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921.
2004年,国际民航组织出台了成员国航空运输人员英语熟练度要求,并制定了相关考核和培训标准,这对于我国飞行员和管制员职业化的英语通话教学提出了新的要求。本文分析了该标准与以往所执行相关标准的区别,并根据新的要求对养成学生职业能力培养阶段陆空通话课程教学模式改革提出了目标和方法。笔者还进行了改革实践,对效果进行了评估分析。本文也为我国民航人才的陆空通话能力培养提出了相关建议。 相似文献
922.
923.
简要介绍了末端能量管理的研究情况,然后对末端能量管理段进行轨迹规划。在轨迹规划的基础上,设计基于滑模变结构控制的制导律,对轨迹进行跟踪,对能量进行管理。仿真结果表明,滑模变结构控制在末端能量管理制导中合理、有效,具有很强的鲁棒性。 相似文献
924.
Nonlinear flutter wind tunnel test and numerical analysis of folding fins with freeplay nonlinearities 总被引:1,自引:0,他引:1
《中国航空学报》2016,(1):144-159
The flutter characteristics of folding control fins with freeplay are investigated by numerical simulation and flutter wind tunnel tests. Based on the characteristics of the structures, fins with different freeplay angles are designed. For a 0° angle of attack, wind tunnel tests of these fins are conducted, and vibration is observed by accelerometers and a high-speed camera. By the expansion of the connected relationships, the governing equations of fit for the nonlinear aeroelastic analysis are established by the free-interface component mode synthesis method. Based on the results of the wind tunnel tests, the flutter characteristics of fins with different freeplay angles are analyzed. The results show that the vibration divergent speed is increased, and the divergent speed is higher than the flutter speed of the nominal linear system. The vibration divergent speed is increased along with an increase in the freeplay angle. The developed free-interface component mode synthesis method could be used to establish governing equations and to analyze the characteristics of nonlinear aeroelastic systems. The results of the numerical simulations and the wind tunnel tests indicate the same trends and critical velocities. 相似文献
925.
钱津 《郑州航空工业管理学院学报(管理科学版)》2005,23(2):18-22
资本主义股份制是资本主义生产方式范围内的一种消极扬弃,马克思在<资本论>中对此做了深刻的阐述.马克思强调,资本主义股份制的产生带来私人资本向社会资本转化及私人企业向社会企业转化的社会进步;具有扩大生产规模聚集能力的资本主义股份制是资本主义生产方式向联合的生产方式转化的过渡形式. 相似文献
926.
We present a preliminary analysis of two quiet Sun transition region areas observed with the SOHO/SUMER spectrometer, using
lines from oxygen, nitrogen and silicon. The average quiet Sun physical parameters are studied as a function of line intensity.
Systematic variations of line position and width with increasing intensity are found. A large number of small-scale active
points have been observed, and preliminary analysis of the physical properties and dynamics of these active features is presented.
A jet-like structure, found in an active point, is also investigated and its velocity along the line of sight determined.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
927.
在知识经济时代,社会在突飞猛进地发展。为了更好地适应发展中的时代,高等院校必须要更新教育观念,深化教育改革,构建高校创新型人才培养模式,担负起全面推进素质教育,培养高素质的创新型人才的历史使命。 相似文献
928.
P. Lemaire 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2007,39(12):1876-1881
The two XUV–EUV spectrometers on SOHO have collected a large amount of data in the 6000–106 K solar plasma temperature range. These data have allowed us to greatly enhance our knowledge of the processes acting in the solar atmosphere, from the chromosphere to the corona. Some results on the quiet Sun structure (network, quiet Sun versus coronal hole), on the dynamics (velocities, waves, transient events), and the main characteristics of the quiet Sun atmosphere are presented and discussed. 相似文献
929.
王娜 《长沙航空职业技术学院学报》2007,7(4):27-29
PDCA模式是企业实施目标管理而经常运用的一种管理方法。在介绍PDCA模式的基础上,将其引入高职英语教学管理;论述教学计划、教学实施、教学检查和教学评价(PDCA)四个阶段中管理人员和教学人员的工作内容和工作重点。 相似文献
930.
《中国航空学报》2016,(3):688-703
An adaptive sliding mode control(ASMC) law is proposed in decentralized scheme for trajectory tracking control of a new concept space robot.Each joint of the system is a free ball joint capable of rotating with three degrees of freedom(DOF).A cluster of control moment gyroscopes(CMGs) is mounted on each link and the base to actuate the system.The modified Rodrigues parameters(MRPs) are employed to describe the angular displacements,and the equations of motion are derived using Kane's equations.The controller for each link or the base is designed separately in decentralized scheme.The unknown disturbances,inertia parameter uncertainties and nonlinear uncertainties are classified as a ‘‘lumped" matched uncertainty with unknown upper bound,and a continuous sliding mode control(SMC) law is proposed,in which the control gain is tuned by the improved adaptation laws for the upper bound on norm of the uncertainty.A general amplification function is designed and incorporated in the adaptation laws to reduce the control error without conspicuously increasing the magnitude of the control input.Uniformly ultimate boundedness of the closed loop system is proved by Lyapunov's method.Simulation results based on a three-link system verify the effectiveness of the proposed controller. 相似文献