全文获取类型
收费全文 | 3868篇 |
免费 | 139篇 |
国内免费 | 5篇 |
专业分类
化学 | 2606篇 |
晶体学 | 34篇 |
力学 | 76篇 |
数学 | 273篇 |
物理学 | 1023篇 |
出版年
2023年 | 40篇 |
2022年 | 47篇 |
2021年 | 64篇 |
2020年 | 100篇 |
2019年 | 121篇 |
2018年 | 74篇 |
2017年 | 75篇 |
2016年 | 134篇 |
2015年 | 93篇 |
2014年 | 133篇 |
2013年 | 264篇 |
2012年 | 266篇 |
2011年 | 318篇 |
2010年 | 199篇 |
2009年 | 162篇 |
2008年 | 233篇 |
2007年 | 198篇 |
2006年 | 179篇 |
2005年 | 150篇 |
2004年 | 124篇 |
2003年 | 80篇 |
2002年 | 81篇 |
2001年 | 60篇 |
2000年 | 60篇 |
1999年 | 47篇 |
1998年 | 30篇 |
1997年 | 24篇 |
1996年 | 39篇 |
1995年 | 29篇 |
1994年 | 36篇 |
1993年 | 43篇 |
1992年 | 29篇 |
1991年 | 27篇 |
1990年 | 15篇 |
1989年 | 20篇 |
1988年 | 20篇 |
1987年 | 26篇 |
1986年 | 20篇 |
1985年 | 17篇 |
1984年 | 31篇 |
1983年 | 20篇 |
1982年 | 21篇 |
1981年 | 29篇 |
1980年 | 19篇 |
1979年 | 27篇 |
1978年 | 15篇 |
1977年 | 18篇 |
1976年 | 16篇 |
1975年 | 15篇 |
1957年 | 13篇 |
排序方式: 共有4012条查询结果,搜索用时 343 毫秒
1.
2.
3.
Physics of the Solid State - Temporal instability of acoustic wave is investigated in an infinite semiconductor plasma using classical hydrodynamic approach. We consider a homogeneous semiconductor... 相似文献
4.
Copper bromide was used as a catalyst for the addition of pyrroles to enones. When both the reactants were used in equimolar amounts, mono and dialkylated products were obtained. However, the use of excess enone furnished only dialkylated products. Thus, copper bromide was shown to be an efficient catalyst for the dialkylation of pyrroles. 相似文献
5.
It is explicitly shown that if phase transition occurs at the core of a newborn neutron star with moderately strong magnetic
field strength, which populates only the electron’s Landau levels, then in the β -equilibrium condition, the quark core is
energetically much more unstable than the neutron matter of identical physical condition. 相似文献
6.
An exact formalism for the relativistic version of Landau theory of Fermi liquid in presence of strong quantizing magnetic field is developed. Both direct and exchange type interactions with scalar and vector coupling cases are considered. 相似文献
7.
B. Ghosh 《等离子体物理论文集》1989,29(2):125-134
To describe the long time asymptotic behaviour of weakly nonlinear plasma waves propagating in a strongly magnetized plasmafilled cylindrical waveguide the usual KDV equation which is first order in wave amplitude is extended to second order including the effects of finite temperature, mobile ions and giving a proper treatment to the radial co-ordinate for all possible modes of propagation. The second-order effects on the first-order solitary wave profile, phase speed and first order correction to the wavelength are all determined and discussed. 相似文献
8.
9.
The study of the angular distribution of slow particles during high energy hadron-nucleus interaction indicates that emission of slow particles takes place from a thermally non-equilibrated system. This evidence has come out from the presence of intermittency - a phenomenon that reveals a fractal structure and represents a self-similarity in the particle production process. Hence, this study highlights inadequacy of cascade-evaporation model and advocates the need of its refinement. 相似文献
10.
Sandip P. Trivedi 《Pramana》2004,63(4):777-783
We discuss a recent proposal to construct de Sitter vacua in string theory. It is based on flux compactifications in string
theory where all the moduli are stabilised and supersymmetry is broken with control. The resulting picture is that of a complicated
landscape with many vacua of widely varying values for the cosmological constant. 相似文献