Preparation of natural α-tocopherol from non-α-tocopherols     

杨亦文  闻光东  吴彩娟  任其龙  吴平东 《Journal of Zhejiang University. Science. B》2004,(12)

Non-a-tocopherols are hydroxymethylated and hydrogenated to produce α-tocopherol in one pot process by simultaneously reacting with paraformaldehyde and hydrogen in the presence of catalysts of benzenesulfonic acid and 5% Pd/C in an autoclave. Effects of various operation conditions have been studied. The preferable reaction conditions are: temperature 180 ℃ to 200 ℃, pressure 5.0 MPa, acid concentration 0.5 g/100 ml ethanol, mass ratio of Pd/C to tocopherols 7.1 g/100 g, and reaction time 5.0 h. A product with α-tocopherol content of 80% was obtained by using a raw material with a total tocopherols content of 80.54%. The conversion of non-α-tocopherols is almost 100%, and the mole yield of a-tocopherol is more than 90%.  相似文献   

英雄的悲剧     

杨亦文 《班主任之友》2003,(8):57-58

一到曼谷，泰国的朋友就领我到大罗斗圈。那有一尊戎装铜像，主人策马挥剑，极为英武。指着塑像，朋友向我讲述了这位华裔国王的故事。18世纪中叶，泰国面临一次严峻的考验，缅军的入侵，都城的失陷，使这个伟大的民族到了亡国的边缘。然而“阿育塔从不缺乏优秀的人物”，英雄出现了，他就是郑信(中国史书称之为郑昭)。他率领民众大举反攻，驱逐外寇，重建家园，在阿育塔的废墟上重建了吞武里王朝，这样的英雄在任何一个民族都会受到后人的景仰。而故事的结尾却极为惨烈。郑王最后是被弑还是出家当了和尚已不重要，一个浴血而来的王朝，仅仅…  相似文献   

徐州建设淮海经济区中心城市评估研究     

欧向军  徐玥  杨亦文 《中国名城》2023,(11):10-19

促进徐州淮海经济区中心城市建设,既是落实省域副中心建设和淮海经济区高质量协同发展的内在需求,也是推进国家区域协调发展新进程、有效实施江苏“省域一体化”战略的必然要求。从区域经济中心、科技创新中心、教育文化中心、综合交通枢纽、双向开放高地5个方面,构建区域中心发展指数综合评价指标体系。从2010—2021年的4个时间截面,对淮海经济区10个城市的5个中心指数进行综合分析,在此基础上利用修正引力模型测度出中心城市对外辐射能力和接受辐射能力的强弱,总结归纳徐州中心城市建设存在的主要问题,并针对性地提出对策建议。  相似文献   

Preparation of natural α-tocopherol from non-α-tocopherols     

杨亦文  闻光东  吴彩娟  任其龙  吴平东 《浙江大学学报(A卷英文版)》2004,5(12):1524-1527

Non-α-tocopherols are hydroxymethylated and hydrogenated to produce α-tocopherol in one pot process bysimultaneously reacting with paraformaldehyde and hydrogen in the presence of catalysts of benzenesulfonic acid and 5%Pd/C in an autoclave. Effects of various operation conditions have been studied. The preferable reaction conditions are: temperature 180 ℃ to 200 ℃, pressure 5.0 MPa, acid concentration 0.5 g/100 ml ethanol, mass ratio of Pd/C to tocopherols 7.1 g/100 g, and reaction time 5.0 h. A product with α-tocopherol content of 80% was obtained by using a raw material with a total tocopherols content of 80.54%. The conversion of non-α-tocopherols is almost 100%, and the mole yield ofα-tocopherol is more than 90%.  相似文献