全文获取类型
收费全文 | 111篇 |
免费 | 10篇 |
国内免费 | 18篇 |
专业分类
航空 | 57篇 |
航天技术 | 27篇 |
综合类 | 24篇 |
航天 | 31篇 |
出版年
2023年 | 4篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2016年 | 3篇 |
2015年 | 5篇 |
2014年 | 4篇 |
2013年 | 2篇 |
2012年 | 7篇 |
2011年 | 7篇 |
2010年 | 3篇 |
2009年 | 8篇 |
2008年 | 14篇 |
2007年 | 5篇 |
2006年 | 13篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 6篇 |
2002年 | 2篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1987年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有139条查询结果,搜索用时 15 毫秒
111.
112.
Bruno Mialon Alex Khrabrov Saloua Ben Khelil Andreas Huebner Andrea Da Ronch Ken Badcock Luca Cavagna Peter Eliasson Mengmeng Zhang Sergio Ricci Jean-Christophe Jouhaud Gilbert Rogé Stephan Hitzel Martin Lahuta 《Progress in Aerospace Sciences》2011,47(8):674-694
The dynamic derivatives are widely used in linear aerodynamic models in order to determine the flying qualities of an aircraft: the ability to predict them reliably, quickly and sufficiently early in the design process is vital in order to avoid late and costly component redesigns. This paper describes experimental and computational research dealing with the determination of dynamic derivatives carried out within the FP6 European project SimSAC. Numerical and experimental results are compared for two aircraft configurations: a generic civil transport aircraft, wing-fuselage-tail configuration called the DLR-F12 and a generic Transonic CRuiser, which is a canard configuration. Static and dynamic wind tunnel tests have been carried out for both configurations and are briefly described within this paper. The data generated for both the DLR-F12 and TCR configurations include force and pressure coefficients obtained during small amplitude pitch, roll and yaw oscillations while the data for the TCR configuration also include large amplitude oscillations, in order to investigate the dynamic effects on nonlinear aerodynamic characteristics. In addition, dynamic derivatives have been determined for both configurations with a large panel of tools, from linear aerodynamic (Vortex Lattice Methods) to CFD. This work confirms that an increase in fidelity level enables the dynamic derivatives to be calculated more accurately. Linear aerodynamics tools are shown to give satisfactory results but are very sensitive to the geometry/mesh input data. Although all the quasi-steady CFD approaches give comparable results (robustness) for steady dynamic derivatives, they do not allow the prediction of unsteady components for the dynamic derivatives (angular derivatives with respect to time): this can be done with either a fully unsteady approach i.e. with a time-marching scheme or with frequency domain solvers, both of which provide comparable results for the DLR-F12 test case. As far as the canard configuration is concerned, strong limitations for the linear aerodynamic tools are observed. A key aspect of this work are the acceleration techniques developed for CFD methods, which allow the computational time to be dramatically reduced while providing comparable results. 相似文献
113.
结合某型飞机的研制 ,总结了歼击机配装主动雷达型导弹需要解决的关键技术 ,论述了解决这些关键技术的一般技术途径和方法。 相似文献
114.
115.
Stephen Potter 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,38(12):2832-2835
I discuss methods and results in the use of photo-polarimetry and spectro-polarimetry in the studies of magnetic cataclysmic variables. In particular I show how polarimetry can be used to derive the geometry of the accretion region on the surface of the white dwarf, the accreting geometry of the system as a whole and how polarimetry aides in the interpretation of X-ray/optical photometry and spectroscopy. I finish by describing the high speed spectro-polarimetric capabilities of SALT (Southern African Large Telescope) due for completion in 2005. 相似文献
116.
Optimization problems are often highly constrained and evolutionary algorithms(EAs)are effective methods to tackle this kind of problems. To further improve search efficiency and convergence rate of EAs, this paper presents an adaptive double chain quantum genetic algorithm(ADCQGA) for solving constrained optimization problems. ADCQGA makes use of doubleindividuals to represent solutions that are classified as feasible and infeasible solutions. Fitness(or evaluation) functions are defined for both types of solutions. Based on the fitness function, three types of step evolution(SE) are defined and utilized for judging evolutionary individuals. An adaptive rotation is proposed and used to facilitate updating individuals in different solutions.To further improve the search capability and convergence rate, ADCQGA utilizes an adaptive evolution process(AEP), adaptive mutation and replacement techniques. ADCQGA was first tested on a widely used benchmark function to illustrate the relationship between initial parameter values and the convergence rate/search capability. Then the proposed ADCQGA is successfully applied to solve other twelve benchmark functions and five well-known constrained engineering design problems. Multi-aircraft cooperative target allocation problem is a typical constrained optimization problem and requires efficient methods to tackle. Finally, ADCQGA is successfully applied to solving the target allocation problem. 相似文献
117.
高焓风洞及其试验技术是助力人类进入高超声速飞行时代的基石,近年来取得了长足的进展。本文首先重点介绍了四种典型驱动模式的高焓风洞,即直接加热型高超声速风洞、加热轻气体驱动激波风洞、自由活塞驱动激波风洞和爆轰驱动激波风洞。通过这些代表性风洞的介绍,讨论了相关风洞的理论基础和关键技术及其长处与不足。由于高超声速高焓流动具高温热化学反应特征,风洞试验技术研究还包含着针对高焓特色的测量技术发展。本文介绍了三种主要测量技术:气动热测量技术、气动天平技术和光学测量技术。这些技术是依据常规风洞试验测量需求而研制的,又根据高焓风洞的特点得到了进一步的改进和完善。最后对高超声速高焓风洞试验技术发展做了简单展望。 相似文献
118.
在传统结构优化设计中.基于近似技术和灵敏度分析的结构重分析技术可以显降低结构有限元分析的次数。本提出了一套适于遗传算法应用的近似模型——分段近似模型。该分段近似模型可以极大地降低结构有限元分析的次数,并且可以提高遗传算法的收敛性,从而提高遗传算法的计算效率。本通过两个实例验证了该分段近似模型的有效性。 相似文献
119.
眼动分析技术及其在航空领域的应用进展 总被引:1,自引:0,他引:1
分析了眼动仪系统构成与原理,对几种典型眼动仪进行了性能比较。讨论了国内外眼动跟踪技术在航空领域的研究成果以及应用状况,对其应用研究特点进行了分析总结。最后,对在民用航空领域开展人为因素眼动系统研究的方法与前景进行了探讨和展望。 相似文献
120.
气动中心1.2米高速风洞外挂物可控轨迹系统中的测、控、处系统是一个由电子计算机闭环控制以获得外挂物由其母机上分离的轨迹的大系统,已多次成功用于测定外挂物分离轨迹的试验,表明其操作方便、控制灵活和可靠、精度高、抗干扰能力强,适用于进行各种外挂物的可控轨迹试验。 相似文献