全文获取类型
收费全文 | 458篇 |
免费 | 28篇 |
专业分类
化学 | 330篇 |
晶体学 | 5篇 |
力学 | 9篇 |
综合类 | 1篇 |
数学 | 65篇 |
物理学 | 76篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 24篇 |
2021年 | 31篇 |
2020年 | 23篇 |
2019年 | 16篇 |
2018年 | 17篇 |
2017年 | 14篇 |
2016年 | 35篇 |
2015年 | 20篇 |
2014年 | 26篇 |
2013年 | 35篇 |
2012年 | 42篇 |
2011年 | 36篇 |
2010年 | 24篇 |
2009年 | 21篇 |
2008年 | 17篇 |
2007年 | 15篇 |
2006年 | 21篇 |
2005年 | 11篇 |
2004年 | 4篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有486条查询结果,搜索用时 15 毫秒
111.
Mareš Kamil Vavřinec Šebesta Ferdinand John Jan 《Journal of Radioanalytical and Nuclear Chemistry》2019,322(2):377-387
Journal of Radioanalytical and Nuclear Chemistry - A novel metal sulfide: potassium niobium sulfide (KNbS) was prepared by hydrothermal method. The morphology and composition of KNbS were... 相似文献
112.
Guan-Yeow Yeap Tiang-Chuan Hng Wan Ahmad Kamil Mahmood Masato M. Ito Yamashita Youhei Yoichi Takanishi Hideo Takezoe 《Liquid crystals》2006,33(9):979-986
A series of eight liquid crystalline compounds, N,N'-bis[(2-hydroxy-4-alkoxyphenyl)methylene]benzene-1,4-diamines, has been synthesized and characterized. These homologous compounds differ in the length of terminal alkyl group C n H2n+1 wherein n is an even number ranging from 4 to 18. The spectroscopic techniques, FTIR, 1H NMR and 13C NMR, were employed to characterize the molecular structure. The transition temperatures of all the title compounds and their mesophases were studied by differential scanning calorimetry and polarizing microscopy. All the compounds were smectogenic, exhibiting both tilted and non-tilted molecular orientation in their smectic phases. Further investigation to ascertain the anisotropic nature of subphases within the smectogenic region was carried out using X-ray diffraction. 相似文献
113.
Calix[4]arenes bearing two p-nitrophenyl-ureido functions at the upper rim are effective anion binders. The stoichiometry of complexation depends on the substitution pattern (distal vs proximal) and anion concentration. While the distally substituted receptor forms 1:1 complexes with anions, the corresponding proximal derivative prefers the 2:1 stoichiometry (calixarene:anion) under identical conditions. 相似文献
114.
115.
116.
117.
118.
Ilyas S. Nizamov Andrey A. Yakovlev Ilnar D. Nizamov Dmitriy A. Terenzhev Kamil A. Ivshin Olga N. Kataeva Marina P. Shulaeva Oscar K. Pozdeev Elvira S. Batyeva Rafael A. Cherkasov 《应用有机金属化学》2018,32(5)
Chiral S‐tributylstannyl dithiophosphates and dithiophosphonates were obtained by the reactions of optically active dithiophosphoric and dithiophosphonic acids containing (S)‐(–)‐menthyl and (R)‐(+)‐menthyl substituents with gaseous ammonia and tributyl chlorostannane. The reactions of chiral ammonium dithiophosphate containing (1R)‐endo‐(+)‐fenchyl substituent with tributyl chlorostannane or tetrachlorostannane result in corresponding S‐tributylstannyl dithiophosphate or tetrakis(dithiophosphato)stannane. Molecular structure of ammonium O,O‐di‐(–)‐menthyldithiophosphate was studied by X‐ray single crystal diffraction. Bactericidal activity of S‐tributylstannyl dithiophosphates was tested. 相似文献
119.
Kamil Reza K. Azahar Ali Md. Singh Manish Kumar Agrawal Ved Varun Biradar A. M. 《Mikrochimica acta》2017,184(6):1809-1816
Microchimica Acta - The authors describe a nanostructured hybrid platform for amperometic determination of the plasticizer bisphenol A (BPA). It consists of two dimensional sheets of reduced... 相似文献
120.
Azobenzene-based calamitic liquid crystals, 4-((4-(4-methoxymethyl-1,2,3-triazol-1-yl)phenyl)diazenyl)phenylalkanoates have been isolated and their structures were characterised. The structure–property correlation with respect to the different alkanoyloxy terminal chain (–COOCnH2n+1 where n adopts odd numbers ranging from 3 to 15) has also been given attention in the present study. In this series, all compounds exhibit smectogenic properties. The lower homologues shows enantiotropic SmA phase as well as monotropic SmC phase. The higher homologues exhibit homeotropic alignment of smectic phases. These compounds possess very high anisotropic inclination in which the mesomorphic region covers nearly 80°C. 相似文献