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171.
PEPEC考试现状调查研究——以中国民航飞行学院为例   总被引:2,自引:2,他引:0  
近年来,各航空公司及相关单位积极实施民航英语系统工程,想方设法提高民航飞行人员的英语能力。中国民航飞行员英语等级考试(PEPEC)作为检验飞行员英语水平的重要手段,其测试结果在一定程度上反映了飞行技术专业学生英语教学工作和民航英语系统工程的重要成果与得失。本研究通过问卷调查、教学实践和访谈等形式多方面调查中国民航飞行学院飞行技术专业学生英语水平和PEPEC考试现状,并根据调查结果提出相应的飞行学生英语教学启示,进一步提高飞行技术专业学生英语综合能力,特别是英语听说能力,以适应未来工作的需要。  相似文献   
172.
中外合作办学已经成为我国高等教育中独特的办学模式,教学质量监控是中外合作办学发展的重要保证。要想使中外合作办学教学质量得到保障,必须掌握所开设的课程改革情况,必须对课程改革方式进行调研,查找出目前考核方式的不足之处,及时修改课程标准,加强教学内容整合,完善项目选择,平衡理论讲授和技能考核,探索对小组学习及互评方式的改进,以便进一步建立和完善中外合作学院教学质量的内部监控体系与运行机制。  相似文献   
173.
通过对航图课程的特点和学习方法进行分析,从学生和教师两方面出发,探讨了理论+实践教学实施的过程,提出了充分利用航图资料、模拟飞行实验室和JeppView软件等多种可用的教学资源,采取实践教学和因材施教相结合的手段,合理整合教学资源,调整教学内容,改革考核方式的几点建议。  相似文献   
174.
The Experimental Satellite on Electromagnetism Monitoring (ESEM) was proposed in 2003 and proved in 2013 after 10-years' scientific demonstration. The ESEM mission was proposed to be the first satellite of space-based geophysical fields observation system in China with a lot of application prospects in earthquake science, geophysics, space sciences and so on. And coincide with the mission objectives, the satellite decides to use the Circular Sun Synchronous Orbit with an altitude of 507km and descending node time at 14:00LT. The payload assemble includes 8 instruments, Search-Coil Magnetometer, Electric Field Detector, High precision Magnetometer, GNSS occupation Receiver, Plasma Analyzer, Langmuir Probe, Energetic Particle Detector, and Three-frequency Transmitter. According to the planned schedule, the satellite is due to be launched in 2016-2017 and will be onboard operated for 5 years.   相似文献   
175.
Knowledge of the thermal behavior of airships is crucial to the development of airship technology. An experiment apparatus is constructed to investigate the thermal response characteristics of airships, and the transient temperature distributions of both hull and inner gas are obtained under the irradiation of a solar simulator and various airflow conditions. In the course of the research, the transient temperature change of the experimental airship is measured for four airflow speeds of 0 m/s (natural convection), 3.26 m/s, 5.5 m/s and 7.0 m/s, and two incident solar radiation values of 842.4 W/m2 and 972.0 W/m2. The results show that solar irradiation has significant influence on the airship hull and inner gas temperatures even if the airship stays in a ground airflow environment where the heat transfer is dominated by radiation and convection. The airflow around the airship is conducive to reduce the hull temperature and temperature nonuniformity. Transient thermal response of airships rapidly varies with time under solar radiation conditions and the hull temperature remains approximately constant in ∼5–10 min. Finally, a transient thermal model of airship is developed and the model is validated through comparison with the experimental data.  相似文献   
176.
《中国航空学报》2021,34(7):211-218
The morphing wing concept aims to constantly adapt the aerodynamics to different flight stages. The wing is able to adapt to different flight conditions by an adjustable Aspect Ratio (AR) and sweep. A high AR configuration provides high aerodynamic efficiency, while a low AR configuration, with highly swept wings offers a good maneuverability. Additionally, the flexible membrane allows the wing surface to stretch and contract in-plane as well as the airfoil to adapt to different aerodynamic loads. In the context of this work, the aerodynamic characteristics of a full model with form-adaptive elasto-flexible membrane wings are investigated experimentally. The focus is on the high-lift regime and on the analysis of the aerodynamic coefficients as well as their sensitivities. Especially, the lateral aerodynamic derivatives at asymmetric wing positions are of interest.  相似文献   
177.
