The early history of pulse compression radar-the development ofAN/FPS-17 coded-pulse radar at Lincoln Laboratory

The development of pulse compression radar at MIT Lincoln Laboratory is related on the basis of the author's personal recollections. He describes the formation of the Radar Techniques Group, the development of the concept, the first system constructed, and the selection of an appropriate code for the transmitted waveform     

A short history of the European Transonic Wind Tunnel ETW

This paper is written as a contribution to the celebration of 50 years of Progress in Aerospace Sciences and of the centenary of the birth of its founder, Dietrich Küchemann. It reviews the evolution of the European Transonic Wind Tunnel, ETW, from early conceptual studies to its entry into service and its current capabilities and achievements. It traces the development, from the earliest days, of experimental aerodynamics and of the basic aerodynamic understanding that gave rise to the main periods of wind tunnel building before and after World War II. By about 1960, this activity appeared to have come to a natural halt. The paper gives an account of the role of Küchemann in arguing the need in 1968 for a further step in wind tunnel capability, to provide transonic testing at high Reynolds numbers. It describes his leading role in gaining acceptance of the concept, formulating the specification and promoting studies of alternative, radical design options for the co-operative European project that became ETW. The progress of ETW through design, construction, commissioning and into full operation is recorded. The paper discusses the many technical innovations that have been introduced in order to meet customer requirements in the challenging field of aerodynamic testing in a cryogenic environment and, finally, looks to the future and the further technical challenges that it holds.     

Use of service history for certification credit for COTS [avionic software]

Much has been written in the last ten years about how the use of commercial-off-the-shelf (COTS) components would revolutionize the aerospace industry avionics, communication, navigation, surveillance/air traffic management (CNS/ATM) as well as global air traffic management (GATM). Civil aviation authorities around the world have been faced with numerous requests to certify aircraft containing increasing percentages of COTS components, much of it never designed or intended for use in the safety critical environment of an aircraft. Product service history is one method for demonstrating that such software is acceptable for use. In theory, product service history would seem to be a fairly simple concept, both to understand and to apply. However, in practice, such use has proven extremely problematic, as questions of how to measure the historic performance and the relevance of the provided data have surfaced. This paper elaborates a research effort funded by the United States Federal Aviation Administration to collect, analyze, and synthesize what is known and understood about applying product service history. The effort is limited to the topic of software product service history as applied in the certification of airborne systems and equipment.     

A brief history of UWB antennas

This paper provides an historical overview of ultra-wideband antennas presenting key advances at the root of modern designs.     

内部审计理念及其营销

现代内部审计理念在丰富和完善过程中,形成了诸如独立、服务、增值、风险、审计技能多元化以及人际关系等诸多现代管理理念。长期以来,人们对内部审计工作在公司治理、控制和风险管理过程中的作用不能充分认识。因此,内部审计人员需要借助营销学的内容,针对不同群体(董事会和审计委员会、管理层、分(子)公司、被审计单位以及组织整体)采取不同的营销策略,使组织内部各级管理部门和相关人员接受现代内部审计理念,扩大内部审计的影响。     

《工业设计史》课程的深度教学

传统的<工业设计史>课程教学侧重"史实";时代的变迁促进了工业设计学科的发展,要求对其教学上升到"评论"层面;从"评论"的视角挖掘本土资源,是培养学生建立本土特色设计意识的有效途径,教学过程中要善于发现并实施这些基本点,为以后更深入的专业教学打好思想基础.     

变循环发动机总体结构和模式转换机构研究

根据1种涡扇发动机的总体结构设计方案,围绕变循环特征的适应性进行了改进设计,给出了变循环发动机的总体结构初步方案,设计了模式转换原理及其结构实现方案;以其可调面积涵道引射器的设计为例,进行了模式转换机构运动仿真及其关键件的有限元分析,从机构运动和强度分析方面确定了该方案的可行性.     

Aerodynamic Design and Analysis of a Low-reaction Axial Compressor Stage

There is introduced a new low-reaction, highly-loaded axial compressor design concept which is coupled with boundary layer suction method. The characteristic features of the concept are made clear through its comparison with the MIT boundary layer suction compressor. Also are pointed out the potential applications of this concept as well as its key technological problems. Based on this concept, a single-stage, low-reaction and low-speed axial compressor is constructed in association with analysis and computation of boundary layer suction on vanes with the aid of a three-dimensional numerical approach. The results attest to the effectiveness of this way to control separation in blade cascades by the boundary layer suction and the feasibility of this proposed design concept.     

