全文获取类型
收费全文 | 4188篇 |
免费 | 213篇 |
国内免费 | 21篇 |
专业分类
化学 | 3203篇 |
晶体学 | 16篇 |
力学 | 80篇 |
数学 | 536篇 |
物理学 | 587篇 |
出版年
2023年 | 52篇 |
2022年 | 74篇 |
2021年 | 84篇 |
2020年 | 135篇 |
2019年 | 109篇 |
2018年 | 63篇 |
2017年 | 79篇 |
2016年 | 174篇 |
2015年 | 150篇 |
2014年 | 175篇 |
2013年 | 198篇 |
2012年 | 305篇 |
2011年 | 259篇 |
2010年 | 149篇 |
2009年 | 141篇 |
2008年 | 227篇 |
2007年 | 215篇 |
2006年 | 188篇 |
2005年 | 198篇 |
2004年 | 183篇 |
2003年 | 121篇 |
2002年 | 154篇 |
2001年 | 66篇 |
2000年 | 60篇 |
1999年 | 51篇 |
1998年 | 58篇 |
1997年 | 50篇 |
1996年 | 54篇 |
1995年 | 38篇 |
1994年 | 32篇 |
1993年 | 31篇 |
1992年 | 42篇 |
1991年 | 24篇 |
1990年 | 27篇 |
1989年 | 33篇 |
1988年 | 33篇 |
1987年 | 30篇 |
1986年 | 23篇 |
1985年 | 27篇 |
1984年 | 31篇 |
1983年 | 26篇 |
1982年 | 21篇 |
1981年 | 38篇 |
1980年 | 24篇 |
1979年 | 21篇 |
1978年 | 17篇 |
1977年 | 27篇 |
1976年 | 10篇 |
1975年 | 12篇 |
1970年 | 13篇 |
排序方式: 共有4422条查询结果,搜索用时 15 毫秒
101.
Back Cover: Constrained Peptides with Target‐Adapted Cross‐Links as Inhibitors of a Pathogenic Protein–Protein Interaction (Angew. Chem. Int. Ed. 9/2014) 下载免费PDF全文
102.
103.
104.
Tino Zaehle Pascale Sandmann Jeremy D Thorne Lutz Jäncke Christoph S Herrmann 《BMC neuroscience》2011,12(1):2
Background
Transcranial direct current stimulation (tDCS) is a technique that can systematically modify behaviour by inducing changes in the underlying brain function. In order to better understand the neuromodulatory effect of tDCS, the present study examined the impact of tDCS on performance in a working memory (WM) task and its underlying neural activity. In two experimental sessions, participants performed a letter two-back WM task after sham and either anodal or cathodal tDCS over the left dorsolateral prefrontal cortex (DLPFC). 相似文献105.
Thomas Weymuth Moritz P. Haag Karin Kiewisch Sandra Luber Stephan Schenk Christoph R. Jacob Carmen Herrmann Johannes Neugebauer Markus Reiher 《Journal of computational chemistry》2012,33(27):2186-2198
We present the software package MO VI PAC for calculations of vibrational spectra, namely infrared, Raman, and Raman Optical Activity (ROA) spectra, in a massively parallelized fashion. MO VI PAC unites the latest versions of the programs SNF and AKIRA alongside with a range of helpful add‐ons to analyze and interpret the data obtained in the calculations. With its efficient parallelization and meta‐program design, MO VI PAC focuses in particular on the calculation of vibrational spectra of very large molecules containing on the order of a hundred atoms. For this purpose, it also offers different subsystem approaches such as Mode‐ and Intensity‐Tracking to selectively calculate specific features of the full spectrum. Furthermore, an approximation to the entire spectrum can be obtained using the Cartesian Tensor Transfer Method. We illustrate these capabilities using the example of a large π‐helix consisting of 20 (S)‐alanine residues. In particular, we investigate the ROA spectrum of this structure and compare it to the spectra of α‐ and 310‐helical analogs. © 2012 Wiley Periodicals, Inc. 相似文献
106.
107.
Fabian Benz Christoph Roderburg David Vargas Cardenas Mihael Vucur Jérémie Gautheron Alexander Koch Henning Zimmermann J?rn Janssen Lukas Nieuwenhuijsen Mark Luedde Norbert Frey Frank Tacke Christian Trautwein Tom Luedde 《Experimental & molecular medicine》2013,45(9):e42
MicroRNA (miRNA) levels in serum have recently emerged as potential novel biomarkers for various diseases. miRNAs are routinely measured by standard quantitative real-time PCR (qPCR); however, the high sensitivity of qPCR demands appropriate normalization to correct for nonbiological variation. Presently, RNU6B (U6) is used for data normalization of circulating miRNAs in many studies. However, it was suggested that serum levels of U6 themselves might differ between individuals. Therefore, no consensus has been reached on the best normalization strategy in ‘circulating miRNA''. We analyzed U6 levels as well as levels of spiked-in SV40-RNA in sera of 44 healthy volunteers, 203 intensive care unit patients and 64 patients with liver fibrosis. Levels of U6 demonstrated a high variability in sera of healthy donors, patients with critical illness and liver fibrosis. This high variability could also be confirmed in sera of mice after the cecal ligation and puncture procedure. Most importantly, levels of circulating U6 were significantly upregulated in sera of patients with critical illness and sepsis compared with controls and correlated with established markers of inflammation. In patients with liver fibrosis, U6 levels were significantly downregulated. In contrast, levels of spiked-in SV40 displayed a significantly higher stability both in human cohorts (healthy, critical illness, liver fibrosis) and in mice. Thus, we conclude that U6 levels in the serum are dysregulated in a disease-specific manner. Therefore, U6 should not be used for data normalization of circulating miRNAs in inflammatory diseases and previous studies using this approach should be interpreted with caution. Further studies are warranted to identify specific regulatory processes of U6 levels in sepsis and liver fibrosis. 相似文献
108.
109.