简介：将95％Mg＋3％Ni＋2％MnO2混合粉末在行星式高能球磨机中充氢反应球磨100h，利用X射线衍射（XRD）和扫描电镜（SEM）对球磨后的粉体进行表征，并研究其与水反应的动力学性能。结果表明，充氢球磨能对Mg-3Ni-2MnO2进行充分的氢化，Mg全部形成MgH2。制备的氢化态Mg-3Ni-2MnO2复合粉末的颗粒尺寸为0．1～5gm，晶粒尺寸在1～40nm之间。复合物在二次去离子水中水解时，随温度升高，放氢量增加，当温度为343K时，在20min内放出的氢气达到理论放氢量的91-3％，有望成为1种新的安全高效氢源技术。Avrami指数的数值变化表明，氢化态Mg-3Ni-2MnO2复合粉体的水解过程中，不同阶段其水解机理有所不同。
简介：AsystematicinvestigationofthemagneticandtransportpropertiesofTidopedLa0.67Ca0.33MnO3wasreported.TheTisubstitutionforMnionsresultsinareductioninferromagnetismandconductivity.Themetal-insulatortransitiontemperatureisclosetoCurietemperaturewhichdecreasesfrom274to82Kasxincreasesfrom0to0.17.ThemostimportanteffectofTidopingistointroducespinclustersinthesamplesduetothedistortionoflocallatticeandtheinhomogeneousmagneticstructureinducedprimarilybytherandomdistributionofMnions.Amaximummagnetoresistanceratioaslargeas90%in1Tat122Kwasobtainedforthesamplewithx=0.055,whichisfourtimeslargerthanthatobtainedforLCMOsampleat272K.Thereisaremarkablefield-historydependentMRinthecoolingprocessforthedopedsampleswhilesuchphenomenondisappearsinthewarmingrun.Theresistivityfollowswellthevariablerangehoppingbehaviorinparamagneticstate.Boththesizeeffectandspindependenthoppingofcarriersbetweenthespinclustersshouldbeconsideredinthissystem.
简介：Loadedonthecordierite,therareearthdopedcompositecatalystwaspreparedbysol-gelmethodcombinedwithdippingtechnique.TakingOrthodichlorobenzeneasmodel,thecatalystwasusedtoremovethedioxinsofthewastegas.Theresultsshowedthatat280℃andgasspacevelocitybeing8000h-1,theorthodichlorobenzenecouldberemovedeffectivilybythepreparedCeO2-TiO2-V2O5compositecatalystwhoseactivitywasremarkablyenhancedbythedopingofCe,whiletheindustrialside-streamtestofdioxinsfromrefuseincinerationsmokeindicatedthatthedecompositionratecouldreachabove93%underthesameconditions.
简介：Inthiswork,boththethermalexpansionandelectricalconductivityofnanocrystallineLa2Mo2O9werestudied.ThenanocrystallinepowderofLa2Mo2O9wasobtainedbysol-gelmethod,andwiththehelpofSHP(superhighpressure)upto4.5×104atmat700℃forashorttime,andthenanocrystallinepowderwasdensifiedwithoutobviousparticlesizegrowth.TheelectricalconductivityofnanocrystallineLa2Mo2O9wasoneorderofmagnitudelowerthanthatofthemicrocrystallinesampleatthesametemperature.Owingtothephasetransition,themicrocrystallineLa2Mo2O9hasanabruptincreaseofthermalexpansionwithapeakvalueof48×10-6K-1at556℃.Forthenanocrystallinematerial,thepeakvalueincreasesto112×10-6K-1at520℃.Ontheotherhand,above600℃thesignificantgrowthofparticlesizeofthenanocrystallineLa2Mo2O9wasobserved,accompanyingbyatremendousincreaseofthermalexpansionwithapeakvalueofthirdhigherthanthatofLa2Mo2O9.
