全文获取类型
收费全文 | 1096篇 |
免费 | 66篇 |
国内免费 | 243篇 |
专业分类
航空 | 1001篇 |
航天技术 | 158篇 |
综合类 | 194篇 |
航天 | 52篇 |
出版年
2023年 | 5篇 |
2022年 | 15篇 |
2021年 | 24篇 |
2020年 | 21篇 |
2019年 | 33篇 |
2018年 | 23篇 |
2017年 | 35篇 |
2016年 | 45篇 |
2015年 | 49篇 |
2014年 | 52篇 |
2013年 | 46篇 |
2012年 | 73篇 |
2011年 | 72篇 |
2010年 | 58篇 |
2009年 | 71篇 |
2008年 | 78篇 |
2007年 | 58篇 |
2006年 | 52篇 |
2005年 | 58篇 |
2004年 | 38篇 |
2003年 | 48篇 |
2002年 | 40篇 |
2001年 | 59篇 |
2000年 | 30篇 |
1999年 | 47篇 |
1998年 | 28篇 |
1997年 | 31篇 |
1996年 | 47篇 |
1995年 | 32篇 |
1994年 | 31篇 |
1993年 | 25篇 |
1992年 | 16篇 |
1991年 | 20篇 |
1990年 | 16篇 |
1989年 | 11篇 |
1988年 | 14篇 |
1987年 | 2篇 |
1986年 | 2篇 |
排序方式: 共有1405条查询结果,搜索用时 328 毫秒
1.
Space Science Reviews - We discuss afresh the problem of the auroral electron acceleration based on the controversy reports of Bryant, D. A. et al.: 1992, Phys. Rev. Lett. 68, 37, and Borovsky, J.:... 相似文献
2.
李园庭 《南昌航空工业学院学报》1997,(2):62-66
本文讨论了下面问题的分歧点的存在性:-pxi〔(1+|u|2)p2-1uxi〕=μu+f(x,u),x∈RNu(x)→0,当|x|→+∞时,u0,μ∈R1,N>p≥2{证明了μ=0是上述问题的分歧点。 相似文献
3.
A numerical procedure for the calculation of the transonic dip of airfoils in the time domain is presented. A viscous-inviscid aerodynamic interaction method is taken to calculate the unsteady aerodynamic loads. In the present case the integral boundary layer equations are coupled with the Transonic Small Disturbance (TSD) Potential Equation. The coupling between structural motion and aerodynamic loads is carried out using State Space equation. It is solved by State Transition Matrix technique. Results are presented for NACA 64A010 and NLR 7301 airfoils with structural data from Isogai and DLR, respectively. Comparisons show good agreement with other numerical results. Certain deviations of experimental data taken from literature need more insight in the detailed test conditions. 相似文献
4.
The earth's foreshock is a region where particularly large amplitude MHD waves are commonly observed. They exhibit various
waveforms, suggesting that nonlinear interaction between the waves is in progress. In a previous paper (Hada et al., 2003) we have introduced a method to quantitatively evaluate the strength of phase coherence among the waves from a given
time series data. Here we further develop our method by applying wavelet filtering technique. From the analysis it was found
that, although the turbulence is consisted of waves with a wide range of plasma rest frame frequencies, only those frequencies
lower than the ion gyrofrequency are responsible for generating the phase coherence.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
雍巧玲 《南京航空航天大学学报》1992,(1)
本文讨论了综合模态屈曲理论。该理论同时考虑多个模态及其相互作用对结构屈曲的影响,能解释以往的屈曲理论所不能解释的屈曲现象,对实践有重要的指导意义。 相似文献
6.
EFFECT OF THE RIBLETS SURFACE ON THE BOUNDARY LAYER DEVELOPMENT 总被引:3,自引:0,他引:3
EFFECT OF THE RIBLETS SURFACE ON THE BOUNDARY LAYER DEVELOPMENTWangJinjun;LanShilong;LianQixiang(InstituteofFluidMechanicsIBe... 相似文献
7.
8.
Large amplitude MHD waves are commonly found in the solar wind. Nonlinear interactions between the MHD waves are likely to
produce finite correlation among the wave phases. For discussions of various transport processes of energetic particles, it
is fundamentally important to determine whether the wave phases are randomly distributed (as assumed in quasi-linear theories)
or they have a finite coherence. Using a method based on a surrogate data technique and a fractal analysis, we analyzed Geotail
magnetic field data (provided by S. Kokubun and T. Nagai through DARTS at the Institute of Space and Astronautical Science)
to evaluate the phase coherence among the MHD waves in the earth's foreshock region. The correlation of wave phases does exist,
indicating that the nonlinear interactions between the waves is in progress.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
9.
用激光多普勒技术测量了二维扩压器中不可压湍流边界层分离流动,得到了时均速度和雷诺剪应力分布。实验结果分析表明:以Coles速度律发展的Bardina速度分布可以描述瞬时间歇分离点以前和瞬时间歇再附点以后的时均速度分布,但无法描述分离区的边界层速度型。Cross速度分布可描述分离区的边界层速度分布。Cebeci&Smith涡粘性代数模型难以正确地描述分离边界层的雷诺剪应力。 相似文献
10.