全文获取类型
收费全文 | 2594篇 |
免费 | 213篇 |
国内免费 | 1篇 |
专业分类
2808篇 |
出版年
2022年 | 26篇 |
2021年 | 52篇 |
2020年 | 27篇 |
2019年 | 39篇 |
2018年 | 53篇 |
2017年 | 44篇 |
2016年 | 76篇 |
2015年 | 88篇 |
2014年 | 114篇 |
2013年 | 145篇 |
2012年 | 178篇 |
2011年 | 158篇 |
2010年 | 95篇 |
2009年 | 97篇 |
2008年 | 118篇 |
2007年 | 104篇 |
2006年 | 93篇 |
2005年 | 83篇 |
2004年 | 89篇 |
2003年 | 63篇 |
2002年 | 72篇 |
2001年 | 63篇 |
2000年 | 58篇 |
1999年 | 47篇 |
1998年 | 18篇 |
1997年 | 28篇 |
1996年 | 20篇 |
1993年 | 18篇 |
1992年 | 54篇 |
1991年 | 27篇 |
1990年 | 30篇 |
1989年 | 29篇 |
1988年 | 40篇 |
1987年 | 31篇 |
1986年 | 27篇 |
1985年 | 48篇 |
1984年 | 27篇 |
1983年 | 34篇 |
1982年 | 19篇 |
1981年 | 30篇 |
1980年 | 20篇 |
1979年 | 30篇 |
1978年 | 30篇 |
1977年 | 21篇 |
1976年 | 19篇 |
1975年 | 29篇 |
1974年 | 16篇 |
1973年 | 23篇 |
1972年 | 22篇 |
1971年 | 19篇 |
排序方式: 共有2808条查询结果,搜索用时 15 毫秒
41.
Richard H. Sugatt Dean P. O'Grady Sujit Banerjee Philip H. Howard W. E. Gledhill 《Applied microbiology》1984,47(4):601-606
An acclimated shake flask CO2 evolution test was used to study the biodegradability of 14 commercial phthalate esters that are commonly used as plasticizers. Both CO2 evolution (ultimate biodegradation) and loss of parent phthalate esters (primary biodegradation) were measured. With only a few exceptions, primary biodegradation was 90% or higher, and ultimate biodegradation was in excess of 55% of theoretical results in 28 days. The results showed that all of the commercial phthalate esters were susceptible to biodegradation by mixed populations of microorganisms from natural sources. The results also provide considerable insight into the utility and reproducibility of a standard biodegradation test that is being recommended for widespread screening of chemicals. 相似文献
42.
43.
A.K. Banerjee B.J. Broughton T.S. Burton M.P.L. Caton A.J. Christmas E.C.J. Coffee K. Crowshaw M.A. Heazell K.A.J. Stuttle G.L. Watkins 《Prostaglandins & other lipid mediators》1978,16(4):541-554
The synthesis and gastrointestinal pharmacology of some 11-deoxyprostaglandin E1 analogues are described with results analysed for selectivity from side effects. 11-Deoxygenation reduced potency relative to PGE2 but, as has been reported for natural PGs, 15- or 16-methyl analogues were more potent than the unsubstituted parent compound in the order 16-methyl > 15-methyl > 16, 16-dimethyl. The results suggest that a complex interaction between C-15 and C-16 in methyl analogues affects their profile of activity, but that none of the modifications studied conferred a substantial potency or selectivity advantage over PGE2. 相似文献
44.
45.
46.
47.
A K Banerjee 《Microbiological reviews》1980,44(2):175-205
48.
Franoise Stetzkowski Ramaprasad Banerjee Jean-Yves Lallemand Brigitte Cendrier Daniel Mansuy 《Biochimie》1980,62(11-12)
13C NMR of labelled alkyl isocyanide ligands has been used with a view to probe the protein environment around the heme site of Soybean leghemoglobin, and comparatively, those of sperm whale myoglobin and monomeric Glycera hemoglobin. The terminal carbon of the isocyanide, which is known to be highly sensitive to change in hybridization of the nitrogen, could be expected to reflect the movement of the alkyl group through steric interactions. Three alkyl isocyanides (alkyl = methyl, ethyl & n-butyl) have therefore been used and the 13C° chemical shift values were measured for each ligand bound to the various proteins studied.In all cases, the 13C° resonances of the bound ligand were shifted considerably downfield with respect to those of the free unbound species, but the pattern of these displacements revealed more pronounced steric hindrance in the case of some proteins compared to others. The modifications of the chemical shift values on binding Δδ = δbound — δfree) were least in the case of leghemoglobin; moreover, the Δδ values were insensitive to the length of the alkyl chain (methyl to n-butyl) when bound to leghemoglobin, in contrast to the other proteins examined. The results are interpreted as arising from a diminished steric hindrance to isocyanide binding with leghemoglobin, in conformity with the recently published X-ray structure which reports the existence of a large heme pocket on the distal side. 相似文献
49.
50.
Nirupama Banerjee Rakesh Bhatnagar L. Viswanathan 《Applied microbiology and biotechnology》1981,11(4):226-228
Summary Furfural, a Maillard reaction product, was found to inhibit growth and alcohol production by Saccharomyces cerevisiae. Furfural concentrations above 1 mg ml–1 significantly decreased CO2 evolution by resuspended yeast cells. Important glycolytic enzymes such as hexokinase, phosphofructokinase, triosephosphate dehydrogenase, aldolase and alcohol dehydrogenase were assayed in presence of furfural. Dehydrogenases appeared to be the most sensitive enzymes and are probably responsible for the observed inhibition of alcohol production and growth. 相似文献