全文获取类型
收费全文 | 80168篇 |
免费 | 12162篇 |
国内免费 | 8199篇 |
专业分类
化学 | 54780篇 |
晶体学 | 797篇 |
力学 | 5230篇 |
综合类 | 610篇 |
数学 | 9734篇 |
物理学 | 29378篇 |
出版年
2024年 | 70篇 |
2023年 | 1563篇 |
2022年 | 1622篇 |
2021年 | 2333篇 |
2020年 | 2999篇 |
2019年 | 2900篇 |
2018年 | 2583篇 |
2017年 | 2281篇 |
2016年 | 3506篇 |
2015年 | 3548篇 |
2014年 | 4217篇 |
2013年 | 5726篇 |
2012年 | 6934篇 |
2011年 | 7173篇 |
2010年 | 4874篇 |
2009年 | 4818篇 |
2008年 | 5135篇 |
2007年 | 4636篇 |
2006年 | 4317篇 |
2005年 | 3763篇 |
2004年 | 3007篇 |
2003年 | 2335篇 |
2002年 | 2060篇 |
2001年 | 1815篇 |
2000年 | 1582篇 |
1999年 | 1751篇 |
1998年 | 1491篇 |
1997年 | 1303篇 |
1996年 | 1346篇 |
1995年 | 1215篇 |
1994年 | 1120篇 |
1993年 | 960篇 |
1992年 | 854篇 |
1991年 | 760篇 |
1990年 | 607篇 |
1989年 | 526篇 |
1988年 | 399篇 |
1987年 | 375篇 |
1986年 | 328篇 |
1985年 | 330篇 |
1984年 | 221篇 |
1983年 | 190篇 |
1982年 | 159篇 |
1981年 | 127篇 |
1980年 | 90篇 |
1978年 | 58篇 |
1976年 | 54篇 |
1975年 | 63篇 |
1974年 | 55篇 |
1973年 | 62篇 |
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
31.
Circularly polarized luminescence (CPL) has attracted attention as a next-generation light signal because of its carrying more information compared with normal and linearly polarized lights as well as its potential wide application in information fields. Recently, much attention has been paid to small organic molecules-based CPL emitters because of easy synthesis, fine structural modification at molecular level, and tunable wide range emission wavelength. This review highlights the development of small organic molecules-based CPL emitters in the past 5 years (2017–2021). The progress suggests that small organic molecules-based CPL emitters provide a simple and efficient way to generate CPL. 相似文献
32.
Ye Jingyao Al-Jobory Alaa Zhang Qian-Chong Cao Wenqiang Alshehab Abdullah Qu Kai Alotaibi Turki Chen Hang Liu Junyang Ismael Ali K. Chen Zhong-Ning Lambert Colin J. Hong Wenjing 《中国科学:化学(英文版)》2022,65(9):1822-1828
Science China Chemistry - Destructive quantum interference (DQI) provides a unique approach to controlling the leakage current in the OFF state of molecular devices. However, the DQI in... 相似文献
33.
34.
A capillary electrophoresis-acid barrage stacking online enrichment method has been established to detect the four isoflavones which are Daidzein, Genistein, Formononetin, and Biochanin A. The proposed method was optimized using a single factor alternative method, and the optimal conditions obtained from the optimization were: the BGE was 25 mM borax and 2 mM β-cyclodextrin, the applied separation voltage was 20 kV, and the detection wavelength was 260 nm. The time ratio of the injection of sample and the injection of acid was 150 s:20 s, and the acid used was 250 mM acetic acid. The sample solvent used was 60% v/v acetonitrile. The established method had the enrichment factor of these four isoflavones at 24.5, 32.0, 29.2, and 33.7, respectively, LOD and LOQ are as low as nanograms per milliliter. Finally, the CE-acid barrage stacking method was successfully applied to the determination of four isoflavones in rat plasma and red clover extract, verifying the applicability and feasibility of the method. 相似文献
35.
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
36.
Yao Wen Chen Yangfan Li Jiangling Yang Jian Ren Shan Liu Weizao Liu Qingcai 《Research on Chemical Intermediates》2022,48(5):1813-1829
Research on Chemical Intermediates - Industrial wastewater is becoming a universal environmental problem, wherein toxic organic compounds are important sources of pollution. For the degradation... 相似文献
37.
Yuanbo Gao Tingting Yang Xueli Wang Jizong Chen Yong He 《Journal of polymer science. Part A, Polymer chemistry》2022,60(10):1610-1623
Two series of novel alternating copolyoxamides (PAnT-alt-n2 and PAn2-alt-62) are synthesized via solution/solid-state polycondensation (SSP). The alternating structures are analyzed carefully with 1H NMR and 13C NMR spectra. The melting behaviors, thermal stabilities, crystal structures and crystallinities are systematically evaluated by DSC, TGA and WAXD. The results reveal that these alternating copolyoxamides possess almost perfect alternating chain structures and have high melting temperature (Tm > 270 °C), high crystallinity (Xc > 32%) and high decomposition temperature (T5 > 405 °C) as well as low saturated water absorption (<3.5 wt%), which suggests that they have high potential as engineering plastic of high heat resistant. 相似文献
38.
Liu Wei Li Kehong Deng Hao Wang Jing Zhao Peng Liao Wei Zhuo Liangang Wei Hongyuan Yang Xia Chen Yue 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(2):747-754
Journal of Radioanalytical and Nuclear Chemistry - There is an urgent need to develop more specific targeted therapies for lung cancer treatment due to the its low survival rate. EGFR is a... 相似文献
39.
Yang T. L. Kao C. L. Kuo C. E. Yeh H. C. Li W. J. Li H. T. Chen C. Y. 《Chemistry of Natural Compounds》2022,58(5):825-827
Chemistry of Natural Compounds - A novel bibenzyl derivative, hydrangchinenin (1), was isolated from the stems of Hydrangea chinensis Maxim. (Hydrangeaceae). Its structure was determined on the... 相似文献
40.
Chen Zi-Han Li Yue-Hua Qi Ming-Yu Tang Zi-Rong Xu Yi-Jun 《Research on Chemical Intermediates》2022,48(1):1-12
Research on Chemical Intermediates - Owing to the simultaneous utilization of photogenerated electrons and holes, coupling light-driven hydrogen (H2) evolution reaction (HER) and biomass-derived... 相似文献