简介：TheeffectofrareearthelementyttriumonthehightemperatureoxidationresistanceofadirectionallysolidifiedNi-basesuperalloywasstudiedwithscanningelectronmicroscopy(SEM),energydispersivespectrum(EDS)andX-raydiffraction(XRD)techniques.Theresultsshowthattheoxidationresistanceofthealloyissubstantiallyimprovedbyaddingproperamountofyttrium.

简介：(Ba0.66Sr0.33)Mg0.8Al11.47O19:Tm0.013+(BSMA:Tm3+)phosphorwassynthesizedbysolid-statereactions.ThesamplewascharacterizedbyX-raydiffraction(XRD),scanningelectronicmicroscope(SEM),vacuumultraviolet(VUV)spectra,ultraviolet(UV)spectraandFT-IRspectrum.XRDpatternrevealsthatBSMA:Tm3+hasthesamestructureasBaAl12O19phase.SEMimageillustratesthatthephosphorhasthehexagonalshapeanddeepslicestructure.VUVandUVemissionspectraat20,50and100Kshowthatthelowtemperatureluminescenceintensitiesbecomeweakgraduallywiththeincreasingofthetemperatureunder147and254nmexcitation.Thestrongbroadbandpeaksataround357and397nmandthepeakat516nmunder147nmexcitationallcorrespondtothecharacteristictransitionsofTm3+ions.However,underUV(254nm)excitation,themainpeakbecomes530nmwhichhasveryhighlineintensity,andthepeaksatabout362and403nmareveryweak.Theexcitationspectrumat20Kshowsthattherearethreeabsorptionpeaksataround153,186and193nmwhen516nmemissionismonitored.Theabsorptionpeaksof[AlO4],[AlO6]andAl-OcanbeobservedinFT-IRspectrum.

简介：Melt-spunribbonswhicharetheimportantrawmaterialforhot-deformedmagnetscanbepreparedbysingle-rollermelt-spinning.Inordertopreparewell-structuredribbons,themodeloftemperaturefieldforsingle-rollermelt-spinningprocesswasconstructedinthiswork.Theheatconductioninthisprocesswassimplifiedasonedimensionalheatconductionproblem.Itwasshownbymodelingthat,thetemperaturefieldinthemelt-spinningbeforesolidificationinthismodelcouldbedescribedasthisequationT(x,t)=Tmoexp[–k(x–x0)–k2αt]+T0.ThetemperatureT(x,t)ofthealloymeltsdecreasedwithincreasedpositionxandcoolingtimetexponentiallyfromthewheel-freesurfacetothewheel-sidesurface.TheconstantkdeterminedthedecreasespeedofalloytemperatureT(x,t),whichwasproportionaltotheinterfacialheattransfercoefficienthandtheinterfacialareaofheatconductionA0,butinverselyproportionaltothethermalconductivityK.x0wasthethicknessofthealloymelt.Withincreasedx0,thetemperaturedifferencebetweenwheel-freesurfaceandthewheel-sidesurfacebecamelarger,whichwouldleadtolargerdifferenceingrainsize.Inexperiments,theinfluenceofmelt-spinningprocessparametersonthetemperaturefieldmodelwasdiscussed,suchascoolingrollermaterials,wheelspeed,andsoon.Melt-spunribbonspreparedbysingle-rollermeltspinningatdifferentwheelspeedwereinvestigatedandmagneticpropertiesofdie-upsetmagnetsfrommelt-spunribbonsondifferentcoolingrollerwereanalyzed.Thevariationofgrainsizeinthedepthdirectionconsistedwithtemperaturefieldmodel.Thismodelprovideddirectionsforthepreparationofmelt-spunribbonswithuniformlydistributedfinegrains,whichwereverynecessaryforproducinghot-deformedmagnetswithhighmagneticperformance.

简介：Theeffectoftherareearthsonthehightemperaturepropertiesofdeformedleaded-brasseshasbeenstu-diedwiththehightemperaturetensiletest.Theresultsshowthattherareearthadditivescanincreaseelongationofalloysathightemperature,buttheyhadlittleeffectonthemaximumflowstress.WiththehelpofSEM.X-raydiffractioninstrument,quantitativemetallographyanalysisinstrument,etc.,theeffectoftherareearthelementsonthemierostruetureofalloyshasalsobeenexamined.

简介：Theactivatedaluminaasacatalystcarrierwerewidelyusedinautomotiveexhaustcatalystsunderhightemperature,suchas,petroleumrefiningcatalysts,hydrogenationandhydrodesulfurizationcatalystcarrierinChinaandabroad.γ-Al2O3wasthecatalystcarrierthatwasthemostwidelyusedandthebestcarrierofimprovedspecificsurfacearea.However,theactivationofthecoatingconsistedofγ-Al2O3wereusuallytransformedintoα-Al2O3at800oC,causingincreaseddensity,reducedspecificsurfacearea,andthecollapseresultofporestructure.Whilethetemperaturereached1200oC,activationofcoatingdetachedfromthecarrier,theresistanceofflowinggasincreased,catalyticactivitydecreased.AdditionofLa2O3stabilizedtheγ-Al2O3crystalstructure,whichwouldkeeptheactivationstabilityofcoatingatahightemperatureandinhibitactivityloss.Theactivatedaluminacarriertreatedwiththesolid-pore-expandingagentcontaining[La(EDTA)]-thatsynthesizedusingsolidandsolid-hybridapproachwiththethermalstabilizerlanthanaandEDTAatthehigh-temperaturehada10-30μmlargeporeporousnetwork-likestructure,afteraluminawascalcinedat1200oCfor1h.Thespecificsurfaceareaoffourspecimenwerebeyond120m2/g,whilethesamplespecificsurfaceareaofx([La(EDTA)]-)=1%wasupto150.36m2/g.

