全文获取类型
收费全文 | 103699篇 |
免费 | 6931篇 |
国内免费 | 29篇 |
专业分类
110659篇 |
出版年
2023年 | 586篇 |
2022年 | 1074篇 |
2021年 | 1976篇 |
2020年 | 1360篇 |
2019年 | 1731篇 |
2018年 | 2626篇 |
2017年 | 2254篇 |
2016年 | 3386篇 |
2015年 | 4785篇 |
2014年 | 5080篇 |
2013年 | 6743篇 |
2012年 | 7793篇 |
2011年 | 7347篇 |
2010年 | 4678篇 |
2009年 | 4065篇 |
2008年 | 5667篇 |
2007年 | 5515篇 |
2006年 | 5153篇 |
2005年 | 4455篇 |
2004年 | 4352篇 |
2003年 | 3998篇 |
2002年 | 3710篇 |
2001年 | 2033篇 |
2000年 | 1839篇 |
1999年 | 1621篇 |
1998年 | 1051篇 |
1997年 | 756篇 |
1996年 | 734篇 |
1995年 | 704篇 |
1994年 | 607篇 |
1993年 | 578篇 |
1992年 | 906篇 |
1991年 | 856篇 |
1990年 | 791篇 |
1989年 | 746篇 |
1988年 | 673篇 |
1987年 | 670篇 |
1986年 | 586篇 |
1985年 | 591篇 |
1984年 | 504篇 |
1983年 | 444篇 |
1982年 | 374篇 |
1981年 | 320篇 |
1980年 | 310篇 |
1979年 | 464篇 |
1978年 | 301篇 |
1975年 | 292篇 |
1974年 | 337篇 |
1973年 | 346篇 |
1972年 | 302篇 |
排序方式: 共有10000条查询结果,搜索用时 6 毫秒
21.
22.
23.
B Alexandre F Thiébaut M Allary E Boschetti C Séné J Saint-Blancard 《Revue fran?aise de transfusion et immuno-hématologie》1987,30(1):57-66
In this work the human plasma fibronectin was purified by affinity chromatography using a tandem column system. The first affinity column was filled with gelatin-Trisacryl whereas the second one contained heparin-Trisacryl. This double affinity chromatography demonstrated its high efficiency in term of purity and yield. Several analytical methods (electrophoresis, immunoelectrophoresis, F.P.L.C. and adhesion assay on cultured eucaryotic cells) evidenced in fact the high purity of the preparation as well as its biological behaviour in term of cell adhesion and spreading. The performances of the sorbents used facilitate the scaling up when large quantities of FNP are needed. 相似文献
24.
R M Agüero G Picó E Guibert J L Corchs 《Comparative biochemistry and physiology. B, Comparative biochemistry》1987,86(1):7-10
The interaction of ANS with rat hepatocytes in time was studied by fluorescence spectroscopy. The intercept of the first linear portion of the time curve of interaction showed a positive value over all the ANS concentration range employed. This value was maintained after cellular disruption by homogenization. It was affected by ionic strength, pH, and divalent cation in the incubation medium, all conditions affecting the cellular surface. These data suggest that this phenomenon might be a binding of the compound to the hepatocytes surface. Due to the time constant and its disappearance after cellular disruption the other slower component of the curve seems to correspond to a process of translocation across the membrane. 相似文献
25.
A Sólyom S Tóth I Holczinger J Vajda Z Tóth R Kálmánchey 《Applied neurophysiology》1985,48(1-6):222-225
Four thalamic and cortical recordings were carried out in 5 patients. The thalamic-evoked potentials were typical and revealed a triphasic complex, but their latencies showed a relatively high standard deviation. They could be divided into two groups according to their latencies, both of which had low SD. These data suggested that there could be two types of latency of thalamic SEP, because the 4 patients' body sizes were very similar. More detailed surface, cortical and depth recordings are needed to resolve these questions. 相似文献
26.
27.
28.
Chafik Maazouzi Gérard Masson Maria Soledad Izquierdo Jean-Claude Pihan 《Journal of thermal biology》2008
The effects of the 2003 European heat wave on a freshwater plankton assemblage and its fatty acid (FA) composition were investigated. Composition and FA profiles of four size categories of planktonic organisms collected in 2003 were compared to those of the colder year 2002. 相似文献
29.
M Górska 《Polski tygodnik lekarski (Warsaw, Poland : 1960)》1992,47(46-48):1069-1071
30.