学科分类
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27 个结果
  • 简介:香港创作单位sbya-la-la在平面设计,产品包装等媒体创作上享有盛名,单位中极具代表性的摄影师Wing,Shya操刀是装声国际,这次首度跟日本年青时装品牌A/T来个3-D交叉合作,由sbya-la-la负责款式和图案设计,Wing.Shya操九目录摄影,更邀请了日籍名模RilsOkazorri亲身演绎,在各方实力单位共同努力下,一只名叫Grabbitl的粉紫小兔诞生了。

  • 标签: 演绎 平面设计 产品包装 WING 时装品牌 图案设计
  • 简介:电子温度和电子数字密度是在血浆的描述的重要参数。在电子温度和土壤血浆的电子数字密度由激光产生了的这份报纸,脱离在不同分泌物电压与毫微秒分泌物火花结合了被学习了。Saha-Boltzmann阴谋并且空拓宽被用来决定温度和电子数字密度。本地热平衡在毫微秒火花被完成,这被证明提高的血浆。提高的光排放,到噪音比率的信号和以在不同火花电压的信号紧张的相对标准差的稳定性详细被调查。一个相对稳定的分泌物过程在带的试验性的配置下面与10kV分泌物电压的使用被观察。

  • 标签: 土壤温度 电子密度 等离子体 Stark加宽 电子数密度 放电电压
  • 简介:Inthispaper,MPt/C(M=La,Nd)catalystsofPEMFCweresynthesizedbymicrowaveradiationprocess.ThecrystallinityandstructureofcatalystswererespectivelyanalyzedbyXRDandnitrogenadsorptiontests.Theactivityofcatalystswasinvestigatedbyelectrochemistryexperiment.Theresultsshowedthat:1)comparedwithPt/Ccatalystpreparedbytypicalimpregnation-reductionprocess,thesizeofMPt/CcatalystparticledecreasedandtheavailablecrystalforO2reductionincreased;2)theMPt/CcatalystshadrelativelyhighBETsurfaceareas;and3)thesecrystaltransformationsoftheMPt/Ccatalystbroughthightheelectrocatalyticactivity,andasaresult,improvedthepowerofPEMFC.

  • 标签: 合成 微波辐射 聚合物电解质膜燃料电池 催化剂 X射线衍射 氮吸附试验
  • 简介:ThepartialoxidationofethanoltohydrogenwasinvestigatedoverNi/Fe/Lacatalystspreparedbytheco-precipitationmethod.TheeffectsofintroductionofLapromoterandthereactiontemperatureonthecatalyticperformancewerestudied.ItwasfoundthattheintroductionofLaintoNi/Fecatalystsishelpfultoincreasetheselectivitytohydrogenandthestabilityofthecatalysts.TheresultsofXRDandXPScharacterizationshowthatthestructureofthecatalystwaschangedduringthereaction.TheexistenceofLaFeO3speciesispossiblythemainreasonoftheincreaseofthecatalyststability.

  • 标签: 乙醇 局部氧化 镍/铁催化剂 氢转移
  • 简介:Thebilayerorganiclight-emittingdiode(OLED)withabluefluorescentlanthanumcomplex,tris(1-phenyl-3-methyl-4-isobutyryl-5-pyrazolone)-(2,2′-dipyridyl)lanthanum[La(PMIP)3(Bipy)],asalightemittingmaterialandN,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine(TPD)asaholetransportingmaterialemitsbrightgreenlightinsteadofbluelight.Thedataoftheabsorption,thephotoluminescence(PL)andthephotoluminescenceexcitation(PLE)spectraofTPD,La(PMIP)3(Bipy)andthemixtureofTPDandLa(PMIP)3(Bipy)(molarratio1∶1)provethattheelectroluminescentemissionoriginatesfromtheexciplexontheinterfacebetweenTPDandLa(PMIP)3(Bipy).Byimprovingdeviceconfigurationwithtris(8-hydroxyquinoline)aluminum(ALQ)asanelectrontransportingmaterial,amaximumluminanceof800cd/m2wasobtained.

  • 标签: 电致发光 光致发光 镧配合物 双分子层有机发光二极管 1-苯基-3-甲基-4-异丁酰-5-吡唑啉酮)- (2 2'-二吡啶基)
  • 简介:AseriesofdoubleperovskitesRSrMnFeO_6(R=La,Pr,Nd,Sm)wassynthesizedundermildhydrothermalconditions.Crystalgrowthsofthesamplesweresensitivetoalkalinity,temperature,fillingfraction,andcompositionofinitialreactionmixture.ThedesiredseriesofcompoundsbelongstotheclassofAA'BB'O_6perovskiteswitharandomdistributionofMnandFeatomsovertheB-cationsub-lattice.TheirstructuresshowthedistortedorthorhombicsymmetrywithspacegroupPnma.TheshapesandsizesofthecrystalswereanalyzedonaRigakuJSM-6700Fbyscanningelectronmicroscopy.AnalysisdonebyXPS,MssbauerspectroscopyandiodometrictitrationrevealsthatMnandFeionshave+4and+3oxidationstates,respectively.