简介：AseriesofMn-basedcatalysts,MnOx,MnOx-CeO2,Pd-Mn-Ce,MnOx/ACwereprepared.AndtheirperformancesforNOlow-temperatureSCRwereinvestigatedinthisstudy.TheNOconversionisabout90%at100℃onMnOx-CeO2andalmostallNOcanbeconvertedat120℃.SimilarresultsarealsoobservedinthetestsonMnOx-CeO2/AC.Theexcellentlow-temperaturecatalyticactivityofmodifiedMn-basedcatalysts,whichmaybemainlyduetotheoxygenstoragefunctionofCeO2,canimprovetheoxygenflowonthecatalystssurface.ThentheoxidationofNOtoNO2isaccelerated,whichisthekeystepofNOSCR.

简介：

简介：陶器的LaNiO3样品被稳固的州的反应方法在不同sintering温度准备。这被发现结果不是ABO3perovskite单身者阶段，但是双阶段La2NiO4和NiO，和二个阶段的百分比与sintering温度变化了。在1400湩的陶艺sintered？？

简介：Au/TbMnO3/YBa2Cu3O7-xcapacitorswerefabricatedonSrTiO3substratesbypulselaserdepositiontechnique,ofwhichelectricpropertieswereinvestigatedinthetemperaturerangefrom25to300K.Bothcurrent-voltagecharacteristicsandjunctionresistanceswithbiasvoltagesshowedremarkabletemperaturedependence,inwhichobviousthermallyexcitedrelaxationprocesseswerefoundbetween150and200K.Atthetemperatureslowerthantheactivationprocess,theleakagecurrentsofthecapacitorswerestudied.Interestingly,athighelectricfield,themechanismoftheleakagewasPoole-Frenkelemission.However,atlowelectricfield,theconductionwasnotOhmic,andideallnJ∝E1/4characteristicswereobserved.Analysisshowedthatthepossibleoriginwasrelatedtotheinherentinhomogeneousnatureofactivationlesspercolatingtransport.

简介：Aseriesofcoal-basedactivecarbon(AC)catalystsloadedbyFe-Cu,Fe-Cu-CeandFe-Cu-Lawerepreparedbythesol-gelmethodforcarbondisulfide(CS2)hydrolysisandtheirperformancesforCS2hydrolysisinafixed-bedreactorwereinvestigatedinthiswork.TheresultsshowedthatthekindofrareearthoxideanditscontenthadobviouseffectonhydrolysisremovalofCS2.Theeffectsoftemperature,spacevelocity,CS2concentrationandO2concentrationwerealsodiscussedrespectively.Furthermore,thesuitableoperatingconditionswereobtained.Itwasfoundthatthepoisoningofhydrolysisactivesitescouldresultintheformationofsulfuricacidonthecatalystsurface.

简介：我们在甲烷(POM)的部分氧化上调查了填满的格子氧的锻烧温度，反应温度，和不同数量的效果到把perovskite类型LaFeO3氧化物用作氧施主而不是气体的氧的合成气体，它被大音阶的第五音胶化方法准备，并且氧化物被XRD，TG/DTA，和赌注描绘。结果显示粒子尺寸增加了，锻烧温度增加，当赌注和CH4变换衰退了，锻烧温度当气体的氧不在时作为氧施主用LaFeO3氧化物增加时。在象上面那样的高水平仍然是的公司选择92%，并且当锻烧温度增加了，稍微增加了。到甲烷空气的LaFeO3氧化物的暴露提高了氧迁居在有由于格子氧和氧化说的Fe离子的减小的损失联机的时间的体积同时。高反应温度对从向为有高公司选择的合成气体生产的表面的体积的氧种类的迁居有利。为由顺序的氧化还原作用反应的POM的产品分发和进化被填满的格子氧的数量与气体的氧决定。最佳的过程应该衰退甲烷的全部的氧化，和增加甲烷的部分氧化的选择。

简介：CeB6粉末被CeO2，B2O3和Mg作为反应物在被拿的高温度的自我繁殖的合成(SHS)准备。SHS反应的断热的温度和动力学被调查。SHS反应产品和沥滤的产品被X光检查衍射(XRD)和扫描电子显微镜学(SEM)描绘。结果比让反应由自己宣传的1800K，和明显的激活精力(Ea)和反应在微分扫描热量测定(DSC)曲线是的Mg-B2O3-CeO2上订发热的山峰的(n)的显示Mg-B2O3-CeO2反应系统的断热的温度相当高23.03kJ/mol并且1.31，分别地。明显的激活精力更低，因此反应容易发生了。SHS产品由MgO，CeB6和小Mg3B2O6组成了。沥滤的产品由单个CeB6阶段组成了，它的纯净比99.0%高，并且CeB6的平均粒子尺寸比150nm小。

