全文获取类型
收费全文 | 188篇 |
免费 | 8篇 |
国内免费 | 25篇 |
专业分类
化学 | 7篇 |
力学 | 167篇 |
数学 | 9篇 |
物理学 | 38篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 1篇 |
2020年 | 9篇 |
2019年 | 13篇 |
2018年 | 1篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 12篇 |
2014年 | 19篇 |
2013年 | 14篇 |
2012年 | 7篇 |
2011年 | 16篇 |
2010年 | 7篇 |
2009年 | 14篇 |
2008年 | 12篇 |
2007年 | 11篇 |
2006年 | 12篇 |
2005年 | 10篇 |
2004年 | 8篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1996年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1979年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有221条查询结果,搜索用时 0 毫秒
71.
Fumiya Togashi Takeshi Fujita Yasushi Ito Kazuhiro Nakahashi Yoshikazu Makino 《国际流体数值方法杂志》2005,48(8):801-818
Flows around the NAL jet‐powered experimental airplane with a small rocket booster under the fuselage are computed by solving the Euler equations using the overset unstructured grid method. The main objective of the present study is to evaluate the effect of a small rocket booster, which accelerates the airplane to supersonic speed, on the aerodynamic performance of the airplane during the ascent flight and the booster separation. Two unstructured meshes, one for the airplane and one for the booster, overlap. For the accurate separation simulation, the two bodies are in contact at first, and then the booster mesh is contact mesh is moved relative to the airplane mesh to evaluate flow interactions between two bodies. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
72.
73.
Ruimin Sun 《力学快报》2011,1(3):032001
The tip vortices and aerodynamics of a NACA0012 wing in the vicinity of the ground were studied in a wind tunnel. The wing tip vortex structures and lift/drag forces were measured by a seven-hole probe and a force balance, respectively. The evolution of the flow structures and aerodynamics with a ground height were analyzed. The vorticity of tip vortices was found to reduce with the decreasing of the ground height, and the position of vortex-core moved gradually to the outboard of the wing tip. Therefore, the down-wash flow induced by the tip vortices was weakened. However, vortex breakdown occurred as the wing lowered to the ground. From the experimental results of aerodynamics, the maximum lift-to-drag ratio was observed when the angle of attack was 2.5° and the ground clearance was 0.2. 相似文献
74.
耦合求解NS方程和刚体动力学方程数值模拟80°后掠三角翼强迫俯仰、自由滚转双自由度耦合运动特性,研究了转动惯量、轴承机构阻尼、翼面流态以及俯仰运动频率、振幅、平均俯仰角等因素对三角翼俯仰、滚转双自由度耦合运动特性的影响。结果表明:机翼的转动惯量和轴承的机械阻尼显著影响自由滚转的频率和振幅;在转动惯量、轴承摩擦和湍流等多种因素的共同影响下,三角翼的双自由度运动可能会形成台阶形式的振荡曲线;俯仰运动的振幅、频率以及平均俯仰角对强迫俯仰、自由滚转双自由度耦合运动特性存在不同程度的影响。 相似文献
75.
76.
O.M. AAMO T.I. FOSSEN 《Mathematical and Computer Modelling of Dynamical Systems: Methods, Tools and Applications in Engineering and Related Sciences》2013,19(1):47-75
In this paper, we develop a new finite element model for a cable suspended in water. Global existence and uniqueness of solutions of the truncated system is shown for a slightly simplified equation describing the motion of a cable with negligible added mass and supported by fixed end-points. Based on this, along with well known results on local existence and uniqueness of solutions for symmetrizable hyperbolic systems, we conjecture a global result for the initial-boundary value problem. The FEM model for the cable is assembled to give a model of a multi-cable mooring system, which, in turn, is coupled to a rigid body model of the floating vessel. The result is a coupled dynamical model of a moored vessel, which can be applied to applications such as turret-based moored ships, or tension leg platforms. 相似文献
77.
Hydrophobic nano silver films were fabricated on butterfly wings as bio-template. The micrometric/nano structures and hydrophobicity of the surfaces were investigated with the help of scanning electron microscope(SEM) and video-based contact angle meter. The hydrophobic mechanism of silver film was analyzed with the aid of Cas- sie's formula. On the nano silver films of various thicknesses(5, 10, 20, 40, 60, 80, 100 nm), all the contact an- gles(CAs) of water were bigger than 120°. When the silver film was 5 nm, the CAs of water on it on the wing surfa- ces of Mimathyma nycteis and Speyeria aglaja were 143.2° and 139.2°, respectively. Coated with the sliver film of the same thickness, butterfly wing surface exhibited the CA remarkably bigger than glass slide surface, exhibiting its high hydrophobicity. With the increase of silver film thickness on butterfly wing surface, the hydrophobicity kept de- creasing. The micrometric/nano hierarchical structures on butterfly wing surface result in the transition of metal silver from hydrophilicity to hydrophobicity. 相似文献
78.
Y. Pu 《Optics Communications》2009,282(21):4308-1322
Time-resolved polarization-dependent kinetics of near infrared (NIR) spectral wing (SW) emission from human cancerous and normal prostate tissues was investigated. The differences between the temporal profiles, intensities and polarization properties of SW emission from cancerous and normal prostate tissues were observed. The intensity of SW emission from cancerous prostate tissue at peak position was found ∼2 times stronger than the normal prostate tissue indicating changes of fluorophores contained in the cancerous tissue compared with normal tissue. The decay time of anisotropy of SW emission from cancerous tissue was found ∼1.4 times longer than that of normal tissue reflecting changes of the micro-environment of fluorophores in the cancerous tissue as compared with the normal tissue. The stronger intensity of SW emission from cancerous tissue was used to image and identify cancerous areas surrounded by normal tissue. 相似文献
79.
80.
LIU Yang ZUO LinXuan & WANG JinJun Institute of Fluid Mechanics Beijing University of Aeronautics Astronautics Fluid Mechanics Key Laboratory Ministry of Education Beijing China 《中国科学:物理学 力学 天文学(英文版)》2010,(5)
Force measurement and surface oil flow visualization experiments were conducted in a wind tunnel to investigate the effects of flexibility on aerodynamic performance of delta wings with different sweep angles.The experimental results indicate that the maximum lift coefficient is increased and the stall angle is delayed as the sweep angle increases for both rigid and flexible wings.It is also found that the maximum lift coefficients of the flexible wings with a sweep angle from 35° to 50° are higher than those of the rigid ones.The increment of the maximum lift coefficient in particular achieves 32.9% compared with the case without lift enhancement for the 40° flexible delta wing.Moreover,the surface oil flow visualization experiments show that the stall of the flexible wing of the moderate low sweep angle is accompanied by helical flow structure,while the vortex bursting appears on the corresponding rigid wing. 相似文献