全文获取类型
收费全文 | 6457篇 |
免费 | 267篇 |
国内免费 | 47篇 |
专业分类
化学 | 4810篇 |
晶体学 | 35篇 |
力学 | 177篇 |
数学 | 890篇 |
物理学 | 859篇 |
出版年
2023年 | 45篇 |
2022年 | 80篇 |
2021年 | 113篇 |
2020年 | 122篇 |
2019年 | 127篇 |
2018年 | 96篇 |
2017年 | 75篇 |
2016年 | 170篇 |
2015年 | 176篇 |
2014年 | 194篇 |
2013年 | 340篇 |
2012年 | 424篇 |
2011年 | 507篇 |
2010年 | 241篇 |
2009年 | 196篇 |
2008年 | 431篇 |
2007年 | 429篇 |
2006年 | 433篇 |
2005年 | 346篇 |
2004年 | 308篇 |
2003年 | 274篇 |
2002年 | 228篇 |
2001年 | 75篇 |
2000年 | 55篇 |
1999年 | 51篇 |
1998年 | 57篇 |
1997年 | 59篇 |
1996年 | 91篇 |
1995年 | 50篇 |
1994年 | 48篇 |
1993年 | 54篇 |
1992年 | 38篇 |
1991年 | 51篇 |
1990年 | 44篇 |
1989年 | 32篇 |
1988年 | 33篇 |
1987年 | 23篇 |
1986年 | 23篇 |
1985年 | 54篇 |
1984年 | 54篇 |
1983年 | 26篇 |
1982年 | 42篇 |
1981年 | 39篇 |
1980年 | 33篇 |
1979年 | 44篇 |
1978年 | 37篇 |
1977年 | 41篇 |
1976年 | 35篇 |
1975年 | 32篇 |
1974年 | 33篇 |
排序方式: 共有6771条查询结果,搜索用时 31 毫秒
1.
Dr. Chen-Ming Lin Maritess Arancillo Jonathan Whisenant Prof. Kevin Burgess 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(24):9484-9488
Secondary structures tend to be recognizable because they have repeating structural motifs, but mimicry of these does not have to follow such well-defined patterns. Bioinformatics studies to match side-chain orientations of a novel hydantoin triazole chemotype ( 1 ) to protein-protein interfaces revealed it tends to align well across parallel and antiparallel sheets, like rungs on a ladder. One set of these overlays was observed for the protein-protein interaction uPA⋅uPAR. Consequently, chemotype 1 was made with appropriate side-chains to mimic uPA at this interface. Biophysical assays indicate these compounds did in fact bind uPAR, and elicit cellular responses that affected invasion, migration, and wound healing. 相似文献
2.
3.
4.
5.
Kevin Phelps 《Designs, Codes and Cryptography》2015,77(2-3):357-363
6.
Optics and Spectroscopy - Scattering of light by disordered structures is normally detrimental to their applicability in many optoelectronic devices. However, some micro and nanostructures are... 相似文献
7.
In this paper, we investigate the evolution of joint invariants under invariant geometric flows using the theory of equivariant moving frames and the induced invariant discrete variational complex. For certain arc length preserving planar curve flows invariant under the special Euclidean group , the special linear group , and the semidirect group , we find that the induced evolution of the discrete curvature satisfies the differential‐difference mKdV, KdV, and Burgers' equations, respectively. These three equations are completely integrable, and we show that a recursion operator can be constructed by precomposing the characteristic operator of the curvature by a certain invariant difference operator. Finally, we derive the constraint for the integrability of the discrete curvature evolution to lift to the evolution of the discrete curve itself. 相似文献
8.
Facile non‐lithographic route to highly aligned silica nanopatterns using unidirectionally aligned polystyrene‐block‐polydimethylsiloxane films 下载免费PDF全文
Zhe Qiang Maurice L. Wadley Bryan D. Vogt Kevin A. Cavicchi 《Journal of Polymer Science.Polymer Physics》2015,53(15):1058-1064
Thin films (monolayer and bilayer) of cylinder forming polystyrene‐block‐polydimethylsiloxane (PS‐b‐PDMS) were shear aligned by the swelling and deswelling of a crosslinked PDMS pad that was physically adhered to the film during solvent vapor annealing. The nanostructures formed by self‐assembly were exposed to ultraviolet‐ozone to partially oxidize the PDMS, followed by calcination in air at 500 °C. In this process, the PS segments were fully decomposed, while the PDMS yielded silica nanostructures. The highly aligned PDMS cylinders were thus deposited as silica nanolines on the silicon substrate. Using a bilayer film, the center‐to‐center distance of these features were effectively halved from 38 to 19 nm. Similarly, by sequential shear‐alignment of two distinct layers, a rhombic array of silica nanolines was fabricated. This methodology provides a facile route to fabricating complex topographically patterned nanostructures. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1058–1064 相似文献
9.
10.