The Interaction Hypothesis,which was first advanced by Michael Long,is considered as a further supplement or extension of the Input Hypothesis in the field of second language acquisition. This paper explains the main ...The Interaction Hypothesis,which was first advanced by Michael Long,is considered as a further supplement or extension of the Input Hypothesis in the field of second language acquisition. This paper explains the main claims of Michael Long's Interaction Hypothesis,the three steps to study how input and interaction affect the acquisition of a second language,and the importance of the interactional modifications applied by both participants of the interaction. Emphasis is placed on the evaluation of the theory as well as its relation to second language teaching,with many researchers' findings and arguments discussed as supporting evidence. It aims to help the effective application of this theory in second language teaching.展开更多
Potassium tert-butoxide has been found to be a highly efficient catalyst for one-pot,three-component reaction of aryl aldehydes, acetophenones,and thiols via Claisen-Schmidt/Michael addition reactions for the synthesi...Potassium tert-butoxide has been found to be a highly efficient catalyst for one-pot,three-component reaction of aryl aldehydes, acetophenones,and thiols via Claisen-Schmidt/Michael addition reactions for the synthesis of thia-Michael adducts in high yields. The reactions are best carried out in tert-butyl alcohol at room temperature.展开更多
1 Results Much effort has been focused on organocatalytic asymmetric synthesis in these several years. We have already documented highly efficient organocatalytic asymmetric acylation of a wide variety of racemic alco...1 Results Much effort has been focused on organocatalytic asymmetric synthesis in these several years. We have already documented highly efficient organocatalytic asymmetric acylation of a wide variety of racemic alcohols and meso-diols catalyzed bya chiral 1,2-diamine derived from (S)-proline[1]. (S)-Homoproline seems to be a potentially interesting organocatalyst, but no examples using (S)-homoproline itself in asymmetric synthesis has been reported. We have accomplished an efficient and practical syn...展开更多
文摘The Interaction Hypothesis,which was first advanced by Michael Long,is considered as a further supplement or extension of the Input Hypothesis in the field of second language acquisition. This paper explains the main claims of Michael Long's Interaction Hypothesis,the three steps to study how input and interaction affect the acquisition of a second language,and the importance of the interactional modifications applied by both participants of the interaction. Emphasis is placed on the evaluation of the theory as well as its relation to second language teaching,with many researchers' findings and arguments discussed as supporting evidence. It aims to help the effective application of this theory in second language teaching.
文摘Potassium tert-butoxide has been found to be a highly efficient catalyst for one-pot,three-component reaction of aryl aldehydes, acetophenones,and thiols via Claisen-Schmidt/Michael addition reactions for the synthesis of thia-Michael adducts in high yields. The reactions are best carried out in tert-butyl alcohol at room temperature.
文摘1 Results Much effort has been focused on organocatalytic asymmetric synthesis in these several years. We have already documented highly efficient organocatalytic asymmetric acylation of a wide variety of racemic alcohols and meso-diols catalyzed bya chiral 1,2-diamine derived from (S)-proline[1]. (S)-Homoproline seems to be a potentially interesting organocatalyst, but no examples using (S)-homoproline itself in asymmetric synthesis has been reported. We have accomplished an efficient and practical syn...
