全文获取类型
收费全文 | 454篇 |
免费 | 55篇 |
出版年
2021年 | 4篇 |
2020年 | 5篇 |
2016年 | 6篇 |
2015年 | 9篇 |
2014年 | 11篇 |
2013年 | 39篇 |
2012年 | 26篇 |
2011年 | 11篇 |
2010年 | 12篇 |
2009年 | 10篇 |
2008年 | 15篇 |
2007年 | 19篇 |
2006年 | 16篇 |
2005年 | 21篇 |
2004年 | 18篇 |
2003年 | 20篇 |
2002年 | 11篇 |
2001年 | 18篇 |
2000年 | 15篇 |
1999年 | 15篇 |
1998年 | 6篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 15篇 |
1991年 | 11篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1979年 | 4篇 |
1975年 | 3篇 |
1972年 | 3篇 |
1970年 | 3篇 |
1969年 | 4篇 |
1965年 | 3篇 |
1932年 | 2篇 |
1929年 | 2篇 |
1928年 | 3篇 |
1927年 | 4篇 |
1926年 | 2篇 |
1925年 | 4篇 |
排序方式: 共有509条查询结果,搜索用时 328 毫秒
61.
Florian T. Wetzel W. Daniel Kissling Helmut Beissmann Dustin J. Penn 《Global Change Biology》2012,18(9):2707-2719
Sea‐level rise (SLR) due to global warming will result in the loss of many coastal areas. The direct or primary effects due to inundation and erosion from SLR are currently being assessed; however, the indirect or secondary ecological effects, such as changes caused by the displacement of human populations, have not been previously evaluated. We examined the potential ecological consequences of future SLR on >1,200 islands in the Southeast Asian and the Pacific region. Using three SLR scenarios (1, 3, and 6 m elevation, where 1 m approximates most predictions by the end of this century), we assessed the consequences of primary and secondary SLR effects from human displacement on habitat availability and distributions of selected mammal species. We estimate that between 3–32% of the coastal zone of these islands could be lost from primary effects, and consequently 8–52 million people would become SLR refugees. Assuming that inundated urban and intensive agricultural areas will be relocated with an equal area of habitat loss in the hinterland, we project that secondary SLR effects can lead to an equal or even higher percent range loss than primary effects for at least 10–18% of the sample mammals in a moderate range loss scenario and for 22–46% in a maximum range loss scenario. In addition, we found some species to be more vulnerable to secondary than primary effects. Finally, we found high spatial variation in vulnerability: species on islands in Oceania are more vulnerable to primary SLR effects, whereas species on islands in Indo‐Malaysia, with potentially 7–48 million SLR refugees, are more vulnerable to secondary effects. Our findings show that primary and secondary SLR effects can have enormous consequences for human inhabitants and island biodiversity, and that both need to be incorporated into ecological risk assessment, conservation, and regional planning. 相似文献
62.
Kähne T Kolodziej A Smalla KH Eisenschmidt E Haus UU Weismantel R Kropf S Wetzel W Ohl FW Tischmeyer W Naumann M Gundelfinger ED 《Proteomics》2012,12(15-16):2433-2444
Changes in synaptic efficacy underlying learning and memory processes are assumed to be associated with alterations of the protein composition of synapses. Here, we performed a quantitative proteomic screen to monitor changes in the synaptic proteome of four brain areas (auditory cortex, frontal cortex, hippocampus striatum) during auditory learning. Mice were trained in a shuttle box GO/NO-GO paradigm to discriminate between rising and falling frequency modulated tones to avoid mild electric foot shock. Control-treated mice received corresponding numbers of either the tones or the foot shocks. Six hours and 24 h later, the composition of a fraction enriched in synaptic cytomatrix-associated proteins was compared to that obtained from na?ve mice by quantitative mass spectrometry. In the synaptic protein fraction obtained from trained mice, the average percentage (±SEM) of downregulated proteins (59.9 ± 0.5%) exceeded that of upregulated proteins (23.5 ± 0.8%) in the brain regions studied. This effect was significantly smaller in foot shock (42.7 ± 0.6% down, 40.7 ± 1.0% up) and tone controls (43.9 ± 1.0% down, 39.7 ± 0.9% up). These data suggest that learning processes initially induce removal and/or degradation of proteins from presynaptic and postsynaptic cytoskeletal matrices before these structures can acquire a new, postlearning organisation. In silico analysis points to a general role of insulin-like signalling in this process. 相似文献
63.
Tombline G Holt JJ Gannon MK Donnelly DJ Wetzel B Sawada GA Raub TJ Detty MR 《Biochemistry》2008,47(10):3294-3307
The multidrug efflux pump P-glycoprotein (Pgp) couples drug transport to ATP hydrolysis. Previously, using a synthetic library of tetramethylrosamine ( TMR) analogues, we observed significant variation in ATPase stimulation ( V m (D)). Concentrations required for half-maximal ATPase stimulation ( K m (D)) correlated with ATP hydrolysis transition-state stabilization and ATP occlusion (EC 50 (D)) at a single site. Herein, we characterize several TMR analogues that elicit modest turnover ( k cat 相似文献
64.
Georg Wetzel 《Development genes and evolution》1928,114(1):65-107
Ohne Zusammenfassung 相似文献
65.
Dr. Robert Wetzel 《Development genes and evolution》1925,106(1-4):463-468
Ohne Zusammenfassung 相似文献
66.
67.
R. L. Wetzel 《Microbial ecology》1994,28(2):331-334
Contemporary models of the microbial loop should be critically evaluated relative to their compartmental structures, flow networks, and treatment of upper ocean physics (vertical and horizontal boundary conditions). The development of new models that include better representation of the autotrophic components and mixotrophy/competitive interactions is warranted. The mathematical structures should reflect contemporary knowledge of controls (e.g., multiple resource limitation), thresholds and limits, and be based on testable assumptions. Stochastic processes must at some point be included to evaluate known patterns of spatial and temporal variability. 相似文献
68.
69.
Richard Karban Kaori Shiojiri Satomi Ishizaki William C. Wetzel Richard Y. Evans 《Proceedings. Biological sciences / The Royal Society》2013,280(1756)
The ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviours; such ability is less well studied for plants. Many plants, including Artemisia tridentata, have been found to respond to volatile cues emitted by experimentally wounded neighbours to increase levels of resistance to herbivory. We report that this communication was more effective among A. tridentata plants that were more closely related based on microsatellite markers. Plants in the field that received cues from experimentally clipped close relatives experienced less leaf herbivory over the growing season than those that received cues from clipped neighbours that were more distantly related. These results indicate that plants can respond differently to cues from kin, making it less likely that emitters will aid strangers and making it more likely that receivers will respond to cues from relatives. More effective defence adds to a growing list of favourable consequences of kin recognition for plants. 相似文献
70.
Ying Qing Lei Dong Lei Gao Chenying Li Yangchan Li Li Han Emily Prince Brandon Tan Xiaolan Deng Collin Wetzel Chao Shen Min Gao Zhenhua Chen Wei Li Bin Zhang Daniel Braas Johanna ten Hoeve Gerardo Javier Sanchez Jianjun Chen 《Molecular cell》2021,81(5):922-939.e9
- Download : Download high-res image (167KB)
- Download : Download full-size image