简介：Basedonthethermodynamicallyself-consistentanalysisandoptimizationofthreesub-binarysystemsoftheternarysystemPrCl3-CaCl2-MgCl2,thethermodynamicsofthisternarysystemhasbeenstudied.UsingHillertmodelandtakingMgCl2asanasymmetriccomponent,thePrCl3-CaCl2-MgCl2phasediagramhasbeencalculated.Theagreementbetweencalculatedandmeasuredcompositionsandtemperaturesatdeflectingpointsonliquidusisgood.Thesystemisasimpleeutecticonewithaeutecticpointat26.0mol%PrCl3,41.5mol%CaCl2,32.5mol%MgCl2;560℃（calculated）and26.0mol%PrCl3,39.4mol%CaCl2,34.6mol%MgCl2;546℃（measured）,respectively.
简介：TheZrO2-Al2O3ceramiccompositeswerepreparedbyappropriatetechniqueswithcommercialZrO2andAl2O3powdersasrawmaterialsandY2O3asstabilizer.TheresultsindicatethatwiththeintroductionofAl2O3intotheZrO2matrixwherethequantityofadditiveY2O3is3.5%(molefraction),thegrowthofZrO2grainsisefficientlyinhibited,whichhelpstheZrO2grainsexistinametastabletetragonalmanner;thushigherstrengthandtoughnessareacquired.Whenthecontentofaluminais20%(massfraction),thebendingstrengthandfracturetoughnessofthecompositesare676.7MPaand10MPa·m1/2respectively,themechanicalbehaviorsareclosetothosepreparedwithZrO2andAl2O3powderssynthesizedthroughwetchemicalapproach.Themechanicalbehaviorsofthecompositesarewellimprovedowingtothedispersiontougheningofaluminagrainsandphasetransformationtougheningofzirconiagrains.
简介：Differentrareearth(RE)ionsdopantswereaddedintotheSrAl2SiO7:Eu2+phosphorsinordertoenhancethephosphorescenceproperties,andtheeffectoftheREionsincludingYb3+,Ce3+,Nd3+,Dy3+andTm3+,wascomparativelyinvestigated.ItwasfoundthatNd3+additionimprovedthephosphorescencepropertiesobviouslyamongallthestudiedREions.Therefore,Sr1.96–xAl2SiO7:xEu2+,yNd3+phosphorswerestudiedindetail,andtheoptimumEu2+andNd3+concentrationsweredeterminedwiththeafterglowtimeofabout20min.Thephasestructures,photoluminescence(PL)properties,long-lastingphosphorescence(LLP)properties,afterglowdecaycurvesandthermo-luminescence(TL)fortheselectedphosphorsduringthecorrespondingstudywereinvestigated.AllthephosphorsexhibitedgreenPLemissionandLLPemission.ThereweretwoTLbandslocatedatabout325and380Kforthestudiedsamples,andtherelationshipbetweenREadditionandphosphorescencepropertieswasdiscussed.
简介：FluorescencespectraofSm2+andEu2+→Sm2+energytransferwerestudiedinSrB4O7.Thereappearsonlyfluorescencefrom5D0transitionofSm2+at77K.Thevibroniclinesassociatedwith5D0→7F0transitionwereobserved.Thethermalpopulationtoupperstatesof5D1and4f5dlevelsfrom5D0givesriseto5D1→7FJand5d→4fradiativetransitionsofSin2+athighertemperature.
简介：Reactionof(MeC5H4)3LnwithHOCH2CH2NMe2intetrahydrofuran(THF)givesthenewcomplexes[(MeC5H4)2Ln(μ-OCH2CH2NMe2)]2(Ln=Sm,Y,Nd)withnitrogenfunctionalizedμ-alkoxideligand.ThecomplexeswerecharacterizedbyelementalanalysisandIR,and[(MeC5H4)2Sm(μ-OCH2CH2NMe2)]2wasstructurallycharacterizedbytheX-raydiffractiontobeadimerformedbytwounsymmetricoxygenbridges.ThecomplexhasatricyclicskeletonwiththeadditionaltwoSm-NbondsviaintramolecularcoordinationofOCH2CH2NMe2.ThecoordinationnumberofthecentralmetalSmisnine.Thetitlecomplexesshowgoodcatalyticactivityforring-openingpolymerizationofε-caprolactone.
