全文获取类型
收费全文 | 36297篇 |
免费 | 1061篇 |
国内免费 | 230篇 |
专业分类
化学 | 23210篇 |
晶体学 | 191篇 |
力学 | 843篇 |
综合类 | 1篇 |
数学 | 7205篇 |
物理学 | 6138篇 |
出版年
2022年 | 229篇 |
2021年 | 356篇 |
2020年 | 459篇 |
2019年 | 421篇 |
2018年 | 429篇 |
2017年 | 439篇 |
2016年 | 913篇 |
2015年 | 906篇 |
2014年 | 969篇 |
2013年 | 1981篇 |
2012年 | 1798篇 |
2011年 | 2182篇 |
2010年 | 1238篇 |
2009年 | 1058篇 |
2008年 | 1729篇 |
2007年 | 1713篇 |
2006年 | 1721篇 |
2005年 | 1468篇 |
2004年 | 1441篇 |
2003年 | 1221篇 |
2002年 | 1170篇 |
2001年 | 566篇 |
2000年 | 536篇 |
1999年 | 511篇 |
1998年 | 495篇 |
1997年 | 531篇 |
1996年 | 487篇 |
1995年 | 442篇 |
1994年 | 475篇 |
1993年 | 424篇 |
1992年 | 405篇 |
1991年 | 392篇 |
1990年 | 360篇 |
1989年 | 351篇 |
1988年 | 335篇 |
1987年 | 285篇 |
1986年 | 312篇 |
1985年 | 453篇 |
1984年 | 480篇 |
1983年 | 385篇 |
1982年 | 436篇 |
1981年 | 411篇 |
1980年 | 418篇 |
1979年 | 365篇 |
1978年 | 387篇 |
1977年 | 358篇 |
1976年 | 324篇 |
1975年 | 283篇 |
1974年 | 287篇 |
1973年 | 236篇 |
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
41.
Tricyclic skeletons have been generated from acyclic enyne precursors by using an intramolecular Pauson-Khand reaction in combination with aldol, Michael and alkylation reactions. 相似文献
42.
Peter Dräxler 《Journal of Pure and Applied Algebra》2002,169(1):33-42
We show that the cleaving functors introduced in [Bautista et al., Invent. Math. 81 (1985) 217] as a tool for proving infinite representation type of finite-dimensional algebras can also be used to establish controlled wildness. The main application is that an algebra is controlled wild if there is an indecomposable projective module with a Loewy factor having a homogeneous direct summand which is of length at least 3. As a second application we derive Han's covering criterion. 相似文献
43.
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
44.
45.
Lubomír Kubáček 《Applications of Mathematics》2006,51(6):565-582
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
46.
Eduard Prugovečki 《Foundations of Physics》1991,21(1):93-124
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
47.
48.
49.
50.
Given a principal value convolution on the Heisenberg group Hn = Cn×R, we study the relation between its Laguerre expansion and the Fourier-Bessel expansion of its limit on Cn. We also calculate the Dirichlet kernel for the Laguerre expansion on the group Hn. 相似文献