学科分类
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176 个结果
  • 简介:Whitelight-emittingYVO_4:1mol.%Dy~(3+),xmol.%Eu~(3+)phosphorpowderswithordermorphologyandwellcrystallizationwerehydrothermallysynthesizedat180°C.Themicrostructure,white-lightemission,andlight-emittingmechanismofthepowderswerecarefullystudiedusingX-raydiffractometry,scanningelectronmicroscopyandphotoluminescencespectra.TheexcitationandemissionspectraofthephosphorpowdersindicatedthecoexistenceofefficientenergytransferfromEu~(3+)toDy~(3+)andinefficientenergytransferfromDy~(3+)toEu~(3+)besidestheenergytransferfromVO_4~(3–)toEu~(3+).IncreasingtheEu~(~(3+))concentrationinitiallyenhancedandthenweakenedtheluminescentintensityofDy~(3+).Thewhite-lightemissionsofYVO_4:1mol.%Dy~(3+),xmol.%Eu~(3+)phosphorpowderswerebothrelatedtotheenergytransferbetweenVO_4~(3–)andDy~(3+)/Eu~(3+),aswellasbetweenEu~(3+)andDy~(3+).TheinefficientenergytransferfromDy~(3+)toEu~(3+)wasfirstfound.

  • 标签: POWDERS PHOSPHOR DIFFRACTOMETRY coexistence luminescent excitation
  • 简介:近日,北方稀土旗下包头瑞鑫稀土金属材料股份有限公司与中科院包头稀土研发中心携手开展企业青年科技创新"11"行动计划,选派专业人才成立联合研究小组,开展稀土熔盐电解自动化技术研究。

  • 标签: 科技创新 研发中心 中科院 稀土 包头 北方
  • 简介:Coldrolledmartensiticsheetsteelsareachievingmoreandmoreapplicationsincar-makingbecauseoftheirultra-highstrengthandpotentialforweightreduction.Therelativelylowplasticityofultra-highstrengthmartensiticsteelsmightbeadrawbackfortheapplicationsintheaspectsofformingandsafetyprotectionfunctionandshouldbesignificantlynoted.A1500MPagradecoldrolledmartensiticsheetsteelhasbeenstudiedtoinvestigatethebendabilityat90degreebendingandimpacttoughnessaswellasfracturesurfacemorphologyatvarioustemperatures.Somediscussionshavebeenmadebasingupontheexperimentdatatogetsomeunderstandingontheperformanceofthematerialsundervariousconditionsandonhowtomakeuseofthiskindofultrahighstrengthsteelproperly.

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  • 简介:某工厂使用3.5mm厚冷轧退火产品1Cr17不锈钢在生产不锈钢餐勺时,材料发生冲压开裂。利用SEM、光学显微镜、显微硬度测试仪等手段,对开裂处进行断口观察、金相分析、显微硬度测试。研究结果表明,该产品冲压开裂主要原因是不恰当热处理导致1Cr17不锈钢在退火过程中进入α+γ双相区,最终在冷却到室温后出现马氏体相,马氏体大大降低了材料塑性和韧性,导致了冲压开裂。

  • 标签: 1Cr17 冲压开裂 组织转变
  • 简介:近日,从包头海关获悉,包头地区1至7月份出口稀土均价大幅增长。据包头海关统计数据,1至7月份,包头地区累计出口稀土2473.5吨,比去年同期(下同)减少20.5%;出口稀土价值1.2亿元人民币,增长21.7%;出口稀土平均价格为每吨4.8万元,上涨54.8%。

  • 标签: 包头地区 稀土 出口 统计数据 人民币 海关
  • 简介:俄罗斯自然资源部部长谢尔盖一顿斯科伊(SergeyDonskoi)周一在社交平台脸书上称,截至2015年年底,俄罗斯铜储量超过1亿吨,并没有枯竭。

  • 标签: 自然资源部 储量 部长 俄罗斯
  • 简介:本文就影响损失和贫化主要因素进行了探讨,就如何降低采矿损失及贫化提出具体措施,目的是有效地降低“两”,提高矿山企业经济效益。

  • 标签: 采场 损失率 贫化率 改进措施
  • 简介:按照公司《关于深入开展调查研究工作通知》精神,人力资源部根据工作职能,紧贴工作实际,紧紧围绕公司“136”基本发展思路,以不断提高人力资源管理水平和促进公司发展为目标,有重点、有方向、有针对性选择了部分与公司发展及管理紧密相关调研课题,分别开展了调查研究工作。

  • 标签: 劳动生产率 集团公司 挖掘潜力 调研 人力资源管理 工作职能
  • 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.

