全文获取类型
收费全文 | 5764篇 |
免费 | 607篇 |
国内免费 | 6篇 |
出版年
2022年 | 44篇 |
2021年 | 81篇 |
2019年 | 40篇 |
2018年 | 75篇 |
2017年 | 56篇 |
2016年 | 95篇 |
2015年 | 172篇 |
2014年 | 206篇 |
2013年 | 260篇 |
2012年 | 282篇 |
2011年 | 298篇 |
2010年 | 189篇 |
2009年 | 198篇 |
2008年 | 260篇 |
2007年 | 283篇 |
2006年 | 246篇 |
2005年 | 222篇 |
2004年 | 219篇 |
2003年 | 235篇 |
2002年 | 208篇 |
2001年 | 166篇 |
2000年 | 141篇 |
1999年 | 137篇 |
1998年 | 96篇 |
1997年 | 69篇 |
1996年 | 64篇 |
1995年 | 75篇 |
1994年 | 61篇 |
1993年 | 71篇 |
1992年 | 108篇 |
1991年 | 86篇 |
1990年 | 123篇 |
1989年 | 78篇 |
1988年 | 73篇 |
1987年 | 81篇 |
1986年 | 67篇 |
1985年 | 65篇 |
1984年 | 50篇 |
1983年 | 58篇 |
1982年 | 59篇 |
1981年 | 53篇 |
1980年 | 52篇 |
1979年 | 56篇 |
1978年 | 34篇 |
1977年 | 49篇 |
1976年 | 54篇 |
1975年 | 39篇 |
1974年 | 42篇 |
1972年 | 38篇 |
1971年 | 46篇 |
排序方式: 共有6377条查询结果,搜索用时 15 毫秒
101.
Grey seals on the West Hoyle Bank feed on a variety of fish and have a high incidence of dermal lesions, often associated with emaciation and nematode parasite infection. Corynebacterium phocae has been isolated from an active lesion. The significance of large numbers of seals in the Dee Estuary bearing lesions is discussed and the occurrence of seals with lesions elsewhere in British waters is reviewed. No evidence was found to associate the dermal lesions with any environmental factor and it is probable that lesions develop as a result of infection of minor wounds. 相似文献
102.
103.
Plasmalogenase activity in normal and demyelinating tissue of the central nervous system 总被引:4,自引:1,他引:3
下载免费PDF全文
![点击此处可从《The Biochemical journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
1. The plasmalogenase activity of brain was found to be associated with the white matter but was absent from myelin fractions. 2. Increased enzyme activity was found in demyelinating spinal cords from vitamin B12-deficient monkeys and in white matter from a patient with multiple sclerosis. 相似文献
104.
Compartmentation of glutamic acid metabolism in brain slices 总被引:12,自引:4,他引:8
— (1) Compartmentation of glutamate metabolism in brain cortex previously observed only in vivo, has now been demonstrated in vitro.This was shown by using [U-14C]aspartate and [U-14C]glutamate as tracer substrates. (2) Preparation and maintenance of the slices at 0° resulted in reversible inhibition of glutamine synthesis. Preincubation at 37° for 10 min or preparation of the slices at room temperature partially overcame this inhibition. (3) Transfer to fresh medium after preincubation had an added stimulatory effect on glutamine synthesis. (4) Incubation in high K+ medium (27 mm ) altered the relative specific activity of glutamine. (5) The data are in keeping with the postulate of the existence of at least two different pools of citric acid cycle intermediates in the cerebral cortex. 相似文献
105.
106.
Summary Data are given on the fungi isolated from 30-day-old adventitious roots and seedling roots of severalAllium species by means of the root-washing technique. These fungi were typical root-surface forms includingCylindrocarpon, Fusarium, and sterile forms. The amount of root colonization observed, however, was not so great as with other higher plant roots.The nature and role of bulb surface contaminants is discussed in relation to the colonization of young roots, and is compared with the role of seed-coat contaminants in such colonization. 相似文献
107.
108.
109.
110.