简介:Pt/WO3/CnanocompositeswithparallelWO3nanorodsweresynthesizedandappliedasthecathodecatalystforprotonexchangemembranefuelcells(PEMFCs).Electrochemicalresultsandsinglecelltestsshowthatanenhancedactivityfortheoxygenreductionreaction(ORR)isobtainedforthePt/WO3/CcatalystcomparedwithPt/C.ThehighercatalyticactivitymightbeascribedtotheimprovedPtdispersionwithsmallerparticlesizes.ThePt/WO3/Ccatalystalsoexhibitsagoodelectrochemicalstabilityunderpotentialcycling.Thus,thePt/WO3/CcatalystcanbeusedasapotentialPEMFCcathodecatalyst.
简介:Theshapeofnanostructurehasimportanteffectsontheirproperties,thereforeinthisstudy,wehavepreparedandcharacterizedthreedifferentmorphologiesofWO3nanostructuresi.e.nanorod,nanosphereandnanoplateforsurveyingshapeeffectontheirphotocatalyticpropertiestowarddegradationofRhodamineB(RhB)dye.ObtainedresultsshowthatnanoplateWO3incomparisonwithothershasthebestphotocatalyticactivity.AccordingtoSEM,andphotocatalyticdegradationresults,thereasonforthisbehavioristhesharpedgesandcornersofWO3nanoplates.Becauseoftheirlowcoordinationnumber,atomslocatedintheedgesandcornersoftheWO3nanoplateshavemoreactivity,adsorbmoreRhBandthereforegivemorephotocatalyticactivitytotheWO3nanoplates.UsingofdifferentscavengersshowedthathydroxylradicalsaremainlyresponsibleforphotocatalyticactivityofWO3nanoplatesandnanospheresbutforWO3nanorods,superoxideradicalsarethemainphotocatalyticdegradationagents.
简介:在这研究,为海洋的申请目的,我们评估了在微观结构,机械加强和经由电极淀积生产的Zn-TiO2-WO3nanocomposite的腐蚀抵抗性质上装载的过程参数和粒子的效果。我们与与一个精力散分光计(版本)装备的一台扫描电子显微镜(SEM)描绘了合成涂层的词法性质。我们用一个Dura扫描坚硬测试者和一件必然发生的事情执行了机械检查UMT-2多功能的tribological测试者。我们在3.5%NaCl由线性极化评估了腐蚀性质。结果证明涂层展出了好稳定性,极大地装载的量的粒子提高了结构、词法的性质,坚硬行为和涂层的腐蚀抵抗。我们观察到钢上的这合金的降水被合成特征极大地影响。
简介:Ti-dopedW03filmswerepreparedbythemid-frequencydual-targetmagnetronsputteringmethod.ThestructureandelectrochromicpropertiesoftheTi-dopedWO3filmswereanalysedbyX-Raydiffraction(XRD),Ramanspectroscopy,spectrophotometer,cyclicchronoam-perometryandatomicforcemicroscopy(AFM).Theresultsindicatethatthecrystallinitydecreaseafterthedopingoftitanium,thechannelsforioninjectionandextractionincrease,therespondingspeedwith5.1%titaniumdopedbecomesfaster,anditscirclelifeincreasesmorethanfourtimescomparedwiththeundopedWOafilm.Inthecolouredstate,theW-O-Wbondsdecrease,buttheW=Obondsincrease.SincetheW-O-WbondsbreakdownforLi~+ions'injectionandmoreW=Obondsform,itismoreconvenienttoinjectLi~+ionsintotheTi-dopedfilmthanundopedfilmbecausemoreW-O-Wbondsbreakdowninthecolouredstate.
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.
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.
简介:ThesinglecrystalgrowthofstoichiometrichostluminescentcrystalNa5Eu(WO4)4hasbeeninvestigated.UsingNa2WO4asaflux,theoptimumconditionstogrowapuresinglecrystalbyflux-slow-coolingmethodhavebeendetermined.Ahighopticalqualitysinglecrystalofdimention4.5mmhasbeengrown,whichisthelargestoneasweknowsofar.Themicro-hardnessofNa5Eu(WO4)4singlecrystalis3.46×103MPa.Itsrefractiveindexis1.81inwhitelightwavelengthregionandthespecificgravityis5.65g/cm3.Thefluorescentandexcitationspectrahavebeendeterminedandthereasonofthefluorescentquenchof5D2and5D1to7FjofEu3+canbeexplainedasmulti-phononnon-radiationtransition.
简介:中文摘要:随着现代计算机网络技术和现代网络通信技术的不断飞速发展,人们常常受到各种新型网络服务管理系统的严重影响。变化的结果是,中国中国网络商品交易市场的活跃用户群体规模和网络交易人员规模正在呈现出巨大的快速增长变化趋势。"网络交易"的这个概念一直影响着各行各业。根据中国互联网络信息中心(cnnic)网站发布的《第36次中国互联网发展状况统计报告》,截至2015年6月,中国中国网民浏览数量已经到达6.68亿,互联网网民普及率预计为48.8%。半年共累计新增注册网民1894万5千人。互联网对人们个人日常生活方式的直接影响进一步得到深化,从基于网络信息流的获取、通讯、娱乐多种需求的新型个性化服务应用,到与现代医疗、教育、交通等各类公共服务方式深度相互融合的新型民生公共服务。为了更好满足广大消费者对无线网络的各种需求,网络家装二手市场应运而生。今天我们就主要一起来详细分析一下二手交易服务平台的系统运行机制、独特服务优势以及对二手商圈的未来发展和商业引流模式有何重要影响。
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:ElectrocrystallizationMechanismofTungsteninMoltenKF-B_2O_3-K_2WO_4WenZhenhuanandLiGuoxun文振环,李国勋(GeneralResearchInstiiuteforNo...
简介:AnewtypeofcomplexsolidsuperacidcatalystWO3-ZrO2-SO42-withanacidstrengthH0≤-16.04waspreparedbykneadingZr(OH)4oramorphousZrO2withtungsticacid(H2WO4)(W/Zr=0.15),followedbyexposingthiscomplexhydroxidesto0.5tool/LH2SO4,calcininginairat700~800℃for3h.ThiscatalystpossessesbothstrongBronstedacidityandstrongLewisacidityexperimentallyshowedbyIRobservationofpyridineabsorbedonit.XPSandAEStechniqueswereemployedtoexaminethevalencestatesoftungsten,zirconium,sulfurandtheirinteractions.Thestructureofsulfurspecieswasstudiedbyinfraredspectroscopyandastructuremodelofactivesitewasproposedupontheseresults.