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81.
石墨烯由于拥有超高比表面积和超高电导率而被作为电化学电容器材料广泛研究.本文采用树脂为碳源,通过一种方便快捷的树脂交换法制备一种具有高比表面积的多级孔三维石墨烯(3DG).经过此种方法的催化、造孔、热处理等主要工艺步骤后,可显著增加石墨烯材料的小、介孔数量,从而提高材料的电化学性能.通过BET测试表明,3DG的比表面积可达2400 m2/g,孔体积达到2.0 cm3/g.以3DG作为正负极材料制备高比能量高功率型锂离子电容器(3DG-LIC),可使3DG-LIC的工作电压从传统超级电容器的2.5 V扩展到4.0 V,能量密度也从20 Wh/kg提高到105 Wh/kg.另外,相同的化学和微观结构能很好地平衡正负极的容量及速率,使高比能量高功率的3DG-LIC具有更宽阔的应用领域. 相似文献
82.
A new method for the synthesis of novel C‐substituted piperazine derivatives bearing aryl substituents on 2,6‐C positions has been developed by one‐pot three‐component sequential reaction of α‐bromoarylethanones with ethanolamine in the presence of formic acid. The structure of the novel compounds was established by nuclear magnetic resonance (NMR), mass spectrometry (MS), and elemental analysis. In addition, the crystal structure of 4e was determined by single X‐ray crystallography and a possible reaction mechanism was proposed. 相似文献
83.
Ly Dieu Ha Poul Erik Hansen Fritz Duus Hung Dinh Pham Lien‐Hoa D. Nguyen 《Magnetic resonance in chemistry : MRC》2012,50(3):242-245
Four new prenylated depsidones, oliveridepsidones A–D, were isolated from the bark of Garcinia oliveri collected in Vietnam. Their structures were elucidated using mainly NMR techniques (1H and 13C NMR, HMQC, HMBC and NOE experiments). Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Weihua Zhou Zoukangning Yu Ming Zhang Lifu Zhang Jingping Yin Qingyun Ai Liqiang Huang Feng Liu Jianrong Zeng Yiwang Chen 《Journal of Polymer Science.Polymer Physics》2019,57(14):941-951
In order to explore the role of fluorine atoms on photostability as well as morphology control of active layer in the presence of 1,4‐butanedithiol (BT), the four polymers with or without fluorine atoms in the backbones including polythieno[3,4‐b]thiophene/benzodithiophene, poly[(4,8‐bis‐(2‐ethylhexyloxy)‐benzo(1,2‐b:4,5‐b9)dithiophene)‐2,6‐diyl‐alt‐(4‐(2‐ethylhexanoyl)‐thieno[3,4‐b]thiophene‐)‐2‐6‐diyl)], poly[4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b;4,5‐b′]dithiophene‐2,6‐diyl‐alt‐(4‐(2‐ethylhexyl)‐3‐fluorothieno[3,4‐b]thiophene‐)‐2‐carboxylate‐2‐6‐diyl)], and poly[4,8‐bis‐(2‐ethyl‐hexyl‐thiophene‐5‐yl)‐benzo[1,2‐b:4,5‐b0]dithiophene‐2,6‐diyl]‐alt‐[2‐(20‐ethyl‐hexanoyl)‐thieno [3,4‐b]thiophen‐4,6‐diyl] were selected for comparison. It is found that the specimens containing fluorine atoms in polymer backbones showed of higher stability after illumination for 1 h in the presence of BT additive, contributing to the higher domain purity. The specific interaction between fluorine atoms and thiol groups was demonstrated by the appearance of novel absorption peak at 2663.1 cm?1, in addition to the broadening of peak at 2556.2 cm?1 ascribing to S? H stretching vibration as confirmed by Fourier transform infrared (FTIR) spectroscopy. The finding may guide the accurate use of thiols as effective solvent additive in morphology and stability optimization. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 941–951 相似文献
86.
