全文获取类型
收费全文 | 3888篇 |
免费 | 229篇 |
国内免费 | 66篇 |
专业分类
化学 | 2842篇 |
晶体学 | 48篇 |
力学 | 146篇 |
综合类 | 2篇 |
数学 | 442篇 |
物理学 | 703篇 |
出版年
2024年 | 38篇 |
2023年 | 68篇 |
2022年 | 285篇 |
2021年 | 361篇 |
2020年 | 228篇 |
2019年 | 196篇 |
2018年 | 185篇 |
2017年 | 143篇 |
2016年 | 228篇 |
2015年 | 164篇 |
2014年 | 180篇 |
2013年 | 291篇 |
2012年 | 271篇 |
2011年 | 294篇 |
2010年 | 170篇 |
2009年 | 137篇 |
2008年 | 163篇 |
2007年 | 147篇 |
2006年 | 112篇 |
2005年 | 101篇 |
2004年 | 59篇 |
2003年 | 55篇 |
2002年 | 49篇 |
2001年 | 20篇 |
2000年 | 15篇 |
1999年 | 10篇 |
1998年 | 13篇 |
1997年 | 13篇 |
1996年 | 18篇 |
1995年 | 12篇 |
1994年 | 6篇 |
1993年 | 11篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 10篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1976年 | 10篇 |
1975年 | 6篇 |
1974年 | 4篇 |
1973年 | 10篇 |
1972年 | 6篇 |
排序方式: 共有4183条查询结果,搜索用时 15 毫秒
991.
Alharbi F. F. Aman Salma Ahmad Naseeb Ejaz Syeda Rabia Khosa Rabia Yasmin Abid Abdul Ghafoor Manzoor Sumaira Al-Buriahi M. S. Alrowaili Z. A. Farid Hafiz Muhammad Tahir 《Journal of Solid State Electrochemistry》2022,26(5):1251-1258
Journal of Solid State Electrochemistry - Scientists are increasingly interested in improving electroactive technologies for supercapacitor applications, since energy storage devices have improved... 相似文献
992.
993.
Karimov Khasan S. Riaz Muhammad Nabi Jameel-Un 《Journal of Thermal Analysis and Calorimetry》2021,143(4):3033-3038
Journal of Thermal Analysis and Calorimetry - In this paper, fabrication and characterization of Cu/PTB7-Th (35 mass%)/PC $$_{61}$$ BM (35 mass%)/graphene (30 mass%)/Ag... 相似文献
994.
995.
Muhammad Muzammal Hussain Dr. Muhammad K. Majeed Prof. Haitao Ma Prof. Yunpeng Wang Dr. Adil Saleem Mina Lotfi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(2):e202103220
Organic resin cross-linking ZIF-67/SiO2 superhydrophobic (SHPB) multilayer coating was successfully fabricated on metal substrate. The perfluoro-octyl-triethoxy silane (POTS) modified ZIF-67 and SiO2 coating was applied on primary coated polytetrafluoroethylene (PTFE) and epoxy resin (EP) via spray coating method. Here, we present that the robust superhydrophobicity can be realized by structuring surfaces at two different length scales, with a nanostructure design to provide water repellence and a microstructure design to provide durability. The as-fabricated multilayer coating displayed superior water-repellence (CA=167.4°), chemical robustness (pH=1–14) and mechanical durability undergoing 120th linear abrasion or 35th rotatory abrasion cycle. By applying different acidic and basic corrosive media and various weathering conditions, it can still maintain superior-hydrophobicity. To get a better insight of interaction between inhibitor molecules and metal surface, density functional theory (DFT) calculations were performed, showing lower energy gap and increased binding energy of ZPS/SiO2/PTFE/EP (ZPS=ZIF-67+POTS) multilayer coating compared to the ZIF-67/SiO2/PTFE/EP, thereby supporting the experimental findings. Additionally, such coatings may be useful for applications such as anti-corrosion, self-cleaning, and anti-icing multi-functionalities. 相似文献
996.
