A Novel Green Preparation of a, a''''-Bis (substituted benzylidene)-cycloalkanones Promoted by FeCl_3 6H-2O in Ionic Liquid

a, a'-Bis(substituted benzylidene)cycloalkanones were efficiently prepared from cycloalkanones and benzaldehydes in [bmim][BF4] by using iron(III) chloride hexahydrate as a catalyst. It is shown that [bmim][BF4] and iron(III) chloride hexahydrate can be quantitatively recovered and be reused effectively for many times. Compared with the known methods, this novel process has the advantage of being an envkonmentally benign process together with good yields and mild reaction conditions.     

动,静态硫化（NR＋SBR）／PE共混体系的结构与性能

用TEM研究了(NR SBR)/PE共混体系经动、静态硫化后的形态结构及其与力学性能的关系。未硫化和静态硫化体系的形态结构与其组成有关,均以含量大的组份为连续相;对动态硫化体系,当(NR=SBR)/PE<70/30时,均以PE为连续相,其性能主要依赖于构成连续相组份的性质。 动态硫化体系的T_g值低于静态体系,随PE组份含量的增加变化不大,而静态硫化体系的T_g值则随PE含量增加向高温方向迁移。用DSC测得动态硫化体系的结晶度比静态体系的大。前者的应力-应变性能也低于后者。     

二价氯化稀土催化丁二烯聚合的活性

<正> 稀土催化聚合双烯烃的研究表明,不同稀土元素的催化活性极不一样,对此虽有不同的解释,但通常公认Sm、Eu等活性骤低,可归之于它们在制备催化剂过程中极易被烷基铝从三价还原到二价,又根据大部分具活性的其它稀土元素在催化体系中总是三价的事实,进而推断:只有在体系中能保持三价的稀土化合物方有产生活性的可能,二价化合物则不具活性。然而,由于二价稀土化合物,特别是除Sm、Eu之外的二价化合物难以制得,迄今为止并无直接的实验事实来判断这些推断是否正确。     

黄芪中微量锌的测定

用分光光度法测定了黄芪中锌的含量,该法的平均回收率为99.01%.变异系数为1.50%.     

Synthesis and characterization of perfluorohexylated poly(3,4-ethylenedioxythiophene)

The perfluorohexylated 3,4-ethylenedioxythiophene 5 was prepared via Mitsunobu reaction of perfluorohexylatyed diol 2 with diethyl 3,4-dihydroxythiophenedicarboxylate followed by decarboxylation. The polymerization of 5 was conducted with both oxidative chemical and electrochemical polymerizations. The polymers were characterized by cyclic voltammogram, UV, IR, TGA and DSC.     

CdSe/ZnS-labeled carboxymethyl chitosan as a bioprobe for live cell imaging

A simple and convenient method for the construction of CdSe/ZnS-labeled polysaccharides as bioprobes were developed, which are highly biocompatible and photostable, and have been proven to be suitable for live cell imaging.     

等离子体辅助合成分子筛膜及其催化性能的研究

首次将等离子体技术应用于分子筛膜的制备，研究了以微波等离子体处理基材表面分子筛膜前驱体辅助水热反应合成支撑β型分子筛膜．利用XRD、SEM、XPS、BET、TPD表征了分子筛膜的物相、形貌、孔结构、表面元素组成和表面酸性，并通过甲醇与异丁烯液相反应体系实验考察了分子筛膜的催化性能．结果表明，等离子体处理能有效改善分子筛膜前驱体在基材表面的分散状况，减小了分子筛膜晶体的尺度，使晶体大小均匀，形成的膜致密、牢固．与采用常规方法合成的分子筛膜相比，等离子体辅助合成的分子筛膜对甲醇与异丁烯的反应有更好的催化活件．