  • 标签: POWDERS IONS crystalline CALCINED attributed cubic
  • 简介:CrNanopowder:CrGGG和nanopowder,Nd:有从0.1at.%到1.5at.%Cr3+不同集中GGG被大音阶第五音胶化方法用醋酸和乙烯乙二醇综合。热gravimetric分析和微分扫描热量测定(TGA-DSC),X光检查衍射(XRD)和光致发光光谱学被用来描绘粉末。当在1000点对待时,雏晶尺寸是大约58nm?????????????????猯灵?匠?猼'T资???猼灵?????????猯'T??猼灵???? ̄?????猯'T????猯灵??猼'T?????吗????????????????‵渠????????浮??

  • 标签: NANOPOWDER Cr, Nd : GGG 大音阶的第五音胶化 荧光一生 精力转移效率 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:ThesurfaceofacommercialY3Al5O12:Ce3+phosphorwasmodifiedby99%NH4F+CH3COOHsolutioninasupersonicbathwithwatertemperatureof80oCfor4h.Thescanningelectronmicroscopy(SEM)resultsshowedthattheedgeangleswerenotassharpastheunmodifiedparticlesandtheflatsurfacesturnedroughwithmanymicro-structurescovered.Positronlifetimemeasurementsquantitativelyshowedthatsurfacedefectswereremovedawaybymorethan50%.Asaresult,thephotoluminescencedeterminationsshowedthatthebackscatterlosswasreducedby4.2%andtheemissionpowerwasenhancedby5.6%afterthesurfacemodification.Theconversionefficiencywasgreatlyimprovedfrom47.3%to51.1%,aspresentedbythefluorescenceimages.Therefore,itwouldbegreatlyhelpfulfortheimprovementofefficiency,transparencyandstabilityofpc-LED.Moreover,thismethodwassignificantlysuitableformassproductionduetoitseasyoperationandlowcost.

  • 标签: 表面特征 表面缺陷 溶胶-凝胶法 荧光粉 选择性腐蚀 CE
  • 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.

  • 标签: 硅酸铅玻璃 近红外激光 发射特性 激发条件 共掺杂 TM
  • 简介:单斜晶、六角形LaPO4:5mol.%Eu3+黄磷与仅仅在一样合成温度由一个热水方法调整答案pH价值被综合。被不同准备影响Eu3+-dopedLaPO4,微观结构,形态学和光致发光调节,被X光检查衍射(XRD)描绘,扫描电子显微镜学(SEM),Fourier变换红外线光谱学(英尺红外),拉曼光谱学和光光谱学分别地。然而,标本在强壮酸答案显示出单斜晶结构它在弱酸答案和强壮碱答案变成了六角形结构。单斜晶LaPO4:Eu3+显示出最长长度到直径比率,它被归因于优先生长[-112]。单斜晶标本与六角形标本相比在红外线系列,拉曼乐队位置和费用转移(CT)展出了细微红移动。而且,谷物尺寸计算结果,格子参数,在在拉曼模式和排放积分紧张半最大值完整宽度在对分析结果好同意。单斜晶标本显示出最大绝对光量收益(0.4)和第二一生2(0.52ms),它与在CIE红橘子排放是一致。5D07F1在六角形标本占据了一个dominate位置,它显示在六角形结构更多Eu3+被占据对称地点倒置中心。

