全文获取类型
收费全文 | 4415篇 |
免费 | 366篇 |
出版年
2022年 | 36篇 |
2021年 | 63篇 |
2020年 | 44篇 |
2019年 | 39篇 |
2018年 | 67篇 |
2017年 | 55篇 |
2016年 | 112篇 |
2015年 | 158篇 |
2014年 | 175篇 |
2013年 | 258篇 |
2012年 | 330篇 |
2011年 | 345篇 |
2010年 | 205篇 |
2009年 | 203篇 |
2008年 | 287篇 |
2007年 | 277篇 |
2006年 | 279篇 |
2005年 | 243篇 |
2004年 | 236篇 |
2003年 | 246篇 |
2002年 | 246篇 |
2001年 | 43篇 |
2000年 | 34篇 |
1999年 | 45篇 |
1998年 | 62篇 |
1997年 | 40篇 |
1996年 | 40篇 |
1995年 | 38篇 |
1994年 | 35篇 |
1993年 | 29篇 |
1992年 | 30篇 |
1991年 | 22篇 |
1990年 | 29篇 |
1989年 | 21篇 |
1988年 | 16篇 |
1987年 | 17篇 |
1986年 | 11篇 |
1985年 | 19篇 |
1984年 | 20篇 |
1983年 | 19篇 |
1982年 | 19篇 |
1981年 | 20篇 |
1980年 | 11篇 |
1979年 | 19篇 |
1978年 | 15篇 |
1977年 | 16篇 |
1976年 | 21篇 |
1975年 | 13篇 |
1974年 | 17篇 |
1972年 | 21篇 |
排序方式: 共有4781条查询结果,搜索用时 0 毫秒
81.
Spermatium formation in G. juniperi-virginianae is phialidic. The spermatia are blown out of the tips of spermatiophores which possess a thickened neck region and a distinct, flared collarette. Each spermatium initial is surrounded by a thin wall which is attached to the inner surface of the spermatiophore wall just below the thickened neck region. A spermatium is delimited by a centripetally developing septum and then pushed into the spermogonial cavity by the next spermatium initial. Mature spermatia are ellipsoid with tapered ends and are surrounded by a thin wall. Each contains a single nucleus, many ribosomes, a few small vacuoles, and a number of lipid bodies and mitochondria. 相似文献
82.
Galactokinase Mutants of Chinese Hamster Somatic Cells Resistant to 2-Deoxygalactose 总被引:6,自引:0,他引:6
下载免费PDF全文
![点击此处可从《Genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The growth of Chinese hamster somatic cells was inhibited by 0.2 mg/cc of 2-deoxygalactose. Mutants partially or fully resistant to 2-deoxygalactose were isolated in a single-step or two-step selection. Some of them did not grow as well as the wild type; one of them which lacked galactokinase(EC.2.7.1.6) activity did not grow at all in galactose medium. The galactokinase kinetic properties (Vmax & kmax of the other mutants and of the wild type were different. Therefore resistance resulted either from the possible absence of galactokinase synthesis or from a structural mutation, possible a missence mutation, in the galactokinase gene.- A simple diagnostic test for juvenile cataract is proposed. 相似文献
83.
84.
85.
86.
Pascal Bonnarme Serge Moukha Patrick Moreau Eric Record Laurence Lesage Claude Cassagne Marcel Asther 《FEMS microbiology letters》1994,120(1-2):155-161
Abstract Mycelia from the basidiomycete Phanerochaete chrysosporium , producing lignin and manganese peroxidases, were homogenized and fractionated on a sucrose gradient. The main subcellular fungal membrane fractions were successfully separated. Lipid composition analyses of the isolated membranes as well as associated marker enzymes distribution gave evidence to similarities with membranes originating from plants. Lignin and manganese peroxidases were investigated by immunodetection in subcellular fractions. Our results show that lignin and manganese peroxidases are mainly associated with Golgi apparatus vesicles and, to a lesser extent, with endoplasmic reticulum and light density vesicles, but not with plasma membranes. 相似文献
87.
88.
89.
90.