全文获取类型
收费全文 | 3597篇 |
免费 | 342篇 |
国内免费 | 191篇 |
专业分类
化学 | 2358篇 |
晶体学 | 54篇 |
力学 | 164篇 |
综合类 | 26篇 |
数学 | 363篇 |
物理学 | 1165篇 |
出版年
2023年 | 40篇 |
2022年 | 94篇 |
2021年 | 106篇 |
2020年 | 99篇 |
2019年 | 116篇 |
2018年 | 93篇 |
2017年 | 90篇 |
2016年 | 147篇 |
2015年 | 136篇 |
2014年 | 174篇 |
2013年 | 262篇 |
2012年 | 293篇 |
2011年 | 278篇 |
2010年 | 199篇 |
2009年 | 171篇 |
2008年 | 261篇 |
2007年 | 213篇 |
2006年 | 209篇 |
2005年 | 180篇 |
2004年 | 138篇 |
2003年 | 134篇 |
2002年 | 147篇 |
2001年 | 84篇 |
2000年 | 83篇 |
1999年 | 40篇 |
1998年 | 35篇 |
1997年 | 27篇 |
1996年 | 42篇 |
1995年 | 39篇 |
1994年 | 17篇 |
1993年 | 16篇 |
1992年 | 8篇 |
1991年 | 12篇 |
1990年 | 10篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 11篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1977年 | 4篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1974年 | 9篇 |
1973年 | 5篇 |
1970年 | 4篇 |
1968年 | 8篇 |
排序方式: 共有4130条查询结果,搜索用时 15 毫秒
121.
Jie Pan Yan Bao Hao Wang Fucong Lyu Lu Liu Chong Wang Xinxue Tang Jian Lu Yang Yang Li 《Particle & Particle Systems Characterization》2021,38(10):2100094
The high-entropy materials have raised much attention in recent years due to their extraordinary performances in mechanical, catalysis, energy storage fields. Herein, a new type of high-entropy hydroxides (e.g., NiFeCoMnAl(OH)x) that are amorphous and capable of broad solar absorption is reported. A facile one-pot co-precipitation method is employed to synthesize these amorphous high-entropy hydroxides (a-HEHOs) under ambient conditions. The a-HEHOs thus obtained display widely tunable bandgap (e.g., from 2.6 to 1.1 eV) due to their high-entropy and amorphous characteristics, enabling efficient light absorbance and photothermal conversion in the solar regime. Further solar water evaporation measurements show that the a-HEHOs delivered a considerable energy conversion efficiency of 55%, comparable to black titanium oxides that are synthesized using more complex and expensive methods. 相似文献
122.
123.
124.
125.
126.
Tong Chengguo Zhang Tao Li Jianqi Wang Pengfei Kang Chong Yuan Libo 《Optical Review》2017,24(1):33-38
Optical Review - We designed and manufactured a novel annular-core hollow beam fiber which could directly yield ring light with a central dark spot inside the beam employing MCVD technique and a... 相似文献
127.
128.
Wenlin Li Fengyang Zhang Chong Li Heshan Song 《International Journal of Theoretical Physics》2016,55(4):2097-2109
Although many quantum correlation criteria have been proposed successively in recent years, it is still an open question how to observe these criteria with the non–Hermitian terms in themselves. We propose an indirect scheme in this paper to observe non-Hermitian criteria and to judge whether or not quantum correlation exists in the system even though the expectation value measurement of non-Hermitian operator is invalid in quantum mechanics system. Our idea is to establish a critical state of mesoscopic oscillator under mean–field approximation, and the oscillator state will take place transition when the quantum correlation destroys the mean–field approximation. The non–Hermitian measurement will replace the position measurement in this process and it can be seen as a non–destructive detection. We give an example to explain this idea in a designed mesoscopic optomechanical system. 相似文献
129.
130.
Junwye Lee Jonghyun Koo Si Un Hwang Sunmin Min Sang Jung Ahn Yonghan Roh Sung Ha Park 《Current Applied Physics》2012,12(4):1207-1211
We report the structural and functional stabilities of artificially synthesized DNA ultra-thin films. Fully covered DNA ultra-thin films on a silica substrate were fabricated by the silica-assisted growth method and those samples were then incubated in various chemicals and physical conditions. The DNA ultra-thin films showed high maintainability under those harsh conditions and these results would aid to facilitate the use of artificial DNA ultra-thin films in advanced research areas such as biophotonics and bioelectronics. 相似文献