全文获取类型
收费全文 | 8280篇 |
免费 | 1170篇 |
国内免费 | 803篇 |
专业分类
化学 | 4044篇 |
晶体学 | 35篇 |
力学 | 1724篇 |
综合类 | 91篇 |
数学 | 1372篇 |
物理学 | 2987篇 |
出版年
2024年 | 11篇 |
2023年 | 52篇 |
2022年 | 153篇 |
2021年 | 229篇 |
2020年 | 254篇 |
2019年 | 246篇 |
2018年 | 259篇 |
2017年 | 293篇 |
2016年 | 302篇 |
2015年 | 306篇 |
2014年 | 402篇 |
2013年 | 789篇 |
2012年 | 457篇 |
2011年 | 514篇 |
2010年 | 403篇 |
2009年 | 463篇 |
2008年 | 429篇 |
2007年 | 472篇 |
2006年 | 459篇 |
2005年 | 436篇 |
2004年 | 381篇 |
2003年 | 387篇 |
2002年 | 304篇 |
2001年 | 278篇 |
2000年 | 263篇 |
1999年 | 217篇 |
1998年 | 248篇 |
1997年 | 188篇 |
1996年 | 154篇 |
1995年 | 132篇 |
1994年 | 109篇 |
1993年 | 103篇 |
1992年 | 89篇 |
1991年 | 83篇 |
1990年 | 79篇 |
1989年 | 43篇 |
1988年 | 38篇 |
1987年 | 30篇 |
1986年 | 31篇 |
1985年 | 32篇 |
1984年 | 22篇 |
1983年 | 11篇 |
1982年 | 27篇 |
1981年 | 16篇 |
1980年 | 13篇 |
1979年 | 10篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1972年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
912.
R.P. Malik 《Annals of Physics》2003,307(1):1-40
Some of the key cohomological features of the two (1 + 1)-dimensional (2D) free Abelian- and self-interacting non-Abelian gauge theories (having no interaction with matter fields) are briefly discussed first in the language of symmetry properties of the Lagrangian densities and the same issues are subsequently addressed in the framework of superfield formulation on the four (2 + 2)-dimensional supermanifold. Special emphasis is laid on the on-shell- and off-shell nilpotent (co-)BRST symmetries that emerge after the application of (dual) horizontality conditions on the supermanifold. The (anti-)chiral superfields play a very decisive role in the derivation of the on-shell nilpotent symmetries. The study of the present superfield formulation leads to the derivation of some new symmetries for the Lagrangian density and the symmetric energy-momentum tensor. The topological nature of the above theories is captured in the framework of superfield formulation and the geometrical interpretations are provided for some of the topologically interesting quantities. 相似文献
913.
914.
本文我们证明了带有动力学条件的高维一相Stefan总题局部古典解的存在唯一性。 相似文献
915.
A new type of element which is suitable for solving the modes of the galloping long multi-span bundle conductor structures
is presented. The element is composed of all sub-conductor segments between two spacers. Based on the linearized governing
differential equations of the conductors, the mass matrix and stiffness matrix of the element in consideration of the constrained
relations imposed on the conductors by spacers are derived. The dynamic characteristics of the galloping control devices can
be directly added to the element. The modes for an actual power line structure are computed by using the element formula and
FEM procedures, where seven cases of different galloping control device allocations are considered. Compared with the measured
data, the method is shown to be reliable and effective. Analysis and discussions of the computational results are given. Some
hints that are helpful to further investigation of galloping are also obtained. 相似文献
916.
917.
单缝石英管火焰原子吸收法测定蒜头、茶叶、大米中微量硒 总被引:9,自引:0,他引:9
本法利用单缝石英管,提高火焰原子吸收法的灵敏度并降低测试成本。方法用于大米、蒜头、茶叶中硒的测定,获得满意的结果。 相似文献
918.
Free-surface flow past a semi-infinite flat plate in a channelof finite depth is considered. The fluid is assumed to be inviscidand incompressible, and the flow to be two-dimensional and irrotational.Surface tension is included in the dynamic boundary conditionbut the effects of gravity are neglected. It is shown that thereis a three-parameter family of solutions with waves in the farfield and a discontinuity in slope at the separation point.This family includes as particular cases the solutions previouslycomputed by Osborn & Stump (2001, Phys. Fluids, 13, 616623)and by Andersson & Vanden-Broeck (1996, Proc. R. Soc., 452,19851997). 相似文献
919.
We show that every 3‐connected claw‐free graph which contains no induced copy of P11 is hamiltonian. Since there exist non‐hamiltonian 3‐connected claw‐free graphs without induced copies of P12 this result is, in a way, best possible. © 2004 Wiley Periodicals, Inc. J Graph Theory 47: 111–121, 2004 相似文献
920.