全文获取类型
收费全文 | 8351篇 |
免费 | 944篇 |
国内免费 | 1篇 |
专业分类
9296篇 |
出版年
2021年 | 100篇 |
2019年 | 65篇 |
2018年 | 111篇 |
2017年 | 103篇 |
2016年 | 140篇 |
2015年 | 265篇 |
2014年 | 284篇 |
2013年 | 377篇 |
2012年 | 421篇 |
2011年 | 421篇 |
2010年 | 277篇 |
2009年 | 224篇 |
2008年 | 368篇 |
2007年 | 405篇 |
2006年 | 348篇 |
2005年 | 368篇 |
2004年 | 325篇 |
2003年 | 303篇 |
2002年 | 294篇 |
2001年 | 167篇 |
2000年 | 174篇 |
1999年 | 144篇 |
1998年 | 125篇 |
1997年 | 122篇 |
1996年 | 106篇 |
1995年 | 97篇 |
1994年 | 116篇 |
1993年 | 101篇 |
1992年 | 160篇 |
1991年 | 128篇 |
1990年 | 113篇 |
1989年 | 119篇 |
1988年 | 109篇 |
1987年 | 125篇 |
1986年 | 97篇 |
1985年 | 137篇 |
1984年 | 144篇 |
1983年 | 106篇 |
1982年 | 125篇 |
1981年 | 115篇 |
1980年 | 102篇 |
1979年 | 93篇 |
1978年 | 65篇 |
1977年 | 70篇 |
1976年 | 79篇 |
1975年 | 63篇 |
1974年 | 76篇 |
1973年 | 65篇 |
1972年 | 57篇 |
1971年 | 55篇 |
排序方式: 共有9296条查询结果,搜索用时 0 毫秒
41.
Effect of Glutaraldehyde on the Outer Layers of Escherichia coli 总被引:5,自引:4,他引:1
S ummary : Sodium lauryl sulphate (SLS) at pH 3 and 8 lysed cell walls of Escherichia coli. Pretreatment with glutaraldehyde at pH 3 and at pH 8 prevented this lysis. SLS induced maximum lysis of E. coli cells at 40°; pretreatment of cells with glutaraldehyde prevented this lysis also. Electrophoretic studies indicated that glutaraldehyde accumu lated on the surface of E. coli cells more rapidly in acid than in alkaline conditions, and that it blocked amino groups on the surface layer of Bacillus subtilis spores. The relationship of these findings to the bactericidal efficiency of glutaraldehyde in acid and alkaline solution is discussed. 相似文献
42.
43.
Two forms of the glucoamylase of Aspergillus niger 总被引:3,自引:0,他引:3
44.
45.
46.
47.
R. I. Russell 《BMJ (Clinical research ed.)》1967,3(5568):781-782
48.
1. The rate of metabolism of propionate by aged sheep-liver mitochondria in the presence of oxygen + carbon dioxide (95:5) was 5·0 (± s.e.m. 0·8) μmoles/mg. of mitochondrial N/hr. 2. When aged in the presence of the mitochondrial supernatant the rate was increased. Mitochondria from 0·33g. of liver, when combined with the corresponding mitochondrial supernatant from 0·08g. of liver, metabolized propionate at a rate of 11·4 (± s.e.m. 1·2) μmoles/mg. of mitochondrial N/hr. This rate is comparable with rates previously obtained with aged nuclear-free homogenates. 3. Two factors in the mitochondrial supernatant were detected, which when combined reproduced the effect of the fresh supernatant and prevented loss of activity on aging. One of these was non-diffusible and was recovered by fractionation of the dialysed mitochondrial supernatant with ammonium sulphate. The second factor was present in an ultrafiltrate of fresh mitochondrial supernatant and in boiled mitochondrial supernatant; it was isolated and identified as l(+)-glutamate. 4. The effect of the non-diffusible factor was due to protection of the mitochondria from the aging process, whereas glutamate served both in this capacity and as a direct stimulant of propionate metabolism at low concentration. 相似文献
49.
50.