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鉴于当前社会治安的复杂形势,本技术设计了一种适合安装于家庭大门,并且具有定位功能的震动报警装置。该报警装置在感应到一定强度的震动(可预先设置好)后,会发送预编辑的提醒短信给相应的手机号码。同时,为了方便有多处住宅的用户确定报警位置,该装置还嵌入了GPS模块。 相似文献
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Cellulose is one of the mostabundantnatural pol-ymers that have received much attention in research tomodify its physical and chemical structures to improveits properties and broaden its applications. A lot ofwork[1—5]has been reported on the modification viagraft copolymerization of vinyl monomers onto cellu-lose, often using different initiator systems. Variousvinyl monomers such as methyl methacrylate[6,7], 4-vinylpyridine[8], acrylonitrile[9,10], and styrene[11]have been used for cellulos… 相似文献
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提出一种制备高磁含量聚合物的方法 .首先用乙醇对共沉淀法制备的磁流体进行处理 ,然后在处理过的 Fe3O4粒子存在情况下 ,以聚乙二醇为分散剂 ,偶氮二异丁腈为引发剂 ,乙醇为分散介质 ,进行丙烯酰胺的分散聚合 .讨论了分散介质、搅拌强度、磁性粒子性质及用量等因素对聚合反应及聚合物磁含量的影响 .制备出了磁含量高达 3 2 .2 % (质量比 )的聚丙烯酰胺微球 相似文献
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Tung oil-based polyols were synthesized by the esterification and transesterification between Tung oil-based anhydride and butanediol. The hydroxyl values of the polyols prepared were tested and discussed. Polyurethane was prepared by using Tung oil-based polyols and/or poly (propylene glycol) as polyols and by using isophorone diisocyanate as isocyanate. The effect of the ratio of Tung oil-based polyols to poly (propylene glycol) on the proper- ties of polyurethane prepared was investigated by the water resistance, alcohol resistance and hardness tests. The results show that Tung oil-based polyols are effective to improve the hardness, water resistance and alcohol resistance of polyurethane. 相似文献
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Controlledradicalpolymerizationhasrapidlypro gressedsinceitsintroduction,andseveralnewmeth odshavebeendevisedforitspractice.Thesenewtechniquesincludeiniferterpolymerization,radical polymerizationwith2,2,6,6tetramethyl1piperidiny loxyl(TEMPO),atomtransferradicalpolymerization(ATRP)andreversibleadditionfragmentationchain transfer(RAFT)polymerization[1—4].Inallcasescontrolledradicalpolymerizationprocessescanbeachievedbyintroducingareversiblereactionbetween livinganddormantspecies.Especially… 相似文献
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三角形是平面几何中最简单、最基本的图形,也是同学们最熟悉的图形,中考中常碰见这一类题.这类题常常不给出几何图形,很多同学在做题时不知道分类讨论,导致结论不完整.为帮助同学们渡过这个难关.现将有关三角形中需要分类讨论的情况总结如下.供同学们学习时参考. 相似文献
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本文针对行车记录仪录制电路的设计,提出基于模拟摄像头和数字摄像头两种电路设计的观点。在电子行业起到一定的指导作用。如付诸现实将产生可观的经济效益。 相似文献
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时下。关于学生的发展问题的思考都是就事论事.即围绕教师的“教”和学生的“学”这两个环节花心思,想办法,也就是说,教和学似乎是学生发展的全部,实际上,这是一种头疼医头、脚疼医脚的办法.要让学生能有很好的发展。离不开自身前进的动力,而要让学生具有发展的动力。就必须让全社会为学生创造适合学生发展的动力环境。即“诗外”的工夫必不可少。这个“诗外”的工夫应该从以下方面着手锻炼。 相似文献