全文获取类型
收费全文 | 13811篇 |
免费 | 2218篇 |
国内免费 | 2540篇 |
专业分类
化学 | 10942篇 |
晶体学 | 194篇 |
力学 | 980篇 |
综合类 | 225篇 |
数学 | 1801篇 |
物理学 | 4427篇 |
出版年
2024年 | 32篇 |
2023年 | 290篇 |
2022年 | 353篇 |
2021年 | 456篇 |
2020年 | 585篇 |
2019年 | 576篇 |
2018年 | 426篇 |
2017年 | 481篇 |
2016年 | 723篇 |
2015年 | 643篇 |
2014年 | 781篇 |
2013年 | 1035篇 |
2012年 | 1203篇 |
2011年 | 1229篇 |
2010年 | 914篇 |
2009年 | 862篇 |
2008年 | 911篇 |
2007年 | 763篇 |
2006年 | 738篇 |
2005年 | 701篇 |
2004年 | 567篇 |
2003年 | 562篇 |
2002年 | 648篇 |
2001年 | 576篇 |
2000年 | 395篇 |
1999年 | 381篇 |
1998年 | 250篇 |
1997年 | 211篇 |
1996年 | 235篇 |
1995年 | 196篇 |
1994年 | 184篇 |
1993年 | 139篇 |
1992年 | 94篇 |
1991年 | 87篇 |
1990年 | 67篇 |
1989年 | 41篇 |
1988年 | 43篇 |
1987年 | 34篇 |
1986年 | 47篇 |
1985年 | 24篇 |
1984年 | 14篇 |
1983年 | 21篇 |
1982年 | 13篇 |
1981年 | 12篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1973年 | 1篇 |
1959年 | 4篇 |
1957年 | 8篇 |
1936年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 453 毫秒
1.
Applied Mathematics and Mechanics - Spiral springs have a wide range of applications in various fields. As a result of the complexity of friction, few theoretical analyses of spring belts under... 相似文献
2.
3.
Interactions of the vector breathers for the coupled Hirota system with $$4\times 4$$ 4 × 4 Lax pair
Nonlinear Dynamics - In this paper, we investigate the interactions of the vector breathers for the coupled Hirota system with $$4\times 4$$ Lax pair. Firstly, we give the first-order breather... 相似文献
4.
Zhen Xi 《中国科学:化学(英文版)》2015,(3):434-435
Redox-based post-translational modification of protein thiols has become an attractive strategy in cellular homeostasis and cell signaling.Due to the reductive end of the redox buffer network,the vicinal dithiol-containing proteins(VDPs)maintains an appropriate oxidation-reduction state of proteins through the reversible transformation from vicinal dithiols to disulfide,which is responsible for a variety of 相似文献
5.
6.
We present the fabrication of core-shell-satellite Au@SiO2-Pt nanostructures and demonstrate that LSPR excitation of the core Au nanoparticle can induce plasmon coupling effect to initiate photocatalytic hydrogen generation from decomposition of formic acid. Further studies suggest that the plasmon coupling effect induces a strong local electric field between the Au core and Pt nanoparticles on the SiO2 shell, which enables creation of hot electrons on the non-plasmonic-active Pt nanoparticles to participate hydrogen evolution reaction on the Pt surface. In addition, small SiO2 shell thickness is required in order to obtain a strong plamon coupling effect and achieve efficient photocatalytic activities for hydrogen generation. 相似文献
7.
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
8.
9.
10.
Yongjie Zhou Yuqi Mei Tian Luo Wenxue Chen Qiuping Zhong Haiming Chen Weijun Chen 《Molecules (Basel, Switzerland)》2021,26(9)
The contribution of rheological properties and viscoelasticity of the interfacial adsorbed layer to the emulsification mechanism of enzymatic modified sugar beet pectin (SBP) was studied. The component content of each enzymatic modified pectin was lower than that of untreated SBP. Protein and ferulic acid decreased from 5.52% and 1.08% to 0.54% and 0.13%, respectively, resulting in a decrease in thermal stability, apparent viscosity, and molecular weight (Mw). The dynamic interfacial rheological properties showed that the interfacial pressure and modulus (E) decreased significantly with the decrease of functional groups (especially proteins), which also led to the bimodal distribution of particle size. These results indicated that the superior emulsification property of SBP is mainly determined by proteins, followed by ferulic acid, and the existence of other functional groups also promotes the emulsification property of SBP. 相似文献