学科分类
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30 个结果
  • 简介:Yttriumaluminumgarnet(YAG)transparentceramicswerefabricatedbysinteringatoxygenatmosphere.Tetraethylorthosilicate(TEOS)wasaddedasthesinteringadditivetocontrolthegraingrowthanddensification.Poreswereeliminatedclearlyattemperaturelowerthan1700oC,whilegrainsizewasaround3μm.Thein-linetransmittancewas80%at1064nmwhensamplesweresinteredat1710oC.TheeffectofTEOSwasstudiedinoxygenatmospheresinteringforNd:YAGtransparentceramics.Athighertemperaturelike1710oC,thegraingrowthmechanismwassolutedrag,whileat1630and1550oCthegraingrowthwascontrolledbyliquidphasesinteringmechanism.And0.5wt.%TEOSwasthebestaddingcontentforNd:YAGsinteredinoxygenatmosphere.

  • 标签: Nd YAG陶瓷 烧结助剂 氧气氛 晶粒生长 TEOS
  • 简介:钕做了金轧镓氧化物(Nd:GGG)当燃料被报导,nanopowders用丙氨酸由微波胶化燃烧综合了。有丙氨酸燃料的金属硝酸盐答案是在微波的combusted给先锋。微波先锋粉末从800~1100°C在不同温度被锻烧。分阶段执行纯Nd:GGG形成在由X光检查衍射(XRD)和Fourier变换观察了的800~1100°C发生了红外线(FTIR)光谱学。然而,粒子尺寸在1100°C在800°C从25nm与锻烧温度增加了到200nm。Nd:在不同锻烧温度获得的GGGnanopowder被压缩并且在为在空中的3h的1550°C的sintered。最使增加密度陶器从Nd被获得:在1100°C锻烧的GGGnanopowder。从扫描电子显微镜学(SEM)观察了的微观结构证明大多数使增加密度陶器,从在更高的锻烧温度锻烧的nanopowder获得了,有更一致的谷物尺寸分布,更少毛孔和更大的densification。sintered样品的XRD显示出阶段纯净的保留。

  • 标签: 纳米粉体 燃烧合成 GGG 微波 烧结 凝胶
  • 简介:Magnetizationanddemagnetizationcurvesandhysteresisloopsapplieddifferentmagnetizing.fieldsinsinteredNd-Fe-BandNd-Dy-Fe-Bmagnetsfromthermallydemagnetizedanddcfield-demagnetizedstateswereinvestigatedattemperaturesofupto150℃.Thefirst-quadrantremagnetizationcurvesandthecurvesofcoerciveforces_MH_CversusrernagnetizingfietdsH_mfromdcfield-demagnetizedstateatroomtemperatureshowasteparoundmagnetizingfieldasabsolutevalueofthemaximumintrinsiccoercivity.Thestepsof_MH_C-H_mcurvesshiftedtolowerremagnetizingfieldsandtheshapesofmagnetizationcurveschangedfromsteptypetoprecipitoustypewhentemperaturewentupto100~150℃orafterthespecimenwasthermallydemagnetizedatatemperaturehigherthantheCurietemperature.Thesteepriseofkneecoereivitywithincreasingmagnetizingfieldisbehindthatof_MH_C.NotethatthemagnetichardeninginsinteredNd-Fe-Bmagnetsiscontrolledbypinningofdomainwalls.

  • 标签: MAGNETIZATION COERCIVITY thermally HYSTERESIS ABSOLUTE walls
  • 简介:Cr的Nanopowder:Cr的GGG和nanopowder,Nd:有从0.1at.%到1.5at.%的Cr3+的不同集中的GGG被大音阶的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:分光镜并且在钠fluoroborate(SFB)的Nd3+离子的荧光性质眼镜通过光吸收,排放和腐烂大小被准备并且描绘。精力水平分析用免费离子的Hamiltonian模型被执行。试验性的振荡器力量被测量记录的吸收山峰包含的区域决定因为1.0mol.%Nd3+-做了眼镜。Judd-Ofelt参数(2,4,6)被用来评估象放射的转变那样的激光特征参数概率(AR),放射的腐烂时间(R),荧光分叉比率(R)和刺激排放为4F3/2的剖面图(e)亚稳的状态。为Nd3+离子的不同集中的荧光系列被在514.5nmAr+离子激光使样品激动记录。

  • 标签: 激光发射 眼镜 Judd-Ofelt参数 ND 硼酸 离子荧光光谱
  • 简介:AnenhancedadsorptionanddesorptionprocedureofNd(III)ontoD113-IIIresinwerepreparedwithvariouschemicalmethods.BatchstudieswerecarriedoutwithvariouspH,contacttime,temperatureandinitialconcentrations,andthencolumnstudieswereconducted.TheresultsshowedthattheoptimaladsorptionconditionwasatpHvalueof6.90.Theprocesswasfastinitiallyandarrivedequilibriumwithin60h.TheresinexhibitedahighNd(III)uptakeas232.56mg/gat298K.Theadsorptiondatafittedwellwithpseudo-second-orderkineticmodel.Thermodynamicparameterswerestudied,whichindicatedthattheadsorptionprocesswasspontaneousandendothermic.Thomasmodelwasdelineatedheretopredictthebreakthroughcurvesbasedontheexperimentalcolumnstudydata.Intheelutiontest,1mol/LHClsolutioncouldachieveasatisfactoryelutionrate,whichindicatedthatD113-IIIresincouldberegeneratedandreused.Finally,theIRspectroscopictechniquewasundertaken,andanoveladsorptionmechanismwasproposed.

