全文获取类型
收费全文 | 291515篇 |
免费 | 6728篇 |
国内免费 | 4978篇 |
专业分类
化学 | 148654篇 |
晶体学 | 3374篇 |
力学 | 15482篇 |
综合类 | 300篇 |
数学 | 52150篇 |
物理学 | 83261篇 |
出版年
2020年 | 2084篇 |
2019年 | 2207篇 |
2018年 | 12181篇 |
2017年 | 12013篇 |
2016年 | 9308篇 |
2015年 | 3732篇 |
2014年 | 4250篇 |
2013年 | 10087篇 |
2012年 | 11188篇 |
2011年 | 19114篇 |
2010年 | 11715篇 |
2009年 | 11880篇 |
2008年 | 14153篇 |
2007年 | 16251篇 |
2006年 | 7737篇 |
2005年 | 7948篇 |
2004年 | 7367篇 |
2003年 | 7057篇 |
2002年 | 5962篇 |
2001年 | 6630篇 |
2000年 | 5194篇 |
1999年 | 4118篇 |
1998年 | 3260篇 |
1997年 | 3211篇 |
1996年 | 2904篇 |
1995年 | 2767篇 |
1994年 | 2594篇 |
1993年 | 2420篇 |
1992年 | 2859篇 |
1991年 | 2724篇 |
1990年 | 2664篇 |
1989年 | 2662篇 |
1988年 | 2596篇 |
1987年 | 2580篇 |
1986年 | 2404篇 |
1985年 | 3275篇 |
1984年 | 3265篇 |
1983年 | 2664篇 |
1982年 | 2868篇 |
1981年 | 2812篇 |
1980年 | 2700篇 |
1979年 | 2870篇 |
1978年 | 3114篇 |
1977年 | 2914篇 |
1976年 | 2862篇 |
1975年 | 2711篇 |
1974年 | 2658篇 |
1973年 | 2701篇 |
1967年 | 2137篇 |
1966年 | 1938篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
11.
Kacher Y. G. Karlova M. G. Glukhov G. S. Zhang H. Zaklyazminskaya E. V. Loussouarn G. Sokolova O. S. 《Crystallography Reports》2021,66(5):711-725
Crystallography Reports - Membrane proteins, including ion channels, became the focus of structural proteomics midway through the 20th century. Methods for studying ion channels are diverse and... 相似文献
12.
Kobayashi M. Zhang Y. Ishikawa H. Sun J. Oddershede J. Juul Jensen D. Miura H. 《Experimental Mechanics》2021,61(5):817-828
Experimental Mechanics - The internal strain distribution developing during plastic deformation is important for understanding the mechanical properties of polycrystalline materials. Such... 相似文献
13.
Alawainati F. A. Manaa H. Henari F. Z. Biyiklioglu Z. Arslan T. Jaafar A. 《Journal of Applied Spectroscopy》2021,88(5):951-957
Journal of Applied Spectroscopy - Detailed measurements of nonlinear optical properties and optical limiting for four phthalocyanine (Pc) derivatives (PcCo, PcCu, PcMn, and PcSi) are reported. The... 相似文献
14.
15.
Analysis Mathematica - We introduce and study the k-Hankel Gabor transform. We investigate the localization operators for this transform. In particular, we study their trace class properties and we... 相似文献
16.
A numerical model was developed and validated to investigate the fluid–structure interactions between fully developed pipe flow and core–shell-structured microcapsule in a microchannel. Different flow rates and microcapsule shell thicknesses were considered. A sixth-order rotational symmetric distribution of von Mises stress over the microcapsule shell can be observed on the microcapsule with a thinner shell configuration, especially at higher flow rate conditions. It is also observed that when being carried along in a fully developed pipe flow, the microcapsule with a thinner shell tends to accumulate stress at a higher rate compared to that with a thicker shell. In general, for the same microcapsule configuration, higher flow velocity would induce a higher stress level over the microcapsule shell. The deformation gradient was used to capture the microcapsule's deformation in the present study. The effect of Young's modulus on the microcapsule shell on the microcapsule deformation was investigated as well. Our findings will shed light on the understanding of the stability of core–shell-structured microcapsule when subjected to flow-induced shear stress in a microfluidic system, enabling a more exquisite control over the breakup dynamics of drug-loaded microcapsule for biomedical applications. 相似文献
17.
18.
Li Y. Shi W. H. Dong L. M. Xu S. X. Huang H. J. Yin J. R. 《Journal of Applied Spectroscopy》2022,89(3):534-541
Journal of Applied Spectroscopy - Sr3B2O6:Dy3+, Eu3+ single-matrix white-light-emitting materials are prepared using the high-temperature solid-state method. The microstructure, emission spectrum,... 相似文献
19.
Vasile M. Loots H. Vercammen L. Bruggeman M. Verrezen F. 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(8):3349-3357
Journal of Radioanalytical and Nuclear Chemistry - In this paper a study for the selection of an NPE (nonylphenol ethoxylates)—free cocktail is discussed in order to be used for our routine... 相似文献
20.
Hu Duo-Duo Gao Qian Dai Jing-Cheng Cui Ru Li Yuan-Bo Li Yuan-Ming Zhou Xiao-Guo Bian Kang-Jie Wu Bing-Bing Zhang Kai-Fan Wang Xi-Sheng Li Yan 《中国科学:化学(英文版)》2022,65(4):753-761
Science China Chemistry - A light-induced, nickel-catalyzed three-component arylsulfonation of 1,3-enynes in the absence of photocatalyst is reported. This methodology exhibited mild conditions,... 相似文献