全文获取类型
收费全文 | 53篇 |
免费 | 7篇 |
出版年
2016年 | 5篇 |
2015年 | 3篇 |
2013年 | 4篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 3篇 |
2006年 | 3篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2003年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1993年 | 2篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有60条查询结果,搜索用时 31 毫秒
1.
2.
3.
Effect of Hydrogenase and Mixed Sulfate-Reducing Bacterial Populations on the Corrosion of Steel 总被引:4,自引:2,他引:2 下载免费PDF全文
Richard D. Bryant Wayne Jansen Joe Boivin Edward J. Laishley J. William Costerton 《Applied microbiology》1991,57(10):2804-2809
The importance of hydrogenase activity to corrosion of steel was assessed by using mixed populations of sulfate-reducing bacteria isolated from corroded and noncorroded oil pipelines. Biofilms which developed on the steel studs contained detectable numbers of sulfate-reducing bacteria (104 increasing to 107/0.5 cm2). However, the biofilm with active hydrogenase activity (i.e., corrosion pipeline organisms), as measured by a semiquantitative commercial kit, was associated with a significantly higher corrosion rate (7.79 mm/year) relative to noncorrosive biofilm (0.48 mm/year) with 105 sulfate-reducing bacteria per 0.5 cm2 but no measurable hydrogenase activity. The importance of hydrogenase and the microbial sulfate-reducing bacterial population making up the biofilm are discussed relative to biocorrosion. 相似文献
4.
Clostridium pasteurianum total cellular saturated fatty acids increased through its growth cycle from 81% to 91% but varied significantly in the composition
under nitrogen- and non-nitrogen-fixing conditions. During ammonia-assimilating growth, palmitic acid decreased from 67.7%
to 43.5% by late log while marked increases in shorter chain saturated fatty acids (C15:0 and below) and a long chain saturated C22:0 occured. In contrast, under N2-fixing growth conditions, palmitic acid increased from 45.5% to 84.3% by late log, representing nearly the total amound of
saturated fatty acids found inC. pasteurianum. The total cellular lipid concentration decreased as the culture aged. irrespective of the nitrogen sources; however, the
phospholipid concentration increased significantly during N2-fixing growth as compared with a 50% decrease during ammonia-assimilating conditions. The implication of these differences
and possible role of palmitic acid and phospholipids inC. pasteurianum nitrogen fixation process are discussed. 相似文献
5.
Abstract. Woodland colonization on wetlands is considered to have a detrimental effect on their ecological value, even though detailed analysis of this process is lacking. This paper provides an evaluation of the ecological changes resulting from succession of poor fen (base‐poor mire) to willow wet woodland on Goss Moor NNR in Cornwall, UK. Different ages of willow carr were associated with eight understorey communities. During willow colonization, in the ground flora, there was a progressive decrease in poor fen species and an associated increase in woodland species, which appeared to be related to an increase in canopy cover and therefore shade. The most diverse community was found to be the most recent willow and was dominated by poor fen species. The oldest willow was the second most diverse and was associated with a reduction in poor fen species and an increase in woodland species. Architectural features were used successfully to assess the general condition and structure of willow. Tree height and DBH were identified as useful parameters to accurately assess willow age in the field. The implications of active intervention to remove willow in order to conserve the full range of communities within the hydrosere are discussed. 相似文献
6.
7.
Annemarie MM Vlaar Angela EP Bouwmans Marinus JPG van Kroonenburgh Werner H Mess Selma C Tromp Piet GWM Wuisman Alfons GH Kessels Ania Winogrodzka Wim EJ Weber 《BMC neurology》2007,7(1):28
Background
Parkinson's disease (PD) is the second most common neurodegenerative disorder. As there is no definitive diagnostic test, its diagnosis is based on clinical criteria. Recently transcranial duplex scanning (TCD) of the substantia nigra in the brainstem has been proposed as an instrument to diagnose PD. We and others have found that TCD scanning of substantia nigra duplex is a relatively accurate diagnostic instrument in patients with parkinsonian symptoms. However, all studies on TCD so far have involved well-defined, later-stage PD patients, which will obviously lead to an overestimate of the diagnostic accuracy of TCD. 相似文献8.
During growth on minimal salts--sucrose media supplemented with various concentrations (10-4-10-2 M) of sodium sulfate, Clostridium pasteurianum grew at a normal rate and only evolved sulfide in late stages of growth on 10-2 M SO4-2-. The evolved sulfide was slightly enriched in 34S as compared to the medium sulfur. On the other hand, sulfide was evolved during growth on all concentrations of sulfite tested. Large normal and inverse isotopic effects were observed in the evolved sulfide during SO3-2- reductions. In contrast, the intracellular sulfur showed much smaller fractionations. The complexity of the isotopic patterns suggests that a dissimilatory sulfite reductase system may be induced by high concentrations of sulfite. 相似文献
9.
The reserve glucans of C. pasteurianum, previously assumed to be a single polysaccharide, have been fractionated into two polysaccharides which resemble amylopectin and dextran. Both polysaccharides are produced when cells are grown with sucrose, D-glucose, or D-fructose as carbon sources. 相似文献
10.