2012年人教版小学英语四年级下册unit5围绕话题my clothes展开,重点学习服装名称及其单复数的使用习惯,该案例针对本单元＂partAlet’slearn＂一课进行教学设计。
一、教学目标
（1）知识目标：1能够听、说、认读：clothes,hat,skirt,...2012年人教版小学英语四年级下册unit5围绕话题my clothes展开,重点学习服装名称及其单复数的使用习惯,该案例针对本单元＂partAlet’slearn＂一课进行教学设计。
一、教学目标
（1）知识目标：1能够听、说、认读：clothes,hat,skirt,dress,pants.2能够熟练运用句型：I like that green skirt/those pants.展开更多
New initiator systems for the ring-opening polymerization of 1,4-dioxan-2-one (PDO), AlEt 3-M(AcAc) n-H 2O, where M=Nd, La, Zn, Fe, Co and Ni, were used to initiate the ring-opening polymerization of PDO in bulk, and ...New initiator systems for the ring-opening polymerization of 1,4-dioxan-2-one (PDO), AlEt 3-M(AcAc) n-H 2O, where M=Nd, La, Zn, Fe, Co and Ni, were used to initiate the ring-opening polymerization of PDO in bulk, and to synthesize poly(1,4-dioxan-2-one)(PPDO) with high molecular weights within very short reaction time. A high conversion of monomer can be reached. Of all those initiator systems, AlEt 3-Nd(AcAc) 3-H 2O is the best one. The effects of n(Al)∶n(Nd) and n(H 2O)∶n(Al) on the polymerization of PDO were investigated. It was found that n(AlEt 3)∶ n[Nd(AcAc) 3]∶n(H 2O)=8∶1∶4 could obtain the best initiating effects. PPDO with a viscosity-average molecular weight of 3.1×105 can be obtained when n(PDO)∶n[AlEt 3-Nd(AcAc) 3-H 2O] is 2 000, the reaction temperature 80 ℃, and the reaction time 24 h. Meanwhile, a high conversion of 94.7% can be reached.展开更多
文摘2012年人教版小学英语四年级下册unit5围绕话题my clothes展开,重点学习服装名称及其单复数的使用习惯,该案例针对本单元＂partAlet’slearn＂一课进行教学设计。
一、教学目标
（1）知识目标：1能够听、说、认读：clothes,hat,skirt,dress,pants.2能够熟练运用句型：I like that green skirt/those pants.
文摘New initiator systems for the ring-opening polymerization of 1,4-dioxan-2-one (PDO), AlEt 3-M(AcAc) n-H 2O, where M=Nd, La, Zn, Fe, Co and Ni, were used to initiate the ring-opening polymerization of PDO in bulk, and to synthesize poly(1,4-dioxan-2-one)(PPDO) with high molecular weights within very short reaction time. A high conversion of monomer can be reached. Of all those initiator systems, AlEt 3-Nd(AcAc) 3-H 2O is the best one. The effects of n(Al)∶n(Nd) and n(H 2O)∶n(Al) on the polymerization of PDO were investigated. It was found that n(AlEt 3)∶ n[Nd(AcAc) 3]∶n(H 2O)=8∶1∶4 could obtain the best initiating effects. PPDO with a viscosity-average molecular weight of 3.1×105 can be obtained when n(PDO)∶n[AlEt 3-Nd(AcAc) 3-H 2O] is 2 000, the reaction temperature 80 ℃, and the reaction time 24 h. Meanwhile, a high conversion of 94.7% can be reached.
