首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5643篇
  免费   274篇
  国内免费   687篇
化学   257篇
晶体学   4篇
力学   123篇
综合类   98篇
数学   5184篇
物理学   938篇
  2024年   9篇
  2023年   53篇
  2022年   73篇
  2021年   93篇
  2020年   87篇
  2019年   159篇
  2018年   158篇
  2017年   167篇
  2016年   149篇
  2015年   120篇
  2014年   164篇
  2013年   921篇
  2012年   163篇
  2011年   250篇
  2010年   231篇
  2009年   288篇
  2008年   386篇
  2007年   367篇
  2006年   328篇
  2005年   285篇
  2004年   289篇
  2003年   285篇
  2002年   290篇
  2001年   208篇
  2000年   199篇
  1999年   172篇
  1998年   160篇
  1997年   167篇
  1996年   98篇
  1995年   58篇
  1994年   35篇
  1993年   33篇
  1992年   23篇
  1991年   25篇
  1990年   16篇
  1989年   15篇
  1988年   10篇
  1987年   6篇
  1986年   7篇
  1985年   7篇
  1984年   11篇
  1983年   6篇
  1982年   5篇
  1981年   5篇
  1980年   3篇
  1979年   5篇
  1978年   4篇
  1977年   3篇
  1974年   1篇
  1936年   5篇
排序方式: 共有6604条查询结果,搜索用时 31 毫秒
1.
郑凌玲 《化学教育》2022,43(10):100-106
深挖高职院校公选课“生活中的化学”的育人元素,精心设计教学内容,运用课堂主题辩论、趣味生活实验的设计与展示、探秘生活中的化学等理论知识传授与课内外实践相结合的教学方式,实现全过程育人,充分展现了公选课在立德树人方面的价值。  相似文献   
2.
3.
4.
5.
In this paper, the deformation of the Heisenberg algebra, consistent with both the generalized uncertainty principle and doubly special relativity, has been analyzed. It has been observed that, though this algebra can give rise to fractional derivative terms in the corresponding quantum mechanical Hamiltonian, a formal meaning can be given to them by using the theory of harmonic extensions of function. Depending on this argument, the expression of the propagator of the path integral corresponding to the deformed Heisenberg algebra, has been obtained. In particular, the consistent expression of the one dimensional free particle propagator has been evaluated explicitly. With this propagator in hand, it has been shown that, even in free particle case, normal generalized uncertainty principle and doubly special relativity show very much different result.  相似文献   
6.
In this paper, we study the global (in time) existence of small data solutions to the Cauchy problem for the semilinear wave equation with friction, viscoelastic damping, and a power nonlinearity. We are interested in the connection between regularity assumptions for the data and the admissible range of exponents p in the power nonlinearity.  相似文献   
7.
Numerical integration of ordinary differential equations on manifolds   总被引:4,自引:0,他引:4  
Summary This paper is concerned with the problem of developing numerical integration algorithms for differential equations that, when viewed as equations in some Euclidean space, naturally evolve on some embedded submanifold. It is desired to construct algorithms whose iterates also evolve on the same manifold. These algorithms can therefore be viewed as integrating ordinary differential equations on manifolds. The basic method “decouples” the computation of flows on the submanifold from the numerical integration process. It is shown that two classes of single-step and multistep algorithms can be posed and analyzed theoretically, using the concept of “freezing” the coefficients of differential operators obtained from the defining vector field. Explicit third-order algorithms are derived, with additional equations augmenting those of their classical counterparts, obtained from “obstructions” defined by nonvanishing Lie brackets.  相似文献   
8.
Algebra matrix and similarity classification of operators   总被引:1,自引:0,他引:1  
In this paper, by the Gelfand representation theory and the Silov idempotents theorem, we first obtain a central decomposition theorem related to a unital semi-simple n-homogeneous Banach algebra, and then give a similarity classification of two strongly irreducible Cowen-Douglas operators using this theorem.  相似文献   
9.
The singularly perturbed boundary value problem for nonlinear higher order ordinary differential equation involving two small parameters has been considered. Under appropriate assumptions, for the three cases:ε/μ2→0(μ→0),μ2/ε→0 (ε→0) andε=μ2, the uniformly valid asymptotic solution is obtained by using the expansion method of two small parameters and the theory of differential inequality.  相似文献   
10.
We give a coring version for the duality theorem for actions and coactions of a finitely generated projective Hopf algebra. We also provide a coring analogue for a theorem of H.-J. Schneider, which generalizes and unifies the duality theorem for finite Hopf algebras and its refinements. This paper was written while the first author visited the Mathematics Departments of Syracuse University and California State University Dominguez Hills. He would like to thank both departments for their hospitality.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号