全文获取类型
收费全文 | 12269篇 |
免费 | 948篇 |
国内免费 | 4篇 |
专业分类
13221篇 |
出版年
2022年 | 84篇 |
2021年 | 197篇 |
2020年 | 136篇 |
2019年 | 183篇 |
2018年 | 196篇 |
2017年 | 185篇 |
2016年 | 316篇 |
2015年 | 451篇 |
2014年 | 590篇 |
2013年 | 713篇 |
2012年 | 864篇 |
2011年 | 904篇 |
2010年 | 557篇 |
2009年 | 547篇 |
2008年 | 703篇 |
2007年 | 723篇 |
2006年 | 702篇 |
2005年 | 635篇 |
2004年 | 615篇 |
2003年 | 599篇 |
2002年 | 581篇 |
2001年 | 148篇 |
2000年 | 101篇 |
1999年 | 127篇 |
1998年 | 132篇 |
1997年 | 112篇 |
1996年 | 105篇 |
1995年 | 117篇 |
1994年 | 85篇 |
1993年 | 116篇 |
1992年 | 88篇 |
1991年 | 61篇 |
1990年 | 77篇 |
1989年 | 62篇 |
1988年 | 53篇 |
1987年 | 61篇 |
1986年 | 47篇 |
1985年 | 66篇 |
1984年 | 91篇 |
1983年 | 67篇 |
1982年 | 95篇 |
1981年 | 82篇 |
1980年 | 66篇 |
1979年 | 48篇 |
1978年 | 49篇 |
1977年 | 41篇 |
1976年 | 35篇 |
1975年 | 37篇 |
1974年 | 63篇 |
1973年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
Internode length in Pisum. I. The effect of the Le/le gene difference on endogenous gibberellin-like substances 总被引:2,自引:0,他引:2
The allelopathic potential of the dry fruits of Washingtonia filifera (L. Linden) H. Wendl. was investigated. Leachates from fruits inhibited the germination of lettuce, wheat, red cabbage and cucumber seeds. The inhibitory effect was partly neutralized by kinetin (20 mg 1−1 ) and gibberellic acid (50 mg 1−1 ). The effect of kinetin was more pronounced at 25°C than at 20°C. Substances inhibiting germination were localized in the pericarp of the fruit and were resistant to high temperature. 相似文献
5.
Ian H. Frasher Timothy Coolbear Sailen Mookerjea 《Biochimica et Biophysica Acta (BBA)/General Subjects》1984,799(2):102-105
Induction of inflammation by turpentine injection caused 1.5–2-fold increase of both sialy- and galactosyltransferase activity in liver homogenates. The effect was apparent after 12 h turpentine treatment. Serum sialytransferase activity started to increase in the inflamed rats after 18 h, reaching a maximum of 4-fold at 48 h. In contrast, galactosyltransferase activity in serum showed no significant increase. The coordinated and temporal increase of sialytransferase activity in liver and serum suggest involvement of a specific mechanism for the preferential release of this enzyme into serum. 相似文献
6.
7.
8.
9.
The Multiskan spectrophotometric system and Coomassie brilliant blue G-250 protein-dye binding method have been used together to measure NaOH-solubilized protein in subcellular membrane fractions prepared from isolated rat adipose cells. Forty-eight samples can be read in duplicate within 1 min. Sucrose in concentrations up to 0.7 m interfere only moderately with the assay. A rapid and convenient method is, therefore, now available for multiple protein determinations following sucellular fractionation on sucrose gradients. 相似文献
10.
Ian R. Brown 《Journal of neurochemistry》1983,40(5):1490-1493
Abstract: Analysis of the cell-free translation products of polysomes isolated from fetal brain and other organs indicates that elevation of maternal body temperature induces the synthesis of a heat shock protein of molecular weight 74,000 (74K). The newborn mammal is particularly sensitive to induction of the 74K protein. As early postnatal development proceeds, higher body temperatures are required to induce synthesis of the 74K heat shock protein. 相似文献