  • 标签: 钙钛矿相 水热合成 扫描电子显微镜 表征
  • 简介:ThedetailedkineticsofFischer-TropschsynthesisoveranindustrialFe/Cu/La/Sicatalystwasstudiedinacontinuousspinningbasketreactorundertheconditionsrelevanttoindustrialoperations.ReactionrateequationswerederivedonthebasisofLangmuir-HinshelwoodHougen-WatsontypemodelsforFischer-Tropschsynthesisbasedonpossiblereactionssetsoriginatedfromthecarbide,enolicandcombinedenol/carbidemechanisms.Kineticmodelcandidateswereevaluatedbytheglobaloptimizationofkineticparameters,whichwererealizedbyfirstminimizationofmulti-responseobjectivefunctionswithconventionalLevenberg-Marquardtmethod.Itwasfoundthatanenolicmechanismbasedmodelcouldproduceagoodfitoftheexperimentaldata.Theactivationenergyforparaffinformationis95kJmol-1whichissmallerthanthatforolefinformation(121kJmol-1).

  • 标签: FISCHER-TROPSCH合成 Levenberg-Marquardt方法 催化剂 反应速率方程 动力学参数 动力学模型
  • 简介:Synthesis,structureandmagneticpropertiesofRudopedperovskitestructuredmanganiteLa0.5Sr0.5MnO3wereinvestigatedexperimentally.Ahydrothermalmethodwasusedforthepreparationofthesamples.Ahigh-temperatureannealingprocesswasalsoemployedtomakeacomparison.AslightlyenhancementoftheunitcellvolumewasobservedwiththeincreaseofRuconcentration.Scanningelectronmicroscopyshowsthatthematerialsaremadeupofcube-shapedparticleswithdimensionofseveralmicrometers.Importantly,itisfoundthatboththeCurietemperatureTCandsaturationmomentcanbereducedbyRudoping.ThevalueofcoercivefieldisnotaffectedbytheintroductionofRu.

  • 标签: La0.5Sr0.5MnO3 HYDROTHERMAL synthesis RU DOPING CURIE
  • 简介:ThetemperaturedependenceofresistivityρofYSZdopingcompositeof(1-x)La0.67Ca0.33MnO3+xYSZandY2O3dopingcompositeof(1-y)La0.67MnO3+yY2O3isinvestigated,respectively,inatemperaturerange77-300K,wheretheYSZrepresentsyttria-stabilizedzirconia(8mol%Y2O3+92mol%ZrO2).ExperimentalresultsshowthattheYSZdopinglevelhasimportanteffectsonboththemetal-insulator(M-I)transitiontemperaturesandzerofieldresistivityofthecompositesof(1-x)La0.67Ca0.33MnO3+xYSZ.However,theY2O3dopinglevelhaslittleeffectontheM-Itransitiontemperaturesandthezerofieldresistivityof(1-y)La0.67Ca0.33MnO3+yY2O3onlyincreasesslightly.Thedifferencebetweenthetwotypesofcompositesmaymainlyresultsfromthedifferentdistributionofhighresistancephasesatthegrainboundariesand/orsurfacesofLa0.67Ca0.33MnO3grainsratherthanthesubstitutionofLa^3+ionswithY^3+ions.

  • 标签: LA0.67CA0.33MNO3 镧钙锰氧化物 巨磁致电阻效应 磁性材料 温度 高阻相效应
  • 简介:采用微波合成法制备了含掺杂P,Al和La元素的正极材料LiCoO2,确定了工艺条件,包括反应时间、微波功率和反应温度.采用XRD,SEM和电化学测试仪研究了添加元素对LiCoO2结构和电化学性能的影响.研究发现,微波功率和反应时间对产物的结构有比较明显的影响.充放电试验结果表明,掺加La元素正极材料LiCoO2首次充放电容量达到了130mAh·g^-1.

  • 标签: 掺杂 锂离子电池 正极材料 微波合成
  • 简介:Inthecurrentpaper,dry(CO2)-reformingofglycerol,anewreformingroute,wascarriedoutoveralumina(Al2O3)-supported,non-promotedandlanthanum-promotednickel(Ni)catalysts.Bothsetsofcatalystsweresynthesizedviaawetco-impregnationprocedure.Physicochemicalcharacterizationofthecatalystsshowedthatthepromotedcatalystpossessedsmallermetalcrystallitesize,hencehighermetaldispersioncomparedtothevirginNi/Al2O3catalyst.ThiswasalsocorroboratedbythesurfaceimagescapturedbytheFESEManalysis.Fromtemperature-programmedcalcinationanalysis,thederivativeweightprofilesrevealedtwopeaks,whichrepresentawatereliminationpeakatatemperaturerangeof373to473Kfollowedbynickelnitratedecompositionfrom473to573K.Inaddition,BETsurfaceareameasurementsgave85.0m2g-1forthenon-promotedNicatalyst,whilstthepromotedcatalystsshowedanaverageof1%to6%improvementdependingontheLaloadings.Significantly,reactionstudiesat873KshowedthatglyceroldryreformingsuccessfullyproducedH2.The2%La-Ni/Al2O3catalyst,whichpossessedthelargestBETsurfacearea,gaveanoptimumH2generation(9.70%)ataglycerolconversionof24.5%.

