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130 个结果
  • 简介:SphericalYAG:Ce3+phosphorparticleswithnarrowsizedistributionwerepreparedbyspraypyrolysis.Theeffectsoftheconcentrationofsolution,theflowrateofcarriergasandtheannealingtemperatureonthephosphormorphologywerestudied.Theproductivityofprecursorparticlesshowsatrendofdropafterrisingwiththeincreaseofconcentration.Raisingtheflowrateofnitrogencanimprovetheproductivityoftheprecursorparticles.Phosphorpreparedbyspraypyrolysishasobviouslyhigheremissionintensitythanthatsynthesizedbysolidstatereaction,spraypyrolysismakesCe3+ionswelldistributedinthecrystallatticeastheluminescentcenters,andphosphorparticleshaveregularsphericityandnarrowsizedistribution.

  • 标签: 钇铝石榴石 稀土 热解 制备 发光二极管 荧光性质
  • 简介:中铝山西分公司氧化铝3号因转窑窑前鼓风机因轴承失效、机壳移位等原因造成风机振动大,虽更换了轴承恢复了机壳位置,但振动未消除:后采用因素排除的方法,在检修过程中实行过程工序确认制度,最终找出了风机振动大的原因,和对缺陷处理的方法.

  • 标签: 氧化铝 回转窑 鼓风机 振动 动平衡 裂缝
  • 简介:Differentfluxeswereusedtosynthesizelongpersistencephosphors,calciumsulfidesactivatedbyEu2+andTm3+,byconvenientsolid-statemethod.ThephosphorusingNH4Fasafluxhasgoodcrystallinityandlargeparticlesize,itsstabilityagainstwaterandotheratmosphericcomponentsisenhanced,anditsafterglowislongerandfluorescentintensityismoreintensethanthoseofthephosphorusingNH4Clasflux.TheirPLintensitiesvariedwithtimeinmoistairweremeasured,noremarkablechangewasfoundforthosepreparedwithNH4FfluxincontrastwithNH4Clasflux.SousingNH4Fasfluxisagoodmethodtoenhancethestabilityofalkalineearthsulfides.

  • 标签: 磷光体 CaS:Eu^2+/Tm^3+ 化学稳定性 稀土 硫化钙 铕二价
  • 简介:Basedonthethermodynamicallyself-consistentanalysisandoptimizationofthreesub-binarysystemsoftheternarysystemPrCl3-CaCl2-MgCl2,thethermodynamicsofthisternarysystemhasbeenstudied.UsingHillertmodelandtakingMgCl2asanasymmetriccomponent,thePrCl3-CaCl2-MgCl2phasediagramhasbeencalculated.Theagreementbetweencalculatedandmeasuredcompositionsandtemperaturesatdeflectingpointsonliquidusisgood.Thesystemisasimpleeutecticonewithaeutecticpointat26.0mol%PrCl3,41.5mol%CaCl2,32.5mol%MgCl2;560℃(calculated)and26.0mol%PrCl3,39.4mol%CaCl2,34.6mol%MgCl2;546℃(measured),respectively.

  • 标签: TERNARY system Phase DIAGRAM Rare earth
  • 简介:NominalcompositionofCa1-xZnxTiO3:0.002Pr3+(x=0.000~0.200)phosphorswerepreparedbyconventionalsolidreactionroute.XRDandPLmeasurementswereusedtoinvestigatethesolid-solutionstructureandluminescencepropertiesofZn-dopedCa1-xZnxTiO3:0.002Pr3+phosphors.Theeffectofsolid-solutionstructureformedbysubstitutionbetweenCa2+andZn2+ionsontheluminescentpropertieswasanalyzed.Theresultsrevealthat,withtheincreaseofZnsubstitutioncontentbelow0.010,latticeparametersandtheintensityofexcitationpeakatboth260and330nmaswellasthecorresponding610nmemissionintensityaremonotonouslydecreasedquicklyinasimilartendency.Also,theevolutionofluminescenceintensityandcrystalcellparametersagainstZndopingconcentrationareingoodagreement.AboveresultsarecloselyrelatedwiththestructurechangewithinCa1-xZnxTiO3:0.002Pr3+solid-solutionphaseformedbytheZnionssubstitutionfortheCasites.Presentstudyrevealsthatthesolid-solutionstructureformedbysubstitutionbetweenCa2+andZn2+ionshassignificanteffectontheluminescencepropertiesofsinglephaseCa1-xZnxTiO3:0.002Pr3+phosphors.

  • 标签: Ca1-xZnxTiO3 固溶体 发光性能 稀土 掺杂 荧光材料
  • 简介:美国宇航局在加州帕萨迪纳的喷气推进实验室研究成功了一种制造YBa2Cu3O7-α高温超导电缆(封装在金属套管内)的新方法。据称,这种方法成本较低,过程易于控制,且对各种前体材料有很强的适应能力。该法分4个步骤:生产具有化学(配)比的前体(Precursor)粉;将前体粉包封在金属套管内;用轧制的方法使前体粉固结;在液态锂金属浴槽内进行处理,使之转变成超导组

  • 标签: 粉末冶金 金属套管 高温超导电缆 锂金属 实验室研究 喷气推进
  • 简介:针对3~#皮带的产尘特点,分别在尾轮和首轮采用独立的防尘系统,加大收尘风量、定向气流排尘、活动刚性密闭、空气幕隔离、扁平罩收尘及低速文丘里除尘器除尘等综合防尘措施,防尘效果良好:3~#皮带工作场所粉尘浓度最高时才1.5mg/m~3,低于粉尘卫生标准2mg/m~3的允许值,尾气排放粉尘浓度最高时达47.0mg/m~3,在卫生标准100mg/m~3的允许范围之内.