简介：增加的CeO2(ZrO2)/TiO2催化剂独立由大音阶的第五音胶化和受精的方法准备了的一系列镨为选择催化减小被测试没有，并且由X光检查衍射(XRD)描绘了，N2-brumauer-emmett-teller(N2-BET),NH3-temperature规划了解吸附作用(NH3-TPD),H2-temperature规划了减小(H2-TPR),PL系列，拉曼系列，电子顺磁的回声(EPR)一催化性能上的准备方法的影响被学习。结果证明CeO2(ZrO2)/TiO2催化剂的催化性能上的Pr增加的影响在大音阶的第五音胶化方法和受精方法之间是不同的。Pr增加趋于与TiO2交往并且当它是更可能的与在受精方法形成Ce-O-Pr的结构的CeO2交往时，在大音阶的第五音胶化方法形成了Ti-O-Pr的结构。大音阶的第五音胶化方法准备的催化剂的全部的酸数量和氧化还原作用性质与Pr元素的增加减少了，它导致了催化活动的减少。相反，受精方法准备的增加Pr的催化剂被发现拥有更容易的reducibility，更多的全部的酸数量和Ce3+种类的更高的比例，它为更高催化的活动是赞成的。
简介：在甲烷(POM)的部分氧化的催化活动和稳定性混合方法的CeO2-ZrO2和-Al2O3的影响在Ni/Ce0.7Zr0.3O2-Al2O3催化剂上被调查。催化剂被XRD，TPR，H2-chemsorption，和TG-DTA描绘。为新鲜催化剂，结果证明混合催化剂(原子)的盐先锋比混合方法(摩尔)和机械地混合方法(MECH)的粉末的催促的人准备的催化剂介绍了更好的性能。XRD的结果建议在在原子样品的CeO2-ZrO2和Al2O3之间的相互作用比其它强壮，它导致了更多的格子缺点和从而更好的起始的活动。而且，MECH样品在24h稳定性测试有最好的稳定性和最少的焦炭免职。TPR和H2-chemsorption的结果显示在MECH样品的Ni-Al的亲密接触提高了抵抗焦炭免职和金属sintering的能力。
简介：Inthispaper,varioustechniquesincludingBET,XRD,SEMandXPSwereusedtostudythesinteringofpureandLa2O3-dopedtitania.Theexperimentalresultsshowthatsinteringoftitaniaproceedsviavolumediffu-sion.Addingoflanthanumoxidedecreasestherateofsinteringandhindersthephasetransitionfromanatasetorutilecrystalbystrongsurfaceinteractionbetweenthemixedcrystals(La4Ti9O24,La0.66TiO2.99)andTiO2.
简介：Ni-W-P-CeO2-SiO2nano-compositecoatingswerepreparedonthecarbonsteelsurfacebypulseco-depositionofnickel,tungsten,phosphorus,nano-CeO2andnano-SiO2particles.Theinfluenceofnano-SiO2particlesconcentrationsinelectrolyteonmicrostructuresandpropertiesofthenano-compositecoatingswereresearched,andthecharacteristicswereassessedbychemicalcompositions,elementdistribution,depositionrate,microhardnessandmicrostructures.Theresultsindicatethatwhennano-SiO2particlesconcentrationsinelectrolytearecontrolledat20g·L-1,thedepositionratewith27.07μm·h-1andthemicrohardnesswith666Hvofthenano-compositecoatingsarehighest,elementlinescanningandareascanninganalysesshowthattheaveragecontentsofelementsW,P,SiandCeinthenano-compositecoatingsareclose,displayingthatthedistributionofeveryelementwithinthenano-compositecoatingsiseven.Anincreaseinnano-SiO2particlesconcentrationsinelectrolyte(whenlowerthan20g·L-1)leadstorefinementingrainstructureofnano-compositecoatings,butwhenitimprovedto30g·L-1,thecrystallitesizesincreaseagainandinthemeantimetherearealotofsmallbosswithnodulationshapeappearingonthesurfaceofnano-compositecoatings.
