterations are needed to converge to the same criterion for different SOR factors and optimal choice of SOR factor can improve the computational efficiency greatly.