全文获取类型
收费全文 | 7520篇 |
免费 | 157篇 |
国内免费 | 2篇 |
专业分类
化学 | 4263篇 |
晶体学 | 163篇 |
力学 | 152篇 |
数学 | 1126篇 |
物理学 | 1975篇 |
出版年
2022年 | 168篇 |
2021年 | 160篇 |
2020年 | 103篇 |
2019年 | 135篇 |
2018年 | 135篇 |
2017年 | 136篇 |
2016年 | 234篇 |
2015年 | 184篇 |
2014年 | 258篇 |
2013年 | 610篇 |
2012年 | 363篇 |
2011年 | 411篇 |
2010年 | 329篇 |
2009年 | 299篇 |
2008年 | 340篇 |
2007年 | 332篇 |
2006年 | 289篇 |
2005年 | 235篇 |
2004年 | 223篇 |
2003年 | 226篇 |
2002年 | 167篇 |
2001年 | 142篇 |
2000年 | 131篇 |
1999年 | 94篇 |
1998年 | 101篇 |
1997年 | 72篇 |
1996年 | 75篇 |
1995年 | 99篇 |
1994年 | 58篇 |
1993年 | 43篇 |
1992年 | 72篇 |
1991年 | 47篇 |
1990年 | 68篇 |
1989年 | 58篇 |
1988年 | 74篇 |
1987年 | 55篇 |
1986年 | 65篇 |
1985年 | 97篇 |
1984年 | 107篇 |
1983年 | 67篇 |
1982年 | 64篇 |
1981年 | 68篇 |
1980年 | 83篇 |
1979年 | 57篇 |
1978年 | 63篇 |
1977年 | 67篇 |
1976年 | 66篇 |
1975年 | 51篇 |
1974年 | 47篇 |
1973年 | 44篇 |
排序方式: 共有7679条查询结果,搜索用时 15 毫秒
11.
Hubert Grudziński 《Reports on Mathematical Physics》2004,53(2):317-328
The eigenvalues and eigenfunctions of an elementary 3-fermion 2-body operator 3P2g∧I1A3∑1≤i≤j≤3P2g(i, j)A3 acting on a 3-particle antisymmetric finite-dimensional Hilbert space have been found. Here Pg2 denotes the projection operator onto a 2-particle antisymmetric function g2, while A3 denotes the 3-particle antisymmetrizing operator. 相似文献
12.
Halszka TutajGasiska 《Mathematische Nachrichten》2003,257(1):108-116
13.
We introduce here some Itô calculus for non-continuous Dirichlet processes. Such calculus extends what was known for continuous Dirichlet processes or for semimartingales. In particular we prove that non-continuous Dirichlet processes are stable under C
1 transformation. 相似文献
14.
Time structure of iodine laser pulse in the free running mode of operation was studied using the power amplifier of laser system PERUN as the laser oscillator. Two characteristic shapes of laser pulse correspond to different regimes of laser operation, the existence of which is ascribed to the critical concentration of I2 molecules. Simultaneously an additional chemical pumping was proved at least in the initial phase of photodissociation and in a late-time lasing after the end of flashlamps pumping light. 相似文献
15.
JPC – Journal of Planar Chromatography – Modern TLC - This paper reports the efficiency of the C30 phase for HPLC and TLC separation of a mixture of tocopherol homologs and... 相似文献
16.
JPC – Journal of Planar Chromatography – Modern TLC - Flavonoid glycosides are much more polar than their aglycones and the two groups of compounds are difficult to separate by planar... 相似文献
17.
Anna Dbiska‐Nagrska Andrzej Just Zdzisaw Stempie 《Mathematical Methods in the Applied Sciences》2004,27(2):221-230
This paper presents the Galerkin approximation of the optimization problem of a system governed by non‐linear second‐order evolution equation where a non‐linear operator depends on derivative of the state of the system. The control is acting on a non‐linear equation. After giving some results on the existence of optimal control we shall prove the existence of the weak and strong condensation points of a set of solutions of the approximate optimization problems. Each of these points is a solution of the initial optimization problem. Finally we shall give a simple example using the obtained results. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
18.
S. Kwieciński M. Weychert A. Jasiński P. Kulinowski I. Wawer E. Sieradzki 《Applied magnetic resonance》2002,22(1):23-29
The disintegration of bromhexin tablets was monitored by magnetic resonance imaging. The fast imaging method FLASH with spoiling
gradients was used to obtain images of the tablets in short time intervals. The rate of the disintegration depends on the
preparation method, kind and percentage of the carrier (polyethylene glycol, lactose). Solid dispersion with slow evaporation
of solvent yields materials with decreased dissolution rate. Increasing molecular mass of polyethylene glycol and its percentage
content also hampers disintegration. 相似文献
19.
Supported by SFB 170 “Geometrie und Analysis” at the University of G?ttingen 相似文献
20.
Zdzislaw Skupień 《Graphs and Combinatorics》1993,9(2-4):353-363
The aim of this paper is to introduce the notions of floor and ceiling functions related to graph edge-decompositions intot mutually isomorphic parts. It is shown that, given any natural numbert, uniform and extremal t-packing andt-covering exist for each complete graph and each complete bipartite graph. Extremal in this context means that both a remainder and a surplus are absolutely minimum. In proofs, decompositions of multigraphs into matchings are involved. Open problems and conjectures are stated. 相似文献