全文获取类型
收费全文 | 1309篇 |
免费 | 98篇 |
国内免费 | 6篇 |
专业分类
化学 | 1100篇 |
晶体学 | 10篇 |
力学 | 14篇 |
数学 | 110篇 |
物理学 | 179篇 |
出版年
2023年 | 11篇 |
2022年 | 10篇 |
2021年 | 30篇 |
2020年 | 38篇 |
2019年 | 54篇 |
2018年 | 36篇 |
2017年 | 27篇 |
2016年 | 53篇 |
2015年 | 45篇 |
2014年 | 68篇 |
2013年 | 74篇 |
2012年 | 94篇 |
2011年 | 109篇 |
2010年 | 50篇 |
2009年 | 39篇 |
2008年 | 87篇 |
2007年 | 69篇 |
2006年 | 81篇 |
2005年 | 81篇 |
2004年 | 77篇 |
2003年 | 51篇 |
2002年 | 50篇 |
2001年 | 16篇 |
2000年 | 14篇 |
1999年 | 15篇 |
1998年 | 9篇 |
1997年 | 16篇 |
1996年 | 4篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 10篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1968年 | 2篇 |
排序方式: 共有1413条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
85.
Yoshida R Sakai T Ito S Yamaguchi T 《Journal of the American Chemical Society》2002,124(27):8095-8098
Self-oscillation of polymer chains in an aqueous solution has been achieved. The ruthenium catalyst for the Belousov-Zhabotinsky reaction was polymerized by using N-isopropylacrylamide and dissolved into the solution containing the BZ substrates. Periodical soluble-insoluble changes of the polymer chain were spontaneously induced by the BZ reaction. The conformational oscillations of the polymer were measured as the optical transmittance changes of the solution. This is the first report that rhythmical and reversible soluble-insoluble changes of polymer chains are realized under constant and homogeneous conditions. The transducing system from chemical energy of the BZ reaction to optical information has been constructed. 相似文献
86.
We report the results of in situ AFM measurements examining the phase transition of bilayers formed from the zwitterionic phospholipid, DMPC, 1,2-dimyristoyl-sn-glycero-3-phosphocholine, supported on mica. The images show that the fluid to gel phase transition process features substantial tearing of the bilayer due to the density change between the two phases. The gel to fluid transition is strongly affected by the resultant stress introduced into the gel phase, which changes the degree of cooperativity, the shape of developing fluid phase regions, and the course of the transition. 相似文献
87.
π, π*-Induced Photocleavage of γ, δ-Epoxy-eucarvone . On 1π, π*-excitation 1 undergoes cleavage of the C, C-oxirane bond ( 1 → c ) and isomerizes to the bicyclic dihydrofurane compound 5 . In addition, 1 shows photocleavage of the C (γ), O-oxirane bond ( 1 → d ) and gives the isomers 2, 3, 6, 7 and 8. Furthermore, the cyclohexenone 9 and the cyclohexene-1, 4-dione 10 are formed presumably via an intermediate 13 , which could also arise from d. Besides these products the compounds 11 and 12 are obtained, which are photoproducts of 2 . 相似文献
88.
Ohne Zusammenfassung 相似文献
89.
Ohne Zusammenfassung 相似文献
90.
We report the first experimental demonstration of an optical quantum controlled-NOT gate without any path interference, where the two interacting path interferometers of the original proposals have been replaced by three partially polarizing beam splitters with suitable polarization dependent transmittance and reflectance. The performance of the device is evaluated using a recently proposed method, by which the quantum process fidelity and the entanglement capability can be estimated from the 32 measurement results of two classical truth tables, significantly less than the 256 measurement results required for full quantum tomography. 相似文献