  • 标签: 吸附条件 树脂 ND 水溶液 行为 红外光谱技术
  • 简介:TheNd3+3.2%(atomfraction):KGd(WO4)2crystalwasgrownbyKyropoulosmethod.TheabsorptionspectrumandfluorescencespectrumofNd3+:KGWcrystalweremeasured.Theabsorptioncrosssectionsat808nm(0.6799×10-20cm2)werecalculated,andtheoutputwavelengthoffluorescenceis1064and1351nm.Thediode-pumpedlaserwasoperatedbothinthefree-runningandpassivelyQ-switchedoperatingmodes.Themaximumlaseroutput(1064nm)is326mWwith62.7%slopeefficiencywheninputenergyis900mW.ThebeamqualityfactorM2≈1.1.Thegreenlightof532nmisobtainedinfrequencydoublingoperation.ThelaserispassivelyQ-switchedbyusingCr4+:LuAGassaturableabsorber.Thepulsewidthis170nsatrepetitivefrequencyof15kHZ.

  • 标签: Nd : KGW晶体 晶体生长 LD泵浦 激光材料
  • 简介:Nd:钇铝柘榴石先锋粉末被同类的降水,和Nd综合:钇铝柘榴石透明陶艺被真空sintering为5h在1700°C作好准备。陶器的材料被轻发射度和地排放枪环境扫描显微镜描绘。用统计和立方米科学理论,学习在在轻发射度和立体声之间的量的关系上被执行在三维的欧几里德几何学的空格的逻辑参数。这被发现Nd的发射度:有在厚度的1公里的钇铝柘榴石分别地在可见、在红外线附近的波长是大约45%和58%。发射度线性地与增加相等的范围直径增加并且当相等的范围直径是20μm时,到达单个水晶的理论价值。有每统一谷物和分离谷物的体积增加吝啬的特定的区域的发射度减少,和有增加的发射度减少在Nd意味着谷物的免费距离:钇铝柘榴石陶艺。

  • 标签: 钕掺杂钇铝石榴子石 透明陶瓷 立体学 显微结构 稀土元素
  • 简介:Microporoustitaniumdioxidefilmswerepreparedbythesol-gelmethodsonglasssubstrates,usingtetrabutyltitanateassourcematerial.Inordertoabsorbthevisiblelightandincreasethephotocatalyticactivities,differentconcentrationsofneodymiumions(Nd/Timolarratiowas0.5%,0.7%,0.9%,and1.1%respectively)wereaddedintothesol.X-raydiffraction(XRD),X-rayphotoelectronspectros-copy(XPS),andatomforcemicroscopy(AFM)wereappliedtocharacterizethemodifiedfilms.Akindoftypicaltextileindustrypollutant(RhodamineB)wasusedtoevaluatethephotocatalyticactivitiesofthefilmsundervisiblelight.TheresultsshowedthattheactivitiesofthefilmswereimprovedbydopingNdionsintothesol.

  • 标签: TITANIUM dioxide VISIBLE light DOPING ion
  • 简介:Thesolutionreactionmechanisms,composition,donoratoms,propertiesofcoordinatelinkandstabilityofthecomplexesonthesystemsofadrenalinewithNa3+,Gd3+andTm3+havebeenstudiedbypH-potentiometrictitrationandelectronicspectroscopy.Adrenalineperturbsthef-felectronictransitionofNd3+andTm3+sothattheabsorptionspectraoftheircomplexesareshiftedtowardlongerwavelengths.Theabsorptionspectraofthecomplexesformedbythethreef-blockelementionswithadrenalineareshiftedtowardshorterwavelengthswiththeincreaseofPHinΔγ=350~650nm

