全文获取类型
收费全文 | 780篇 |
免费 | 22篇 |
国内免费 | 3篇 |
专业分类
化学 | 551篇 |
晶体学 | 5篇 |
力学 | 10篇 |
数学 | 150篇 |
物理学 | 89篇 |
出版年
2021年 | 4篇 |
2020年 | 8篇 |
2019年 | 11篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 25篇 |
2015年 | 20篇 |
2014年 | 13篇 |
2013年 | 27篇 |
2012年 | 32篇 |
2011年 | 39篇 |
2010年 | 39篇 |
2009年 | 19篇 |
2008年 | 50篇 |
2007年 | 54篇 |
2006年 | 55篇 |
2005年 | 43篇 |
2004年 | 28篇 |
2003年 | 31篇 |
2002年 | 23篇 |
2001年 | 11篇 |
2000年 | 15篇 |
1999年 | 5篇 |
1998年 | 7篇 |
1997年 | 10篇 |
1996年 | 11篇 |
1993年 | 7篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1984年 | 10篇 |
1983年 | 9篇 |
1982年 | 14篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1979年 | 10篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1974年 | 13篇 |
1973年 | 11篇 |
1972年 | 5篇 |
1970年 | 7篇 |
1968年 | 4篇 |
1964年 | 5篇 |
1961年 | 3篇 |
1959年 | 3篇 |
排序方式: 共有805条查询结果,搜索用时 921 毫秒
801.
802.
Gert‐Jan M. Gruter Alasdair Graham Ben McKay Franois Gilardoni 《Macromolecular rapid communications》2003,24(1):73-80
Currently laboratory automation is a rapidly growing field of interest in chemical process research and development. The idea of using automated and parallel methods for the optimization of chemical processes was initiated by the extensive implementation of combinatorial techniques in medicinal chemistry. The techniques applied involve all methods and concepts aimed at dramatically increasing the output of research by extensive use of automation, parallelization and miniaturization, fast analysis, advanced data handling and by efficient automated planning, scheduling and tracking. In this paper, the “Combi” or high‐throughput experimentation approach consists of the integration of parallel experimentation with four key modeling and simulation methodologies, modeling, multivariate statistics, statistical design of experimentation and empirical model generation.
803.
The tensile deformation behaviour of poly(1-butene) and two of its ethylene copoloymers was studied at room temperature. This was done by investigating true stress-strain curves at constant strain rates, elastic recovery and stress relaxation properties and in-situ WAXS patterns during the deformation process. As for a series of semicrystalline polymers in previous studies, a strain-controlled deformation behaviour was found. The differential compliance, the recovery properties and the stress relaxation curves changed simultaneously at well-defined points. The strains at which these points occurred along the true stress-strain remained constant for the different samples despite their different percentage crystallinities. The well-defined way in which the different samples respond to external stresses complies with the granular substructure of the crystalline lamellae in a semicrystalline polymer. 相似文献
804.
805.
Maike Lettow Kim Greis Eike Mucha Tyler R. Lambeth Murat Yaman Vasilis Kontodimas Christian Manz Waldemar Hoffmann Gerard Meijer Ryan R. Julian Gert von Helden Mateusz Marianski Kevin Pagel 《Angewandte Chemie (International ed. in English)》2023,62(24):e202302883
Fucose is a signaling carbohydrate that is attached at the end of glycan processing. It is involved in a range of processes, such as the selectin-dependent leukocyte adhesion or pathogen-receptor interactions. Mass-spectrometric techniques, which are commonly used to determine the structure of glycans, frequently show fucose-containing chimeric fragments that obfuscate the analysis. The rearrangement leading to these fragments—often referred to as fucose migration—has been known for more than 25 years, but the chemical identity of the rearrangement product remains unclear. In this work, we combine ion-mobility spectrometry, radical-directed dissociation mass spectrometry, cryogenic IR spectroscopy of ions, and density-functional theory calculations to deduce the product of the rearrangement in the model trisaccharides Lewis x and blood group H2. The structural search yields the fucose moiety attached to the galactose with an α(1→6) glycosidic bond as the most likely product. 相似文献