全文获取类型
收费全文 | 90622篇 |
免费 | 16370篇 |
国内免费 | 9204篇 |
专业分类
化学 | 61641篇 |
晶体学 | 916篇 |
力学 | 5751篇 |
综合类 | 515篇 |
数学 | 10097篇 |
物理学 | 37276篇 |
出版年
2024年 | 344篇 |
2023年 | 2043篇 |
2022年 | 3299篇 |
2021年 | 3560篇 |
2020年 | 3932篇 |
2019年 | 3515篇 |
2018年 | 3218篇 |
2017年 | 2870篇 |
2016年 | 4585篇 |
2015年 | 4364篇 |
2014年 | 5325篇 |
2013年 | 6769篇 |
2012年 | 8212篇 |
2011年 | 8405篇 |
2010年 | 5551篇 |
2009年 | 5386篇 |
2008年 | 5785篇 |
2007年 | 5066篇 |
2006年 | 4760篇 |
2005年 | 3820篇 |
2004年 | 2940篇 |
2003年 | 2295篇 |
2002年 | 2108篇 |
2001年 | 1815篇 |
2000年 | 1612篇 |
1999年 | 1844篇 |
1998年 | 1596篇 |
1997年 | 1577篇 |
1996年 | 1563篇 |
1995年 | 1322篇 |
1994年 | 1151篇 |
1993年 | 997篇 |
1992年 | 860篇 |
1991年 | 783篇 |
1990年 | 644篇 |
1989年 | 501篇 |
1988年 | 370篇 |
1987年 | 308篇 |
1986年 | 323篇 |
1985年 | 261篇 |
1984年 | 151篇 |
1983年 | 117篇 |
1982年 | 100篇 |
1981年 | 57篇 |
1980年 | 42篇 |
1979年 | 15篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1957年 | 31篇 |
1922年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Dr. Yaru Gong Chao Qin Yuteng Zhang Prof. Chunyi Sun Prof. Qinhe Pan Xinlong Wang Zhongmin Su 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(49):22218-22222
Systematic design and self-assembly of metal–organic polyhedra with predictable configurations has been a long-standing challenge in crystal engineering. Herein a concave polyoxovanadate cluster, [V6O6(OCH3)9(SO4)4]5−, which can be generated in situ under specific reaction conditions, is reported. Based on this cluster, a potential trivalent molecular building block, [V6O6(OCH3)9(SO4)(CO2)3]2−, can be obtained by the bridging-ligand-substitution strategy and it possesses appropriate angle information for the design of molecular cubes. Utilizing the face-directed assembly of the trivalent molecular building block and a diverse set of tetratopic carboxylate linkers, a series of metal–organic cubes ( VMOC-1 – VMOC-5 ) with the same topology but different functionalities and dimensions were designed and constructed. An inclusion study using VMOC-3 shows that they are potential molecular receptors for selective capture of size-matching polycyclic aromatic hydrocarbon guest molecules. 相似文献
972.
Tongtong Feng Dr. Yingxiang Ye Xiao Liu Hui Cui Dr. Zhiqiang Li Dr. Ying Zhang Dr. Bin Liang Prof. Huanrong Li Prof. Banglin Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(48):21936-21941
Temperature sensors play a significant role in biology, chemistry, and engineering, especially those that can work accurately in a noninvasive manner. We adopted a photoinduced post-synthetic copolymerization strategy to realize a membranous ratiometric luminescent thermometer based on the emissions of two lanthanide ions. This novel mixed-lanthanide polyMOF membrane exhibits not only the integrity and temperature sensing behaviour of the Ln-MOF powder but also excellent mechanical properties, such as flexibility, elasticity, and processability. Moreover, the polyMOF membrane shows remarkable stability under harsh conditions, including high humidity, strong acid and alkali (pH 0–14), which allowed the mapping of temperature distributions in extreme circumstances. This work highlights a simple strategy for polyMOF membrane formation and pushes forward the further practical application of Ln-MOF-based luminescent thermometers in various fields and conditions. 相似文献
973.
Zhang Meihui Zhang Lizhi Wang Wei Yan Tingchang Xu Liying Dong Jinhua 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(3):1463-1467
Journal of Radioanalytical and Nuclear Chemistry - A convenient and inexpensive approach for the synthesis of deuterium-labeled thiamphenicol was described. DL-threo-Thiamphenicol-methyl-d3 was... 相似文献
974.
Flower-like shaped Bi12TiO20 (Bismuth Titanate)/g-C3N4 (graphite-like carbon nitride) heterojunction was prepared through hydrothermal and sonification methods for the degradation of organic pollutants by visible-light irradiation. The preparation process, chemical structures, and the mechanism of photocatalytic enhancement of the heterostructures were studied systematically. Under visible-light irradiation, the novel flower-like shaped Bi12TiO20/g-C3N4 heterojunction demonstrates prominent activities for the degradation of rhodamine B and p-nitrophenol, with the introduction of flower-like shaped Bi12TiO20 into g-C3N4 composites greatly increasing the activity of pure g-C3N4. This activity enhancement for the heterojunction could be mainly attributed to its low recombination speed of electron–hole pairs, high adsorption ability of organic pollutants, and better optical absorption ability. Moreover, in the visible-light system of Bi12TiO20/g-C3N4, •OH also contributed to the degradation of pollutants, which may explain the enhanced photocatalytic activity after the introduction of Bi12TiO20, as •OH is inactive in pure g-C3N4. Furthermore, 10 wt.% Bi12TiO20/g-C3N4 showed not only high activity but also good stability for degradation of aqueous organic pollutants, implying potential applications prospect. 相似文献
975.
976.
977.
Honghua Zhang Huihong Wang Yi Jiang Fei Cao Weiwei Gao Longqing Zhu Yuhang Yang Xiaodong Wang Yongqiang Wang Jinhong Chen Yiyue Feng Xuemei Deng Yingmei Lu Xiaoling Hu Xiangxiang Li Juan Zhang Tao Shi Prof. Zhen Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(72):17289-17317
Sulfur-containing scaffold, as a ubiquitous structural motif, has been frequently used in natural products, bioactive chemicals and pharmaceuticals, particularly C−S/N−S bonds are indispensable in many biological important compounds and pharmaceuticals. Development of mild and general methods for C−S/N−S bonds formation has great significance in modern research. Iodine and its derivatives have been recognized as inexpensive, environmentally benign and easy-handled catalysts or reagents to promote the construction of C−S/N−S bonds under mild reaction conditions, with good regioselectivities and broad substrate scope. Especially based on this, several new strategies, such as oxidation relay strategy, have been greatly developed and accelerated the advancement of this field. This review focuses on recent advances in iodine and its derivatives promoted hybridized C−S/N−S bonds formation. The features and mechanisms of corresponding reactions are summarized and the results of some cases are compared with those of previous reports. In addition, the future of this domain is discussed. 相似文献
978.
979.
980.