Sheng‐wen Lu Ai‐hua Zhang Hui Sun Guang‐li Yan Ying Han Xiu‐hong Wu Xi‐jun Wang 《Biomedical chromatography : BMC》2013,27(12):1657-1663
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A linear optical unambiguous discrimination of hyperentangled Bell states is proposed for two‐photon systems entangled in both the polarization and momentum degrees of freedom (DOFs) assisted by time bin. This unambiguous discrimination scheme can completely identify 16 orthogonal hyperentangled Bell states using only linear optical elements, where the function of the auxiliary entangled Bell state is replaced by time bin. Moreover, the possibility of extending this scheme for distinguishing hyperentangled Bell states in n DOFs is discussed, and it shows that hyperentangled Bell states in n ( ) DOFs can be distinguished with k ( ) auxiliary entangled states of additional DOFs by introducing a time delay, which decreases the auxiliary entanglement resource required for unambiguous discrimination of hyperentangled Bell state. Therefore, this scheme provides a new way for distinguishing hyperentangled states with current technology, which will extend the application of discrimination of hyperentangled states via linear optics to other quantum information protocols besides hyperdense coding schemes in the future. 相似文献
89.
A dynamic mathematical model is developed for production of Cerenol polyether from 1,3‐propanediol in a batch reactor system. The model accounts for polycondensation reactions and side reactions in the liquid phase and for mass transfer of volatile species to the vapor. Parameters are estimated using measured liquid‐phase concentrations of monomer, oligomers, water, and end groups as well as the mass and composition of condensate collected from the overhead condenser system. The proposed model uses novel probability factors to keep the model equations relatively simple while accounting for the complex influence of superacid catalyst on reaction rates. The model is a significant advance over previous Cerenol models because it better accounts for mass‐transfer rates and for the dynamic behavior of the condenser. In addition, the proposed model accounts for the inhibitory influence of water on polycondensation kinetics due to hydration of hydroxyl ends. The model equations and parameter estimates provide a substantial improvement in fit to the data, especially for long reaction times and high catalyst levels, resulting in a 97% reduction in the value of the weighted least squared objective function compared to equations and parameters from a previous model. 相似文献
90.
Serum pharmacochemistry combined with multiple data processing approach to screen the bioactive components and their metabolites in Mutan Cortex by ultra‐performance liquid chromatography tandem mass spectrometry 下载免费PDF全文
Jian‐hua Liu Hui Sun Ai‐hua Zhang Guang‐li Yan Ying Han Chang‐song Xue Xiao‐hang Zhou Hui Shi Xi‐jun Wang 《Biomedical chromatography : BMC》2014,28(4):500-510
Root cortex of Paeonia suffruticosa Andrews (Paeoniaceae), known as Moutan Cortex (MC), is known to have anti‐allergic and anti‐inflammatory properties. However, the constituents absorbed into blood after oral administration of MC remain unknown. A sensitive and rapid method by ultra‐high‐pressure liquid chromatography–electrospray ionization–quadrupole‐time‐of‐flight mass spectrometry (UPLC‐ESI‐Q‐TOF‐MS) technology and the MetaboLynxTM software combined with multiple data processing approach (Mdpa) was established to investigate the absorbed constituents in rats after oral administration of MC, providing unique high‐throughput capabilities for drug metabolism study. A hyphenated electrospray ionization and quadrupole‐time‐of‐flight analyzer was used for the determination of accurate mass of the fragment ion in negative mode, with excellent MS mass accuracy and enhanced data acquisition. This rapid automated analysis method was successfully applied for screening and identification of the constituents absorbed and metabolized studies of MC after oral administration to rats. A total of 46 peaks were obtained from MC, 41 of which were tentatively characterized. In the VIP‐plot of orthogonal partial least‐squares discriminant analysis, 23 interesting ions in serum samples were extracted, and 16 parent components and seven metabolites were detected in vivo. The integrative serum pharmacochemistry technique, UPLC‐ESI‐Q‐TOF‐MS, and Mdpa method were successfully applied for rapid discovery of multiple components from MC. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献