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343 个结果
  • 简介:LanthanidedopedNaYF4microcrystalsweresynthesizedviaafacilehydrothermalmethod.MulticolorupconversionluminescencewasobservedinNaYF4microcrystalsdopedwithYb3+/Er3+,Yb3+/Tm3+,andYb3+/Er3+/Tm3+undertheexcitationof980nminfraredlight.Importantly,theexcitationpowerdensitydependenceofupconversionemissionintensityindicatedclearlytheenergytransferfromTm3+toEr3+ionsundertheexcitationoflowpowerdensity(5×102–9×102W/cm2).Meanwhile,theinverseenergytransferfromEr3+toTm3+ionsundertheexcitationofrelativelyhigherpowerdensity(4.1×104–4.9×104W/cm2)wasalsorevealed.ThiswasadirectevidenceforreversibleenergytransferbetweenEr3+andTm3+ions.Undertheexcitationofhighpowerdensity(4.1×104–4.9×104W/cm2),darksensitizerswerealsomotivatedsothatthebottleneckeffectofhighconcentrationYb3+iondopingwasbroken.ThiswasthemainreasonforrealizinghighupconversionefficiencyofthesampleswithheavydopingofYb3+ion.

  • 标签: 上转换发光 离子掺杂 能量转移 TM 微晶 证据
  • 简介:Redphosphor(Y,Gd)BO3:Eu3+withgrainshape,smallsize,non-agglomerate,highcrystallinityandgoodphotoluminescence(PL)intensitywaspreparedbyacomplexmethodthattheprecursorofthephosphorwaspreparedbyco-precipitationmethodandthephosphorwaspreparedbycombustionmethod.TheSEMphotosandthephotoluminescencespectrumexcitedunderVUVshowthatthemorphologyandluminescentpropertiesofthisphosphoraresatisfiedwhenanappropriateamountofureawasadoptedasthecombustionagentinthepreparationprocedure.

  • 标签: PDP RED PHOSPHOR CO-PRECIPITATION METHOD combustion
  • 简介:TheelectrodeprocessofY3+iononmolybdenumandnickelelectrodeshasbeenstudiedbycyclicvoltammetryandchronopotentiometryintheYCl3-NaCl-KClmelt.Theoverallchargetransferprocessisatwo-stepreaction:Y3++e=Y2+;Y2++2e=Y.YttriumreducedonthenickelelectrodecanformaseriesofNi-Yalloys.X-raydiffractionanalysiswasemployedtodeterminethealloycompositionsformedunderdifferentcon-ditions.

  • 标签: Y3+ion Mo ELECTRODE Ni ELECTRODE ELECTRODE
  • 简介:3#高炉实行强化冶炼,各项技术经济指标都有长足的进步,但强化必须有精料作前提,各项新技术的应用相辅相成。不断完善操作制度。

  • 标签: 高炉 强化冶炼 精料 顺行
  • 简介:ThephotocatalystsK4Nb6017andK4Nb6017dopedwithFe^3+andCr^3+werepreparedbysolidstatereactionandwerecharacterizedbypowderx-raydiffraction,UV-visdiffusivereflectanceandscanningelectronmicroscopy.ThephotocatalyticactivityofK4Nb6O17andK4Nb6O17dopedwithFe^3+,Cr^3+wereinvestigatedwithmethanolaselectrondonorandPtaspromotercatalystunder+400nmUVirradiation.Thedifferenceofphotocatalyticactivitybetweenthemwasalsodiscussed.TheindividualrateofhydrogenevolutionfortheK4Nb6O17,Fe-K4Nb6O17andCr-K4Nb6O17asphotocatalystsare5.35,5.00,6.25mmol·L^-1.h^-1respectively.

  • 标签: 光接触反应活性 K4Nb6O17 铁离子 CR^3+ 冶炼方法 稀土元素
  • 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.