  • 标签: ADRENALINE NEODYMIUM GADOLINIUM THULIUM Solution EQUILIBRIUM
  • 简介:InordertoimproveandstabilizethemagneticpropertiesofnanocompositeNd2Fe14B/α-Femagneticalloysbyacompositionaladjustment,smallamountofDyand/orCowasaddedtoNd9Fe84B7alloys.DTAanalysisontheamorphousofthealloystookplaceasthesoftmagneticphaseswerecrystallized,andthenthehardmagneticNd2Fe14Bwasprecipitatedfromthem.Whileα-Feandametastable1:7(TbCu7-type)phasewereformedsimultaneouslyinDyandCo-freealloys,theywerecrystallizedseparatelyatdifferenttemperaturesafterDyorCowasadded.ThisphaseseparationoccurredmoreclearlyintheDy-treatedalloysandtheothersoftmagneticphaseFe3BwasalsostabilizedbyDyand/orCo.The1:7phasethatwasstabilizedbyDyand/orCowasnoteliminatedat700℃,decreasingmagneticpropertiesofthealloys.Itwaseventuallydisappearedabove725℃,butFe3Bwasnoteliminatedevenat750℃whenDywasaddedmorethan0.5at%orCowasaddedmorethan2.0at%.AmountofNd2Fe14BinthealloystendedtoincreaseasDyadditionincreased,whereasCoadditiondidnotleadtoanyappreciablechangeintheratioofα-FeandNd2Fe14B.Moreover,DyadditionapparentlyincreasedcoercivityofanalloywhileCoadditionhadabeneficialeffectonremanence.ThegrainsintheDytreatedalloyswereusuallyfinerthanthoseintheCo-treatedalloys.Thegrainsizeofbothα-FeandNd2Fe14Binthealloysexhibitingmr≥0.72wasintherangeof20~40nmorevenlarger50nm,whichislargerthanthetheoreticaloptimumsize(~10nm).TypicalmagneticpropertiesobtainedfromaNd7.5Dy1.5Fe82.5Co1.5B7alloyannealedfor12minat725℃wereiHc=4.85kOe,Br=11.32kG,(BH)max=15.73MGOe,andmr=0.73.

  • 标签: NANOCOMPOSITE ND-FE-B MAGNETIC properties REMANENCE COERCIVITY
  • 简介:OpticalabsorptionandemissionintensitiesofNd3+ioninKLu(WO4)2crystalwereinvestigated.BasedontheJudd-Offelttheory,wecalculatedthefollowingspectralparameters:phenomenologicalintensityparametersΩ2=5.567×10–20,Ω4=3.597×10–20,andΩ6=3.800×10–20cm2.Theradiativelifetimeoflevels4F3/2was182.58μs.Thefluorescencebranchingratioforthetransition4F3/2→4I11/2was46.98%.Inaddition,theradiativetransitionprobabilitiesAJ,J’,oscillatorstrengthsPJ,J’andthevaluesofinte...

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  • 简介:EnvironmentalfriendlyrecyclingprocessforNd-Fe-Bsinteredmagnetsludgesgeneratedinthemanufacturingprocess,whichcontainlargeamountofrareearth,includingNd,PrandDy,isbadlyneededsofar.Inpresentstudy,wehavedevelopedaneffectiveroutetoobtainrecycledsinteredmagnetsfromNd-Fe-Bsinteredmagnetsludgesbycalciumreduction-diffusion(RD)process.Comparedtoconventionalrecyclingprocess,ourresearchisfocusedonrecoveringmostoftheusefulelements,includingNd,Pr,Dy,Co,andFetogetherinsteadofjustrareearthelements.Toimprovetherecyclingefficiencyandreducepollution,theco-precipitatingparametersweresimulatedandcalculatedusingMATLABsoftware.Mostofusefulelementswererecoveredbyaco-precipitationmethod,andtheobtainedcompositepowderswerethendirectlyfabricatedasrecycledNd-Fe-Bpowdersbyacalciumreduction-diffusion(RD)method.Therecoveryratesare98%,99%,99%,93%,and99%,forNd,Pr,Dy,Co,andFe,respectively.Theamountofusefulelementscontainedintherecoveredcompositepowdersisgreaterthan99.71wt%.TheprocessofRDforsynthesizingNd2Fe14BandsubsequentlyremovingCaOwasthoroughlyinvestigated.Furthermore,therecycledNd-Fe-Bmagnetexhibitsaremanenceof1.1T,acoercivityof1053kA/m,andanenergyproductof235.6kJ/m3,respectively,indicatingthatrecycledNd-Fe-Bsinteredmagnetwassuccessfullyrecoveredfromtheseverelycontaminatedsludgesviaaneffectiverecyclingroute.

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  • 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:采用粉末注射成形工艺制备含钕的钛合金TixNd(x为Nd的质量分数,%),采用金相显微镜、扫描电镜、电子探针以及硬度和力学性能测试等分析手段,研究钕对注射成形钛合金中氧的分布及力学性能的影响,并分析钕的最佳添加量。结果表明:随钕含量增加,合金的密度和伸长率先增加后降低,其中Ti15Nd的性能最优异,其相对密度为98.2%,强度和伸长率分别达到634MPa和6.5%,比纯钛分别提高248MPa和6.5%。纯钛的断裂面呈现解理断裂特征,而Ti15Nd为延性断裂。添加钕能提高钛合金的致密度,并且钕能吸收周围钛基体中的氧原子形成氧化钕,调节TixNd合金中氧的分布,从而有效提高合金的强度和韧性。计算证明氧化钛的分解和氧化钕的形成在热力学上是可行的。建立Ti-Nd扩散模型,考虑钕的蒸发和氧化等因素,计算得出钕的最佳添加量(质量分数)约为4.3%。

  • 标签: 注射成形 钛合金 Nd元素 显微组织 力学性能