低温上面级和氢氧火箭发动机的研制、生产成本

本文概述了国外低温推进级和氢氧火箭发动机的研制和生产成本问题,可供工程技术人员在设计航天运输系统时参考.     

大功率密封钮子开关的设计

简述了大功率密封钮子开关的研制设计与计算方法，为国内微型化大功率密封钮子开关的研制提供借鉴。     

美国研究人员关注分子规模集成电路

为了制作比以前的体积更小的芯片,美国工业界和大学的科学家们都正在关注新一代集成电路的封装技术。 据美国惠普公司(HP)和洛杉矶加洲大学(UCLA)的研究人员称,他们已获得可能导致生     

"嫦娥"奔月,西昌搭天梯——走进中国探月工程第一港西昌卫星发射中心

公元2007年10月24日18时05分,四川西昌。长征3号甲火箭再一次拔地而起,直刺苍穹。我国探月工程的首颗卫     

METHOD FOR DETECTING AND REPAIRING CYCLE SLIPS IN GPS NAVIGATION

A new method is proposed for detecting and repairing cycle slips in GPS navigation based on the dual frequency observations. It can be implemented through the following three steps: (1) The integer ambiguities of the current epoch are substituted by that of the previous epoch, so the ambiguity parameters are removed from the observation equations. (2) The abnormal observations are detected using the quasi accurate detection (QUAD) method and the satellite pairs of these abnormal observations are determined. Then the coefficient matrix of these satellite pairs is recovered. (3) The cycle slips of these satellite pairs are calculated using the LAMBDA method and integer ambiguities of the current epoch can be determined by adding the cycle slips into the integer ambiguities of the previous epoch. The key of this method is that the abnormal observations must accurately he detected, i.e. , the satellites having cycle slips must correctly be judged. Finally, compared with other methods the feasibility of the method is verified.     

某型机机尾罩多功能焊接夹具的创新设计

介绍了在某型机机尾罩的焊接夹具的设计过程中，将原有的焊接夹具、检验夹具、装配夹具融为一体，进行多功能焊接夹具创新设计，使用后证明装配产品合格率达到100％。