  • 标签: PHOSPHOR narrow ultraviolet doping excitation CALCINATION
  • 简介:作为报导Y2O2S的改进:Tb3+,白光的长持续的黄磷:Y2O2S:Tb3+,Sm3+被准备由固态反应。光致发光系列证明在紫外刺激下面的Tb3+和Sm3+排出物的位置和形状在这位主人是类似的,它在不同刺激下面保证了一种稳定的白排放颜色(IEC的日光标准)。共同做的样品的腐烂曲线显示二个离子的排出物的腐烂时间是靠近的。热照明测量建议做的Sm3+离子创造的陷井是有用的推迟共同做的样品的白晚霞。因此,共同做的Sm3+离子的功能作为改进样品的白排放颜色并且充当新陷井中心被证实。

  • 标签: 白色 无机发光材料 稀土
  • 简介:本文从酒钢3×6000Nm~3/h制氧生产工艺及其控制设备的现状出发,介绍了改造后DCS控制系统软、硬件的构成和实现的主要功能,取得了良好的应用效果。

  • 标签: MACS PROFIBUS-DP 主控单元
  • 简介:TheZrO2-Al2O3ceramiccompositeswerepreparedbyappropriatetechniqueswithcommercialZrO2andAl2O3powdersasrawmaterialsandY2O3asstabilizer.TheresultsindicatethatwiththeintroductionofAl2O3intotheZrO2matrixwherethequantityofadditiveY2O3is3.5%(molefraction),thegrowthofZrO2grainsisefficientlyinhibited,whichhelpstheZrO2grainsexistinametastabletetragonalmanner;thushigherstrengthandtoughnessareacquired.Whenthecontentofaluminais20%(massfraction),thebendingstrengthandfracturetoughnessofthecompositesare676.7MPaand10MPa·m1/2respectively,themechanicalbehaviorsareclosetothosepreparedwithZrO2andAl2O3powderssynthesizedthroughwetchemicalapproach.Themechanicalbehaviorsofthecompositesarewellimprovedowingtothedispersiontougheningofaluminagrainsandphasetransformationtougheningofzirconiagrains.

  • 标签: 无机非金属材料 陶瓷 稳定设备 稀土
  • 简介:AseriesofCeB6-dopedandCeO2-dopedCa1-xSiAlN3:xCe3+(denotedasCASN:Ce3+@CeB6andCASN:Ce3+@CeO2,respectively)weresynthesizedbyalloy-nitridationmethodunderhigh-puritynitrogenatmosphere.Themorphologies,crystalphases,andluminescencepropertieswereinvestigatedindetail.WithanincreaseintheconcentrationofCeB6,theunitcellvolumeofCASN:Ce3+@CeB6slightlyincreasesduetothesubstitutionbetweenions,whichleadstoachangeofmicrostructurearoundCe3+.CASN:Ce3+@CeB6efficientlyemitsyellow-orangelightwithamaximumemissionintensityataround550nmforthecontentxof0.01(beingincomparablesituation,CASN:Ce3+@CeO2isx=0.04)whenexcitedat460nm.ComparedwithCASN:Ce3+@CeO2,theredemissioncomponentofCe3+inCASN:Ce3+@CeB6ismuchstronger.Thisisascribedtoenergytransferofintra-Ce3+(withinoneCe3+ion)andinter-Ce3+(betweenCe3+andCe3+ions).Inaddition,thereplacementsofN3-(0.132nmforCN=4)andO2-(0.124nmforCN=4)byB2-(0.140nmforCN=4),whichcanleadtoamarkedexpansionofthehostlatticeandadecreaseoftheoxidationofsamples,arealsoresponsiblefortheincreaseofredemissioncomponent.Furthermore,CASN:Ce3+@CeB6phosphorhasanexcellentthermalstabilitybecauseofthepartialsubstitutionofCe-O(Ce-N)bondsbymorecovalentCe-B.Asaresult,theoutstandingluminescentpropertiesofCASN:Ce3+@CeB6phosphormakeitpracticaltouseinthesinglephosphor-coatedhigh-color-renderingpowerwhiteLED.

