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   11083篇
  免费   354篇
  国内免费   37篇
化学   6116篇
晶体学   77篇
力学   237篇
数学   2342篇
物理学   2702篇
  2022年   83篇
  2021年   122篇
  2020年   163篇
  2019年   160篇
  2018年   189篇
  2017年   177篇
  2016年   402篇
  2015年   341篇
  2014年   396篇
  2013年   694篇
  2012年   566篇
  2011年   638篇
  2010年   381篇
  2009年   362篇
  2008年   436篇
  2007年   390篇
  2006年   324篇
  2005年   219篇
  2004年   234篇
  2003年   240篇
  2002年   238篇
  2001年   163篇
  2000年   198篇
  1999年   158篇
  1998年   165篇
  1997年   157篇
  1996年   141篇
  1995年   124篇
  1994年   134篇
  1993年   117篇
  1992年   121篇
  1991年   111篇
  1990年   117篇
  1989年   96篇
  1988年   111篇
  1987年   99篇
  1986年   83篇
  1985年   125篇
  1984年   152篇
  1983年   101篇
  1982年   127篇
  1981年   129篇
  1980年   110篇
  1979年   119篇
  1978年   106篇
  1977年   100篇
  1976年   118篇
  1975年   106篇
  1974年   101篇
  1968年   82篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
This paper attempts to develop a theory of sufficiency in the setting of non-commutative algebras parallel to the ideas in classical mathematical statistics. Sufficiency of a coarse-graining means that all information is extracted about the mutual relation of a given family of states. In the paper sufficient coarse-grainings are characterized in several equivalent ways and the non-commutative analogue of the factorization theorem is obtained. As an application we discuss exponential families. Our factorization theorem also implies two further important results, previously known only in finite Hilbert space dimension, but proved here in generality: the Koashi-Imoto theorem on maps leaving a family of states invariant, and the characterization of the general form of states in the equality case of strong subadditivity. Supported by the EU Research Training Network Quantum Probability with Applications to Physics, Information Theory and Biology and Center of Excellence SAS Physics of Information I/2/2005. Supported by the Hungarian grant OTKA T032662  相似文献   
13.
14.
Some remarks to problems of point and interval estimation, testing and problems of outliers are presented in the case of multivariate regression model. This work was supported by the Council of Czech Government J14/98:153100011.  相似文献   
15.
The issue of the intrinsic nonlocality of quantum mechanics raised by J. S. Bell is examined from the point of view of the recently developed method of geometro-stochastic quantization and its applications to general relativistic quantum theory. This analysis reveals that a distinction should be made between the topological concept of locality used in formulating relativistic causality and a type of geometric locality based on the concept of fiber bundle, which can be used in extending the strong equivalence principle to the quantum domain. Both play an essential role in formulating a notion of geometro-stochastic propagation based on quantum diffusions, which throws new light on the EPR paradox, on the origin of the arrow of time, and on other fundamental issues in quantum cosmology and the theory of measurement.  相似文献   
16.
17.
The title compound, [Cu8(C8H24O2Si)2(C3H7NO)8]·C4H4N2·C3H7NO, features a sandwich‐like cage enclosing a pyrazine mol­ecule, both situated on a centre of inversion. In addition, the crystal structure contains one dimethyl­formamide mol­ecule which is disordered over a centre of inversion. The copper layer, containing eight atoms, is located between two siloxanolate fragments. The whole structure of Cu atoms and siloxanolate rings is distorted by the pyrazine mol­ecule, leading to an oval form. As a result, the angles between the Cu atoms differ at the copper layer. The difference in the angles could lead to some deviations in the Cu–Cu exchange inter­actions within the copper ring, which is of inter­est for mol­ecular magnetism.  相似文献   
18.
19.
20.
JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic behavior of fourteen 1-arylpiperazine derivatives has been studied by thin-layer chromatography on both silica...  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