全文获取类型
收费全文 | 831篇 |
免费 | 30篇 |
国内免费 | 1篇 |
专业分类
化学 | 698篇 |
晶体学 | 3篇 |
力学 | 9篇 |
综合类 | 1篇 |
数学 | 54篇 |
物理学 | 97篇 |
出版年
2022年 | 5篇 |
2021年 | 4篇 |
2020年 | 10篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2016年 | 16篇 |
2015年 | 15篇 |
2014年 | 35篇 |
2013年 | 34篇 |
2012年 | 31篇 |
2011年 | 57篇 |
2010年 | 24篇 |
2009年 | 32篇 |
2008年 | 37篇 |
2007年 | 58篇 |
2006年 | 38篇 |
2005年 | 46篇 |
2004年 | 30篇 |
2003年 | 34篇 |
2002年 | 41篇 |
2001年 | 15篇 |
2000年 | 13篇 |
1999年 | 16篇 |
1998年 | 10篇 |
1997年 | 14篇 |
1996年 | 18篇 |
1995年 | 18篇 |
1994年 | 16篇 |
1993年 | 14篇 |
1992年 | 5篇 |
1991年 | 20篇 |
1990年 | 9篇 |
1989年 | 11篇 |
1988年 | 12篇 |
1987年 | 4篇 |
1986年 | 15篇 |
1985年 | 2篇 |
1984年 | 11篇 |
1983年 | 6篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 8篇 |
1974年 | 3篇 |
1971年 | 3篇 |
1967年 | 3篇 |
排序方式: 共有862条查询结果,搜索用时 15 毫秒
131.
We show that there exists a deep link between the two disciplines of information theory and spectral geometry. This allows us to obtain new results on a well-known quantum gravity motivated natural ultraviolet cutoff which describes an upper bound on the spatial density of information. Concretely, we show that, together with an infrared cutoff, this natural ultraviolet cutoff beautifully reduces the path integral of quantum field theory on curved space to a finite number of ordinary integrations. We then show, in particular, that the subsequent removal of the infrared cutoff is safe. 相似文献
132.
Frommelt T Kostur M Wenzel-Schäfer M Talkner P Hänggi P Wixforth A 《Physical review letters》2008,100(3):034502
Mixing presents a notoriously difficult problem in small amounts of fluids. Herein, surface acoustic waves provide a convenient technique to generate time-dependent flow patterns. These flow patterns can be optimized in such a way that advected particles are mixed most efficiently in the fluid within a short time compared to the time pure diffusion would take. Investigations are presented for the mixing efficiency of a flat cylinder that is driven by two surface acoustic waves. The experimental results favorably agree with model calculations of the flow patterns and the advective transport. 相似文献
133.
134.
135.
Cover Picture: Water Repellency in Hydrophobic Nanocapsules—Molecular View on Dewetting (Chem. Eur. J. 22/2014)
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
136.
Journal of Solid State Electrochemistry - 相似文献
137.
138.
Towards a Sustainable Synthesis of Oxymethylene Dimethyl Ether by Homogeneous Catalysis and Uptake of Molecular Formaldehyde
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)
Andreas Peter Samuel M. Fehr Valentin Dybbert Dr. Daniel Himmel Ines Lindner Dr. Eberhard Jacob Mohamed Ouda Dr. Achim Schaadt Dr. Robin J. White Dr. Harald Scherer Prof. Dr. Ingo Krossing 《Angewandte Chemie (International ed. in English)》2018,57(30):9461-9464
Oxymethylene dimethyl ethers (OMEn; CH3(‐OCH2‐)nO‐CH3, n=3–5) are a novel class of sustainable synthetic fuels, which are of increasing interest due to their soot‐free combustion. Herein a novel anhydrous OMEn synthesis route is presented. Catalyzed by trimethyloxonium salts, dimethoxymethane takes up monomeric gaseous formaldehyde instantaneously and forms high purity OMEn at temperatures of 25–30 °C. This new anhydrous approach using molecular formaldehyde and catalytic amounts of highly active trimethyloxonium salts represents a promising new step towards a sustainable formation of OMEn emanating from CO2 and H2. 相似文献
139.
Merca A Bögge H Schmidtmann M Zhou Y Haupt ET Sarker MK Hill CL Müller A 《Chemical communications (Cambridge, England)》2008,(8):948-950
The unique molybdenum oxide-based nucleophilic porous capsule/artificial cell [{(MoVI)MoVI5O21(H2O)6}12{MoV2O4(SO4)30}]72-, according to an X-ray crystallographic study, traps [Al(H2O)6]3+ complexes above the pores while interacting with the latter via hydrogen bonds; this is supported by 27Al NMR studies of the interaction of the capsule with hydrated Al3+ cations in aqueous solution. 相似文献
140.