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简介：TheNaYF4:Yb,Ernanocrystalsweresynthesizedviathethermaldecompositionofmetaloleateprecursors.Thenanocrystalsinhexagonalstructurewerehighlyuniformandinsizeof25nm.Thebrightupconversionluminescencewasobservedundertheexcitationof980nmlaserandtheupconversionemissionspectrawereinvestigatedatdifferentpumppowers.Theemissionintensityratioofredlighttogreenlightlinearlyincreasedwithpumppowerincreasing.ThisresultindicatedthatthereexistedalargethresholdpowerofsaturationpumpforthefirstexcitationstateinNaYF4:Yb,Ernanocrystalscomparingtothatinbulkmaterial.

简介：FrequencyupconversionofEr3+inalkalilanthanumgallateglasses(Na2O-La2O3-Ga2O3orNLG)wasinvestigated.Visibleemissionsat532,546,and660nmcorrespondingtothe2H11/2→4I15/2,4S3/2→4I15/2,and4F9/2→4I15/2transitionswereobservedundercontinuouswaveexcitationat980nm.Thequadraticpumppowerdependenceoftheseemissionsindicatedatwophotonupconversionprocess.Atapumpintensityof52W·cm-2at980nm,frequencyupconversionefficienciesof1.1×10-2and2.7×10-3wereobtainedforgreenandredemissions,respectively.

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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.

简介：通过对焊接用钢ER70S-G的钢种特点的研究,得出浇注、吐丝温度以及冷却速度是提高ER70S-G内在质量关键.通过试制生产,提出相应的措施并获得良好的效果.

简介：LiNbO3单个水晶与的生长嗯(3+)并且Zn(2+)共同做使用布里奇曼方法和它的典型吸收系列和荧光系列被报导。开始包含Zn(2+)(3%)的大尺寸的晶体并且嗯(3+)(0.6%)用象0.81.5公里·h的生长率那样的优化条件与好光质量被获得(?1)并且大约3035°C·厘米的一个温度坡度(?1)越过稳固液体的接口和封上的铂坩锅。X光检查衍射和微分热分析(DTA)被用来描绘晶体。结果显示集中嗯(3+)在晶体，他们的吸收紧张，和他们的荧光紧张的离子在晶体从底部减少到顶。为水晶的上面的部分，然而，起来变换荧光紧张比800或970nm泵激动的更低的部分的高。水晶格子，他们的结构的缺点和他们的有效分离的效果嗯(3+)离子关于起来变换荧光紧张的变化被讨论。

简介：YbF2.357,YbF3,Ba2YbF7,andBa2upconversionnanocrystalsdopedwithemitterEr3+ionweresynthesizedinthesamesolventsystemjustwithchangingthemolarratioofBa2+toYb3+intheprecursor,whichcorresponedtothecrystalphasesofrhombohedral,orthorhombic,tetragonal,andcubic,respectively.Allthesamplesemittedboth660nmredlightand543/523nmgreenlightwhichoriginatedfromEr3+-4fnelectronictransitions4F9/2-4I15/2and4S3/2/2H11/2-4I15/2,respectively.ItwasworthmentioningthatYbF3:Er3+,Ba2YbF7:Er3+,andBaF2:Er3+couldemitdazzlinglybrightlightevenundertheexcitationofa980nmCWlaserwithoutputpowerof0.1W.Upconversionemissionmechanismanalysisindicatedthattheintensityratioofredtogreenlighthighlydependedonthesynergisticeffectofcrystalstructure,concentrationquenching,andparticlesize,butwerenotsensitivetocrystallinityaspreviouslyreportedforNaLnF4（Ln=lanthanide）.

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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.

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简介：Er/Ybco-dopedborate-silicateglasseswithvariousYbconcentrationswerefabricatedbyhigh-temperaturesolid-reactionmethod.Thephotoluminescencespectraaround1.55μmandthevisibleupconversionspectraweremeasured.TheradiativelifetimeofEr-4I13/2,com-paredwiththemeasuredone,wasobtainedbyJudd-Ofelttheorybasedontheabsorptionspectra.ArateequationmodelforEr/Ybco-dopedsystemhasbeenestablishedbasedonthedataobtainedfromthemeasurements,includingtheabsorptionandemissio...

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简介：Er3+-Tm3+-Yb3+tri-dopedBaMoO4phosphorsweresynthesizedbyco-precipitationtechniqueandcharacterizedbyX-raydiffractionanalysis,absorptionstudyandfieldemissionscanningelectronmicroscopyanalysis.Upconversionaswellasdownconversionluminescencestudieswereperformedbyusingnearinfrared（980nm）andultraviolet（380nm）excitations.Energyleveldiagram,pumppowerdependenceandcolourcoordinatestudywereutilizedtodescribethemulticolorupconversionemissionproperties.Undersingle980nmdiodelaserexcitationthedualmodesensingbehaviourisrealizedviaStarksublevelsandthermallycoupledenergylevelsoftheTm3+andEr3+ionsinthepreparedtri-dopedphosphors.AcomparativefluorescenceintensityratioanalysisforintegratedemissionintensitiesarisingfromtheStarksublevels{1G4（a）and1G4（b）}andthermallycoupledenergylevels{2H11/2and4S3/2}oftheTm3+andEr3+ions,respectivelywascarriedoutinthepreparedtri-dopedBaMoO4phosphors.ThemaximumsensitivityforthermallycoupledenergylevelsoftheEr3+andStarksublevelsoftheTm3+ionwasreported.Thedevelopedphosphorscouldbeusefulinthedisplaydevicesandopticalthermometricapplications.

