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   9162篇
  免费   322篇
  国内免费   331篇
化学   2116篇
晶体学   191篇
力学   103篇
综合类   37篇
数学   6055篇
物理学   1313篇
  2023年   36篇
  2022年   108篇
  2021年   74篇
  2020年   100篇
  2019年   210篇
  2018年   212篇
  2017年   142篇
  2016年   148篇
  2015年   151篇
  2014年   259篇
  2013年   553篇
  2012年   369篇
  2011年   604篇
  2010年   448篇
  2009年   579篇
  2008年   614篇
  2007年   639篇
  2006年   507篇
  2005年   402篇
  2004年   374篇
  2003年   327篇
  2002年   293篇
  2001年   240篇
  2000年   209篇
  1999年   217篇
  1998年   216篇
  1997年   153篇
  1996年   175篇
  1995年   201篇
  1994年   177篇
  1993年   143篇
  1992年   134篇
  1991年   82篇
  1990年   103篇
  1989年   72篇
  1988年   49篇
  1987年   48篇
  1986年   27篇
  1985年   73篇
  1984年   50篇
  1983年   39篇
  1982年   52篇
  1981年   48篇
  1980年   28篇
  1979年   15篇
  1978年   27篇
  1977年   25篇
  1976年   22篇
  1974年   11篇
  1973年   11篇
排序方式: 共有9815条查询结果,搜索用时 0 毫秒
91.
Oscillatory properties of a weak convergent sequence of functions bounded inL p , 1 ≤p ≤ ∞, may be summarized by the parametrized measure it generates. When such a measure is generated by the gradients of a sequence of functions bounded inH 1,p , it must have special properties. The purpose of this paper is to characterize such parametrized measures as the ones that obey Jensen’s inequality for all quasiconvex functions with the appropriate growth at infinity. We have found subtle differences between the casesp < ∞ andp = ∞. A consequence is that any measure determined by biting convergence is in fact generated by a sequence convergent in a stronger sense. We also give a few applications. Research groupTransitions and Defects in Ordered Materials, funded by the NSF, the AFOSR, and the ARO. The work of the second author is also supported by DGICYT (Spain) through “Programa de Perfeccionamiento y Movilidad del Personal Investigador” and through Grant PB90-0245.  相似文献   
92.
93.
In this paper, We give a varlational-type definition of (CnP) integrals. It is equivalent to the original definition of Perron-type and to the definition of Riemann-type, in this way the problem on definition of(CnP)′s Riemann-type has been solved completely.  相似文献   
94.
The V^t-integral as defined in[2], which is eqnivalent to M^2-integrsl as defined in Trigonometre series by Zygmund is used to sum trigonometric seies in[1]. In this paper, some convergent theorems of V^2-integral are established.  相似文献   
95.
The main results of this paper are as follows;Let F be approximately continuous on[a,b]and g be of bounded variation on[a,b]. Then (APS)∫^ba Fexists if and only if (APS)∫^ba gdf existe. Furthermore,suppose (APS)∫^ba Fdy or (APS)∫^ba gdF exists, then we have (APS)∫^ba Fdg (APS)∫^bagdf=F(b)g(b)-F(a)g(a)  相似文献   
96.
97.
In this work, some results related to superatomic Boolean interval algebras are presented, and proved in a topological way. Let x be an uncountable cardinal. To each I x, we can associate a superatomic interval Boolean algebra B I of cardinality x in such a way that the following properties are equivalent: (i) I I x, (ii) B I is a quotient algebra of B J, and (iii) there is an homomorphism f from B J into B I such that for every atom b of B I, there is an atom a of B J satisfying f(a)=b. As a corollary, there are 2 x isomorphism types of superatomic interval Boolean algebras of cardinality x. This case is quite different from the countable one.  相似文献   
98.
The splay tree is a self-adjusting binary search tree which has a good amortized performance. This paper studies some properties of top-down splay trees. Different ways to charge for the primitive operations of top-down splaying are discussed. We also give some empirical results concerning the behaviour of different top-down restructuring algorithms.This work was supported by the Academy of Finland.  相似文献   
99.
Optimal stopping and impulse control problems for degenerate diffusion with jumps are studied in this paper. Lipschitzian coefficients for the diffusion process, data with polynomial growth, and evolution in the whole space are the main assumptions on the models. Several characterizations of the optimal cost functions are given. Existence of optimal policies is obtained.This research has been supported in part by Army Research Office Contract DAAG29-83-K-0014 and by National Science Foundation Grant DMS-8601998.  相似文献   
100.
High-resolution Fourier transform spectroscopy has been applied to confirm previously proposed assignments for nine far infrared (FIR) laser lines from the CH3-deformation state of CH3OH and one line from the CH3-rocking state. Accurate frequencies are deduced for the observed and other predicted FIR laser transitions. FIR torsional branch frequencies in the ground state which were used in the confirmation are presented. Comments are also made on the OH-bending mode of CH3OH.  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