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Dr. Nan Wang Dr. Shuping Wang Prof. Luping Tang Dr. Lilei Ye Björn Cullbrand Abdelhafid Zehri Dr. Behabitu Ergette Tebikachew Prof. Johan Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(29):6561-6568
Poor bonding strength between nanomaterials and cement composites inevitably lead to the failure of reinforcement. Herein, a novel functionalization method for the fabrication of functionalized graphene oxide (FGO), which is capable of forming highly reliable covalent bonds with cement hydration products, and therefore, suitable for use as an efficient reinforcing agent for cement composites, is discussed. The bonding strength between cement and aggregates was improved more than 21 times with the reinforcement of FGO. The fabricated FGO also demonstrated many important features, including high reliability in cement pastes, good dispersibility, and efficient structural refinement of cement hydration products. With the incorporation of FGO, cement mortar samples demonstrated up to 40 % increased early and ultimate strength. Such results make the fast demolding and manufacture of light constructions become highly possible, and show strong advantages on improving productivity, saving cost, and reducing CO2 emissions in practical applications. 相似文献
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Matthias Mawick Carolin Jaworski Jens Bittermann Dr. Ljuba Iovkova Yinglan Pu Prof. Dr. Carmen Wängler Prof. Dr. Björn Wängler Prof. Dr. Klaus Jurkschat Prof. Dr. Norbert Krause Prof. Dr. Ralf Schirrmacher 《Angewandte Chemie (International ed. in English)》2023,62(50):e202309002
The ring-opening Si-fluorination of a variety of azasilole derivatives cyclo-1-(iPr2Si)−4-X−C6H3−2-CH2NR ( 4 : R=2,6-iPr2C6H3, X=H; 4 a : R=2,4,6-Me3C6H2, X=H; 9 : R=2,6-iPr2C6H3, X=tBuMe2SiO; 10 : R=2,6-iPr2C6H3, X=OH; 13 : R=2,6-iPr2C6H3, X=HCCCH2O; 22 : R=2,6-iPr2C6H3, X=tBuMe2SiCH2O) with different 19F-fluoride sources was studied, optimized and the experience gained was used in a translational approach to create a straightforward 18F-labelling protocol for the azasilole derivatives [18F] 6 and [18F] 14 . The latter constitutes a potential clickable CycloSiFA prosthetic group which might be used in PET tracer development using Cu-catalysed triazole formation. Based on our findings, CycloSiFA has the potential to become a new entry into non-canonical labelling methodologies for radioactive PET tracer development. 相似文献
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Per Martin Björemark Dr. Susanne Olsson Dr. Theonitsa Kokoli Prof. Mikael Håkansson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(24):8750-8753
Even though the isolation of tetrahedral stereoisomers usually presents a synthetic challenge, a highly enantioenriched tetrahedral silver complex could be easily accessed by either crystallization or Viedma ripening. The overall preparation may be regarded as an example of absolute asymmetric synthesis. Experimental results indicate that both crystallization and Viedma ripening follow a similar cluster‐controlled mechanism. 相似文献
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Well‐Defined Palladium Nanoparticles Supported on Siliceous Mesocellular Foam as Heterogeneous Catalysts for the Oxidation of Water 下载免费PDF全文
Dr. Oscar Verho Dr. Torbjörn Åkermark Dr. Eric V. Johnston Karl P. J. Gustafson Dr. Cheuk‐W. Tai Henrik Svengren Dr. Markus D. Kärkäs Prof. Jan‐E. Bäckvall Prof. Björn Åkermark 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(15):5909-5915
Herein, we describe the use of Pd nanoparticles immobilized on an amino‐functionalized siliceous mesocellular foam for the catalytic oxidation of H2O. The Pd nanocatalyst proved to be capable of mediating the four‐electron oxidation of H2O to O2, both chemically and photochemically. The Pd nanocatalyst is easy to prepare and shows high chemical stability, low leaching, and recyclability. Together with its promising catalytic activity, these features make the Pd nanocatalyst of potential interest for future sustainable solar‐fuel production. 相似文献
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Björn Bohman Gavin R. Flematti Russell A. Barrow 《Journal of mass spectrometry : JMS》2015,50(8):987-993
Pyrazines are well‐known natural products that are present in bacterial odours and food flavouring agents and are used as insect pheromones. Recently, a number of hydroxymethylpyrazines have been identified as thynnine wasp pheromones and orchid semiochemicals that are essential for pollination in sexually deceptive plants. These compounds are present in low amounts in complex blends, making GC–MS (including high‐resolution techniques) the method of choice for their structure elucidation. We report the EI mass spectra for 14 representative compounds and have found that based on characteristic fragmentations, it is possible to distinguish between different positional isomers of hydroxymethylpyrazines. The presence or absence of either [M ? 17]+, [M ? 18]+· or [M ? 19]+ fragment species provides characteristic information to allow the distinction between the different isomers. Considering the importance of pyrazines as a group of bioactive natural products, and the recent findings of biological activity for hydroxymethylpyrazines, our results presented here will aid the identification of these compounds in other biological systems. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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