几种仿制的铝合金锻造工艺

2618A铝合金是一种Al-Cu-Mg-Fe-Ni系可热处理强化的铝合金。它基本上是从Al-Cu-Mg系硬铝合金基础上加镍,铁和硅形成的。由于合金中加入了等量的Fe、Ni、元素,生成大量的Al₃FeNi相。Al₃FeNi相是硬脆的化合物,在铝中溶解度极小,经锻造和热处理后弥散分布于组织中,因而合金具有良好耐热性。     

基于部件跟踪滤波器的解析余度技术

研究一种以发动机部件跟踪滤波器(CTF)为基础的解析余度技术, 它将CTF与故障检测、隔离和适应逻辑进行了有效的综合, 以改进发动机数控系统的可靠性。仿真表明, 本文所设计的解析余度技术, 在传感器无故障时, 机载模型能正确跟踪发动机的变化。当传感器发生故障时, 在不损坏机载模型的情况下, 又能及时、有效地进行硬、软故障的检测、隔离与适应。      

飞机结构部件飞行载荷估算方法研究

介绍一种考虑飞机各部件间相互影响（干扰）的气动载荷估算方法。把该方法用于估算全动平尾的飞行载荷,并用它估算了Ｆ－７全动平尾在对称机动情况下的飞行载荷,且与飞行实侧载荷作了比较。结果表明,估算和实测载荷相差１０％左右。这种估算方法,在飞机设计阶段,可用于估算飞机其它部件（机翼、垂尾等）飞行载荷。     

波音737尾段组件的装配和精加工技术

从波音737尾段中的得克萨斯星组件的工程结构、技术要求、工装、关键尺寸的加工控制和刀具选择等方面阐述了由沈飞公司转包生产的得克萨斯星组件的装配和精加工工艺。     

Multilevel Characteristic Basis Function Method with ACA for Accelerated Solution of Electrically Large Scattering Problems

The multilevel characteristic basis function method(MLCBFM)with the adaptive cross approximation(ACA)algorithm for accelerated solution of electrically large scattering problems is studied in this paper.In the conventional MLCBFM based on Foldy-Lax multiple scattering equations,the improvement is only made in the generation of characteristic basis functions(CBFs).However,it does not provide a change in impedance matrix filling and reducing matrix calculation procedure,which is time-consuming.In reality,all the impedance and reduced matrix of each level of the MLCBFM have low-rank property and can be calculated efficiently.Therefore,ACA is used for the efficient generation of two-level CBFs and the fast calculation of reduced matrix in this study.Numerical results are given to demonstrate the accuracy and efficiency of the method.     

新媒体时代马克思主义新闻观研究

新媒体时代,复杂多变的传播环境给马克思主义新闻观带来了巨大挑战。作为我国新闻传播事业的指导思想,坚持马克思主义新闻观的指导地位至关重要。面对新媒体时代新闻传播的趋利性、娱乐化倾向,以及西方国家利用新媒体对我国意识形态的渗透,我们必须要加强马克思主义新闻观教育,坚持正确的舆论导向,在实践中不断创新马克思主义新闻观的理论体系。。     

European small geostationary communications satellites

Hispasat Advanced Generation 1 (HAG1) is the first satellite using the SGEO platform, which is under the development in the ESA Artes-11 program. Since the last presentation in the IAC 2007, a European industrial consortium led by OHB has completed the mission and spacecraft design. The platform Preliminary Design Review has been carried out in May 2008. The customer for the first mission is a commercial operator—Hispasat. The contract was signed in December 2008 and the satellite will be launched in 2012. To give confidence to the customer, SGEO platform will use up to date flight proven technologies. HAG1 carries 20/24 Ku-band and 3/5 Ka-band transponders to provide commercial services. Some innovative payload technologies will also be flown on board of HAG1 to gain in-orbit heritage. SGEO has also been selected as the baseline platform for the ESA Data Relay Satellite (EDRS). Phase-A study has just kicked off in January 2009. The targeted launch date is 2013. Heinrich Hertz will also use the SGEO platform. Heinrich Hertz is funded by the German Space Agency (DLR) and provides flight opportunities for technologies and components developed by the German Space Industry. With the HAG1 contract in hand, and EDRS and Heinrich Hertz in the line, OHB with its partners has the confidence that it will be able to speed up the product development of the SGEO platform for potential customers in the commercial market. This paper will first present the updated platform design and the status of the product development will be followed with the introduction of innovative payload technologies on board the first mission—HAG1 and ended with the mission concepts of EDRS and Heinrich Hertz missions.     

企业信息系统建设方法论

根据笔者参加ＣＩＭＳ工程的实际经验,从方法论的角度总结了企业信息系统建设应注意的六个方面。内容涉及信息系统建设总的指导原则、系统分析的核心方法、系统集成成功的关键、系统开发的实用方法与方式等。     

三维编织复合材料细观结构的几何学分析

对四步法1：1编织过程及编织结构进行了详细几何学分析,完善了基元、面元和柱元的几何模型;导出了平均纤维体积比与编织工艺参数之间的关系等,并得到实际验证。可供编织复合材料结构力学性能分析与预估使用。     

四参数正弦波拟合软件的评价

四参数正弦波拟合法是一种在精密测量中广泛使用的数学手段.它建立在模型化测量的基础上,有很多非常有价值的应用.但是,该拟合软件的指标及其所带来的参数误差,由于涉及到的因素较多且复杂,一直没有得到评价.本文介绍了四参数正弦波拟合软件的简要工作过程、主要用途,总结出其几项主要指标及其简单实用的评价方法.针对一个具体的四参数正弦波拟合软件,使用本文所述指标和方法,进行了软件评价,并给出了有实用价值的评价结果.