首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   112篇
  免费   7篇
  119篇
  2022年   1篇
  2021年   1篇
  2020年   2篇
  2018年   4篇
  2017年   4篇
  2016年   6篇
  2015年   1篇
  2014年   3篇
  2013年   5篇
  2012年   5篇
  2011年   4篇
  2010年   4篇
  2009年   5篇
  2008年   6篇
  2007年   3篇
  2006年   2篇
  2005年   4篇
  2004年   9篇
  2003年   5篇
  2002年   11篇
  2001年   6篇
  2000年   3篇
  1999年   7篇
  1998年   2篇
  1997年   2篇
  1995年   2篇
  1993年   2篇
  1990年   1篇
  1988年   1篇
  1980年   1篇
  1978年   1篇
  1976年   1篇
  1975年   2篇
  1970年   1篇
  1965年   1篇
  1938年   1篇
排序方式: 共有119条查询结果,搜索用时 0 毫秒
1.
2.
Moran, R.C. & Øllgaard, B. 1995. Six new species of ferns (Polypodiopsida) from Ecuador. - Nord. J. Bot. 15: 177–185. Copenhagen. ISSN 0107–055X.
The following species of ferns from Ecuador are described as new: Blechnum mono-morphum. Bolbitis riparia, Hecistopteris pinnatifida, Hymenophyllum hemidimorphum, Polypodium latissimum , and Saccoloma laxum .  相似文献   
3.
C5L2, a nonsignaling C5A binding protein   总被引:11,自引:0,他引:11  
  相似文献   
4.
5.
6.
China has the world's longest history of soil bioengineering, with the first mention of giant fascines to control torrential floodwaters dating from over 2000 BC. However, soil degradation on steep slopes has accelerated hugely over the last 50 years, due to poor farming practice, deforestation, road and dam construction. The central government has therefore devised a series of major programs to reduce the exploitation of forest resources (Natural Forest Protection Program – NFPP) and to rehabilitate steep slopes by encouraging the conversion of cropland to forest and orchards (Sloping Land Conversion Program – SLCP). In this review, we define soil bio- and eco-engineering and examine China's past experience in both domains. We focus on case studies whereby vegetation has been used in conjunction with civil engineering to prevent landslides in Hong Kong and the social and practical aspects of planting on steep slopes to conserve soil on a large-scale in mainland China. The successes and failures of tree planting and forest management in the NFPP and SLCP are discussed along with the priorities for future research and practical applications. This review introduces a special edition of the journal Ecological Engineering, whereby a selection of papers presented at the Second International Conference ‘Ground Bio- and Eco-engineering: The Use of Vegetation to Improve Slope Stability – ICGBE2’ held in Beijing, China, 14–18 July 2008, are published. This congress joined together scientists and practitioners with the aim of discussing new theory, methods and applications for using vegetation to fix soil on steep slopes prone to landslides and erosion. In this review, we consider the key points from the conference and place them in the context of managing and restoring degraded slopes in China, one of the world's most pertinent study sites.  相似文献   
7.
Methanobacterium sp. Mb1, a hydrogenotrophic methanogenic Archaeon, was isolated from a rural biogas plant producing methane-rich biogas from maize silage and cattle manure in Germany. Here we report the complete genome sequence of the novel methanogenic isolate Methanobacterium sp. Mb1 harboring a 2,029,766 bp circular chromosome featuring a GC content of 39.74%. The genome encodes two rRNA operons, 41 tRNA genes and 2021 coding sequences and represents the smallest genome currently known within the genus Methanobacterium.  相似文献   
8.
The ribosomal S1 protein (rS1) is indispensable for translation initiation in Gram-negative bacteria. rS1 is a multidomain protein that acts as an RNA chaperone and ensures that mRNAs can bind the ribosome in a single-stranded conformation, which could be related to fast recognition. Although many ribosome structures were solved in recent years, a high-resolution structure of a two-domain mRNA-binding competent rS1 construct is not yet available. Here, we present the NMR solution structure of the minimal mRNA-binding fragment of Vibrio Vulnificus rS1 containing the domains D3 and D4. Both domains are homologues and adapt an oligonucleotide-binding fold (OB fold) motif. NMR titration experiments reveal that recognition of miscellaneous mRNAs occurs via a continuous interaction surface to one side of these structurally linked domains. Using a novel paramagnetic relaxation enhancement (PRE) approach and exploring different spin-labeling positions within RNA, we were able to track the location and determine the orientation of the RNA in the rS1–D34 bound form. Our investigations show that paramagnetically labeled RNAs, spiked into unmodified RNA, can be used as a molecular ruler to provide structural information on protein-RNA complexes. The dynamic interaction occurs on a defined binding groove spanning both domains with identical β2-β3-β5 interfaces. Evidently, the 3′-ends of the cis-acting RNAs are positioned in the direction of the N-terminus of the rS1 protein, thus towards the 30S binding site and adopt a conformation required for translation initiation.  相似文献   
9.
A series of 5,6-diaryl-2-amino-pyrazines were prepared and found to have antagonist-like properties at the CB1 receptor. Subsequent SAR studies optimized both receptor potency and drug-like properties including solubility and Cytochrome-P450 inhibition potential. Optimized compounds were demonstrated to be inverse agonists and compared in vivo with rimonabant for their ability to inhibit food intake, to occupy central CB1 receptors and to influence hormonal markers associated with obesity.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号