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乙酸丙酯的催化合成研究进展 总被引：3，自引：0，他引：3
综述了固体超强酸Al2O3/SO42-、阳离子交换树脂附载Fe3 、硅藻土附载硫酸盐、无机盐及稀土氧化物等不同催化剂催化合成乙酸丙酯的方法.通过比较发现硅藻土附载硫酸盐具有较高的催化活性,在催化剂用量、反应时间、产品收率,催化剂的重复使用等方面都优于其他催化剂. 相似文献
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以固体超强酸Fe2O3-SO4^2-催化合成苹果酯，并考察了催化剂的活化温度、催化剂的用量、反应物摩尔比等因素对收率的影响。实验结果表明，合成苹果酯的最佳条件为：乙酰乙酸乙酯的用量在0．1mol的情况下，用固体超强酸FeO2-SO4^2-为催化剂，催化剂的活化温度500℃，催化剂的用量1．75g，反应物摩尔比1：2。 相似文献
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以固体超强酸Fe2 O3 -SO2 -4 为催化剂合成了苹果酯 ,并考察了催化剂的活化温度、催化剂的用量、反应物摩尔比等因素对收率的影响。实验结果表明 ,合成苹果酯的最佳条件为 :乙酰乙酸乙酯的用量在 0 .1mol的情况下 ,用固体超强酸Fe2 O3-SO2 -4 为催化剂 ,催化剂的活化温度 50 0℃ ,催化剂的用量 1 .75g ,反应物摩尔比 1 :2。 相似文献
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以固体超强酸Fe2O3-SO2-4为催化剂合成苹果酯,考察了催化剂的活化温度、催化剂的用量、反应物摩尔比等因素对收率的影响.实验结果表明,合成苹果酯的最佳条件为乙酰乙酸乙酯的用量在0.1mol的情况下,用固体超强酸Fe2O3-SO2-4为催化剂,催化剂的活化温度500℃,用量1.75g,反应物乙酰乙酸乙酯与乙二醇的摩尔比12,苹甲酯的收率为89.7%. 相似文献
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以固体超强酸Fe3O3-SO24-为催化剂合成了苹果酯,并考察了催化剂的活化温度、催化剂的用量、反应物摩尔比等因素对收率的影响.实验结果表明,合成苹果酯的最佳条件为乙酰乙酸乙酯的用量在0.1mol的情况下,用固体超强酸Fe2O3-SO24-为催化剂,催化剂的活化温度500℃,催化剂的用量1.75g,反应物摩尔比12. 相似文献
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以固体超强酸 Fe2 O3 —SO2 -4为催化剂合成苹果酯 ,考察了催化剂的活化温度、催化剂的用量、反应物摩尔比等因素对收率的影响。实验结果表明 ,合成苹果酯的最佳条件为 :乙酰乙酸乙酯的用量在 0 .1 mol的情况下 ,用固体超强酸 Fe2 O3 —SO2 -4为催化剂 ,催化剂的活化温度 5 0 0℃ ,用量 1 .75 g,反应物乙酰乙酸乙酯与乙二醇的摩尔比 1∶ 2 ,苹甲酯的收率为 89.7%。 相似文献
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乙酸苄酯的合成研究进展 总被引：4，自引：0，他引：4
综述了固体超强酸、有机酸、无机盐、阳离子交换树脂、H-β沸石、铌酸和相转移催化剂等催化合成乙酸苄酯的方法．通过对比分析发现固体超强酸及有机固体酸类催化剂催化合成乙酸苄酯有较大的实用价值。 相似文献
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本文研究了8种固体酸催化剂催化乙酸与异戊醇的酯化反应 ,结果表明 :FeCl3.6H2O ,CuSO4.5H2O和AlCl3 催化效果最好 ,酯转化率达90 %以上. 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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Rajesh Kanoi 《海外英语》2007,(1):52
Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer. 相似文献
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正A One day a pig went to the stable(马棚)to see his good friend,an oldhorse,and was going to stay there forthenight.Night came and it was time forsleep.The pig went into the straw heap(稻草堆)and lay comfortably.A longtime passed,but the horse was stillstanding there and did not move.Thepig asked the horse why he did not go tosleep."Standing like this is the begin-ning ofsleeping,"answered the horse. 相似文献
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《今日中学生》2014,(9)
正1.Any fool can count the seeds in an apple.Only God can count all the apples in one seed.2.Happy families are all alike;every unhappy family is unhappy in its own way.3.Memories are the key not to the past,but to the future.4.Sometimes in the dark you see what you want to see.5.There is a great difference between 相似文献
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《重庆大学学报(英文版)》2014,(2)
正Scope and Policy The Journal of Chongqing University-English Edition(JCQU-E)is a peerreviewed journal publishing research articles in multiple disciplines of science and technology,covering civil and environmental engineering,chemical engineering,biotechnology,mechanical and electrical engineering,computer and data processing,mining,metallurgy,materials science,and interdisciplines thereof. 相似文献