全文获取类型
收费全文 | 99970篇 |
免费 | 2081篇 |
国内免费 | 1190篇 |
专业分类
化学 | 39673篇 |
晶体学 | 950篇 |
力学 | 7568篇 |
综合类 | 44篇 |
数学 | 35079篇 |
物理学 | 19927篇 |
出版年
2023年 | 181篇 |
2022年 | 210篇 |
2021年 | 388篇 |
2020年 | 557篇 |
2019年 | 450篇 |
2018年 | 10728篇 |
2017年 | 10512篇 |
2016年 | 6618篇 |
2015年 | 1446篇 |
2014年 | 970篇 |
2013年 | 1559篇 |
2012年 | 5120篇 |
2011年 | 12106篇 |
2010年 | 6507篇 |
2009年 | 6810篇 |
2008年 | 7800篇 |
2007年 | 9936篇 |
2006年 | 1523篇 |
2005年 | 2416篇 |
2004年 | 2532篇 |
2003年 | 2816篇 |
2002年 | 1853篇 |
2001年 | 584篇 |
2000年 | 614篇 |
1999年 | 453篇 |
1998年 | 504篇 |
1997年 | 474篇 |
1996年 | 525篇 |
1995年 | 393篇 |
1994年 | 349篇 |
1993年 | 332篇 |
1992年 | 263篇 |
1991年 | 272篇 |
1990年 | 233篇 |
1989年 | 202篇 |
1988年 | 235篇 |
1987年 | 228篇 |
1986年 | 175篇 |
1985年 | 280篇 |
1984年 | 281篇 |
1983年 | 209篇 |
1982年 | 280篇 |
1981年 | 262篇 |
1980年 | 269篇 |
1979年 | 249篇 |
1978年 | 230篇 |
1977年 | 199篇 |
1976年 | 198篇 |
1974年 | 173篇 |
1973年 | 179篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
1.
Tian Xiu-Zhi Yang Rui Ma Jia-Jia Ni Yong-Hao Deng Hai-Bo Dai Lei Tan Jiao-Jun Zhang Mei-Yun Jiang Xue 《高分子科学》2022,40(7):789-798
Chinese Journal of Polymer Science - Antistatic and strength properties are of vital importance for polyurethane rubber used in moving parts of many industrial instruments. Herein, polyurethane was... 相似文献
2.
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
3.
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
4.
5.
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
6.
7.
8.
Hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) have been deemed as clean and sustainable strategies to solve the energy crisis and environmental problems. Various catalysts have been developed to promote the process of HER and OER. Among them, two-dimensional covalent organic frameworks (2D COFs) have received great attention due to their diverse and designable structure. In this minireview, we mainly summarize the diverse linkages of 2D COFs and strategies for enhancing the catalytic performance of 2D COFs for HER and OER, such as introducing active building blocks, metal ions and tailored linkages. Furthermore, a brief outlook for the development directions of COFs in the field of HER and OER is provided, expecting to stimulate new opportunities in future research. 相似文献
9.
Yuwei Wang Jia-Jun Yan Shengnan Hu Prof. David James Young Prof. Hong-Xi Li Prof. Zhi-Gang Ren 《化学:亚洲杂志》2021,16(18):2681-2686
A photoluminescent bimetallic cluster [Ag10Cu6(bdppthi)2(C≡CPh)12(MeOH)2(H2O)](ClO4)4 ( 1 , bdppthi=N,N’-bis(diphenylphosphanylmethyl)-tetrahydroimidazole} was synthesized from the PNNP type ligand bdppthi generated in-situ. Upon excitation at 365 nm, 1 exhibited strong phosphorescent emission at 630 nm, which was selectively quenched by NH3 in air or water. The sensing of NH3 was rapid and recoverable, with detection limits of 53 ppm (v/v) in N2 and 21 μmol/L (0.36 ppm, w/w) for NH3 ⋅ H2O in water. Cluster 1 could potentially serve as a bifunctional chemical sensor for the efficient detection of ammonia in waste-gas and waste-water. 相似文献
10.