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   1452895篇
  免费   26321篇
  国内免费   7833篇
化学   735675篇
晶体学   20961篇
力学   77314篇
综合类   112篇
数学   253768篇
物理学   399219篇
  2021年   13817篇
  2020年   16253篇
  2019年   16466篇
  2018年   16129篇
  2017年   14638篇
  2016年   30136篇
  2015年   21791篇
  2014年   31309篇
  2013年   76317篇
  2012年   44442篇
  2011年   45486篇
  2010年   41350篇
  2009年   42735篇
  2008年   42914篇
  2007年   39845篇
  2006年   42135篇
  2005年   36254篇
  2004年   35535篇
  2003年   32551篇
  2002年   32854篇
  2001年   32868篇
  2000年   27472篇
  1999年   23808篇
  1998年   21670篇
  1997年   21614篇
  1996年   21611篇
  1995年   19508篇
  1994年   19039篇
  1993年   18626篇
  1992年   19036篇
  1991年   19223篇
  1990年   18323篇
  1989年   18322篇
  1988年   17889篇
  1987年   17848篇
  1986年   16789篇
  1985年   23213篇
  1984年   24324篇
  1983年   20383篇
  1982年   21981篇
  1981年   21175篇
  1980年   20543篇
  1979年   20903篇
  1978年   22089篇
  1977年   21675篇
  1976年   21468篇
  1975年   20146篇
  1974年   19844篇
  1973年   20271篇
  1972年   14701篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
The simple relation between representations of the covering groups of SL2 and GL2 makes it possible to fuse and extend the recent metaplectic results of Shimura, Waldspurger, Flicker, and ourselves. By giving a new (purely local andL-function theoretic) treatment of the Waldspurger-Shintani correspondence, we also simplify some of Waldspurger’s original results.  相似文献   
104.
The problem of the vector and axial-vector dominance of weak interactions within the framework of the quark model of superconductivity type is discussed.  相似文献   
105.
106.
Estimates of a rate of convergence of orderO(n –1) are obtained for integral functionals of an empirical process.Translated fromTeoriya Sluchainykh Protsessov, Vol. 15, pp. 10–16, 1987.  相似文献   
107.
Translated fromProblemy Ustoichivosti Stokhasticheskikh Modelei. Trudy Seminara, 1988, pp. 84–92.  相似文献   
108.
A mixed boundary-value problem for the nonlinear Schrödinger equation and its generalization is studied by the method used for the inverse scattering problem. A connection is established between conservation laws and boundary conditions in integrable boundary-value problems for higher nonlinear Schrödinger equations. It is shown that the generalized boundary-value problem requires a joint consideration of regular and singular solutions for the nonlinear Schrödinger equation with repulsion.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 169, pp. 151–165, 1988.  相似文献   
109.
The theory of tree-growing (RECPAM approach) is developed for outcome variables which are distributed as the canonical exponential family. The general RECPAM approach (consisting of three steps: recursive partition, pruning and amalgamation), is reviewed. This is seen as constructing a partition with maximal information content about a parameter to be predicted, followed by simplification by the elimination of ‘negligible’ information. The measure of information is defined for an exponential family outcome as a deviance difference, and appropriate modifications of pruning and amalgamation rules are discussed. It is further shown how the proposed approach makes it possible to develop tree-growing for situations usually treated by generalized linear models (GLIM). In particular, Poisson and logistic regression can be tree-structured. Moreover, censored survival data can be treated, as in GLIM, by observing a formal equivalence of the likelihood under random censoring and an appropriate Poisson model. Three examples are given of application to Poisson, binary and censored survival data.  相似文献   
110.
We present a stratification by “normal flatness” associated to an analytic mapping, analogous to Hironaka's classical result for analytic spaces. Our construction is based on a generic normal flatness theorem for mappings, proved using techniques concerning the variation of modules of meromorphically parametrized formal power series [1]. The existence of such a stratification was announced by Hironaka [13], but the other claims made in [13] are false. Counterexamples are also presented here.  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