全文获取类型
收费全文 | 2325篇 |
免费 | 8篇 |
国内免费 | 11篇 |
专业分类
化学 | 1546篇 |
晶体学 | 15篇 |
力学 | 54篇 |
数学 | 359篇 |
物理学 | 370篇 |
出版年
2021年 | 7篇 |
2020年 | 18篇 |
2019年 | 7篇 |
2018年 | 16篇 |
2017年 | 10篇 |
2016年 | 15篇 |
2015年 | 13篇 |
2014年 | 30篇 |
2013年 | 131篇 |
2012年 | 94篇 |
2011年 | 115篇 |
2010年 | 77篇 |
2009年 | 49篇 |
2008年 | 119篇 |
2007年 | 125篇 |
2006年 | 141篇 |
2005年 | 146篇 |
2004年 | 130篇 |
2003年 | 98篇 |
2002年 | 85篇 |
2001年 | 34篇 |
2000年 | 30篇 |
1999年 | 22篇 |
1998年 | 23篇 |
1997年 | 36篇 |
1996年 | 36篇 |
1995年 | 26篇 |
1994年 | 43篇 |
1993年 | 38篇 |
1992年 | 25篇 |
1991年 | 26篇 |
1990年 | 25篇 |
1989年 | 24篇 |
1988年 | 25篇 |
1987年 | 21篇 |
1986年 | 17篇 |
1985年 | 34篇 |
1984年 | 33篇 |
1983年 | 18篇 |
1982年 | 56篇 |
1981年 | 43篇 |
1980年 | 40篇 |
1979年 | 36篇 |
1978年 | 33篇 |
1977年 | 39篇 |
1976年 | 26篇 |
1975年 | 21篇 |
1974年 | 21篇 |
1973年 | 17篇 |
1971年 | 8篇 |
排序方式: 共有2344条查询结果,搜索用时 31 毫秒
1.
This paper considers the problem of building a set of hybrid abstractions for affine systems in order to compute over approximations of the reachable space. Each abstraction is based on a decomposition of the continuous state space that is defined by hyperplanes generated by linear combinations of two vectors. The choice of these vectors is based on consideration of the dynamics of the system and uses, for example, the left eigenvectors of the matrix that defines these dynamics. We show that the reachability calculus can then be performed on a combination of such abstractions and how its accuracy depends on the choice of hyperplanes that define the decomposition. 相似文献
2.
Enrique Fernández-Cara Sergio Guerrero Oleg Yurievich Imanuvilov Jean-Pierre Puel 《Comptes Rendus Mathematique》2004,338(5):375-380
This Note deals with the controllability of Stokes and Navier–Stokes systems with distributed controls with support in possibly small subdomains. We first present a new global Carleman inequality for the solutions to Stokes-like systems that leads to the null controllability at any time T>0. Then, we present a local result concerning exact controllability to trajectories of the Navier–Stokes system. To cite this article: E. Fernández-Cara et al., C. R. Acad. Sci. Paris, Ser. I 338 (2004). 相似文献
3.
Reaction of acetylene dicarboxaldehyde monoacetal with substituted Meldrum’s acid leads good yields in 2-pyranones-4-carboxaldehydes substituted in position 3. 相似文献
4.
Alexey Yurasov Alexander Granovsky Sergey Tarapov Jean-Pierre Clerc 《Journal of magnetism and magnetic materials》2006
The transmission of millimeter-range electromagnetic waves (30–50 GHz) through a magnetic nanocomposite thin film exhibiting tunnel magnetoresistance (TMR) is calculated. The relative change of transmission coefficient in an applied magnetic field due to the magnetorefractive effect is approximately linear with TMR and strongly depends on nanocomposite resistivity and film thickness. The obtained results are in a good agreement with experiment. 相似文献
5.
Particle filters are presently among the most powerful tools for filtering discrete time non linear systems. However the presence of unknown parameters in the system equations makes their use more complex and can even impair their convergence properties. This Note shows how an on-line consistent estimation of these parameters can be obtained simultaneously to that of the state variables to be filtered. This approach relies upon a kernel-based non parametric estimation of conditional probability densities from successive Monte Carlo generations of system particles. To cite this article: V. Rossi, J.-P. Vila, C. R. Acad. Sci. Paris, Ser. I 340 (2005). 相似文献
6.
Jean-Pierre Dedieu Gregorio Malajovich Mike Shub 《Foundations of Computational Mathematics》2005,5(2):145-171
We prove a linear bound on the average total curvature of the
central path of linear programming theory in terms of the number
of independent variables of the primal problem, and independent of
the number of constraints. 相似文献
7.
D. Chithrani R. L. Williams J. Lefebvre P. J. Poole G. C. Aers 《Physica E: Low-dimensional Systems and Nanostructures》2004,21(2-4):290
We discuss the preparation and spectroscopic characterisation of a single InAs/InP quantum dot suitable for long-distance quantum key distribution applications around λ=1.55 μm. The dot is prepared using a site-selective growth technique which allows a single dot to be deposited in isolation at a controlled spatial location. Micro-photoluminescence measurements as a function of exciton occupation are used to determine the electronic structure of the dot. Biexciton emission, shell filling and many-body re-normalization effects are observed for the first time in single InAs/InP quantum dots. 相似文献
8.
Jean-Pierre Changeux Alain Connes M. B. DeBevoise Jean Petitot Mark Anspach 《Mathematical Intelligencer》2005,27(4):48-56
Conclusion The debate between Jean-Pierre Changeux and Alain Connes is one of the most, interesting to take place in recent years. It
re-frames in a very up-to-date context a whole series of traditional and difficult questions from the standpoint of the knowledge
and experience of two of the leading protagonists of contemporary science. To the choice presented by the neurobiologist between
a Platonist ontology and a neurocognitive psychology of mathematical activity, the mathematician replies with a conception
that is objective (neither ontological nor psychological) of the thoroughly consistent universe of mathematical idealities.
It is indeed in this three-sided arena that the major difficulties play themselves out. One of the great virtues of the book
is to cast a spotlight on this confrontation. 相似文献
9.
Jean-Pierre Demailly 《Mathematische Zeitschrift》1987,194(4):519-564
Sans résumé 相似文献
10.