  • 标签: Ni CATALYSTS dry REFORMING LANTHANIDE promotion
  • 简介:Perovskite-typeLa1-xCexMnO3(x=0-10%)catalystswerepreparedbyflamespraypyrolysisandtheiractivitiesduringthecatalyticoxidationofbenzenewereexaminedoverthetemperaturerangeof100-450℃.ThestructuralpropertiesandreducibilityofthesematerialswerealsocharacterizedbyX-raydiffraction(XRD),N2adsorption/desorption,H2temperature-programmedreduction(H2-TPR)andX-rayphotoelectronspectroscopy(XPS).TheincorporationofCewasfoundtoimprovethebenzeneoxidationactivity,andtheperovskiteinwhichxwas0.1exhibitedthehighestactivity.Phasecompositionandsurfaceelementalanalysesindicatedthatnon-stoichiometriccompoundswerepresent.TheincorporationofCehadanegligibleeffectonthespecificsurfaceareaoftheperovskitesandhencethisfactorhaslittleimpactonthecatalyticactivity.IntroductionofCe44+resultedinmodificationofthechemicalstatesofbothB-siteionsandoxygenspeciesandfacilitatedthereducibilityoftheperovskite.ThesurfaceMn4+/Mn3+ratiowasincreasedasaresultofCe4+substitution,whileadecreaseinthesurface-adsorbedO/latticeO(Oads/Olatt)ratiowasobserved.Therelationshipbetweenthesurfaceelementalratiosandcatalyticactivitywasestablishedtoallowabetterunderstandingoftheprocessbywhichbenzeneisoxidizedoverperovskites.

  • 标签: 钙钛矿型 氧化铈 催化剂 掺入 火焰 X射线光电子能谱
  • 简介:Rare-earthcompoundsolidsuperacidSO42-/TiO2/La3+wasprepared.Itscatalyticactivitywasexaminedunderdifferentsyntheticconditionsfortheesterificationofpropanoicacidandn-butylalcoholasprobingreaction.Theoptimumconditionswerealsofound,whichwerethepH=8,thedepositingtimewas24h,themassfractionofLa(NO3)3usedinsolidsuperacidwas5%,theconcentrationofH2SO4was1.25mol/L,thesoakingtimeinH2SO4was16handthecalciningtemperaturewas500°C.TheethyloleatewassynthesizedfromoleicacidandethanolinthepresenceofSO42-/TiO2/La3+.Theoptimumreactionconditionswereobtainedwhichwerethereactiontimewas6h,molarratioofoleicacidtoethanolwas1:4andthemassfractionofcatalystwas4%.

  • 标签: 复合固体超强酸 油酸乙酯 催化合成 硫酸浓度 最佳反应条件 存放时间
  • 简介:Thispaperreportsonthelongevityofglycerol-dry(CO2)reformingoverthelanthanum(La)promotedNi/Al2O3catalysts.TheXRDresultsshowedthattheNiparticlewaswell-dispersedinthepresenceofLapromoter.Inaddition,viatheNH3-TPDanalysis,itwasfoundthattheLapromoterhasreducedtheacidityofNicatalystwhichmayhaveexplainedthemitigationofcarbonlaydown.Itwasdeterminedthatthe3.0wt%La-promotedNi/Al2O3catalystpossessedthelargestBETspecificsurfaceareaof97m2g-1.Consequently,ityieldedthebestcatalyticlongevityperformancewithconversionattainedmorethan90%,evenafter72hofreactionduration.Significantly,itcanbeconfirmedthatthepresenceofCO2duringtheglyceroldryreformingwasessentialinreducingcarbondeposition,mostlikelyviagasificationpathway.Thishasensuredastabilityofcatalyticactivityforalongreactionperiod(72h).

  • 标签: 镍催化剂 Al2O3 CO2 甘油 重整 长寿
  • 简介:采用燃烧法合成了La1.6(MoO_4)_3:Eu_0.4^3+纳米晶末,研究了其声子一掺杂-晶格相互作用和发光性质。x射线粉末衍射(XRD)分析表明,在500~900℃退火后,La1.6(MoO_4)_3:Eu_0.4^3+样品为单一晶相。对样品进行了光致发光(PL)测量,激发Mo^6+-O^2-电荷迁移带,观察到Eu^3+的系列发光,表明Mo^6+-O^2-带和Eu^3+间存在能量传递,中心波长分别在λ1=469nm和λ2=426nm处的两个one-phonon边带,相应的声子能量分别为767和1202cm^-1,分别对应于Mo=0和Mo-0-Mo伸缩振动。同时,计算了两个局域模电子一声子耦合强度的黄昆因子分别为S1=0.055和S2=0.037,为揭示其三价离子高传导特性及其负热膨胀物理特性提供了实验基础。

  • 标签: 发光特性 燃烧法 La1.6(MoO_4)_3:Eu_0.4^3+纳米晶 局域模 one-phonon边带