Not invented here? Check your history

The operations of the US Army Corps of Engineers' Manhattan Project, started on September 17, 1942, are examined as an example of US success in R&D     

The history of communications-from cave drawings to mail messages

The considerations that shaped human communication over time are identified and used as a framework for discussing the early history of communication. The communication means examined include voice, drumbeat, horn and whistle, fire, and letters     

民用航空涡轮发动机持久试验条款发展历程

全面回顾了航空发动机适航规章CCAR-33R2第33.87条持久试验的演变历程,在解读适航规章条款要求的基础上,深入跟踪了当前国际上针对33.87条持久试验的研究动态。跟踪研究发现,自1957年规定了6 h×25阶段的150 h试验谱以来,涡轮发动机持久试验的主体要求基本保持不变,而涡轮发动机设计则出现了显著的发展。发动机设计技术的进步带来了与适航规章要求不协调的问题,针对该问题当前国际上已开展了150 h持久试验替代试验的探索性研究及应用,虽然现阶段还存在一系列问题有待澄清和解决,但相关研究为我国民用航空发动机适航符合性方法及适航标准制定与修订提供了参考和借鉴。持续深入跟踪国内外适航技术动态,及时采取积极的应对策略,并开展有针对性的条款研究工作,对于提升我国适航技术规章的编制和修订能力具有十分重要的意义。      

邓小平关于加强全民法制观念的思考

邓小平依法治国的思想对全民法制观念的提高提出了要求，实施政治体制改革，依治惩治腐败的思想，为全民法制观念的提高提出了合理的制度前提，市场经济体制的建立使全民法制观念的提高成为客观必要。     

飞机结构的耐久性与损伤容限设计

飞机结构设计思想随着航空技术的发展而不断进步,经历了从静强度、动强度、疲劳强度到断裂强度的变化过程,耐久性/损伤容限设计是当前飞机结构设计规范的核心方法.本文归纳了飞机结构设计思想的发展历程,重点讨论了耐久性/损伤容限设计的基本思想、基本理论和基本方法,有助于深入理解该设计思想的本质.     

论高新技术企业管理者的风险观

在强调企业管理者观念对企业经营活动的作用的基础上，本文指出高新技术企业管理者必须树立正确的风险观念，即时刻具有风险意识，系统认识企业风险，积极应对企业风险，建立风险管理组织，具有“冒风险”精神。     

d—电子理论在单晶高温合金发展中的应用

对ｄ－电子理论在单晶高温合金发展中的应用进行了阐述。介绍了ｄ－电子理论和用此理论设计单晶高温合金的方法和过程。采用此理论对现有单晶合金进行了分析和讨论。     

航空发动机电子控制器可测试性技术应用研究

基于边界扫描的测试思想,提出了1种航空发动机电子控制器可测试性设计方案。通过器件管脚的边界扫描单元,在板级甚至多个目标板组成的复杂系统间,构建了1条在集成电路边界绕行的移位寄存器链,可以实现复杂集成电路的嵌入式测试。该方案还可以实现故障注入,对航空发动机电子控制器机内自测试(B IT)能力进行验证。     

MMWR/FLIR/ATR sensor fusion: proof of concept

To improve the relocatable target capabilities of strategic aircraft, a sensor fusion concept using a millimeter-wave radar (MMWR) and a forward-looking infrared (FLIR) system providing inputs to an auto target recognizer (ATR) has been developed. To prove this concept, a cooperative research effort is being conducted by a group of industry leaders in bomber avionics, MMWR, and ATR technologies. The author discusses the concept and the plan developed to test, evaluate, and demonstrate the expected performance     

高超声速飞行与TBCC方案简介

介绍了TBCC(燃气涡轮发动机为基础的联合(组合)循环)方案,以及以TBCC发动机为动力装置的高超声速攻击机方案。     

A concept of increasing efficiency for ramjet operation

The vortical mixing concept in the ramjet channel is analyzed. The results of simulating the gasodynamic scheme permit the concept of increasing efficiency for ramjet operation to be substantiated.     

Resonant power supplies: their history and status

The various types of converter are described, and the history of resonant power supplies is briefly sketched. The differences between pulse-width-modulated (PWM) switch mode power supplies and resonant power supplies are discussed. Single-switch, multiple-switch, and series and parallel resonant converters are examined. The control of resonant converters is addressed. Hardware is briefly considered