全文获取类型
收费全文 | 302563篇 |
免费 | 18564篇 |
国内免费 | 12359篇 |
专业分类
化学 | 172688篇 |
晶体学 | 4419篇 |
力学 | 14944篇 |
综合类 | 671篇 |
数学 | 34949篇 |
物理学 | 105815篇 |
出版年
2022年 | 4072篇 |
2021年 | 5167篇 |
2020年 | 5865篇 |
2019年 | 5832篇 |
2018年 | 6231篇 |
2017年 | 5789篇 |
2016年 | 8558篇 |
2015年 | 6935篇 |
2014年 | 9338篇 |
2013年 | 16514篇 |
2012年 | 16159篇 |
2011年 | 17957篇 |
2010年 | 12536篇 |
2009年 | 12139篇 |
2008年 | 14453篇 |
2007年 | 13888篇 |
2006年 | 13147篇 |
2005年 | 11408篇 |
2004年 | 9974篇 |
2003年 | 8501篇 |
2002年 | 8096篇 |
2001年 | 8530篇 |
2000年 | 6790篇 |
1999年 | 5786篇 |
1998年 | 4736篇 |
1997年 | 4566篇 |
1996年 | 4313篇 |
1995年 | 3954篇 |
1994年 | 3684篇 |
1993年 | 3321篇 |
1992年 | 3572篇 |
1991年 | 3435篇 |
1990年 | 3237篇 |
1989年 | 2890篇 |
1988年 | 2817篇 |
1987年 | 2780篇 |
1986年 | 2610篇 |
1985年 | 3217篇 |
1984年 | 3395篇 |
1983年 | 2780篇 |
1982年 | 2922篇 |
1981年 | 2847篇 |
1980年 | 2694篇 |
1979年 | 2748篇 |
1978年 | 2841篇 |
1977年 | 2831篇 |
1976年 | 2906篇 |
1975年 | 2690篇 |
1974年 | 2652篇 |
1973年 | 2786篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Physics of Atomic Nuclei - In this paper, the analysis of the relation between the multiplication factor of neutrons of the multiplying system measured in critical experiments and the system... 相似文献
22.
Siberian Mathematical Journal - Suppose that $ n $ is an integer, $ n\geq 3 $ . We prove that a periodic group saturated with a set of the finite simple groups $ O_{2n+1}(q) $ , where $ q $ is... 相似文献
23.
M. Amar D. Andreucci R. Gianni C. Timofte 《Journal of Mathematical Analysis and Applications》2021,493(2):124533
We prove a well-posedness result for two pseudo-parabolic problems, which can be seen as two models for the same electrical conduction phenomenon in heterogeneous media, neglecting the magnetic field. One of the problems is the concentration limit of the other one, when the thickness of the dielectric inclusions goes to zero. The concentrated problem involves a transmission condition through interfaces, which is mediated by a suitable Laplace-Beltrami type equation. 相似文献
24.
Kobayashi M. Zhang Y. Ishikawa H. Sun J. Oddershede J. Juul Jensen D. Miura H. 《Experimental Mechanics》2021,61(5):817-828
Experimental Mechanics - The internal strain distribution developing during plastic deformation is important for understanding the mechanical properties of polycrystalline materials. Such... 相似文献
25.
Kopytov G. F. Malyshko V. V. Goryachko A. I. Sharafan M. V. Churkina A. V. Moiseev A. V. Shashkov D. I. Lyasota O. M. 《Russian Physics Journal》2021,64(2):255-260
Russian Physics Journal - The specific features of the sorption activity of silver nanoparticles (AgNPs) on biodegradable polymers of natural (collagen) and artificial (polyamide 6.6) origin have... 相似文献
26.
27.
This study is to numerically test the interfacial instability of ferrofluid flow under the presence of a vacuum magnetic field. The ferrofluid parabolized stability equations(PSEs) are derived from the ferrofluid stability equations and the Rosensweig equations, and the characteristic values of the ferrofluid PSEs are given to describe the ellipticity of ferrofluid flow. Three numerical models representing specific cases considering with/without a vacuum magnetic field or viscosity are created to mathematically examine the interfacial instability by the computation of characteristic values. Numerical investigation shows strong dependence of the basic characteristic of ferrofluid Rayleigh-Taylor instability(RTI) on viscosity of ferrofluid and independence of the vacuum magnetic field.For the shock wave striking helium bubble, the magnetic field is not able to trigger the symmetry breaking of bubble but change the speed of the bubble movement. In the process of droplet formation from a submerged orifice, the collision between the droplet and the liquid surface causes symmetry breaking. Both the viscosity and the magnetic field exacerbate symmetry breaking. The computational results agree with the published experimental results. 相似文献
28.
Liu Jun-Wei Shen Shu-Qian Li Ming Li Lei 《International Journal of Theoretical Physics》2021,60(5):1712-1719
International Journal of Theoretical Physics - Quantum coherence, coming from quantum superposition, occupies a significant position in the field of physics. We put forward a lower bound of the... 相似文献
29.
30.
Journal of Visualization - Forecast calibration methods based on historical similar atmospheric state are effective means weather forecast accuracy. Conventional approaches search similar forecasts... 相似文献