全文获取类型
收费全文 | 70377篇 |
免费 | 9858篇 |
国内免费 | 6645篇 |
专业分类
化学 | 46987篇 |
晶体学 | 659篇 |
力学 | 4661篇 |
综合类 | 515篇 |
数学 | 8449篇 |
物理学 | 25609篇 |
出版年
2024年 | 228篇 |
2023年 | 1399篇 |
2022年 | 2280篇 |
2021年 | 2468篇 |
2020年 | 2523篇 |
2019年 | 2422篇 |
2018年 | 2188篇 |
2017年 | 1939篇 |
2016年 | 2964篇 |
2015年 | 3078篇 |
2014年 | 3650篇 |
2013年 | 4843篇 |
2012年 | 5889篇 |
2011年 | 6014篇 |
2010年 | 4079篇 |
2009年 | 4017篇 |
2008年 | 4187篇 |
2007年 | 3788篇 |
2006年 | 3567篇 |
2005年 | 3092篇 |
2004年 | 2478篇 |
2003年 | 1895篇 |
2002年 | 1682篇 |
2001年 | 1520篇 |
2000年 | 1418篇 |
1999年 | 1563篇 |
1998年 | 1330篇 |
1997年 | 1169篇 |
1996年 | 1227篇 |
1995年 | 1072篇 |
1994年 | 1007篇 |
1993年 | 865篇 |
1992年 | 768篇 |
1991年 | 665篇 |
1990年 | 556篇 |
1989年 | 481篇 |
1988年 | 366篇 |
1987年 | 349篇 |
1986年 | 297篇 |
1985年 | 300篇 |
1984年 | 202篇 |
1983年 | 176篇 |
1982年 | 145篇 |
1981年 | 112篇 |
1980年 | 82篇 |
1978年 | 56篇 |
1977年 | 52篇 |
1976年 | 50篇 |
1975年 | 57篇 |
1973年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
In this paper, we deal with the nonlinear second-order differential equation with damped vibration term involving p-Laplacian operator. Of particular interest is the resolution of an open problem. An interesting outcome from our result is that we can obtain the fast homoclinic solution with general superlinear growth assumption in suitable Sobolev space. To our knowledge, our theorems appear to be the first such result about damped vibration problem with p-Laplacian operator. 相似文献
92.
In this paper, we prove the global well-posedness of the 3-D magnetohydrodynamics(MHD) equations with partial diffusion in the periodic domain when the initial velocity is small and the initial magnetic field is close to a background magnetic field satisfying the Diophantine condition. 相似文献
93.
Liang Chen 《Communications in Mathematical Physics》1995,167(2):431-469
A class of differential operator Lie algebras on the unit circle is introduced and discussed. They are the natural generalizations of the Witt algebra and the Virasoro algebra. Among them are the higher-spin algebrasW
1+ andW
which occur in the physics literature. 相似文献
94.
95.
96.
97.
98.
A full-wave solution is presented for the waveguide to microstrip transition. The exact Green's function of the transition is used in a moment method procedure. The behavior of the microstrip transition to a rectangular waveguide is studied with respect to the critical dimensions of the microstrip width, length and backshort location. The convergence characteristics of the full wave analysis method are investigated, along with the current distribution and the input impedance. Results given for the return loss is compared with measurements. 相似文献
99.
X. Zhou Y. Guo X. Sun X. Lei X. Chen Z. Liu Y. Zhang H. Jin Y. Luo S. X. Wen G. J. Yuan G. S. Li C. X. Yang 《Zeitschrift für Physik A Hadrons and Nuclei》1995,351(1):3-4
The high spin states of119Te, populated in110Pd(13C,4n) and110Pd(12C,3n) reactions, have been studied through -ray spectroscopy. The level scheme has been established upto a spin of 55/2. Three-quasiparticle states, based on g2
7/2h11/2 and g7/2d5/2h11/2 configurations, have been identified. The 35/2 and 39/2 states are suggested to be the fully aligned states constituted by five valence h11/2
3, g7/2, d5/2 quasiparticles. 相似文献
100.
The effects of media properties including buffers, acidity, solvents and surfactant on horseradish peroxidase-catalyzed fluorogenic reaction were investigated. The results showed that the so-called non-fluorescent hydrogen donors were in fact fluorescent. There existed an acid—base equilibrium in the fluorescent dimer product. For p -hydroxyphenylpropionic acid, a pKa value of 8.0 for the product was obtained from its titration curve. The product fluorescence increased with higher pH, however, a longer time was needed to reach the reaction equilibrium due to the pH mismatch problem. Cationic micelles cetyltrimethylammonium bromide and cetyltrimethylammonium chloride could reduce the pH mismatch and offered a way to further increase the determination sensitivity. Finally, a micelle-enhanced flow-injection analysis of horseradish peroxidase is suggested. 相似文献