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991.
谭燕 《中国民航飞行学院学报》2011,22(4):24-26,29
介绍了CFM56-7B发动机的启动过程,说明了其热启动和启动悬挂时的故障现象。根据影响发动机启动的一些主要因素,对造成CFM56-7B发动机热启动和启动悬挂的原因进行了分析,为排除此类故障提供了依据。 相似文献
992.
针对相对疏松的铸造钛合金和相对密实的锻造钛合金的焊接问题,开展了两种状态的TC4钛合金电子束焊接工艺研究,对比了不同焊接参数对焊接质量的影响。研究结果表明,采用方波扫描可以较好地实现铸造钛合金与锻造钛合金的连接,焊缝成形良好,内部无缺陷;焊接接头力学性能分析表明,拉伸断裂位置全部在铸件母材区一侧。实焊结果证明,电子束焊接可以实现异种状态TC4钛合金焊接的工程化应用。 相似文献
993.
In706合金经650℃×500h,1000h长期时效处理后,测定显微组织和力学性能.试验结果表明,In706合金组织稳定,高温持久断裂寿命、塑性亦较高,可用于航空发动机涡轮盘、轴类转动部件. 相似文献
994.
小普托卷接机在烟厂中主要用于烟的生产试制,由于原机电气故障频发,维修费用昂贵,致使其无法正常运行,急需改造。改造后的系统采用FX2N PLC、FX2N-4D/A、MR-J2S-A伺服放大器、HC-KFS伺服电机以及F940GOT-SWD-C图形操作终端,实现了对烟支长度的控制。文中介绍了系统硬件组成、参数设定、软件设计以及运行结果。 相似文献
995.
臧天杰 《华北航天工业学院学报》2003,13(4):36-41
中日两国是一衣带水、隔海相望的近邻,有着两千多年的交往历史。在政治、经济、文化等诸多领域,两国人民始终有着密切的联系,特别是中国传统文化对日本本土文化的形成和发展产生了重大影响。本文通过在日本发现的大量中国文物,结合文献资料,从宏观上回顾了10世纪以前的中日物质文化交流。在此基础上,选取中国与日本发现的唐代铜镜为主要依据,在微观上对中日物质文化交流的实态、意义以及日本民族对待先进外来文化积极继承和发扬的态度进行思考、研究。 相似文献
996.
In 2012 we celebrate the 70th anniversary of the first successful rocket launch that reached a height of 84.5 km and had a speed of 4.824 km/h (5x sonic speed). This rocket flew 190 km to the target location. One of the masterminds of this launch was Walter Thiel, a German chemist and rocket engineer. Thiel was highly talented, during his education from primary school until diploma exams he always received a grade of A in his exams. He was called “the student with the 7 A grades”. In 1934 Thiel became Dr.-Ing. (chem.), with the highest possible honor (summa cum laude), when he was only 24 years old. He started to work for the rocket development department at Humboldt University, Berlin. Walter Dornberger asked him to leave the university research department and become head of rocket propulsion development in his team in Kummersdorf, near Berlin. Thiel's groundbreaking ideas for the rocket engine would lead to a significant reduction in material, weight and work processes, as well as a shortening in the length of the engine itself. Thiel and his team also defined the fuel itself and the best ratio of mixture between ethanol and liquid oxygen for the engine. In 1940 the propulsion team moved from Kummersdorf to Peenemünde after the launch sites were completed there. Thiel became deputy of Wernher von Braun at the R&D units. One of Thiel's team members was Konrad Dannenberg, who later became famous in the development of the Saturn program. On the night from August 17 to August 18, 1943, Thiel and his family (wife and two children) were killed during a Royal Air Force bombing raid (Operation Hydra). The Moon crater “Thiel” on the far side of the Moon is named after Walter Thiel. The research results of Walter Thiel had a strong impact on the United States' rocket program as well as the Russian rocket development program. 相似文献
997.
HY-1A is China's first ocean color satellite, and was launched on 15 May 2002as a piggyback satellite on the FY-1D satellite using the Long March rocket.There are two sensors on the satellite: China's Ocean Color and Temperature Scanner (COCTS), and the CCD Coastal Zone Imager (CZI). In the report,first, the properties and characteristics of HY-1A are briefly introduced; Second, the quality and availability of the data are evaluated by the mean of the Complex Signal Noise Ratio (CSNR) which is simulated theoretically; Third,the received HY-1A data are compared with SeaSTAR data to understand the accuracy of radiance measurement by the HY-1A; Finally, the remote sensing products of ocean color and temperature are mapped by HY-1A to study its application potentiality. The results show that the HY-1A has a latent capability for the application of marine environment detection, the management and protection of marine resources, and the furthering of national rights and interests.Meanwhile, some modifications are proposed for the next ocean satellite, suchas adding the case of tilt scanning, modification of the CCD element uniformity,and adding more ocean satellite receiving stations. 相似文献
998.
型材一次折斜角成形是航空零件制造工艺的重要方法之一。本文通过新研制的5A90铝锂合金型材折斜角成形试验的研究,得到了极限开斜角和闭斜角值,为新机的设计及生产工艺提供了重要的指导依据。 相似文献
999.
1000.
程湛汪光文苏和平 《民用飞机设计与研究》2014,(2):59-61
民用飞机的排烟能力直接影响到座舱出现烟雾情况下的飞行安全,对CCAR 25.831(d)条款和对应的咨询通告25-9A进行研究,为民用飞机座舱排烟的设计和适航验证提供支持。 相似文献