谈中国航空运输企业的发展方向——购并与联合

因为中国国民经济持续、快速的增长,使中国民航业近年进入了高速发展时期,取得的长足进步令世人瞩目.正如国际航空运输协会(IATA)预测,1995～2010年,世界航空运输的增长率为5%,亚洲的航空运输增长率将为8.6%,居全球各洲之最,而中国将是亚洲地区增长最快的国家.巨大的航空市场带动了中国航空企业的迅速发展,也促进了新生力量的诞生及成长.自1988年,中国民航创建了国航、东方、南方等直属的六家骨干航空公司以外,在1988年～1993     

振动试验和颤振分析的一体化——颤振实时分析系统

 <正> “颤振实时分析系统”是航空航天工业部振动环境课题组于1985年～1988年期间组织研制的一项课题,它是参考80年代美国波音公司的振动和颤振分析方法,吸收国内最新研究成果而发展的一套计算机辅助工程软件。     

中型闭环微机控制纤维缠绕机简介

经原航天工业部批准,由哈尔滨工业大学研制的JK CR100/600B 型闭环微机控制纤维缠绕机,于1988年7月在哈尔滨通过了部级技术鉴定。 该机的主要技术指标(参数)和性能: 1.主轴中心高832mm;2.卡盘与顶针的间距 4580mm;3.可缠绕壳体的直径100～1000mm;4.产品和芯模的总重量 2t;5.主轴转速 0～190r/min;6.小车最高速度 41.2m/min;     

国际金属机械热处理会议

1988年6月6～10日在日本东京将由日本钢铁协会主持召开“钢和其他金属的机械热处理物理冶金国际会议”,会议议题包括:在热加工和温加工中的变形行为;静态与动态再结晶;沉淀和晶粒长大;扩散、扩散相     

CIMT 2007中国国际机床展展前预览

中国国际机床展览会(CIMT)是由中国机床工具工业协会主办的国际公认的四大国际机床展之一,从1989年创办以来,每两年举办一次.2007年4月9～15日,以"创新发展,和谐共赢"为主题的第十届中国国际机床展览会(CIMT 2007)将在中国国际展览中心隆重举行.本届展会是在"十一五"期间举办的首次中国国际机床展,也是在国务院"关于加快发展装备制造业的若干意见"发布之后与"数控机床发展专项规划"即将出台之际举办的首次中国国际机床展.     

韩国航空工业在奋起

韩国航空工业起步较晚.1972年,其空军试装出美国帕兹马尼公司的PZ-2型轻型飞机.1976年以后才开始正式批量组装外国的直升机和飞机.现在具有一定实力的航空工业公司也是1976年以后相继建立的.进入80年代以后,韩国航空工业进入了加速发展时期,1982年至1988年产值年均增长27%.1988年产值达到约2亿美元.为了加速航空工业的发展,韩国颁布了“航空航天产业开发促进法”.到1992年,航空工业产值已增加至7.60亿美元.     

标准审查消息

国军标MJ螺纹的配套标准“MJ螺纹量规及测量MJ螺纹小径用量规”审查会于1988年10月8日～12日在昆明召开:国军标“飞机座舱布置”审查会于1988年10月31日～11月4日在无锡召开;部标准“组合夹具测量元件”审查会于1988年10月22日～27日在湖南省沅陵召开;部标准“气动铣”审查会于1988年10月6日～8日在天津召开。以上标准经与会代表认真、细致的审查,一致同意作为正式标准报上级审批。     

银燕飞过稻谷香——十年华诞访中国东方航空公司

过去的十年是中国国民经济迅猛发展的十年,更是中国民航业快速迈进的十年.十年之前,中国民航开始告别计划经济的模式,走上了政企分开、企业化经营的改革之路.此举加快了我国民航事业的发展步伐.1988年中国民航运输总周转量为23.1亿吨公里,到1996年达到80.6亿吨公里,年均增长为31.1%.中国民航取得的长足进步正是由于政企分开给企业经营带来更大独立性、更大活力.中国东方航空公司作为中国民航直属三大骨干航空公司之一,在企业的开拓与发展上适时地把握住了一次     

第五届全国断裂会议

由中国航空学会、中国力学学会、中国机械工程学会和中国金属学会联合召开的第五届全国断裂会议于1988年5月7日～11日于广西临桂召开。柳春图主持大会开幕式,刘元杰致开幕词,孙训芳作了回顾我国断裂科学发展和对未来展望的报告,吴清可作题为“断裂在机械工程应用”报告,刘才穆作题为“断裂在航空工程应用及发展”的报告。     

我国改革开放以来发展观的演进

中国改革开放三十年来发展观的变迁经历了三个时期:自发地采用以经济增长为核心发展观的时期;自觉反思和探索发展观的时期;形成和实践科学发展观理论体系的时期。发展观的演进一方面受到国内外思潮的影响,另一方面又受到国内经济社会发展状况的制约。评价发展观的标准是其能否适应时代需求,滞后或过于超前都会带来负面的影响。     

差值法与比值法的误差修正效果比较研究及应用

差值法与比值法对不同测量系统的误差修正效果不一样。本文将两种方法的比较用一个比值来描述,并用推得的公式进行量化表示。在进一步的应用研究中,理论分析与实验数据相互印证,同时得到许多有益的结论,有助于全面掌握测量系统的误差来源,从而灵活选择各种修正方法以获得更加准确的测量结果。     

