全文获取类型
收费全文 | 3877篇 |
免费 | 129篇 |
国内免费 | 23篇 |
专业分类
化学 | 2404篇 |
晶体学 | 18篇 |
力学 | 113篇 |
数学 | 805篇 |
物理学 | 689篇 |
出版年
2023年 | 37篇 |
2022年 | 90篇 |
2021年 | 98篇 |
2020年 | 70篇 |
2019年 | 92篇 |
2018年 | 72篇 |
2017年 | 72篇 |
2016年 | 154篇 |
2015年 | 125篇 |
2014年 | 145篇 |
2013年 | 237篇 |
2012年 | 275篇 |
2011年 | 306篇 |
2010年 | 178篇 |
2009年 | 201篇 |
2008年 | 253篇 |
2007年 | 242篇 |
2006年 | 218篇 |
2005年 | 173篇 |
2004年 | 173篇 |
2003年 | 108篇 |
2002年 | 104篇 |
2001年 | 47篇 |
2000年 | 50篇 |
1999年 | 34篇 |
1998年 | 30篇 |
1997年 | 28篇 |
1996年 | 39篇 |
1995年 | 21篇 |
1994年 | 21篇 |
1993年 | 17篇 |
1992年 | 31篇 |
1991年 | 23篇 |
1990年 | 25篇 |
1989年 | 15篇 |
1988年 | 14篇 |
1987年 | 15篇 |
1986年 | 18篇 |
1985年 | 20篇 |
1984年 | 24篇 |
1983年 | 15篇 |
1982年 | 11篇 |
1981年 | 17篇 |
1980年 | 10篇 |
1979年 | 10篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1974年 | 7篇 |
1971年 | 7篇 |
1963年 | 5篇 |
排序方式: 共有4029条查询结果,搜索用时 15 毫秒
1.
Antonio R. Montoro Bustos Marta Garcia-Cortes Hector González-Iglesias Jorge Ruiz Encinar José M. Costa-Fernández Miguel Coca-Prados Alfredo Sanz-Medel 《Analytica chimica acta》2015
A generic strategy based on the use of CdSe/ZnS Quantum Dots (QDs) as elemental labels for protein quantification, using immunoassays with elemental mass spectrometry (ICP-MS), detection is presented. In this strategy, streptavidin modified QDs (QDs-SA) are bioconjugated to a biotinylated secondary antibody (b-Ab2). After a multi-technique characterization of the synthesized generic platform (QDs-SA-b-Ab2) it was applied to the sequential quantification of five proteins (transferrin, complement C3, apolipoprotein A1, transthyretin and apolipoprotein A4) at different concentration levels in human serum samples. It is shown how this generic strategy does only require the appropriate unlabeled primary antibody for each protein to be detected. Therefore, it introduces a way out to the need for the cumbersome and specific bioconjugation of the QDs to the corresponding specific recognition antibody for every target analyte (protein). Results obtained were validated with those obtained using UV–vis spectrophotometry and commercial ELISA Kits. 相似文献
2.
3.
4.
Edson Vargas 《Communications in Mathematical Physics》1991,138(3):521-535
We considerC
2 unimodal mapsf such that all periodic points are hyperbolic, the critical point is non-degenerated and non-recurrent, and the Julia set does not contain intervals. We construct a Markov partition for a big part of the Julia set. Then we use it to estimate the limit capacity and Hausdorff dimension of the Julia set.Partially supported by CNPq, S.C.T.-Brazil 相似文献
5.
When an organization solves a portfolio problem with public projects evaluated by multiple criteria, in which the economic dimension is not essential or not well characterized, the classical methods are not useful. We propose a non-linear preference model developed from normative Value Theory and using fuzzy sets to model some sources of imprecision. This model can be considered as a generalization of the classical approaches. However, the optimization problem is very complex in order to be solved with non-linear programming techniques. Therefore, the model is exploited by an evolutionary algorithm, able to achieve a strong improvement of the quality of solution. 相似文献
6.
Affine Arithmetic: Concepts and Applications 总被引:2,自引:0,他引:2
Affine arithmetic is a model for self-validated numerical computation that keeps track of first-order correlations between computed and input quantities. We explain the main concepts in affine arithmetic and how it handles the dependency problem in standard interval arithmetic. We also describe some of its applications. 相似文献
7.
In this paper, we study the consistency of a variant of fractionalstep Runge–Kutta methods. These methods are designed tointegrate efficiently semi-linear multidimensional parabolicproblems by means of linearly implicit time integration processes.Such time discretization procedures are also related to a splittingof the space differential operator (or the spatial discretizationof it) as a sum of simpler linear differentialoperators and a nonlinear term. 相似文献
8.
9.
The covering graph of a lattice which is contained in an ordered set with a planar covering graph is itself planar.Presented by R. W. Quackenbush. 相似文献
10.
In this article we prove a local existence and uniqueness theorem for the Kadomtsev-Petviashvili Equation (u
t
+u
xxx
+uu
x
)
x
−u
yy
=0) in the Sobolev spaces of orders≥3, with initial values in the same spaces, and periodic boundary conditions. This theorem improves previous results based
upon the application of singular perturbation techniques. 相似文献