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611.
The residual stress generated in the manufacturing process of inertial platform causes the drift of inertial platform parameters in long-term storage condition.However,the existing temperature cycling experiment could not meet the increased repeatability technical requirements of inertial platform parameters.In order to solve this problem,in this paper,firstly the Unigraphics(UG) software and the interface compatibility of ANSYS software are used to establish the inertial platform finite element model.Secondly,the residual stress is loaded into finite element model by ANSYS function editor in the form of surface loads to analyze the efficiency.And then,the generation based on ANSYS simulation inertial platform to accelerate the stability of experiment profile is achieved by the application of the analysis method of orthogonal experimental design and ANSYS thermal-structural coupling.The optimum accelerated stability experiment profile is determined finally,which realizes the rapid,effective release of inertial platform residual stress.The research methodology and conclusion of this paper have great theoretical and practical significance to the production technology of inertial platform. 相似文献
612.
Teleoperation rendezvous and docking can be used as a backup for autonomous rendezvous and docking(RVD) for an unmanned spacecraft when the autonomous system is failure or for guiding the chaser docking with an uncooperative target.The theoretical model for analyzing the handling qualities in teleoperation RVD process is established based on the previous studies conducted by National Aeronautics and Space Administration(NASA).The predictive factor is introduced to describe the pilot’s predictive ability in the teleoperation tasks with time delay,which interrelates with the skills of a pilot and the predictive assist approach used in the tasks such as the predictive display method.Based on the semi-physical simulation system in our laboratory,900 experiments at two levels of time delay are carried out by 18 volunteers for validating the established model.The experimental results demonstrate the correctness of the theoretical model and indicate that a skilled pilot has a predictive ability of approximately 0.9 in teleoperation RVD tasks.The theoretical analysis shows that the handling qualities are greatly affected by the time delay and the predictive factor,and it is impossible to achieve a teleoperation RVD task for the skilled pilot when the time delay is larger than 9.0 s. 相似文献
613.
研究了降雨的自然特性,分析了降雨条件下机翼表面复杂的物理现象.重点从实验测试和数值模拟两方面论述了国内外关于降雨对飞机气动性能影响的研究进展,内容涉及降雨条件下机翼的气动性能损失、降雨对机翼气动性能的影响机理和机翼对各种影响因素的敏感度研究等方面.指出了当前国内外关于这一研究在自然飞行测试、实验相似准则、风洞实验中边界层固定转捩和多相流数值建模等方面所面临的关键问题和重大技术挑战. 相似文献
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农村土地流转与农户权益保障研究——以成都统筹试验区为例 总被引:5,自引:0,他引:5
沈茂英 《郑州航空工业管理学院学报(管理科学版)》2008,26(5):34-39
城乡生产要素流动是统筹城乡发展的基础,而土地是最基本的生产要素之一。随着统筹城乡发展的积极推进,农地流转呈现加速发展态势,并由此带来流转农户的权益保障问题。文章以成都统筹试验区为例,对统筹城乡试验区内的土地入股、土地租赁和土地互换三种典型模式进行全面分析,指出土地流转后农户权益保障存在诸多困境,主要表现为:农户面临基本生计转型困境、农地转用的远期权益保障困境、农地流转收益不确定困境以及劳动力就业收益实现困境,等等。为此,提出保障农户权益的五项措施,即:规范土地流转程序、完善农村社会保障体系、加强对租赁业主的服务监管、积极推行就业培训和建立土地流转风险基金。 相似文献
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R.A. Nymmik 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008
This work analyses basic issues of conformity of the most well-known models of solar energetic particles (SEP) fluxes to the experimental data. It is shown, that the postulates on neglecting SEP fluxes in quiet Sun years and on invariability SEP fluxes in active Sun years, underlying some models, contradict the experimental data. 相似文献