全文获取类型
收费全文 | 1795篇 |
免费 | 64篇 |
国内免费 | 6篇 |
专业分类
化学 | 1163篇 |
晶体学 | 13篇 |
力学 | 42篇 |
数学 | 306篇 |
物理学 | 341篇 |
出版年
2023年 | 15篇 |
2022年 | 18篇 |
2021年 | 50篇 |
2020年 | 53篇 |
2019年 | 53篇 |
2018年 | 40篇 |
2017年 | 34篇 |
2016年 | 59篇 |
2015年 | 46篇 |
2014年 | 52篇 |
2013年 | 90篇 |
2012年 | 112篇 |
2011年 | 114篇 |
2010年 | 48篇 |
2009年 | 55篇 |
2008年 | 78篇 |
2007年 | 92篇 |
2006年 | 67篇 |
2005年 | 63篇 |
2004年 | 53篇 |
2003年 | 26篇 |
2002年 | 35篇 |
2001年 | 26篇 |
2000年 | 34篇 |
1999年 | 15篇 |
1998年 | 26篇 |
1997年 | 17篇 |
1996年 | 15篇 |
1995年 | 27篇 |
1994年 | 16篇 |
1993年 | 18篇 |
1992年 | 27篇 |
1991年 | 32篇 |
1990年 | 14篇 |
1989年 | 14篇 |
1988年 | 20篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 21篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 19篇 |
1979年 | 8篇 |
1978年 | 17篇 |
1977年 | 16篇 |
1975年 | 11篇 |
1974年 | 9篇 |
1973年 | 13篇 |
1972年 | 9篇 |
1968年 | 9篇 |
排序方式: 共有1865条查询结果,搜索用时 265 毫秒
11.
Leibniz agebras are a generalization of Lie algebras, where no symmetry properties of the bracket are required. In this Letter we introduce a notion of R-matrices for this structure and the related Yang–Baxter equations, and discuss some of their basic properties. 相似文献
12.
Felipe Cucker Steve Smale Ding-Xuan Zhou 《Foundations of Computational Mathematics》2004,4(3):315-343
We describe a model for the evolution of the languages used by the agents of a
society. Our main result proves convergence of these languages to a common
one under certain conditions. A few special cases are elaborated in more
depth. 相似文献
13.
14.
Alternatives based on polynomial expansions of gaussian basis set exponents are introduced and evaluated. The formulas presented here outperform methods based upon the even-tempered formula or combinations of it. They closely match the performance of other methods based upon larger polynomial expansions of the logarithm of the exponents using the same or one less parameter per orbital angular symmetry. 相似文献
15.
16.
Nanoscale organization of the pathogen receptor DC-SIGN mapped by single-molecule high-resolution fluorescence microscopy. 总被引:3,自引:0,他引:3
Bärbel I. de Bakker Dr. Frank de Lange Dr. Alessandra Cambi Dr. Jeroen P. Korterik Erik M. H. P. van Dijk Dr. Niek F. van Hulst Prof. Carl G. Figdor Prof. Maria F. Garcia‐Parajo Prof. 《Chemphyschem》2007,8(10):1473-1480
DC-SIGN, a C-type lectin exclusively expressed on dendritic cells (DCs), plays an important role in pathogen recognition by binding with high affinity to a large variety of microorganisms. Recent experimental evidence points to a direct relation between the function of DC-SIGN as a viral receptor and its spatial arrangement on the plasma membrane. We have investigated the nanoscale organization of fluorescently labeled DC-SIGN on intact isolated DCs by means of near-field scanning optical microscopy (NSOM) combined with single-molecule detection. Fluorescence spots of different intensity and size have been directly visualized by optical means with a spatial resolution of less than 100 nm. Intensity- and size-distribution histograms of the DC-SIGN fluorescent spots confirm that approximately 80 % of the receptors are organized in nanosized domains randomly distributed on the cell membrane. Intensity-size correlation analysis revealed remarkable heterogeneity in the molecular packing density of the domains. Furthermore, we have mapped the intermolecular organization within a dense cluster by means of sequential NSOM imaging combined with discrete single-molecule photobleaching. In this way we have determined the spatial coordinates of 13 different individual dyes, with a localization accuracy of 6 nm. Our experimental observations are all consistent with an arrangement of DC-SIGN designed to maximize its chances of binding to a wide range of microorganisms. Our data also illustrate the potential of NSOM as an ultrasensitive, high-resolution technique to probe nanometer-scale organization of molecules on the cell membrane. 相似文献
17.
18.
Alves Lourdes A. Felipe Maria G. A. Silva JoÃo B. Almeida E. Silva Silvio S. Prata Arnaldo M. R. 《Applied biochemistry and biotechnology》1998,70(1):89-98
Applied Biochemistry and Biotechnology - In order to remove or reduce the concentrations of toxic substances present in the sugarcane bagasse hemicellulose hydrolysate for xyloseto-xylitol... 相似文献
19.
20.
Progress and developments made in microwave-assisted combinatorial synthesis and library production since 2002 are reviewed. The use of microwave technology in both solution and solid phase synthesis is discussed with special reference to agrochemical applications where appropriate. 相似文献