简介：Ba0.85Ca0.15Ti0.9Zr0.1O3(BCTZ)lead-freepiezoelectricceramicsco-dopedwithCeO2(x=0.1wt.%,0.2wt.%,0.3wt.%,0.4wt.%,0.5wt.%)andLi2CO3(0.6wt.%)werepreparedbyconventionalsolid-statereactionmethod.InfluenceofCeO2dopingamountonthepiezoelectricproperties,dielectricproperties,phasecompositionandmicrostructureofpreparedBCTZlead-freepiezoelectricceramicsdopedwithLi2CO3wereinvestigatedbyX-raydiffraction(XRD)andscanningelectronmicroscopy(SEM)andotheranalyticalmethods.TheresultsshowedthatthesinteredtemperatureofBCTZlead-freepiezoelectricceramicsdopedwithCeO2decreasedgreatlywhenLi2CO3dopingamountwas0.6wt.%;apureperovskitestructureofBCTZlead-freepiezoelectricceramicsco-dopedwithLi2CO3andCeO2andsinteredat1050°Ccouldalsobeobtained.Thepiezoelectricconstant(d33),therelativepermittivity(εr)andtheplanarelectromechanicalcouplingfactor(kp)ofBCTZceramicsdopedwithLi2CO3increasedfirstlyandthendecreased,thedielectricloss(tanδ)decreasedfirstlyandthenincreasedanddecreasedatlastwhenCeO2dopingamountincreased.TheinfluenceofCeO2dopingonthepropertiesofBCTZlead-freepiezoelectricceramicsdopedwithLi2CO3werecausedby'softeffect'and'hardeffect'piezoelectricadditiveandcausinglatticedistortion.WhenCeO2dopingamount(x)was0.2wt.%,theBCTZceramicsdopedwithLi2CO3(0.6wt.%)andsinteredat1050°Cpossessedthebestpiezoelectricpropertyanddielectricpropertywithd33of436pC/N,kpof48.3%,εrof3650,tanδof1.5%.

简介：试图为高温度的熔融的盐反应堆的安装和电极的建设开发材料，在750和950湩爠晥湩浥湥?瑳敲杮桴湥湩?猠汯摩猠汯瑵潩?瑳敲杮桴湥湩?眠牯?慨摲湥湩?愠摮瀠敲楣楰慴楴湯猠牴湥瑧敨楮杮的Ni-11Fe-10Cu的高温度的氧化行为上的艾尔和Y的效果

简介：

简介：TheLa-CosubstitutedSr_（1–x）La_xFe_（12–x）Co_xO_（19）（x=0–0.5）ferriteswithappropriateBi_2O_3additivewerepreparedbyconventionalsinteringmethodandmicrowavesinteringmethodatlowsinteringtemperaturescompatiblewithLTCC（lowtemperatureco-firedceramics）systems,andtheirsinteringbehaviorwaschieflyinvestigated,includingthecrystalstructure,saturationmagnetizationMs,magneticanisotropyfieldHa,intrinsiccoercivityHci,andCurietemperatureTC.ExperimentresultsclearlyshowedthatthepureM-typecrystalphasewassuccessfullyobtainedwhentheLa-Cosubstitutionamountxdidnotexceed0.3.However,thesingleM-typephasestructuretransformedtomultiphasestructurewithfurtherincreasedx,wheretheM-typephasecoexistedwiththenon-magneticphasesuchasα-Fe_2O_3phase,La_2O_3phase,andLaCoO_3phase.AppropriateLa-CosubstitutionimprovedtheMs（〉62emu/g）,Ha（〉1400kA/m）,andHci（〉320kA/m）fortheferriteswithxvaryingfrom0.1to0.3,buttheTCdecreasedwithincreasingsubstitutionamount.Moreover,themicrowavesinteredferritescouldprovidelargerHciandsimilarMscomparedwiththeconventionalsinteredferrites.

简介：La公司代替了M类型钡铁酸盐(欺骗)由传统的稳固的状态被准备在低温度(1173K)的方法和sintered。X光检查衍射(XRD)，扫描电子显微镜学(SEM)和颤动的样品磁强计(VSM)被采用在样品的结构和磁性上调查La公司的影响。由在为在空中的6h的1173K的sintering，有Ba(LaCo)xFe122xO19(x=0.00.5)的化学作文的单个阶段M类型钡铁酸盐被形成。M-H曲线证明钡铁酸盐的磁性被La公司替换显然完成。浸透磁化(女士)和coercivity(Hc)分别地到达了65.15Am2/kg和4165Oe的最大的价值。这行为被归因于La公司替换和粒子尺寸的地点。SEM表明铁酸盐粒子的形状被La公司替换影响。

简介：

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.