全文获取类型
收费全文 | 18240篇 |
免费 | 1728篇 |
国内免费 | 2596篇 |
出版年
2024年 | 43篇 |
2023年 | 291篇 |
2022年 | 578篇 |
2021年 | 959篇 |
2020年 | 693篇 |
2019年 | 915篇 |
2018年 | 809篇 |
2017年 | 665篇 |
2016年 | 873篇 |
2015年 | 1232篇 |
2014年 | 1438篇 |
2013年 | 1494篇 |
2012年 | 1845篇 |
2011年 | 1633篇 |
2010年 | 1037篇 |
2009年 | 960篇 |
2008年 | 1075篇 |
2007年 | 932篇 |
2006年 | 840篇 |
2005年 | 701篇 |
2004年 | 592篇 |
2003年 | 508篇 |
2002年 | 466篇 |
2001年 | 312篇 |
2000年 | 262篇 |
1999年 | 229篇 |
1998年 | 163篇 |
1997年 | 137篇 |
1996年 | 110篇 |
1995年 | 86篇 |
1994年 | 91篇 |
1993年 | 56篇 |
1992年 | 78篇 |
1991年 | 76篇 |
1990年 | 69篇 |
1989年 | 49篇 |
1988年 | 31篇 |
1987年 | 28篇 |
1986年 | 37篇 |
1985年 | 26篇 |
1984年 | 20篇 |
1983年 | 21篇 |
1982年 | 12篇 |
1981年 | 16篇 |
1980年 | 9篇 |
1979年 | 19篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1975年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
1.
2.
3.
4.
5.
Correlation between bilayer destabilization and activity enhancement by diacylglycerols in reconstituted Ca-ATPase vesicles 总被引:1,自引:0,他引:1
Using the reconstituted Ca-ATPase vesicles as a model system, we demonstrated that the presence of 1,2-dioleoyl-sn-glycerol (diolein) in the membrane introduces a pronounced enhancement in the Ca-transport function of Ca-ATPase, while the 1,2-dipalmitoyl-sn-glycerol (dipalmitin) does not. We also found by both 31P NMR and freeze-fraction electron microscopy that diolein destabilized lipid bilayers to a greater extent than did dipalmitin. We conclude that the tendency of diacylglycerols to destabilize the phospholipid bilayer is related to their capacity to enhance the activity of the membrane calcium pump. 相似文献
6.
7.
D. R. Gustafsson L. Lei K. Luo X. Chu X. Zhao Q. Zhang F. Zou 《Medical and veterinary entomology》2019,33(3):407-419
In total, 366 birds representing 55 species in 24 families and eight orders, were examined for chewing lice (Phthiraptera: Amblycera, Ischnocera) in two high‐altitude localities in Yunnan Province, China. In Ailaoshan, almost all of the birds examined were resident passeriforms, of which 36% were parasitized by chewing lice. In Jinshanyakou, most birds were on migration, and included both passerine and non‐passerine birds. Of the passerine birds caught in Jinshanyakou, only one bird (0.7%) was parasitized by chewing lice. The prevalence of Myrsidea and Brueelia‐complex lice on birds caught in Ailaoshan was higher than in previous reports. Of the chewing lice identifiable to species level, three represent new records for China: Actornithophilus hoplopteri (Mjöberg, 1910), Maculinirmus ljosalfar Gustafsson & Bush, 2017 and Quadraceps sinensis Timmermann, 1954. In total, 17 new host records are included, of which we describe two as new species in the Brueelia‐complex: Guimaraesiella (Cicchinella) ailaoshanensis sp. nov. ex Schoeniparus dubius dubius (Hume, 1874) and G. (C.) montisodalis sp. nov. ex Fulvetta manipurensis tonkinensis Delacour & Jabouille, 1930. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:9FC3D8EE‐2CED‐4DBE‐A1DB‐471B71260D27 . 相似文献
8.
9.
Yang Su-Rong Sun Huan-Xin Hu Zhen-Zhen Wang Si-Heng Sun Hui Xue Yin-Jia Ye Chen-Bo 《Sleep and biological rhythms》2017,15(1):57-65
Sleep and Biological Rhythms - Chronic sleep deprivation (SD) is an overwhelming problem in young students. Firstly, we investigated whether different levels of pre-training SD had effects on... 相似文献
10.