简介：Ca8Mg(SiO4)4Cl2:Eu2+phosphordopedwithSr2+cationforCa2+partially,wassynthesizedbysolid-statereactionathightemperatureunderreducingatmosphere,anditsluminescentpropertieswereinvestigated.TheexperimentalresultsindicatethattheemissionintensityofthephosphorincreasesafterbeingdopedwithafewamountofSr2+ion.Theemissionpeakofthephosphorblueshifttoabout464nmwhenthephosphorisdopedwithlargequantityofSr2+ions.TheexcitationspectrumindicatesthatthephosphorcanbewellexcitedbyUVandbluelightfrom300to460nm,andthephosphorwasfittedwellfortheexcitationbyUVorblue-LED.
简介：CeZr，CeYZr，LaCeZr，LaCePrZr，LaCePrYZr，和LaCePr稳固的答案经由一起沉淀方法被准备，并且借助于X光检查衍射(XRD)和Brunauer-Emmett-Teller(赌注)技术描绘了。稳固的答案的氧存储能力(振荡)被脉搏技术评估，催化活动用一台4隧道催化作用设备被估计。稳固的答案介绍了立方的结构，这被看见。特定的表面区域和热稳定性能被做Y进稳固的答案提高。当做大量La减少了时，做La的小数量在热耐久性上有积极效果特定的表面区域和热稳定性。LaCePrZr和LaCePrYZr固体解决方案用在Nd抽取在特定的表面区域和热稳定性介绍了某个更高的值以后，与LaCePr充实的Baotou稀土元素矿物质残余综合了，当为汽车的经济催化剂用尽纯化，从而启用被过去常。ceria氧化锆固体答案的表面上的涂层Al2O3或SiO2层增加了特定的表面区域和热抵抗。
简介：Ca-dopedBaMgAl10O17:Eu2+,Mn2+(BAM)bluephosphorsweresynthesizedbyfluxassistedsolid-statereactionmethodusingCaF2andBaF2asco-flux.GooddispersityandparticlesizehomogenizationofhexagonalpurephaseBAMwereobtainedbysinteringat1400℃.TheeffectsoftheCa2+ionscontentonthestructure,morphologyandphotoluminescencepropertiesofthephosphorswerestudied.TheresultsindicatedthattheincorporationofCacoulddecreasethelatticeconstant,improvethehomogeneityanddispersityandenhancethephotoluminescence(PL)intensityofthephosphoreffectively.TheoptimumBa0.86Ca0.04Mg0.97Al10O17:0.1Eu2+,0.03Mn2+PLintensitywasenhancedforabout30%andrelativebrightnesswasimprovedabout4%.Furthermore,thesynthesizedBAMandcommercialBAMphosphorswereannealedfor30minat600oCinair.TheCa-dopedphosphorshadstrongeremissionintensity,higherbrightnessandbetterchromaticitystabilitythanthatofthecommercialphosphor.TheseresultsindicatedthatCa-dopedbluephosphorshadgoodpotentialapplicationsinthecommercialtricolorfluorescentlampsaswellasinotherdisplayandlamps.
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![Synthesis, Crystal Structure of [ （MeC5H4）<b style='color:red'>2</b>Ln（μ-OCH<b style='color:red'>2</b> CH<b style='color:red'>2</b>NMe<b style='color:red'>2</b> ） ]<b style='color:red'>2</b> （Ln = Sm, Y, Nd） and Their Catalytic Activity for Ring-Opening Polymerization of ε-Caprolactone](/image/thesis10 "Synthesis, Crystal Structure of [ （MeC5H4）<b style='color:red'>2</b>Ln（μ-OCH<b style='color:red'>2</b> CH<b style='color:red'>2</b>NMe<b style='color:red'>2</b> ） ]<b style='color:red'>2</b> （Ln = Sm, Y, Nd） and Their Catalytic Activity for Ring-Opening Polymerization of ε-Caprolactone")