Chen Xiaolong He Yaowu Ali Muhammad Umair He Yu Zhu Yanan Li Aiyuan Zhao Changbin Perepichka Igor F. Meng Hong 《中国科学:化学(英文版)》2019,62(10):1360-1364
Herein, we propose a new strategy to develop air-stable n-type organic semiconductors with non-classical thiophene aromatic diimide derivatives by replacing aromatic naphthalene with a heteroaromatic isothianaphthene core. We designed and successfully synthesized the isothianaphthene core based diimide material, N,N′-bis(n-hexyl)isothianaphthene-2,3,6,7-tetracarboxylic acid diimide(BTDI-C6) as an n-type semiconductor. Compared to N,N′-bis(n-hexyl)naphthalene-1,4,5,8-tetracarboxylic acid diimide(NDI-C6), BTDI-C6 possesses a deeper LUMO energy level of-4.21 eV, which is 0.32 eV lower than that of NDI-C6. Both molecular modelling and experimental results elucidated that organic thin film transistors(OTFTs)based on both of these materials exhibit comparable mobilities; however, the threshold voltage of BTDI-C6 based device(+7.5 V) is significantly lower than that of NDI-C6 based counterpart(+34V). Moreover, the low-lying LUMO energy level of BTDI-C6 ensures excellent air-stability which is further validated by the device performance. In addition, BTDI-C6 shows high luminescence while NDI-C6 is not luminescent at all in solution, which reveals the potential application of our newly synthesized material in n-type light-emitting transistors. 相似文献
997.
Muhammad K. Majeed Guangyao Ma Yanxiu Cao Hongzhi Mao Dr. Xiaojian Ma Dr. Wenzhe Ma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(51):11991-11997
Silicon (Si)-based anode materials with suitable engineered nanostructures generally have improved lithium storage capabilities, which provide great promise for the electrochemical performance in lithium-ion batteries (LIBs). Herein, a metal–organic framework (MOF)-derived unique core–shell Si/SiOx@NC structure has been synthesized by a facile magnesio-thermic reduction, in which the Si and SiOx matrix were encapsulated by nitrogen (N)-doped carbon. Importantly, the well-designed nanostructure has enough space to accommodate the volume change during the lithiation/delithiation process. The conductive porous N-doped carbon was optimized through direct carbonization and reduction of SiO2 into Si/SiOx simultaneously. Benefiting from the core–shell structure, the synthesized product exhibited enhanced electrochemical performance as an anode material in LIBs. Particularly, the Si/SiOx@NC-650 anode showed the best reversible capacities up to 724 and 702 mAh g−1 even after 100 cycles. The excellent cycling stability of Si/SiOx@NC-650 may be attributed to the core–shell structure as well as the synergistic effect between the Si/SiOx and MOF-derived N-doped carbon. 相似文献
998.
Ylmaz Seda Kuyumcu zge Kerkez Bayazit ahika Sena Ayaz Rana Muhammad Zunain Akyz Duygu Koca Atf 《Journal of Solid State Electrochemistry》2022,26(1):245-255
Journal of Solid State Electrochemistry - Modified TiO2 nanocomposites have been recognized as attractive photocatalytic materials in solar energy conversion. The aim of this study is to enhance... 相似文献
999.
Dr. Syed Meheboob Elahi Dr. Mukul Raizada Pradip Kumar Sahu Prof. Dr. Sanjit Konar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(19):5858-5870
Design, synthesis, and applications of metal–organic frameworks (MOFs) are among the most salient fields of research in modern inorganic and materials chemistry. As the structure and physical properties of MOFs are mostly dependent on the organic linkers or ligands, the choice of ligand system is of utmost importance in the design of MOFs. One such crucial organic linker/ligand is terpyridine (tpy), which can adopt various coordination modes to generate an enormous number of metal–organic frameworks. These frameworks generally carry physicochemical characteristics induced by the π-electron-rich (basically N-electron-rich moiety) terpyridines. In this minireview, the construction of 3D MOFs associated with symmetrical terpyridines is discussed. These ligands can be easily derivatized at the lateral phenyl (4′-phenyl) position and incorporate additional organic functionalities. These functionalities lead to some different binding modes and form higher dimensional (3D) frameworks. Therefore, these 3D MOFs can carry multiple features along with the characteristics of terpyridines. Some properties of these MOFs, like photophysical, chemical selectivity, photocatalytic degradation, proton conductivity, and magnetism, etc. have also been discussed and correlated with their frameworks. 相似文献
1000.
Khan Mumtaz Ali Khattak Nimat Ullah Hanif Muhammad 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(5):1995-2003
Journal of Radioanalytical and Nuclear Chemistry - By using Durridge RAD7, onsite soil radon measurements were performed on 13 profiles and 65 points, across the known geological faults in district... 相似文献