全文获取类型
收费全文 | 346篇 |
免费 | 9篇 |
国内免费 | 9篇 |
专业分类
化学 | 157篇 |
晶体学 | 2篇 |
力学 | 14篇 |
数学 | 136篇 |
物理学 | 55篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 6篇 |
2021年 | 10篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 8篇 |
2017年 | 4篇 |
2016年 | 16篇 |
2015年 | 12篇 |
2014年 | 11篇 |
2013年 | 26篇 |
2012年 | 29篇 |
2011年 | 23篇 |
2010年 | 27篇 |
2009年 | 15篇 |
2008年 | 22篇 |
2007年 | 22篇 |
2006年 | 17篇 |
2005年 | 18篇 |
2004年 | 12篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 10篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 4篇 |
1968年 | 2篇 |
1966年 | 1篇 |
1908年 | 2篇 |
1906年 | 1篇 |
排序方式: 共有364条查询结果,搜索用时 421 毫秒
81.
Diffusional interactions within the Ostwald Ripening process are analyzed in the present paper. An off-centre diffusion approach is performed to point out the direct correlation between the size of clusters. Herein the diffusion solution is derived as a function of both the growing and shriniking cluster sizes. Also, it is shown that the frequency transfer of particles between the shrinking cluster and the growing one may acquire high values due to the medium polarization. As a result, the temporal power law of the cluster growth derived in this theoretical model differs from that predicted by the LSW theory. Experimental data for Ag clusters embedded in a KCl matrix are analyzed both by the present theory and by the LSW theory. 相似文献
82.
83.
Daniela Iuliana Sora Elena Cristea Florin Albu Victor David Andrei Medvedovici 《Biomedical chromatography : BMC》2010,24(6):663-674
Analytical aspects related to the assay of pentoxifylline (PTX), lisofylline (M1) and carboxypropyl dimethylxanthine (M5) metabolites are discussed through comparison of two alternative analytical methods based on liquid chromatography separation and atmospheric pressure electrospray ionization tandem mass spectrometry detection. One method is based on a ‘pure’ reversed‐phase liquid chromatography mechanism, while the second one uses the additional polar interactions with embedded amide spacers linking octadecyl moieties to the silicagel surface (C‐18 Aqua stationary phase). In both cases, elution is isocratic. Both methods are equally selective and allows separation of unknowns (four species associated to PTX, two species associated to M1) detected through specific mass transitions of the parent compounds and owning respective structural confirmation. Plasma concentration–time patterns of these compounds follow typical metabolic profiles. It has been advanced that in‐vivo formation of conjugates of PTX and M1 is possible, such compounds being cleaved back to the parent ones within the ion source. The first method was associated with a sample preparation procedure based on plasma protein precipitation by strong organic acid addition. The second method used protein precipitation by addition of a water miscible organic solvent. Both analytical methods were fully validated and used to assess bioequivalence between a prolonged release generic formulation and the reference product, under multidose and single dose approaches. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
84.
H. Büeler de Florin F. Baum J. W. Holtermann A. E. Andrews und N. L. Gebhard 《Fresenius' Journal of Analytical Chemistry》1908,47(8):501-503
Ohne Zusammenfassung 相似文献
85.
Jürgen Brem Monica Ioana Toşa Csaba Paizs Elemér Vass Florin Dan Irimie 《Tetrahedron: Asymmetry》2010,21(3):365-373
Starting from the racemic ethyl 3-hydroxy-3-(10-alkyl-10H-phenothiazin-3-yl)propanoates as substrates, a multienzymatic procedure was developed for the efficient synthesis of the corresponding highly enantiomerically enriched (R)- and (S)-3-heteroaryl-3-hydroxypropanoic acids. 相似文献
86.
Florin Ciuprina Traian Zaharescu Silviu Jipa Ilona Pleşa Petru V. Notingher Denis Panaitescu 《Radiation Physics and Chemistry》2010,79(3):379-382
The dielectric characteristics of polyvinyl chloride nanocomposites containing titania, silica and alumina at the concentration of 5% were investigated by dielectric spectroscopy. The sharp modification in the permittivity and dielectric loss of neat and irradiated PVC samples over the low frequency range may be explained by the interaction between external electrical field and the dipoles formed during high energy exposure. The material characterization is completed by the thermal stability assay based on the accumulation of carbonyl units in the sample matrices, which provides the differences in the molecular level contact between host polymer and fillers. 相似文献
87.
88.
Corrigendum: Composite Aromatic Boxes for Enzymatic Transformations of Quaternary Ammonium Substrates
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
89.
90.