  • 标签: 皮带防尘 加大风量 定向排尘
  • 简介:1概述我厂现有300m~3高炉三座,总容积900m~3,1994年上半年,高炉工艺操作管理在1993年的基础上,继续全面贯彻"优质、低耗、高产、长寿"的指导思想和"以顺行为基础,维护、保持好合理的操作炉型,提高风温,增加煤量,重视炉缸工作,搞好上部调剂"的操作方针,克服了原燃料供应紧张,

  • 标签: 高炉冶炼 高炉强化冶炼 高炉顺行 操作管理 原燃料 操作炉型
  • 简介:安钢永通2×8m^2竖炉球团工艺始建于上世纪70年代中期,1999年和2001年分别对2^#、1^#竖炉本体及部分配套设施进行了改造。改造后,球团矿产质量均有了明显提高,但与全国同行业相比仍有较大差距。2003年,公司决定对球团工艺进行大的改造,新上配料、烘干、润磨系统,以取代现有的配混料系统,同时预留了3^#竖炉的产能。

  • 标签: 竖炉 达产实践 安钢 球团工艺 配套设施 混料系统
  • 简介:YLiF4:Er3+wassynthesizedbyhydrothermalmethod.ConcentrationofEr3+ischangedfrom0to5%.TheabsorptionofEr3+inallsamplesfrom200to1200nmwasmeasuredatroomtemperature.TheJ-OparameterscalculatedfromabsorptionspectrumareΩ2=1.05×10-20cm2,Ω4=1.25×10-20cm2andΩ6=1.35×10-20cm2.Infrared-to-visibleupconversionemissionofYLiF4:Er3+wasobservedwhenexcitedby980nm.TheresultsshowthattheEr3+contentislessthan1.5%,excite-stateabsorptionisthemainmechanismofupconversionemission.WhenEr3+contentislargerthan1.5%,bothoftheexcite-stateabsorptionandenergytransferleadtotheupconversionluminescence.TheupconversionintensitywasenhancedwiththeincreasingofEr3+concentration.Atroomtemperature,thelifetimeof2H11/2and4S3/2is205μswhilethatof4F9/2is188μsforsampleEr-2.Thetransitionratesandquantumefficiencywerealsocalculated.Thequantumefficienciesof4S3/2and4F9/2are27.9%and10.7%,respectively.

  • 标签: 稀土 掺杂 荧光材料 YLiF4 发光性能 热液法
  • 简介:AseriesofLa2O3/MCnylonnanocompositeswerepreparedviainsitupolymerization.Theeffectsofcontentofnano-La2O3onthemechanicalpropertiesofnanocompositeswerestudied.Dispersionofnano-La2O3inMCnylonmatrixwasobservedwithSEM.ThecrystalstructureofnanocompositeswascharacterizedbymeansofXRD.SEManalysisshowsthatLa2O3nanoparticlesareuniformlydispersedinMCnylonmatrixandlittleclusteringexistswhenthecontentofnano-La2O3islowerthan1%,however,whenthecontentofnano-La2O3ismorethan1%,itbeginstocluster.XRDanalysisindicatsthatnano-La2O3doesnotchangethecrystalstructureofMCnylon.Mechanicalpropertiestestsshowthatthetensilestrength,elongationatbreak,impactstrength,flexuralstrength,andflexuralmodulusofnanocompositesfirstincreasethendecreaseasthecontentofnano-La2O3isincreased.Whenthecontentofnano-La2O3is0.5%,thetensilestrengthandelongationatbreakofnanocompositesreachmaximum,whichare17.9%and52.1%higherrespectivelythanthoseofMCnylon.Whenthecontentofnano-La2O3is1.0%,theimpactstrength,flexuralstrengthandflexuralmodulusofnanocompositesreachmaximum,whichare36.6%,12.7%and16.3%higherrespectivelythanthoseofMCnylon.

  • 标签: LA2O3 MC尼龙 纳米复合材料 聚合反应 稀土 机械性能
  • 简介:Inthispaper,varioustechniquesincludingBET,XRD,SEMandXPSwereusedtostudythesinteringofpureandLa2O3-dopedtitania.Theexperimentalresultsshowthatsinteringoftitaniaproceedsviavolumediffu-sion.Addingoflanthanumoxidedecreasestherateofsinteringandhindersthephasetransitionfromanatasetorutilecrystalbystrongsurfaceinteractionbetweenthemixedcrystals(La4Ti9O24,La0.66TiO2.99)andTiO2.

  • 标签: La2O3 TiO2 SINTERING kinetics Thermal stability
  • 简介:采朋数据统计和绘制散点图方法,分析研究Q235B普碳钢铸坯锰硫比与钢板冷弯性能和冷弯完好率之间的关系。

  • 标签: Q235R普碳钢 锰硫比 冷弯性能