全文获取类型
收费全文 | 8560篇 |
免费 | 320篇 |
国内免费 | 35篇 |
专业分类
化学 | 6834篇 |
晶体学 | 106篇 |
力学 | 110篇 |
数学 | 939篇 |
物理学 | 926篇 |
出版年
2023年 | 96篇 |
2022年 | 416篇 |
2021年 | 443篇 |
2020年 | 250篇 |
2019年 | 253篇 |
2018年 | 215篇 |
2017年 | 184篇 |
2016年 | 334篇 |
2015年 | 239篇 |
2014年 | 333篇 |
2013年 | 517篇 |
2012年 | 552篇 |
2011年 | 617篇 |
2010年 | 421篇 |
2009年 | 339篇 |
2008年 | 503篇 |
2007年 | 473篇 |
2006年 | 442篇 |
2005年 | 340篇 |
2004年 | 306篇 |
2003年 | 220篇 |
2002年 | 198篇 |
2001年 | 110篇 |
2000年 | 77篇 |
1999年 | 55篇 |
1998年 | 67篇 |
1997年 | 56篇 |
1996年 | 75篇 |
1995年 | 49篇 |
1994年 | 52篇 |
1993年 | 45篇 |
1992年 | 36篇 |
1991年 | 38篇 |
1990年 | 33篇 |
1989年 | 40篇 |
1988年 | 27篇 |
1987年 | 29篇 |
1986年 | 34篇 |
1985年 | 49篇 |
1984年 | 28篇 |
1983年 | 21篇 |
1982年 | 31篇 |
1981年 | 21篇 |
1980年 | 24篇 |
1979年 | 20篇 |
1977年 | 14篇 |
1976年 | 17篇 |
1974年 | 13篇 |
1970年 | 12篇 |
1968年 | 12篇 |
排序方式: 共有8915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.
In this paper we construct an example of a word metric on an infinite cyclic subgroup. This example shows that subexponential
distortion does not obstruct non-trivial growth of connected radii. This answers a question of Gromov [6]. The constructed
metric has other pathological properies. Specifically, its asymptotic cone depends on the choice of ultrafilter and scaling
sequence.
The work has been partially supported by the Swiss National Science Foundation. 相似文献
14.
In this paper we introduce the notion of symplectically asystatic Hamiltonian action on a Kahler manifold. In the algebraic
setting we prove that if a complex linear group G acts on a Kahler manifold in a symplectically asystatic fashion, then the
G-orbits are spherical. Finally, we give the complete classification of symplectically asystatic irreducible representations. 相似文献
15.
Photoisomerization of provitamin D 3 (7-dehydrocholesterol) in a nematic liquid crystal (ZLI-1695, Merck) is investigated in detail by UV absorption spectroscopy. It is found that dissolution of chiral molecules of provitamin D 3 induces the cholesteric phase in a nematic. The spectral kinetics of photoisomerization in this phase changes significantly from that in an ethanol solution. A sharp nonmonotonic dependence of the increase in accumulation of trans isomer tachysterol in a liquid crystal matrix with a decrease in the induced cholesteric pitch from 2200 to 25 μm is revealed. 相似文献
16.
Rossella Bartolo Anna Germinario Miguel Sánchez 《Annals of Global Analysis and Geometry》2002,21(1):63-84
In this paper the problem of the geodesic connectedness and convexity ofincomplete Riemannian manifolds is analyzed. To this aim, a detailedstudy of the notion of convexity for the associated Cauchy boundary iscarried out. In particular, under widely discussed hypotheses,we prove the convexity of open domains (whose boundaries may benondifferentiable) of a complete Riemannian manifold. Variationalmethods are mainly used. Examples and applications are provided,including a result for dynamical systems on the existence oftrajectories with fixed energy. 相似文献
17.
18.
It was shown that nonionic surfactants (NS) can be determined by potentiometry using liquid NS-selective electrodes. The effect of medium acidity and foreign substances on the operation of liquid NS-selective electrodes was studied. Some properties of NS-selective electrodes were determined. 相似文献
19.
V. Bradnova M. M. Chernyavsky L. Just S. P. Kharlamov A. D. Kovalenko M. Haiduc K. A. Kotel’nikov V. A. Krasnov V. G. Larionova F. G. Lepekhin A. I. Malakhov G. I. Orlova N. G. Peresadko N. G. Polukhina P. A. Rukoyatkin V. V. Rusakova N. A. Salmanova B. B. Simonov S. Vokal P. I. Zarubin 《Physics of Atomic Nuclei》2003,66(9):1646-1650
A physical program of irradiation of emulsions in beams of relativistic nuclei named the BECQUEREL Project is reviewed. It is destined to study in detail the processes of relativistic fragmentation of light radioactive and stable nuclei. The expected results would make it possible to answer some topical questions concerning the cluster structure of light nuclei. Owing to the best spatial resolution, the nuclear emulsions would enable one to obtain unique and evident results. The most important irradiations will be performed in the secondary beams of He, Be, B, C, and N radioactive nuclei formed on the basis of JINR Nuclotron beams of stable nuclei. We present results on the charged state topology of relativistic fragmentation of the 10B nucleus at low energy-momentum transfers as the first step of the research. 相似文献
20.
Anna L. Mazzucato 《Transactions of the American Mathematical Society》2003,355(4):1297-1364
This paper is devoted to the analysis of function spaces modeled on Besov spaces and their applications to non-linear partial differential equations, with emphasis on the incompressible, isotropic Navier-Stokes system and semi-linear heat equations. Specifically, we consider the class, introduced by Hideo Kozono and Masao Yamazaki, of Besov spaces based on Morrey spaces, which we call Besov-Morrey or BM spaces. We obtain equivalent representations in terms of the Weierstrass semigroup and wavelets, and various embeddings in classical spaces. We then establish pseudo-differential and para-differential estimates. Our results cover non-regular and exotic symbols. Although the heat semigroup is not strongly continuous on Morrey spaces, we show that its action defines an equivalent norm. In particular, homogeneous BM spaces belong to a larger class constructed by Grzegorz Karch to analyze scaling in parabolic equations. We compare Karch's results with those of Kozono and Yamazaki and generalize them by obtaining short-time existence and uniqueness of solutions for arbitrary data with subcritical regularity. We exploit pseudo-differential calculus to extend the analysis to compact, smooth, boundaryless, Riemannian manifolds. BM spaces are defined by means of partitions of unity and coordinate patches, and intrinsically in terms of functions of the Laplace operator.