简介:ZrO_2-SnO_2-TiO_2(ZST)系统陶艺的微波电介质性质作为Sb_2O_5掺杂物的数量的功能被学习。与0-0的增加。5%Sb_2O_5(臼齿的比率),有Sb~(5+)离子的Ti~(4+)离子的替换减少了sintering温度并且由于氧空缺的减小增加了优秀因素Q。当Sb~(5+)的数量进一步增加了时(超过0.5%)。Q被增加电子浓度减少。当与0.5%Sb_2O_5做的系统是在为6h的1150℃的sintered时,相对的绝缘的经常的ε,Qf_0,和反响的频率(TCF)的温度系数是38.46,44500GHz,20.0x10~(-6)/℃,分别地,在6GHz。
简介:研究了用桑色素的氧化来显色测定Co2++H2O2体系产生羟自由基(·OH)的方法,提出Co2++H2O2桑色素分析新体系并用于羟自由基(·OH)的测定.本方法利用Co2+与H2O2反应,类似Fenton试剂产生羟自由基(·OH),所产生的羟自由基与桑色素作用后使其吸光度降低,利用吸光度值的变化可间接测定所产生的羟自由基,确定了体系最佳实验条件.同时测定抗氧化剂清除羟自由基的实验,证明该体系可作为筛选抗氧化剂的方法之一.
简介:Longlastingstrontiumaluminatephosphorsweresynthesizedbymeansofcoatedprecipitationintheexperiment.SrA12O4monoclinicphasewithlongafterglowwassynthesizedat1100℃withtheaidofH3BO3,andthesynthetictemperaturedecreasedabout100℃-150℃thaninsolidstatereaction.TheprocessofheattreatmentwasstudiedbyTG-DTA.ThephasecompositionsofpowderswereanalyzedbyXRD.ThemicrographsofthesampleswereinvestigatedbySEMandtheluminescentpropertieswereresearchedbyopticalspectrum.TheeffectsofH3BO3onthephasecompositionandmicrostructureofthecalcinedpowderswereinvestigated.TheresultsindicatedthatH3BO3acceleratedtheformationofSrAl2O4byconsumingtheintermediatephase.TheadditionofDy2O3stimulatedtheafterglowpropertyduetotheincreaseinthedepthofthetrapcenterinthematerials.
简介:研究了新显色剂2-(2-咪唑偶氮)-5-二乙氨基酚(简称IZAPN)与铜显色反应的条件,结果表明,在pH5.0的HAc-NaAc介质中,试剂与铜形成紫红色的络合物,络合物的λmax为547nm,试剂的λmax为477nm,对比度△λ为70nm,络合比Cu2+:R为1:2,摩尔吸光系数为2.22×104L·mol-1·cm)-1,Cu2+在0~0.8mg/L范围内服从比耳定律,该方法直接测定铸造镁合金和铝合金中微量的铜,结果满意.
简介:研究了新试剂2-(4-苯基-2-噻唑偶氮)-间苯二酚(PTAR)与Co2+的显色反应的条件,结果表明在pH=5-7范围内,该试剂和Co2+所成络合物的最大吸收波长λmux为550nm,摩尔吸光系数ε=4.5×104L·mol-1·cm-1,Co2+量在0-20μg/25ml范围内遵循比耳定律。该方法用于维生素B12中微量Co的测定,结果比较满意。
简介:Inordertoobtainthesolubilitydataofpropylenein2-propanol-watersolutions,gas-liquidequilibrium(GLE)experimentswerecarriedoutat303.15-333.15K,0.27-0.98MPainastaticequilibriumstill.Theoriginalmassratioof2-propanoltowaterwas9∶1,8∶2,7∶3,1∶0,respectively.TheequilibriumdatawerecorrelatedwithanempiricalmodelandtheregressionofmodelparameterswascompletedbyGauss-Newtonnonlinearleastsquare(NLS).Theaveragerelativedeviation(ARD)betweentheexperimentalandcalculatedvalueis1.5700,andthemaximumrelativedeviation(MRD)is4.8200.Inaddition,asimpleapproachthatcorrelatedthemodelparameterswiththesystemcompositionwasalsoprovided.
简介:Studyonoxidizingcelluloseto2,3-dialdehydecellulosebysodiumperiodate(NaIO4)wascarriedout.TheeffectsofreactionconditionssuchaspHofsolution,temperature,oxidantconcentration,oxidationtime,theparticlesizeof2,3-dialdehydecelluloseandalkalitreatmenttemperatureonthedialdehydeconcentrationofcellulosewereinvestigatedindetail.Theresultsshowthatthealdehydegroupcontentwascreatedwhilereactiontemperatureandalkalitreatmenttemperatureincreased.Themostprincipalfactorsaffectingthealdehydegroupcontentof2,3-dialdehydecellulosewerefoundoutandthebestoxidationconditionswereasfollows:thepHwas2,thereactiontemperaturewas45℃,themassratioofcellulosetoNaIO4was1/2,thereactiontimewas4h,thealkalitreatmenttemperaturewas70℃andsmallerparticlesizewas0.80mm.
简介:为有高温度和湿度抵抗的电阻器的一种衬裙被修改环氧树脂,合适的nano-SiO_2在80degC增加了获得。修改环氧树脂衬裙的Thestructure,热稳定性,湿度抵抗,和词法特征被电的测试学习,红外线的系列(红外)分析,ands装电子显微镜学(SEM)。更紧缩、稳定的inter-crosslinkednetwork结构在修改环氧树脂衬裙被形成的结果表演与nano-SiO_2增加了,它极大地改进修改环氧树脂衬裙的表演。有大约2.71%的nano-SiO_2的衬裙,没有絮凝并且聚集,在房间温度为六保留了月,具有油漆电阻器的好稳定性,和表面是一致的,紧密并且在它上的空气洞外面。有油漆的如此的衬裙的抵抗的变化比率在高温度和湿度抵抗测试以后是在1000的不到一个。