全文获取类型
收费全文 | 83525篇 |
免费 | 604篇 |
国内免费 | 401篇 |
专业分类
化学 | 28953篇 |
晶体学 | 812篇 |
力学 | 6765篇 |
数学 | 32466篇 |
物理学 | 15534篇 |
出版年
2023年 | 58篇 |
2022年 | 240篇 |
2021年 | 281篇 |
2020年 | 180篇 |
2019年 | 163篇 |
2018年 | 10495篇 |
2017年 | 10322篇 |
2016年 | 6257篇 |
2015年 | 1054篇 |
2014年 | 521篇 |
2013年 | 667篇 |
2012年 | 4187篇 |
2011年 | 10929篇 |
2010年 | 5926篇 |
2009年 | 6311篇 |
2008年 | 6949篇 |
2007年 | 9111篇 |
2006年 | 532篇 |
2005年 | 1604篇 |
2004年 | 1757篇 |
2003年 | 2167篇 |
2002年 | 1209篇 |
2001年 | 294篇 |
2000年 | 325篇 |
1999年 | 192篇 |
1998年 | 225篇 |
1997年 | 177篇 |
1996年 | 233篇 |
1995年 | 146篇 |
1994年 | 90篇 |
1993年 | 110篇 |
1992年 | 71篇 |
1991年 | 81篇 |
1990年 | 64篇 |
1989年 | 65篇 |
1988年 | 65篇 |
1987年 | 67篇 |
1986年 | 67篇 |
1985年 | 62篇 |
1984年 | 71篇 |
1983年 | 50篇 |
1982年 | 52篇 |
1981年 | 43篇 |
1980年 | 50篇 |
1979年 | 46篇 |
1978年 | 44篇 |
1914年 | 45篇 |
1912年 | 40篇 |
1909年 | 41篇 |
1908年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
In the paper, the authors establish several integral representations for the generating functions of the large and little Schröder numbers and for the large and little Schröder numbers. 相似文献
2.
Mesoscopic modeling at the pore scale offers great promise in exploring the underlying structure transport performance of flow through porous media. The present work studies the fluid flow subjected to capillarity-induced resonance in porous media characterized by different porous structure and wettability. The effects of porosity and wettability on the displacement behavior of the fluid flow through porous media are discussed. The results are presented in the form of temporal evolution of percentage saturation and displacement of the fluid front through porous media. The present study reveals that the vibration in the form of acoustic excitation could be significant in the mobilization of fluid through the porous media. The dependence of displacement of the fluid on physicochemical parameters like wettability of the surface, frequency along with the porosity is analyzed. It was observed that the mean displacement of the fluid is more in the case of invading fluid with wetting phase where the driving force strength is not so dominant. 相似文献
3.
Sarah Peluse 《Israel Journal of Mathematics》2018,227(1):379-396
We prove that the group of diffeomorphisms of the interval [0, 1] contains surface groups whose action on (0, 1) has no global fix point and such that only countably many points of the interval (0, 1) have non-trivial stabiliser. 相似文献
4.
5.
6.
7.
Functional Carbazole Liquid‐Crystal Block Codendrimers with Optical and Electronic Properties 下载免费PDF全文
Ismael Gracia Beatriz Feringán Prof. José Luis Serrano Dr. Roberto Termine Dr. Attilio Golemme Dr. Ana Omenat Prof. Joaquín Barberá 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(3):1359-1369
The synthesis and characterisation of a family of block codendrimers consisting of highly versatile mesogenic and carbazole‐containing 2,2‐bis(hydroxymethyl)propionic acid (bis‐MPA) dendrons are reported. The liquid‐crystal behaviour was investigated by means of differential scanning calorimetry, polarised‐light optical microscopy and X‐ray diffraction. Depending on the chemical structure of the constituent dendrons, the codendrimers show lamellar or columnar mesophases. On the basis of the experimental results, models both at the molecular level and in the mesophase are proposed. The physical properties of the block codendrimers derived from the presence of the carbazole moiety in their structure were investigated: photoluminescence in solution and in the mesophase, electrochemical behaviour and hole transport. Electrodeposition of carbazole dendrons afforded a globular supramolecular conformation in which the mesogenic molecular side plays a key role. 相似文献
8.
9.
10.
Functional Binding Surface of a β‐Hairpin VEGF Receptor Targeting Peptide Determined by NMR Spectroscopy in Living Cells 下载免费PDF全文
Dr. Donatella Diana Anna Russomanno Dr. Lucia De Rosa Dr. Rossella Di Stasi Dr. Domenica Capasso Dr. Sonia Di Gaetano Dr. Alessandra Romanelli Dr. Luigi Russo Dr. Luca D. D'Andrea Prof. Roberto Fattorusso 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):91-95
In this study, the functional interaction of HPLW peptide with VEGFR2 (Vascular Endothelial Growth Factor Receptor 2) was determined by using fast 15N‐edited NMR spectroscopic experiments. To this aim, 15N uniformly labelled HPLW has been added to Porcine Aortic Endothelial Cells. The acquisition of isotope‐edited NMR spectroscopic experiments, including 15N relaxation measurements, allowed a precise characterization of the in‐cell HPLW epitope recognized by VEGFR2. 相似文献