全文获取类型
收费全文 | 4307篇 |
免费 | 353篇 |
国内免费 | 2篇 |
出版年
2022年 | 30篇 |
2021年 | 81篇 |
2020年 | 65篇 |
2019年 | 65篇 |
2018年 | 62篇 |
2017年 | 62篇 |
2016年 | 134篇 |
2015年 | 208篇 |
2014年 | 204篇 |
2013年 | 254篇 |
2012年 | 294篇 |
2011年 | 281篇 |
2010年 | 177篇 |
2009年 | 164篇 |
2008年 | 215篇 |
2007年 | 203篇 |
2006年 | 183篇 |
2005年 | 151篇 |
2004年 | 161篇 |
2003年 | 126篇 |
2002年 | 160篇 |
2001年 | 65篇 |
2000年 | 53篇 |
1999年 | 51篇 |
1998年 | 45篇 |
1997年 | 43篇 |
1996年 | 35篇 |
1995年 | 42篇 |
1994年 | 28篇 |
1993年 | 26篇 |
1992年 | 36篇 |
1991年 | 22篇 |
1990年 | 29篇 |
1989年 | 38篇 |
1988年 | 31篇 |
1987年 | 30篇 |
1986年 | 17篇 |
1985年 | 26篇 |
1984年 | 33篇 |
1983年 | 19篇 |
1982年 | 30篇 |
1981年 | 33篇 |
1980年 | 21篇 |
1979年 | 21篇 |
1978年 | 21篇 |
1977年 | 24篇 |
1976年 | 23篇 |
1968年 | 16篇 |
1963年 | 15篇 |
1960年 | 16篇 |
排序方式: 共有4662条查询结果,搜索用时 15 毫秒
1.
2.
Ewa A. Czy Carla Guilln Escrib Hendrik Wulf Andrew Tedder Meredith C. Schuman Fabian D. Schneider Michael E. Schaepman 《Ecology and evolution》2020,10(14):7419-7430
- The growing pace of environmental change has increased the need for large‐scale monitoring of biodiversity. Declining intraspecific genetic variation is likely a critical factor in biodiversity loss, but is especially difficult to monitor: assessments of genetic variation are commonly based on measuring allele pools, which requires sampling of individuals and extensive sample processing, limiting spatial coverage. Alternatively, imaging spectroscopy data from remote platforms may hold the potential to reveal genetic structure of populations. In this study, we investigated how differences detected in an airborne imaging spectroscopy time series correspond to genetic variation within a population of Fagus sylvatica under natural conditions.
- We used multi‐annual APEX (Airborne Prism Experiment) imaging spectrometer data from a temperate forest located in the Swiss midlands (Laegern, 47°28'N, 8°21'E), along with microsatellite data from F. sylvatica individuals collected at the site. We identified variation in foliar reflectance independent of annual and seasonal changes which we hypothesize is more likely to correspond to stable genetic differences. We established a direct connection between the spectroscopy and genetics data by using partial least squares (PLS) regression to predict the probability of belonging to a genetic cluster from spectral data.
- We achieved the best genetic structure prediction by using derivatives of reflectance and a subset of wavebands rather than full‐analyzed spectra. Our model indicates that spectral regions related to leaf water content, phenols, pigments, and wax composition contribute most to the ability of this approach to predict genetic structure of F. sylvatica population in natural conditions.
- This study advances the use of airborne imaging spectroscopy to assess tree genetic diversity at canopy level under natural conditions, which could overcome current spatiotemporal limitations on monitoring, understanding, and preventing genetic biodiversity loss imposed by requirements for extensive in situ sampling.
3.
4.
Hermann Desselberger 《Journal of Ornithology》1930,78(1):86-106
Ohne Zusammenfassung 相似文献
5.
6.
7.
Michaela Ludolphs Daniela Schneeberger Tolga Soykan Jonas Sch?fer Theofilos Papadopoulos Nils Brose Hermann Schindelin Claudia Steinem 《The Journal of biological chemistry》2016,291(1):244-254
The regulatory protein collybistin (CB) recruits the receptor-scaffolding protein gephyrin to mammalian inhibitory glycinergic and GABAergic postsynaptic membranes in nerve cells. CB is tethered to the membrane via phosphoinositides. We developed an in vitro assay based on solid-supported 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine membranes doped with different phosphoinositides on silicon/silicon dioxide substrates to quantify the binding of various CB2 constructs using reflectometric interference spectroscopy. Based on adsorption isotherms, we obtained dissociation constants and binding capacities of the membranes. Our results show that full-length CB2 harboring the N-terminal Src homology 3 (SH3) domain (CB2SH3+) adopts a closed and autoinhibited conformation that largely prevents membrane binding. This autoinhibition is relieved upon introduction of the W24A/E262A mutation, which conformationally “opens” CB2SH3+ and allows the pleckstrin homology domain to properly bind lipids depending on the phosphoinositide species with a preference for phosphatidylinositol 3-monophosphate and phosphatidylinositol 4-monophosphate. This type of membrane tethering under the control of the release of the SH3 domain of CB is essential for regulating gephyrin clustering. 相似文献
8.
9.
10.
Hoffmann Hermann 《Molecular & general genetics : MGG》1922,29(1):144
Ohne Zusammenfassung 相似文献