全文获取类型
收费全文 | 524篇 |
免费 | 40篇 |
国内免费 | 4篇 |
专业分类
化学 | 357篇 |
晶体学 | 2篇 |
力学 | 15篇 |
数学 | 24篇 |
物理学 | 170篇 |
出版年
2023年 | 2篇 |
2022年 | 7篇 |
2021年 | 6篇 |
2020年 | 21篇 |
2019年 | 8篇 |
2018年 | 9篇 |
2017年 | 3篇 |
2016年 | 8篇 |
2015年 | 11篇 |
2014年 | 26篇 |
2013年 | 29篇 |
2012年 | 33篇 |
2011年 | 21篇 |
2010年 | 21篇 |
2009年 | 22篇 |
2008年 | 32篇 |
2007年 | 29篇 |
2006年 | 30篇 |
2005年 | 39篇 |
2004年 | 33篇 |
2003年 | 24篇 |
2002年 | 6篇 |
2001年 | 17篇 |
2000年 | 16篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 12篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1985年 | 3篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1943年 | 1篇 |
排序方式: 共有568条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.
Zheng Z Xu X Fan X Lau WM Kwok RW 《Journal of the American Chemical Society》2004,126(39):12336-12342
A new synthetic approach for the formation of ultrathin polymer films with customizable properties was developed. In this approach, the kinematic nature of proton collisions with simple organic molecules condensed on a substrate is exploited to break C-H bonds preferentially. The subsequent recombination of carbon radicals gives a cross-linked polymer thin film, and the selectivity of C-H cleavage preserves the chemical functionalities of the precursor molecules. The nature and validity of the method are exemplified with theoretical results from ab initio molecular dynamics calculations and experimental evidence from a variety of characterization techniques. Its applicability is demonstrated by the synthesis of ultrathin polymer films with precursor molecules such as dotriacontane, docosanoic acid, poly(acrylic acid) oligomer, and polyisoprene. The approach is fundamentally different from conventional chemical synthesis as it involves an unusual mix of physical and chemical processes including charge exchange, projectile penetration, kinematics, collision-induced dissociation, inelastic energy transfer, chain transfer, and chain cross-linking. 相似文献
8.
Interpretation of contact angle measurements on two different fluoropolymers for the determination of solid surface tension 总被引:2,自引:0,他引:2
Tavana H Simon F Grundke K Kwok DY Hair ML Neumann AW 《Journal of colloid and interface science》2005,291(2):497-506
Contact angle measurements with a large number of liquids on the semi-fluorinated acryl polymer EGC-1700 films are reported. The surface tension was determined to be gammasv=13.84 mJ/m2 from contact angles of octamethylcyclotetrasiloxane (OMCTS) and decamethylcyclopentasiloxane (DMCPS). Inertness of these two liquids makes them ideal for determination of surface tension of low-energy fluoropolymers. On the other hand, contact angles of many other liquids deviated somewhat from a smooth contact angle pattern that represents the EGC-1700 surface tension. It is argued that noninertness of the molecules of these liquids gives rise to specific interactions with the polymer film, causing the deviations. Furthermore, contact angles of a series of n-alkanes (n-hexane to n-hexadecane) showed systematic deviations from this curve, similar to the trend observed for n-alkanes/Teflon AF 1600 systems studied earlier. Adsorption of vapor of short-chain liquids onto the polymer film caused their contact angles to fall above the gammasv=13.84 mJ/m2 curve, and a parallel alignment of molecules of the long-chain n-alkanes in the vicinity of the solid was the explanation for the deviation of their contact angles below it. It is found that vapor adsorption effect is more significant in the case of Teflon AF 1600, while the alignment of liquid molecules close to the surface is more pronounced for EGC-1700. 相似文献
9.
10.