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991.
992.
Zhen‐Hua Wang Yong‐Lai Lu Jun Liu Zhi‐Min Dang Li‐Qun Zhang Weimin Wang 《先进技术聚合物》2011,22(12):2302-2310
In this paper, nanoalumina (Al2O3) highly filled ethylene propylene diene monomer (EPDM) composites are prepared, and the mechanical (static and dynamic) properties and thermal conductivity are investigated systemically through various characterization methods. Furthermore, influences of in situ modification (mixing operation assisted by silane at high temperature for a certain time) with the silane‐coupling agent bis‐(3‐triethoxy silylpropyl)‐tetrasulfide (Si69) and stearic acid (SA) pretreatment on the nano‐Al2O3 filled composites are as well investigated. The results indicate that nano‐Al2O3 particles can not only perform well in reinforcing EPDM, but also improve the thermal conductivity significantly. Assisted by in situ modification with Si69, the mechanical properties (especially dynamic mechanical properties) of the nano‐Al2O3 filled composites are improved obviously, without influencing the thermal conductivity. By comparing to the traditional reinforcing fillers, such as carbon black (grade N330) and silica, in situ modified nano‐Al2O3 filled composites exhibit excellent performance in mechanical (static and dynamic) properties as well as better thermal conductivity, especially lower compression heat build‐up and better fatigue resistance. In general, our work indicates that nano‐Al2O3, as the novel thermal conductive reinforcing filler, is suitable to prepare rubber products serving in dynamic conditions, with the longer expected service life. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
993.
Jiali Huang Yunbin Li Hao Zhang Zhen Yuan Prof. Shengchang Xiang Prof. Banglin Chen Prof. Zhangjing Zhang 《Angewandte Chemie (International ed. in English)》2023,62(52):e202315987
Hydrogen-bonded organic frameworks (HOFs) have been emerging as a new type of very promising microporous materials for gas separation and purification, but few HOFs structures constructed through hydrogen-bonding tetramers have been explored in this field. Herein, we report the first microporous HOF (termed as HOF-FJU-46) afforded by hydrogen-bonding tetramers with 4-fold interpenetrated diamond networks, which shows excellent chemical and thermal stability. What's more, activated HOF-FJU-46 exhibits the highest xenon (Xe) uptake of 2.51 mmol g−1 and xenon/krypton (Kr) selectivity of 19.9 at the ambient condition among the reported HOFs up to date. Dynamic breakthrough tests confirmed the excellent Xe/Kr separation of HOF-FJU-46a, showing high Kr productivity (110 mL g−1) and Xe uptake (1.29 mmol g−1), as well as good recyclability. The single crystal X-ray diffraction and the molecular simulations revealed that the abundant accessible aromatic and pyrazole rings in the pore channels of HOF-FJU-46a can provide the multiple strong C−H⋅⋅⋅Xe interactions with Xe atoms. 相似文献
994.
Wang SJ Zhang ZQ Zhao YH Ruan JX Li JL 《Rapid communications in mass spectrometry : RCM》2006,20(15):2303-2308
A simple, rapid and sensitive method was developed for the simultaneous quantification of chlorogenic acid (CGA) and caffeic acid (CA) in rat plasma using a high-performance liquid chromatography system coupled to a negative ion electrospray mass spectrometric analysis. The plasma sample preparation was a simple deproteinization by the addition of two volumes of acetonitrile followed by centrifugation. The analytes and internal standard ferulic acid were separated on an Intersil C8-3 column (5 mm; 250 x 2.1 mm) with acetonitrile/0.05% triethylamine solution (70:30, v/v) as mobile phase at a flow rate of 0.2 mL/min with an operating temperature of 30 degrees C. Detection was performed on a quadrupole mass spectrometer equipped with an electrospray ionization (ESI) source operated in selected ion monitoring (SIM) mode. Negative ion ESI was used to form deprotonated molecules at m/z 353 for chlorogenic acid, m/z 179 for caffeic acid, and m/z 193 for the internal standard ferulic acid. Linear detection responses were obtained for CGA concentrations ranging from 0.005 to 2.0 microg/mL and for CA concentrations ranging from 0.010 to 2.0 microg/mL and the lower limits of quantitation (LLOQs) for CGA and CA were 0.005 and 0.01 microg/mL, respectively. The intra- and inter-day precisions (RSD%) were within 9.0% for both analytes. Deviation of the assay accuracies was within +/-10.0% for both analytes. Their average recoveries were greater than 88.0%. Both analytes were proved to be stable during all sample storage, preparation and analytic procedures. The method was successfully applied to the pharmacokinetic study of CGA and CA following an intravenous dose of 5 mL/kg mailuoning injection to rats. 相似文献
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996.
Shao‐Jie Lou Dan‐Qian Xu Zhen‐Yuan Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(39):10498-10503
A novel and facile C H bond fluorination proceeds under remarkably mild conditions (close to room temperature in most cases). Both aromatic and olefinic C(sp2) H bonds with a wide range of electronic properties are selectively fluorinated in the presence of a catalytic amount of simple, cheap, and nontoxic nitrate as the promoter. A PdII/PdIV catalytic cycle that is initiated by an in situ generated cationic [Pd(NO3)]+ species was proposed based on preliminary mechanistic studies. 相似文献
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