简介：Er3+/Yb3+codopedzincateBaGd2ZnO5phosphorsweresynthesizedviaatraditionalsolidstatereaction.ThecrystalstructureandphasepuritywerecheckedbymeansofX-raydiffraction(XRD),andtheresultsshowedthatpurephaseBaGd2ZnO5phosphorswithvariousEr3+,Yb3+concentrationswereobtained.TheinfluenceofEr3+andYb3+dopingconcentrationsonthegreenandredupconversionemissionswasstudied.Itwasfoundthatbothgreenandredupconversionemissionsunder980nmexcitationweretwo-photonprocessesindependentfromtherareearthdopingconcentrations.However,theupconversionluminescenceintensitiesgreatlydependedontherareearthdopingconcentration.Furthermore,thepopulationprocessesofupconversionluminescenceandthequenchingmechanismswereanalyzed.Thetemperature-dependentgreenupconversionluminescencewasstudied,andthetemperaturequenchingprocessoftwogreenupconversionemissionswasmodeled.Thethermalquenchingprocessesofthegreenupconversionemissionscouldbewellexplainedbythemodelweproposed.

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简介：Er~（3＋）andLa~（3＋）codopedY_2O_3nanocrystallinepowdersweresynthesizedbygelcombustionmethodandcharacterizedwiththermalanalysis,X-raydiffraction（XRD）,transmissionelectronmicroscopy（TEM）,high-resolutionTEM（HRTEM）techniquesandfluorescencespectroscopy.Afterbeingcalcinedat1200oC,the（Y_（1–x）La_x）_2O_3：Er~（3＋）powderswereconfirmedtobecubicY_2O_3phasewiththecrystallinegrainsizeintherangeof20–40nm.TheEr~（3＋）emissionat1.53μmfromthe~4I_（13/2）→~4I_（15/2）transitionwasobserved,whichwasfoundtobeenhancedbyintroducingLa~（3＋）ions.SuchenhancementcouldbeattributedtotheadjustmentofEr~（3＋）ions＇localenvironmentbythecodopingofLa~（3＋）ions,leadingtotheincreasedgroundstateabsorptioncrosssectionofEr~（3＋）ions.

简介：AdetailedstudyofthefluorescenceemissionpropertiesandenergytransfermechanisminEr3+/Tm3+co-dopedleadsilicateglasseswasreported.Enhancednearinfrared1.8μmandvisibleup-conversionemissionswereinvestigatedunder808and980nmexcitations,respectively.TheenergytransfermechanismbetweenEr3+andTm3+wasanalyzedaccordingtotheabsorptionspectra,theemissionspectraandthelevelstructuresofEr3+andTm3+.TheenergytransferefficiencybetweenEr3+andTm3+reached68.1%intheEr3+/Tm3+co-dopedleadsilicateglasseswhenpumpedby808nmlaserdiode.Basedontheabsorptionspectra,theJudd-Ofeltparameters,spontaneousemissionprobability,absorptionandemissioncrosssections,gaincoefficientswerecalculatedandanalyzed.Itwasfoundthatthecalculatedemissioncrosssectionandthemaximumgaincoefficientaround1.8μmwere4.9×10–21cm2and1.12cm–1,respectively.TheseresultsindicatedthattheEr3+/Tm3+co-dopedlead-silicateglasseshadpotentialapplicationinnearinfraredlasers.

简介：通过对永平铜矿的井下斜坡道车辆定化、信号灯自动控制及调度监控系统工程应用，为保障井下车辆运输安全、提高运输效率发挥了重要作用。交通信号系统直接关系交通安全，系统本身必须以安全稳定为绝埘前提，以服务生产提高效率为主要任务，在此基础上兼顾功能扩展和其他信息化项目的无缝接入。因此交通信号系统所选技术必须以成熟叮靠为前提并兼顾先进性扩展性。系统实现了对井下车辆的实时跟踪监测、定位、红绿灯自动控制，有效地避免了汽车相互堵塞及安全事故的发牛，从而提高了矿井的车辆运输效率。

简介：一系列立方的稀土元素sesquioxidesRE2O3的拉曼系列(RE=Eu，Gd，Dy，惊讶，嗯，Tm，Yb，陆，Sc和Y)被拉曼光谱学与532和785根nm激光线调查。丰富的另外的乐队由于激光激动的光被观察。为Eu2O3，Dy2O3，Ho2O3，Er2O3，Tm2O3和Yb2O3，，光主要为Gd2O3，Lu2O3，Sc2O3和Y2O3来自内在的三价的lanthanide离子，他们的光被归因于象Eu3+，Nd3+和Er3+那样的另外的光lanthanide离子的踪迹杂质。这调查为检测踪迹作为一个有用工具证实了拉曼光谱学光lanthanide杂质。