全文获取类型
收费全文 | 60312篇 |
免费 | 11204篇 |
国内免费 | 20431篇 |
专业分类
化学 | 43501篇 |
晶体学 | 2360篇 |
力学 | 4582篇 |
综合类 | 2181篇 |
数学 | 9796篇 |
物理学 | 29527篇 |
出版年
2024年 | 122篇 |
2023年 | 528篇 |
2022年 | 1915篇 |
2021年 | 1857篇 |
2020年 | 1843篇 |
2019年 | 1806篇 |
2018年 | 1708篇 |
2017年 | 2549篇 |
2016年 | 1902篇 |
2015年 | 2830篇 |
2014年 | 3483篇 |
2013年 | 4564篇 |
2012年 | 4457篇 |
2011年 | 5753篇 |
2010年 | 5310篇 |
2009年 | 5424篇 |
2008年 | 5601篇 |
2007年 | 4909篇 |
2006年 | 4900篇 |
2005年 | 4478篇 |
2004年 | 4199篇 |
2003年 | 2960篇 |
2002年 | 2927篇 |
2001年 | 2795篇 |
2000年 | 2595篇 |
1999年 | 1583篇 |
1998年 | 1008篇 |
1997年 | 757篇 |
1996年 | 664篇 |
1995年 | 592篇 |
1994年 | 631篇 |
1993年 | 927篇 |
1992年 | 885篇 |
1991年 | 593篇 |
1990年 | 601篇 |
1989年 | 624篇 |
1988年 | 333篇 |
1987年 | 224篇 |
1986年 | 190篇 |
1985年 | 145篇 |
1984年 | 133篇 |
1983年 | 142篇 |
1982年 | 119篇 |
1981年 | 86篇 |
1980年 | 67篇 |
1979年 | 63篇 |
1978年 | 26篇 |
1977年 | 19篇 |
1971年 | 17篇 |
1959年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Guo-Xing Li Xiao-Wei Qu Lu-Wei Hao Qing Li Su Chen 《Journal of polymer science. Part A, Polymer chemistry》2022,60(11):1710-1717
From the implementation point of view, the printable magnetic Janus colloidal photonic crystals (CPCs) microspheres are highly desirable. Herein, we developed a dispensing-printing strategy for magnetic Janus CPCs display via a microfluidics-automatic printing system. Monodisperse core/shell colloidal particles and magnetic Fe3O4 nanoparticles precursor serve as inks. Based on the equilibrium of three-phase interfacial tensions, Janus structure is successfully formed, followed by UV irradiation and self-assembly of colloid particle to generate magnetic Janus CPCs microspheres. Notably, this method shows distinct superiority with highly uniform Janus CPCs structure, where the TMPTA/Fe3O4 hemisphere is in the bottom side while CPCs hemisphere is in the top side. Thus, by using Janus CPCs microspheres with two different structural colors as pixel points, a pattern with red flower and green leaf is achieved. Moreover, 1D linear Janus CPCs pattern encapsulated by hydrogel is also fabricated. Both the color and the shape can be changed under the traction of magnets, showing great potentials in flexible smart displays. We believe this work not only offers a new feasible pathway to construct magnetic Janus CPCs patterns by a dispensing-printable fashion, but also provides new opportunities for flexible and smart displays. 相似文献
4.
以羧甲基纤维素(CMC)、明胶和MOF(Cu)@biochar为原料,采用简单有效的冷冻干燥方法制备了(CMC/Gelatin/MOF(Cu)@biochar)杂化气凝胶,并用傅里叶变换红外光谱(FT-IR)、热重分析(TG)、X射线粉末衍射(XRD)、扫描电镜(SEM)和X射线光电子能谱(XPS)技术对其进行了表征;研究了MOF(Cu)@biochar含量、pH和不同的盐水溶液对杂化气凝胶溶胀行为的影响;以该气凝胶负载氯化铵,制备了一种新型缓释肥料(SRF),并研究了含2%(wt)SRF的沙性土壤的保水能力;SRF在土壤中第30天的累积释放率为79.4%;肥料在土壤中释放符合非Fickian扩散和阳离子交换的协同作用机理。 相似文献
5.
6.
Wenpin Wang Qing Yao Jianhui Song Binbin Yao Hui Wang Zhibo Li 《Journal of Polymer Science.Polymer Physics》2019,57(11):662-669
The PeakForce Quantitative Nanomechanical Mapping based on atomic force microscope (AFM) is employed to first visualize and then quantify the elastic properties of a model nitrile rubber/poly(vinyl chloride) (NBR/PVC) blend at the nanoscale. This method allows us to consistently observe the changes in mechanical properties of each phase in polymer blends. Beyond measuring and discriminating elastic modulus and adhesion forces of each phase, we tune the AFM tips and the peak force parameters in order to reliably image samples. In view of viscoelastic difference in each phase, a three‐phase coexistence of an unmixed NBR phase, the mixed phase, and PVC microcrystallites is directly visualized in NBR/PVC blends. The nanomechanical investigation is also capable of recognizing the crosslinked rubber phase in cured rubber. The contribution of the mixed phase was quantified and it was found that the mechanical properties of blends are mainly determined by the homogeneity and stiffness of the mixed phase. This study furthers our understanding the structure–mechanical property relationship of thermoplastic elastomers, which is important for their potential design and applications. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 662–669 相似文献
7.
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
8.
UJ24型电位差计使用时出现的故障,可以利用数字万用表排查故障,提出排查方案,进行维修与调节,使它尽快恢复到最佳工作状态,这样既节省厂家的维修时间又节省学校的维修费用。 相似文献
9.
10.
Dr. Qing Xu Dr. Shanshan Tao Dr. Qiuhong Jiang Prof. Donglin Jiang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(11):4587-4593
A strategy based on covalent organic frameworks for ultrafast ion transport involves designing an ionic interface to mediate ion motion. Electrolyte chains were integrated onto the walls of one-dimensional channels to construct ionic frameworks via pore surface engineering, so that the ionic interface can be systematically tuned at the desired composition and density. This strategy enables a quantitative correlation between interface and ion transport and unveils a full picture of managing ionic interface to achieve high-rate ion transport. Moreover, the effect of interfaces was scaled on ion transport; ion mobility is increased in an exponential mode with the ionic interface. This strategy not only sets a benchmark system but also offers a general guidance for designing ionic interface that is key to systems for energy conversion and storage. 相似文献