《中国航空学报》2021,34(8):143-163
The forming of textile reinforcements is an important stage in the manufacturing of textile composite parts with Liquid Composite Molding process. Fiber orientations and part geometry obtained from this stage have significant impact on the subsequent resin injection and final mechanical properties of composite part. Numerical simulation of textile reinforcement forming is in strong demand as it can greatly reduce the time and cost in the determination of the optimized processing parameters, which is the foundation of the low-cost application of composite materials. This review presents the state of the art of forming modeling methods for textile reinforcement and the corresponding experimental characterization methods developed in this field. The microscopic, mesoscopic and macroscopic models are discussed. Studies concerning the simulation of wrinkling are also presented since it is the most common defect occurred in the textile reinforcement forming. Finally, challenges and recommendations on the future research directions for textile reinforcement modeling and experimental characterization are provided.  相似文献   
178.
《中国航空学报》2021,34(10):248-264
This study presents a method for measuring the imbalance in a small-sized cylindrical roller. The roller imbalance was calibrated on the built static-pressure-air flotation measurement machine. The impact of the roller imbalance on the dynamic characteristics of a cage were then studied on the aero-bearing test rig. The displacement spectrums with different roller imbalance of the obtained cage orbits under various bearing speed and radial load were used to evaluate the cage stability. The results show that the cage cannot form a stable operating state at a lower bearing speed with or without the unbalanced rollers. The cage with balanced rollers gradually develops stable motion with the increase of the bearing speed. The existence of a small roller imbalance causes the stability of the cage to deteriorate. With an increase in the bearing speed and radial load, the cage with the unbalanced rollers runs unsteadily accompanied by a high-frequency vibration when the roller imbalance is large enough. The vibration amplitude of the cage in the horizontal direction is greater than that in the vertical direction during an unstable operation, which is similar in the stable status.  相似文献   
179.
王西耀  赵慧勇  谭宇 《推进技术》2021,42(10):2367-2376
为了在冲压发动机试验过程中丰富试验参数类别和提高参数分析速度,针对直连式超燃冲压发动机,原创性地提出了基于壁面压力测量结果的试验参数分析方法。该方法引入原子流量守恒方程 构建了封闭方程组,在无需任何额外测量仪器的条件下,以壁面压力、来流参数和燃烧室面积变化律为输入,求解方程组可快速获得超燃冲压发动机的马赫数、温度、速度、组份浓度、燃烧效率等参数。结合三维数值计算和地面试验,通过两个算例对该方法的可行性进行了验证。结果表明,该算法可以获得较高的精度,在燃烧室出口,速度、温度等误差均在5%以内,组份浓度分布和数值结果非常吻合。  相似文献   
180.
《中国航空学报》2020,33(12):3100-3111
To predict the flutter dynamic pressure of a wind tunnel model before flutter test, an accurate Computational Fluid Dynamics/Computational Structural Dynamics (CFD/CSD)-based flutter prediction method is proposed under the conditions of a 2.4 m × 2.4 m transonic wind tunnel with porous wall. From the CFD simulations of the flows through an inclined hole of this wind tunnel, the Nambu’s linear porous wall model between the flow rate and the differential pressure is extended to the porous wall with inclined holes, so that the porous wall can be conveniently modeled as a boundary condition. According to the flutter testing approach for the current wind tunnel, the steady CFD calculation is conducted to achieve the required inlet Mach number. A time-domain CFD/CSD method is then employed to evaluate the structural response of the experimental model, and the critical flutter point is obtained by increasing the dynamic pressure step by step at a fixed Mach number. The present method is applied to the flutter calculations for a vertical tail model and an aircraft model tested in the current transonic wind tunnel. For both models, the computed flutter characteristics agree well with the experimental results.  相似文献   
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