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重质稠环芳烃的固体核磁共振光谱研究 被引量:3
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作者 宋怀河 陈晓红 +1 位作者 刘朗 张碧江 《化学学报》 SCIE CAS CSCD 北大核心 2001年第7期1130-1134,共5页
以固体核磁共振光谱为主要分析手段,比较研究了两种合成中间相沥青吡啶不溶组分的结构.结果表明:均四甲苯基中间相沥青吡啶不溶组分具有较低的芳香度和缩合度,富含甲基和环烷结构,分子呈渺位缩合构型;与此相反,四氢萘基中间相沥青则呈... 以固体核磁共振光谱为主要分析手段,比较研究了两种合成中间相沥青吡啶不溶组分的结构.结果表明:均四甲苯基中间相沥青吡啶不溶组分具有较低的芳香度和缩合度,富含甲基和环烷结构,分子呈渺位缩合构型;与此相反,四氢萘基中间相沥青则呈现很高的芳香度和缩合度,芳环上仅带有一些甲基取代基,平均分子为完全迫位缩合构型.造成这种结构差异的原因在于前驱齐聚物的结构及缩聚程度的不同. 展开更多
关键词 中间相沥青 稠环芳烃 固体核磁共振光谱 构型 结构
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氮酮对鼠角质层角蛋白作用的光谱证据 被引量:6
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作者 周雪琴 许晶 +3 位作者 赵晓东 张志慧 姚康德 刘东志 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2004年第7期1273-1276,MJ03,共5页
应用 1 3C NMR和 ATR-FTIR为测试手段 ,探讨角蛋白的分子运动自由度与堆积结构 ,以及氮酮对鼠角质层角蛋白的作用 .经氮酮处理后 ,角蛋白主侧链碳的自旋晶格弛豫时间 t1 从 7.9,8.2和 2 .1 s分别减小到 5 .4,3 .6和 1 .6s,表明氮酮作用... 应用 1 3C NMR和 ATR-FTIR为测试手段 ,探讨角蛋白的分子运动自由度与堆积结构 ,以及氮酮对鼠角质层角蛋白的作用 .经氮酮处理后 ,角蛋白主侧链碳的自旋晶格弛豫时间 t1 从 7.9,8.2和 2 .1 s分别减小到 5 .4,3 .6和 1 .6s,表明氮酮作用加快了角蛋白所有碳的运动 ,获得了氮酮对鼠角质层角蛋白作用的确凿证据 .同时 ,ATR-FTIR结果显示 ,经氮酮处理后 ,角蛋白的酰胺吸收峰 带的峰位从 1 5 44.7cm- 1 向低波数位移到 1 5 41 .4cm- 1 .结果表明氮酮可使部分角蛋白从α-螺旋型结构向β-折叠型结构和无规则卷曲型结构转变 ,导致角蛋白的堆积结构疏松 。 展开更多
关键词 氮酮 角质层 角蛋白作用 分子运动自由度 堆积结构 自旋晶格弛豫时间 透皮给药系统 固体核磁共振光谱 化学促进剂
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Curing Mechanism of Condensed Polynuclear Aromatic Resin and Thermal Stability of Cured Resin 被引量:1
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作者 Li Shibin Sun Qiqian +2 位作者 Wang Yuwei Wu Mingbo Zhang Zailong 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2015年第2期9-16,共8页
In order to improve the thermal stability of condensed polynuclear aromatic(COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by p... In order to improve the thermal stability of condensed polynuclear aromatic(COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by proton nuclear magnetic resonance spectrometry, solid carbon-13 nuclear magnetic resonance spectrometry and Fourier transform infrared spectroscopy. Microstructures of the uncured and the cured COPNA resins were studied by scanning electron microscopy and X-ray diffractometry. The thermal stability of COPNA resins before and after curing was tested by thermogravimetric analysis. The element composition of the cured COPNA resin heated at different temperatures was analyzed by an element analyzer. The results showed that the uncured COPNA resin reacted with the cross-linking agent during the curing process, and the curing mechanism was confirmed to be the electrophilic substitution reaction. Compared with the uncured COPNA resin, the cured COPNA resin had a smooth surface, well-ordered and streamlined sheet structure with more crystalline solids, better molecular arrangement and orientation. The weight loss process of the uncured and cured COPNA resins was divided into three stages. Carbon residue of the cured COPNA resin was 41.65% at 600 ℃, which was much higher than 25.02% of the uncured COPNA resin, which indicated that the cured COPNA resin had higher thermal stability. 展开更多
关键词 condensed polynuclear aromatic resin SYNTHESIS vacuum residue CURING thermal stability
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