全文获取类型
收费全文 | 7130篇 |
免费 | 383篇 |
国内免费 | 108篇 |
专业分类
化学 | 5428篇 |
晶体学 | 40篇 |
力学 | 392篇 |
数学 | 728篇 |
物理学 | 1033篇 |
出版年
2023年 | 53篇 |
2022年 | 125篇 |
2021年 | 318篇 |
2020年 | 367篇 |
2019年 | 371篇 |
2018年 | 373篇 |
2017年 | 361篇 |
2016年 | 487篇 |
2015年 | 347篇 |
2014年 | 455篇 |
2013年 | 834篇 |
2012年 | 632篇 |
2011年 | 553篇 |
2010年 | 357篇 |
2009年 | 346篇 |
2008年 | 346篇 |
2007年 | 295篇 |
2006年 | 204篇 |
2005年 | 174篇 |
2004年 | 118篇 |
2003年 | 115篇 |
2002年 | 76篇 |
2001年 | 30篇 |
2000年 | 12篇 |
1999年 | 20篇 |
1998年 | 16篇 |
1997年 | 19篇 |
1996年 | 20篇 |
1995年 | 10篇 |
1994年 | 14篇 |
1993年 | 10篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 14篇 |
1986年 | 5篇 |
1985年 | 12篇 |
1984年 | 13篇 |
1983年 | 3篇 |
1982年 | 14篇 |
1981年 | 7篇 |
1980年 | 12篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1973年 | 3篇 |
1971年 | 3篇 |
排序方式: 共有7621条查询结果,搜索用时 15 毫秒
101.
Zheng Yuanzhou Zhang Xinzhu Soleimani Mobareke Mohammad Taghi Hekmatifar Maboud Karimipour Arash Sabetvand Roozbeh 《Journal of Thermal Analysis and Calorimetry》2021,144(6):2515-2523
Journal of Thermal Analysis and Calorimetry - It is interesting to investigate the number of nanoparticle (NP) and temperature effects on H2O/CuO nanofluid thermal conductivity and the atomic... 相似文献
102.
Sabbagh Omid Fanaei Mohammad Ali Arjomand Alireza 《Journal of Thermal Analysis and Calorimetry》2021,145(3):851-866
Journal of Thermal Analysis and Calorimetry - A novel NGL/LNG integrated scheme based on C3MR refrigeration system is modeled by using Aspen plus® in this study. The mentioned scheme utilizes... 相似文献
103.
Monajati Saharkhiz Mohammad Hossein Ghorbani Bahram 《Journal of Thermal Analysis and Calorimetry》2021,145(3):1385-1411
Journal of Thermal Analysis and Calorimetry - Due to limited energy supply sources and environmental issues, the use of renewable energy to replace fossil fuels and reduce pollution has increased.... 相似文献
104.
105.
Molecular Diversity - 1,2,4-Triazole-containing scaffolds are unique heterocyclic compounds present in an array of pharmaceuticals and biologically important compounds used in the drug-discovery... 相似文献
106.
107.
108.
Universal power law behavior of the AC conductivity versus frequency of agglomerate morphologies in conductive carbon nanotube‐reinforced epoxy networks 下载免费PDF全文
Brian M. Greenhoe Mohammad K. Hassan Jeffrey S. Wiggins Kenneth A. Mauritz 《Journal of Polymer Science.Polymer Physics》2016,54(19):1918-1923
The Jonscher universal power law for ac conductivity versus frequency (f = ω/2π) in the dispersion region was tested for a multiwall carbon nanotube/epoxy nanocomposite. The effect of changes in agglomerate morphology on the fitting parameters A and n in the equation σac = Aωn was investigated. Changing nanotube agglomerate morphology was tracked by optical microscopy through curing. Evolving morphology was compared alongside ac conductivity obtained via a broadband dielectric spectrometer to elucidate possible physical meaning of the universal power law in the context of this system. The ?logA/n was unaffected by changes in agglomerate morphology affected during cure, yet connected with each other in their dependence on temperature. For this system, the relationship between the fitting parameters in the universal dynamic response equation remains empirical at this stage with regard to biphasic “texture” or morphology within such a network. Electrical conductivity σ versus frequency ω for a composite consisting of agglomerated multiwalled carbon nanotubes dispersed throughout a cured epoxy matrix was discovered to follow the empirical universal dynamic response equation of Jonscher. The frequency behavior of the exponent n is discussed in terms of underlying morphology throughout which charge carriers migrate. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1918–1923 相似文献
109.
110.