简介:做任何事情都有个顺序,有个条理。特别是在做实验时,更应该遵守实验室的操作程序和规范,以免发生意外。无论在何时何地,都必须服从指令,完成任务时确保安全。[模拟对话]A:Shallwegodownthevalleytofindaniceplaceforacamp?B:Goodidea!Andwecanalsohaveabushwalkthere.A:Yes.Ienjoybushwalking.B:Istartthecarandthenmakeasuddengoing.A:Oh,God!Becareful!Theroadisnotflat.B:Don'tworry!Youknow,I'maveryskilleddriver.A:Iknowyou'reskilled,but...Lookout!There'sacarahead!
简介:Inthepresentpaper,novelsidewallmaterialsforaluminumreductioncellwerepreparedinairusingmagnesiaandmagnetiteasstartingmaterials.ThesinteringbehaviorsofthespecimenswereinvestigatedbymeansofX-raydiffraction(XRD)andscanningelectronmicroscope(SEM).AndcorrosiontestsinaNa_3AlF_6-AlF_3-K_3AlF_6bathwereconductedtoevaluatetheelectrolytecorrosionresistance.TheresultsshowthattheFe_3O_4phaseistransformedintoFe_2O_3athightemperatures,whichinturnreactswiththeMgOaddedtoformMgFe_2O_4spinel.AndwithincreasingtheMgOcontentfrom0to30mass%,densificationofthespecimensdecreasesmainlyduetolargervolumeexpansionresultingfromformationofmoreMgFe_2O_4.ThecorrosiontestsshowthatcorrosionlayersareproducedinalltheMgOaddedspecimens.However,forspecimenscontainingMgFe_2O_4phaseonly,Mg(Al,Fe)_2O_4compositespinellayersarealsogenerated,whichremarkablyimprovethecorrosionresistanceofthespecimens.
简介:YPO_4phosphorssingle-dopedwithSb~(3+)orGd~(3+)andco-dopedwithSb~(3+)andGd~(3+)werepreparedbyasolid-statereactionmethod.Thephasepurity,morphology,photoluminescenceexcitationandemissionpropertiesofthepreparedphosphorswereinvestigated.TheresultsshowedthatSb~(3+)couldsensitizeGd~(3+)intheco-dopedphosphorswhichmadethephosphorsexcitablebyshort-waveultraviolet(UV)atawavelengthbetween220and260nm.Under253.7nmexcitation,theco-dopedphosphorsY_(1–x–y)PO_4:Sb~(3+)x,Gd~(3+)yshowedstrongemissionofGd~(3+)atawavelengthof312nmwhoseintensitychangedwiththedopingconcentrationsofGd~(3+)andSb~(3+).TheoptimizedY_(0.77)PO_4:Sb~(3+)0.07,Gd~(3+)0.16phosphorshowedanintensitycomparabletocommercialLaPO_4:Cephosphor(UVB-315),makingitapotentialcandidateformercurylow-pressuredischargenarrow-bandUV-Bemittinglamps.
简介:磁铁矿(Fe3有不同尺寸和形状的O4)nanoparticles被热分解方法综合。二条途径,非注射一个壶和热注射的方法,被设计详细调查生长机制。nanoparticles的尺寸和形状被调整先锋集中和持续时间时间决定,这被发现,它能好在我们的合成系统基于LaMer模型由机制解释了。monodisperseFe3O4nanoparticles从5nm有一条吝啬的直径到16nm,和形状进化从对球形三角形、立方。磁性是尺寸依赖者,和Fe3在关于在房间温度和最大的浸透磁化的5nm展览superparamagnetic性质的小尺寸的O4nanoparticles来临到78emu/g,而Fe3O4nanoparticles当直径增加到大约16nm时,开发铁磁性的性质。