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六苯基环三硅氮烷合成工艺的改进

Hexaphenyl cyclotrisilazane was synthesized from diphenyl dichlorosilane and ammonia with toluene as solvent.The effects of input material concentration, reaction temperature, ammonia flow rate and separation method on product yield were investigated.The structure of hexaphenyl cyclotrisilazane was characterized with FTIR and XRD.It was found that when diphenyl dichlorosilane concentration was 0.96 mol·L -1 , reaction temperature was 111—112℃,NH3 flow rate was 0.02 m3·h -1 , the yield of hexaphenyl cyclotrisilazane could reach 91.1%.Using ammonia water was better than hot filtration to weed out ammonium chloride at the period of product separation.It enhanced separation efficiency and simplified the process.At the same time it also decreased pollution to the environment by reducing volatile matter of toluene.

八甲基环四硅氮烷的合成工艺改进

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培养学生语文学习良好习惯

回顾自己的教学历程．一幕幕的往事历历在目．令我感慨的是搞好语文学科的教学．学生良好的学习习惯不可忽视．它在语文教学中起着举足轻重的作用。经验证明．好的语文成绩不单是靠教师教出来的，学生的学才是主要的。既然如此．怎样才能培养中学生良好的语文学习习惯呢？本文结合自己的教学实际谈几点体会．希望有抛砖引玉之效。