  • 标签: LaPO 4:Eu3+ 震动 光致发光 微观结构 稀土元素
  • 简介:Trivalentsamariumdopedbariummolybdate(BaMoO_4:Sm~(3+))redphosphorwassuccessfullysynthesizedbyhydrothermalmethod.Thecrystalstructure,morphologyandphotoluminescentpropertywerecharacterizedbyX-raydiffraction,fieldenvironmentalscanningelectronmicroscopyandphotoluminescencespectroscopy.TheresultsindicatedthatthesynthesizedBaMoO_4:Sm~(3+)phosphorconsistedofapurephasewithanoctahedralstructure.Themainexcitationpeakswerelocatedat362,404,445and477nm,respectively,andwereobviouslyobserved.Themainemissionpeakswerelocatedat533,566,602and646nm,respectively.Thephosphorsexhibitedaredperformanceat646nm,whichwasappropriatefortheultraviolet-lightemittingdiode(UV-LED)andblueLED.TheluminescentintensityofBaMoO_4:Sm~(3+)increasedwithanincreaseinthedopingamountofSm~(3+).Theluminescentintensityhadtheoptimalvalueforx=0.03.WhenthedopingamountofSm~(3+)wasfurtherincreased,theconcentrationquenchingphenomenonwasobserved.Monovalentlithium(Li+)cationwasusedasachargecompensator.TheluminescenceintensityfirstincreasedwithincreasingLi+dopingconcentration,andthendecreased.TheoptimalcontentofLi+wasabout2%.TheBaMoO_4:Sm~(3+)phosphorpreparedinthisstudycouldactassuperiorredphosphorforwhiteLEDs.

  • 标签: LUMINESCENT PHOSPHOR doping hydrothermal ultraviolet luminescence
  • 简介:TheNaGd(WO_4)_2:Eu~(3+)phosphorswerepreparedbythemicroemulsionmediatedhydrothermalmethod.ThemorphologyandsizeofthesamplescouldbedependentonthepHintheinitialsolution.Thesephosphorsobtainedhadastrongabsorptionat395nmmatchingwiththepopularemissionofnear-UVLEDchips,andcouldemitintenseredlightat616nm.Thesmallellipsoid-likeparticlesorshortrodswereprovidedwithlargeparametersofoscillatorstrength?_2andasymmetryratio.Comparedtotheellipsoid-likephosphors,therod-likephosphorstookonstrongeremission,longerlifetimeandlargerquantumefficiency.Thisworkdemonstratedthattheone-dimensionNaGd(WO_4)_2:Eu~(3+)phosphorsmightbeamorefavorabledevicethanzero-dimensiononesforphotoluminescence.

  • 标签: MICROEMULSION hydrothermal oscillator matching LIFETIME sizes
  • 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).

  • 标签: 上转换发光 晶体结构 光致发光 浓度猝灭 纳米晶 协同效应
  • 简介:太钢型材厂针对无磁钻铤用钢A磁导率合格状况,特立项采用精益六西格玛方法,实施"定义—测量—分析—改进—控制"流程,提高无磁钻铤用钢A磁导率合格。在实施过程中,按照无磁钻铤用钢磁导率合格为80%现状与潜在最佳值之间差距可提高70%~90%原则,确定提高磁导率合格83.3%目标,对无磁钢关键过程进行改进,并严格控制工艺参数,最终使无磁钢A系列磁导率合格已基本稳定,2010年第四季度此值保持在97%以上,全年平均达到95.86%。

  • 标签: 无磁钢A 磁导率 合格率 六西格玛
  • 简介:介绍了160m^3WEMCO和Dorr—oliver浮选机使用状况及故障处理方法,为浮选机使用与维护积累了经验。

  • 标签: 浮选机 速度椎体 导流管
  • 简介:采用超音速等离子喷涂法在1045钢表面制备NiCr-Cr3C2涂层,分析涂层微观结构及化学成分以及涂层晶粒结构,利用MICROMET-6030显微硬度仪和Nano-test600纳米压痕仪测定涂层显微硬度与弹性模量,通过油润滑微动摩擦磨损试验测试涂层微动磨损性能。结果表明,NiCr-Cr3C2涂层为明显层状结构,具有单晶、纳米多晶与过渡区共存复杂晶体学结构,显微硬度HV0.3高达998,约为基体材料硬度3倍,弹性模量为224.6GPa;涂层微动摩擦因数随载荷增大而减小,随温度升高而增大。喷涂层抗微动摩擦磨损性能较基体优异,摩擦因数及体积磨损量分别比基体降低36.7%和55.6%。涂层磨损机理以磨粒磨损和疲劳剥落为主。

  • 标签: 超音速等离子喷涂 NiCr-Cr3C2涂层 微观结构 微动磨损 硬度