P-ACE仿真器的设计与研究

飞控系统主作动器电子控制装置（P-ACE）是现代电传飞控系统的核心部件。飞控系统主作动器电子控制装置仿真器采用数字仿真模块扩展模拟电路接口的仿真技术,具有与真件功能相似、接口相同的特性,可以代替飞控系统主作动器电子控制装置真件,参与飞控系统的调试和试验,对研究飞控系统的功能和性能具有重要意义。     

化学镀层的性能及基体的镀前处理

化学镀作为一种新兴的表面处理技术,已经广泛地应用于各个领域,化学镀的体系和工艺也得到了快速的发展。本文综述了近年来国内在化学镀应用与研究方面的进展,着重介绍了化学镀层的物理化学性能以及不同类型基体材料的表面活化技术。     

Impact and the design of the human-machine interface

In this paper, we consider the concept of the impact of an action or human error. We begin from an informal definition of impact as: the effect that an action or sequence of actions has on the safe and successful operation of a system; and develop a quantitative measure of the impact of specified behaviours. It is important that human-machine interface designers should understand the relationship between operator actions and the hazards associated with a system. We demonstrate how impact can be assessed prior to, or in parallel with, the design of the human-machine interface, and show how impact assessments could be used to allow risk analysts to inform designers about the relationship between operator actions and system hazards. To illustrate our approach we present a simple case study,     

Supernovae and the origin of the solar system

This review concentrates on recent ideas involving a relationship between the early solar system and supernova explosions. It summarizes briefly the data that has helped inspire those ideas. Because the true relationship is still unknown and generates controversy, the distinct ideas are introduced singly in the historical context of their origins, and the active sense of surprise and controversy is visible. Quotations from pivotal papers are used as part of the exposition. The subject involves equally the isotopic anomalies detected in meteorites and the dynamic events of galactic evolution, nucleosynthesis, and protosolar collapse. Whatever the correct situation is, new connections have been found between the origin of the elements and the formation of the solar system. The objective of this review is to enable interested space scientists to quickly identify the competing points of view and the experiments and theories that have led to them.     

Short-Lived Radioactivities and the Birth of the sun

Now extinct short-lived radioactive isotopes were apparently extant in the early solar system. Their abundances can be inferred from isotopic effects in their daughter nuclei in primitive meteorites, and the deviation of these abundances from expectations from continuous galactic nucleosynthesis yields important information on the last nucleosynthetic events that contributed new nuclei to the solar system and on the general circumstances of the Sun's birth. In this paper we present a rudimentary model that attempts to reconcile the abundances of ten short-lived radioactivities in the early solar system. In broad outlines, the picture requires 1) that Type Ia supernovae maintained a steady ISM supply of ⁵³Mn and ¹⁴⁶Sm, 2) that the r-process events that slowly admixed new ¹⁰⁷Pd, ¹²⁹I, ¹⁸²Hf, and ²⁴⁴Pu nuclei to the solar system occurred over an interval of several hundred million years prior to solar system formation, and 3) that a massive star, by injecting only material outside its helium-exhausted core into the proto-solar nebula, contributed ²⁶Al, ³⁶Cl, ⁴¹Ca, ⁶⁰Fe, and ¹⁸²Hf no more than one million years prior to the Sun's birth. In this picture, the live ¹⁸²Hf present in the early solar system was not due to r-process production but rather to a fast s-process in helium or carbon burning shell in the massive star. We conclude with a possible chemical-memory explanation for the putative ⁵³Cr/⁵²Cr gradient in the solar system. This revised version was published online in June 2006 with corrections to the Cover Date.     

Conductance of the channels and the knudsen paradox

In this paper, a physical model of gas flows through the channels is refined. The influence of gas absorbed by the walls of a channel on its conductance is shown. The experimentally obtained minimum on the channel conductance-pressure dependence (as the Knudsen paradox) is interpreted.     

Physical and chemical characteristics of the ISM inside and outside the heliosphere

This paper summarizes some of the discussions of working group 8–9 during the ISSI Conference on The Heliosphere in the Local Interstellar Medium. Because the subject of these working groups has become significantly broader during the last ten years, we have selected three topics for which recent observations have modified and improved our knowledge of the heliosphere and the surrounding interstellar medium. These topics are the number densities and ISM ionization states of hydrogen and helium, the newly discovered hot gas from the H wall seen in absorption, and the comparison between ISM and heliospheric minor element abundances. Papers from this volume in which more details on these topics can be found are quoted throughout the report.     

增稳锥套与软管二级摆建模与仿真

为给增稳锥套的概念设计提供一种仿真验证平台,提出了一种简化的软管与增稳锥套二级摆模型,建立了其运动模型,并进行了仿真研究。首先,使用三维建模软件UG设计了一种加装"十字形"舵面的增稳锥套,通过CFD方法计算得到此锥套在不同迎角下的气动系数,并采用一元线性回归方法对气动系数进行拟合。然后,给出了二级摆模型,建立了其运动学与动力学方程,进一步搭建了其MATLAB/Simunlink仿真模型。最后,利用前面拟合所得的气动系数进行了仿真,获得了稳定气流中增稳锥套的静力平衡位置,为增稳锥套的进一步主动增稳控制方法研究奠定了仿真验证平台基础。