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  • 简介:介绍了南钢2500m^3高炉顺利开炉生产过程,并对2500m^3、2000m^3高炉开炉生产情况进行对比分析。2500m^3高炉采用的对称堵风口、铁口埋设氧枪、4个风口安装热风导管等方法对以后的开炉生产具有借鉴和指导意义。

  • 标签: 高炉 开炉 操作制度
  • 简介:PolycrystallineNd3+andLa3+co-dopedyttriananopowderNd3+:Y1.90La0.10O3fortransparentceramicswassynthesizedbyco-precipitationmethodusingoxalateacidastheprecipitantand(NH4)2SO4astheelectricalstabilizerunderultrasonicradiation.Nanopowderscalcinedatdifferenttemperatureswerecharacterizedwiththermalgravimetric-differentialthermalanalysis(TG/DTA),X-raydiffraction(XRD),transmittingelectronmicroscopy(TEM),energydispersivespectrometry(EDS)andspectralanalysistechniques.Th...

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  • 简介:Ternarycomplexesofeuropiumandterbiumwithbenzoicacidand1,10-phenanthroline[RE(BA)3phen](BA=benzoatephen=1,10-phenanthroline)wereintroducedintoasilicamatrixbysol-gelmethod.Thethermalstabilityandluminescencebehaviorofthecomplexesinsilicagelswerestudiedincomparisonwiththecorrespondingsolid-statecomplexesbythermaldecomposition,excitationandemissionspectra.Thethermalstabilityofthecomplexesisenhancedinsilicagelmatrixandtheluminescenceremainesunchanged.

  • 标签: 溶胶-凝胶 热稳定性 发光性能 二氧化硅 掺杂 稀土
  • 简介:2017年3季度,澳大利亚稀土矿业公司Lynas(莱纳斯)再度报喜,其运营状况和业绩继续因稀土价格上涨受益。Lynas日前发布消息称,在截至2017年9月的三个月内(2017年第3季度),公司收获了创纪录的销售收入,以及创纪录的产量和现金流。莱纳斯报道称,2017年3季度,公司镨钕(Pr、Nd)产量1442吨,同比增长22.6%,

  • 标签: 运营状况 稀土 矿业公司 澳大利亚 价格上涨 销售收入
  • 简介:3.4奥氏体不锈钢传统的奥氏体不锈钢如316不锈钢的第二相转变动力学的特点是非常缓慢的x相和σ相转变(转变需数百个小时),以及强烈依赖于碳含量的碳化物动力学。在低碳钢种中,碳化物析出的时间大约是30分钟至1个小时,足以进行正常的退火和焊接操作而不导致敏化。

  • 标签: 奥氏体不锈钢 转变动力学 碳化物析出 性能 316不锈钢 焊接操作
  • 简介:Er3+/Yb3+codopedzincateBaGd2ZnO5phosphorsweresynthesizedviaatraditionalsolidstatereaction.ThecrystalstructureandphasepuritywerecheckedbymeansofX-raydiffraction(XRD),andtheresultsshowedthatpurephaseBaGd2ZnO5phosphorswithvariousEr3+,Yb3+concentrationswereobtained.TheinfluenceofEr3+andYb3+dopingconcentrationsonthegreenandredupconversionemissionswasstudied.Itwasfoundthatbothgreenandredupconversionemissionsunder980nmexcitationweretwo-photonprocessesindependentfromtherareearthdopingconcentrations.However,theupconversionluminescenceintensitiesgreatlydependedontherareearthdopingconcentration.Furthermore,thepopulationprocessesofupconversionluminescenceandthequenchingmechanismswereanalyzed.Thetemperature-dependentgreenupconversionluminescencewasstudied,andthetemperaturequenchingprocessoftwogreenupconversionemissionswasmodeled.Thethermalquenchingprocessesofthegreenupconversionemissionscouldbewellexplainedbythemodelweproposed.

  • 标签: 上转换发光 温度依赖性 浓度效应 荧光粉 淬火 固相反应合成