全文获取类型
收费全文 | 11232篇 |
免费 | 880篇 |
国内免费 | 6篇 |
出版年
2023年 | 68篇 |
2022年 | 145篇 |
2021年 | 283篇 |
2020年 | 156篇 |
2019年 | 284篇 |
2018年 | 317篇 |
2017年 | 283篇 |
2016年 | 406篇 |
2015年 | 638篇 |
2014年 | 650篇 |
2013年 | 839篇 |
2012年 | 975篇 |
2011年 | 926篇 |
2010年 | 566篇 |
2009年 | 559篇 |
2008年 | 680篇 |
2007年 | 684篇 |
2006年 | 576篇 |
2005年 | 519篇 |
2004年 | 466篇 |
2003年 | 423篇 |
2002年 | 376篇 |
2001年 | 110篇 |
2000年 | 71篇 |
1999年 | 89篇 |
1998年 | 95篇 |
1997年 | 69篇 |
1996年 | 64篇 |
1995年 | 70篇 |
1994年 | 67篇 |
1993年 | 45篇 |
1992年 | 66篇 |
1991年 | 50篇 |
1990年 | 38篇 |
1989年 | 52篇 |
1988年 | 30篇 |
1987年 | 35篇 |
1986年 | 34篇 |
1985年 | 36篇 |
1984年 | 23篇 |
1983年 | 29篇 |
1982年 | 14篇 |
1981年 | 12篇 |
1980年 | 18篇 |
1979年 | 32篇 |
1978年 | 20篇 |
1977年 | 15篇 |
1974年 | 15篇 |
1973年 | 11篇 |
1972年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
Roberto Angelini Simona Lobasso Ruggiero Gorgoglione Ann Bowron Colin G. Steward Angela Corcelli 《Journal of lipid research》2015,56(9):1787-1794
Barth syndrome (BTHS), an X-linked disease associated with cardioskeletal myopathy, neutropenia, and organic aciduria, is characterized by abnormalities of cardiolipin (CL) species in mitochondria. Diagnosis of the disease is often compromised by lack of rapid and widely available diagnostic laboratory tests. The present study describes a new method for BTHS screening based on MALDI-TOF/MS analysis of leukocyte lipids. This generates a “CL fingerprint” and allows quick and simple assay of the relative levels of CL and monolysocardiolipin species in leukocyte total lipid profiles. To validate the method, we used vector algebra to analyze the difference in lipid composition between controls (24 healthy donors) and patients (8 boys affected by BTHS) in the high-mass phospholipid range. The method of lipid analysis described represents an important additional tool for the diagnosis of BTHS and potentially enables therapeutic monitoring of drug targets, which have been shown to ameliorate abnormal CL profiles in cells. 相似文献
993.
994.
995.
996.
An integrative study of Necremnus Thomson (Hymenoptera: Eulophidae) associated with invasive pests in Europe and North America: taxonomic and ecological implications
下载免费PDF全文
![点击此处可从《Zoological Journal of the Linnean Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Marco Gebiola Umberto Bernardo Gary A. P. Gibson 《Zoological Journal of the Linnean Society》2015,173(2):352-423
The species of Necremnus attacking two invasive pests of tomato and canola in Europe and North America, respectively, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) and Ceutorhynchus obstrictus (Marsham) (Coleoptera: Curculionidae), have been revised using an integrative taxonomy approach. Molecular data from the mitochondrial cytochrome oxidase c subunit I and the nuclear D2 expansion region of the 28S ribosomal subunit and internal transcribed spacer 2, the discovery of new morphological features, and study of type material resulted in the delineation of three species groups, the Necremnus artynes, Necremnus cosconius, and Necremnus tidius groups, the discovery of four new species, and the resurrection of three taxa from synonymy. Lectotypes have been designated for 13 species originally described in Eulophus by Walker. Although Necremnus has not been revised, an illustrated key is given to differentiate 23 recognized European species. The key, type images, and treatments of the three species groups will enable more accurate identification of the valid species of Necremnus in the future. They will also benefit biological control practitioners of pest species. The ecological consequences of the new taxonomic concepts are discussed. © 2015 The Authors. Zoological Journal of the Linnean Society published by John Wiley & Sons Ltd on behalf of The Linnean Society of London 相似文献
997.
998.
Thermal specialization across large geographical scales predicts the resilience of mangrove crab populations to global warming
下载免费PDF全文
![点击此处可从《Oikos》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Marco Fusi Folco Giomi Simone Babbini Daniele Daffonchio Christopher D. McQuaid Francesca Porri Stefano Cannicci 《Oikos》2015,124(6):784-795
The broad prediction that ectotherms will be more vulnerable to climate change in the tropics than in temperate regions includes assumptions about centre/edge population effects that can only be tested by within‐species comparisons across wide latitudinal gradients. Here, we investigated the thermal vulnerability of two mangrove crab species, comparing populations at the centre (Kenya) and edge (South Africa) of their distributions. At the same time, we investigated the role of respiratory mode (water‐ versus air‐breathing) in determining the thermal tolerance in amphibious organisms. To do this, we compared the vulnerability to acute temperature fluctuations of two sympatric species with two different lifestyle adaptations: the free living Perisesarma guttatum and the burrowing Uca urvillei, both pivotal to the ecosystem functioning of mangroves. The results revealed the air‐breathing U. urvillei to be a thermal generalist with much higher thermal tolerances than P. guttatum. Importantly, however, we found that, while U. urvillei showed little difference between edge and centre populations, P. guttatum showed adaptation to local conditions. Equatorial populations had elevated tolerances to acute heat stress and mechanisms of partial thermoregulation, which make them less vulnerable to global warming than temperate conspecifics. The results reveal both the importance of respiratory mode to thermal tolerance and the unexpected potential for low latitude populations/species to endure a warming climate. The results also contribute to a conceptual model on the latitudinal thermal tolerance of these key species. This highlights the need for an integrated population‐level approach to predict the consequences of climate change. 相似文献
999.
1000.
Susanne Matschi Katharina Hake Marco Herde Bettina Hause Tina Romeis 《The Plant cell》2015,27(3):591-606
Phytohormones play an important role in development and stress adaptations in plants, and several interacting hormonal pathways have been suggested to accomplish fine-tuning of stress responses at the expense of growth. This work describes the role played by the CALCIUM-DEPENDENT PROTEIN KINASE CPK28 in balancing phytohormone-mediated development in Arabidopsis thaliana, specifically during generative growth. cpk28 mutants exhibit growth reduction solely as adult plants, coinciding with altered balance of the phytohormones jasmonic acid (JA) and gibberellic acid (GA). JA-dependent gene expression and the levels of several JA metabolites were elevated in a growth phase-dependent manner in cpk28, and accumulation of JA metabolites was confined locally to the central rosette tissue. No elevated resistance toward herbivores or necrotrophic pathogens was detected for cpk28 plants, either on the whole-plant level or specifically within the tissue displaying elevated JA levels. Abolishment of JA biosynthesis or JA signaling led to a full reversion of the cpk28 growth phenotype, while modification of GA signaling did not. Our data identify CPK28 as a growth phase-dependent key negative regulator of distinct processes: While in seedlings, CPK28 regulates reactive oxygen species-mediated defense signaling; in adult plants, CPK28 confers developmental processes by the tissue-specific balance of JA and GA without affecting JA-mediated defense responses. 相似文献