全文获取类型
收费全文 | 9005篇 |
免费 | 570篇 |
国内免费 | 9篇 |
出版年
2021年 | 106篇 |
2020年 | 89篇 |
2019年 | 116篇 |
2018年 | 267篇 |
2017年 | 226篇 |
2016年 | 295篇 |
2015年 | 300篇 |
2014年 | 380篇 |
2013年 | 614篇 |
2012年 | 677篇 |
2011年 | 697篇 |
2010年 | 444篇 |
2009年 | 301篇 |
2008年 | 350篇 |
2007年 | 373篇 |
2006年 | 334篇 |
2005年 | 234篇 |
2004年 | 232篇 |
2003年 | 245篇 |
2002年 | 222篇 |
2001年 | 99篇 |
2000年 | 93篇 |
1999年 | 103篇 |
1998年 | 100篇 |
1997年 | 86篇 |
1996年 | 80篇 |
1995年 | 93篇 |
1994年 | 84篇 |
1993年 | 67篇 |
1992年 | 93篇 |
1991年 | 111篇 |
1990年 | 65篇 |
1989年 | 65篇 |
1988年 | 79篇 |
1987年 | 84篇 |
1986年 | 66篇 |
1985年 | 105篇 |
1984年 | 80篇 |
1983年 | 87篇 |
1982年 | 86篇 |
1981年 | 88篇 |
1980年 | 73篇 |
1979年 | 73篇 |
1978年 | 59篇 |
1976年 | 62篇 |
1975年 | 63篇 |
1974年 | 65篇 |
1972年 | 58篇 |
1969年 | 65篇 |
1968年 | 57篇 |
排序方式: 共有9584条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
ADP-ribosylation reactions in nucleoli of exponentially growing HeLa cells were studied. Isolated nuclei or nucleoli were labeled with 32P-NAD; then the nucleolar proteins were analyzed by 1-dimensional and 2-dimensional polyacrylamide gel electrophoresis (PAGE) and modified proteins were detected by autoradiography. The labeled nucleolar proteins were also chromatographically fractionated on DEAE-cellulose. Electrophoretic analysis of total nucleolar and chromatographically purified proteins revealed that besides nuclear ADP-ribosyltransferase and histones two characteristic nucleolar phosphoproteins numatrin/B23 and nucleolin/C23 were modified by ADP-ribosylation. 相似文献
6.
Calcium channel blockers, verapamil, nitrendipin and nifedipin, and cyclosporin A inhibited growth of colonies ofBotrytis cinerea in a concentration-dependent manner and simultaneously induced morphological changes of its hyphal tips. Exogenous calcium
at the concentration of 100 mmol/L decreased the growth-inhibitory effects of channel blockers and cyclosporin A; however,
at the concentration of 500 mmol/L Ca2+ their inhibitory effects were increased. At the latter concentration, calcium partly reversed the morphogenic effects of
the blockers but not of cyclosporin A. 相似文献
7.
We studied 630 bacterial strains isolated from surface waters and determined as enterococci on the basis of their growth on
Slanetz-Bartley agar in typical colonies. The strains were tested and characterized by several key conventional tests for
basic differentiation of enterococci and by commercial test kits. We identified 135 strains ofE. fœcium (21%), 115E. fœcalis (18%), 30E. mundtii (5%), 27E. hirae (4%), 22E. casseliflavus (3%), 21E. gallinarum (3%), 17E. durans-E. hirae complex (3%), 5E. durans (1%), and 1 strain ofE. avium. 150 strains were classified only asEnterococcus sp. (25%) and 107 strains (17%) isolated from Slanetz-Bartley agar were not enterococci. We found that the non-enterococcal
group consisted of other Gram-positive cocci and Gram-positive and Gram-negative rods. Based on the identification we tried
to find a relation between taxonomic position of isolated strains and their colony morphology on Slanetz-Bartley agar. Out
of the total of 523 identified enterococci, 345 strains (66%) formed purple colonies, 136 red colonies (26%), 37 pink colonies
(7%) and 5 cream colored colonies (1%). There was no correlation among the color, size or colony morphology and the taxonomic
characterization of enterococcal strains. 相似文献
8.
9.
10.