简介：为了提高激光二极管的寿命与功率密度,对微片激光器的兴趣正在增加。微片激光器的费用较传统的要低,制造技术也相对简单。此外,这类激光器可以有效地解决将激光二极管的发散光束与低相干性的光束转换或受衍射限制的光束,即光谱上纯的激光模式。而且,微片激光器是波长可调谐的,新近甚至已是Q开关激光器。这样就打开了镇模操作与倍频的途径。

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

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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...

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：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。

简介：通过对二次合金中的铑在盐酸一六次甲基四胺底液中进行的极谱催化控制，结果表明铑的浓度在0.0004-0.0002ug/ml范围内与峰高成正比，便铑的分析精度得到了提高。

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简介：韩国浦项表示，明年二季度前不会调整价格，目前市场上热轧和厚板价格都低于其他钢厂的价格，随着韩元汇率下滑，成本反而会更加增加。

简介：本文简要介绍凤凰山铜矿在尾砂输送系统的砂泵上采用变频调速，达到节能降耗的目的。

简介：利用SMC控制器使泵类负载的机械特性与软起动供电的电气性能相吻合,减小起动电流对负载的机械冲击,提高可靠性,延长其工作寿命.

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简介：激光定尺作为一种新型定尺测量方法，具有精度高，准确、方便的优点，克服了原摄像定尺抗干扰能力差、铸坯温度变化时影响识别精度等缺点。使用新型测距装置后，定尺精度可控制在15mm以下，大大节约了材料。

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简介：通过对加热、控制轧制和控制冷却等工艺进行优化，使Φ5．5mm合金焊丝钢ER69A强度显著下降，塑性提高，获得用户认可。

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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.