拉特格斯大学—新布朗斯维克分校(Rutgers-New Brunswick)的通信、信息与图书馆学院(School ofCommunication Information and Library Scudies,简称SCILS,http://www.scils.rutgers.edu/)——按1999年的统计,在全美图书馆学研究生院中...拉特格斯大学—新布朗斯维克分校(Rutgers-New Brunswick)的通信、信息与图书馆学院(School ofCommunication Information and Library Scudies,简称SCILS,http://www.scils.rutgers.edu/)——按1999年的统计,在全美图书馆学研究生院中排名第七,平均声誉值达到3.9(5分为最高值)。该院位于新泽西州的洛特格斯市,是拉特格斯大学即新泽西州立大学的组成部分之一。在响应信息革命,及在通信、信息与媒体领域中飞速变化中,该学院一直处于先导地位。展开更多
Because of its high purity and excellent orientation, mesophase pitch is a superior precursor for high-performance car-bon materials. However, the preparation of top-notch mesophase pitch faces challenges. Catalytic p...Because of its high purity and excellent orientation, mesophase pitch is a superior precursor for high-performance car-bon materials. However, the preparation of top-notch mesophase pitch faces challenges. Catalytic polycondensation at low temperat-ures is more favorable for synthesizing mesophase pitch, because it circumvents the high-temperature free radical reaction of other thermal polycondensation approaches. The reaction is gentle and can be easily controlled. It has the potential to significantly im-prove the yield of mesophase pitch and easily introduce naphthenic characteristics into the molecules, catalytic polycondensation is therefore a preferred method of synthesizing highly spinnable mesophase pitch. This review provides a synopsis of the selective pre-treatment of the raw materials to prepare different mesophase pitches, and explains the reaction mechanism and associated research advances for different catalytic systems in recent years. Finally, how to manufacture high-quality mesophase pitch by using a cata-lyst-promoter system is summarized and proposed, which may provide a theoretical basis for the future design of high-quality pitch molecules.展开更多
An efficient chiral Br?nsted acid-catalyzed conjugate addition of indoles to azadienes has been successfully developed,which enables a facile approach to optically active hetero-triarylmethanes with excellent enantios...An efficient chiral Br?nsted acid-catalyzed conjugate addition of indoles to azadienes has been successfully developed,which enables a facile approach to optically active hetero-triarylmethanes with excellent enantioselectivities and broad substrate scope.This chiral Br?nsted acid catalytic system provides a new opportunity for the development of asymmetric reactions of azadienes.展开更多
文摘拉特格斯大学—新布朗斯维克分校(Rutgers-New Brunswick)的通信、信息与图书馆学院(School ofCommunication Information and Library Scudies,简称SCILS,http://www.scils.rutgers.edu/)——按1999年的统计,在全美图书馆学研究生院中排名第七,平均声誉值达到3.9(5分为最高值)。该院位于新泽西州的洛特格斯市,是拉特格斯大学即新泽西州立大学的组成部分之一。在响应信息革命,及在通信、信息与媒体领域中飞速变化中,该学院一直处于先导地位。
文摘Because of its high purity and excellent orientation, mesophase pitch is a superior precursor for high-performance car-bon materials. However, the preparation of top-notch mesophase pitch faces challenges. Catalytic polycondensation at low temperat-ures is more favorable for synthesizing mesophase pitch, because it circumvents the high-temperature free radical reaction of other thermal polycondensation approaches. The reaction is gentle and can be easily controlled. It has the potential to significantly im-prove the yield of mesophase pitch and easily introduce naphthenic characteristics into the molecules, catalytic polycondensation is therefore a preferred method of synthesizing highly spinnable mesophase pitch. This review provides a synopsis of the selective pre-treatment of the raw materials to prepare different mesophase pitches, and explains the reaction mechanism and associated research advances for different catalytic systems in recent years. Finally, how to manufacture high-quality mesophase pitch by using a cata-lyst-promoter system is summarized and proposed, which may provide a theoretical basis for the future design of high-quality pitch molecules.
文摘An efficient chiral Br?nsted acid-catalyzed conjugate addition of indoles to azadienes has been successfully developed,which enables a facile approach to optically active hetero-triarylmethanes with excellent enantioselectivities and broad substrate scope.This chiral Br?nsted acid catalytic system provides a new opportunity for the development of asymmetric reactions of azadienes.
