简介：Vanadiumdioxide(VO2)isaphasetransitionmaterialwhichundergoesareversiblemetal-insulatortransition(MIT)whentriggeredbythermal,photo,electrical,andevenstress.ThehugeconductionchangeofVO2rendersitapromisingmaterialforterahertz(THz)manipulation.Inthispaper,someinterestingworksconcerningthegrowthandcharacteristicsoftheVO2filmareselectivelyreviewed.AswitchingofTHzradiationbyphoto-drivenVO2filmisdemonstrated.ExperimentsindicateanultrafastopticalswitchingtoTHztransmissionwithin8picoseconds,andaswitchingratioreachestoover80%duringawidefrequencyrangefrom0.3THzto2.5THz.

简介：Thelow-gradevanadium-containingstonecoalusedinthisexperimentwascollectedfromWuxiCountry,ChongqingCity,China.Theexperimentfocusedonthevanadiumrecoveryfromroastedresiduethroughoptimizingtheprocessconditionsofaneffectiveandenvironmentally-friendlytechnology,namedcalcifiedroasting-sulfuricacidleachingtechnology.Bysingle-factorexperimentsandorthogonalexperiments,theeffectsofroastingtemperature,roastingtime,sulfuricacidconcentrationandleachingtimeontheleachingratioofvanadiumwereanalyzed.Theresultsshowedthattheleachingratioofvanadiumreached85.5%underthepropertechnologicalconditionsofroastingtemperature=950℃,roastingtime=4h,40%concentrationofsulfuricacidandleachingtime=6h.

简介：ThevanadiumspecieswerecontaminatedonFCCcatalystsbyusingtheMitchellmethod.AfterthehydrothermaldeactivationoftheFCCcatalysts,thecrackingreactionwasperformedonthesecatalystsamples.ThetestresultsrevealedthattheconversionoffeedstockandthegasolineyieldobtainedovertheFCCcatalystswithvanadiumtrappingcomponentswereobviouslyhigherthanthosewithoutadditionofvanadiumtrappingcomponents.TheresultsalsoshowedthatthedrygasandcokeselectivityontheFCCcatalystscontainingvanadiumtrappingcomponentswasimproved.TheX-Raydiffractionresultsprovedthatthezeolitecrystalstructurewaswellprotectedbythevanadiumtrappingcomponentsduringitshydrothermaldeactivationstep.TheresultsofSEM-EDXmappingdisclosedthatthevanadiumwasenrichedonthevanadiumtrappingcomponentswhichverifiedthepositivefunctionofvanadiumtrappingcomponents.

简介：Itiswellknownthatvanadiumalloywillfacetostrongneutronirradiationandhydrogenenvironmentsasastructuralmaterialinafusionreactor.Someresearcheshavereportedthatvanadiumalloytookstronglyhardeningafteranexposuretohydrogenenvironmentandirradiationbyneutronatatemperaturelowerthan400℃.Theductilityofthealloywaslostlargely,evenentirelybrittlefractureoccurredsometimesintensionloadingofthealloy.Therefore,it'stogettheknowledgeofthehardeningmechanismandthefracturemechanicalforthepurposetoimprovetheperformancesofthealloyunderthecircumstances.

简介：

简介：Vanadiumalloyisoneofthemostimportantcandidatestructuralmaterialsforafusionreactor.Itsmainadvantagesoverothercandidatesareitslowactivityfeatureandfeasiblepropertiesathightemperature.However,vanadiumiseasilyoxidizedathightemperaturetoformanon-protectivesurfacefilmofV2O5.Oxygenconcentrationwouldthusgethighandthepropertiesgetworseinnotonlythelossoftheductilitybutalsotheenhancedhydrogenembrittlementbytheoxidation.

简介：

简介：

简介：Thisstudydemonstratesanovelapproachforrapidsynthesisofsilver（Ag）nanowiresinducedbyvanadiumtrioxide（V2O3）particlesinaqueoussolutionatroomtemperature.Silvernanowireshaveanaveragediameterof20nmandlengthuptoafewmicrometersbyparametricoptimization.ThemicrostructureofthesilvernanowireswascharacterizedbyTEM,HRTEM,SEM,andXRDtechniques.Theopticalpropertyoftheas-preparedproductwasmeasuredbyultraviolet-visible（UV-vis）spectroscopy.ThepossiblegrowthmechanismofAgnanowiresviaorientedattachmentofAgnanocrystalswasdiscussed.Thepresentapproachshowsseveraluniquefeaturessuchasrapid（afewminutes）,reproducibleandhigh-yieldreactionwithnoneedofanymodifiers.V2O3rodswerereportedforthefirsttimetobeusedforsynthesisofsilvernanowires,playingmultiplerolesasreducingagent,template,andcatalyst.Thesilvernanowiresproducedarepromisingforopticalapplications（e.g.,SERS）duetotheirroughsurface.

简介：Hydrogenembrittlementisoneofthekeyissuesforthevanadiumalloysforfusionapplication.PreviousstudyhasshownthatV4TialloyhadbetterpropertiesagainsttheembrittlementthanV4Cr4TiandV4Ti3A1alloys.Itwasthoughtthatthebetterpropertywasbenefitedfromthesmallratioofitsyieldstrengthoveritsultimatetensilestrength.

简介：Thedissolutionkineticsofvanadiumtrioxideinsulphuricacid-oxygenmediumwasexamined.Itwasdeterminedthattheconcentrationofsulphuricacidandstirringspeedabove800rmin1didnotsignificantlyaffectvanadiumextraction.Thedissolutionrateincreasedwithincreasingtemperatureandoxygenpartialpressure,butdecreasedwithincreasingparticlesize.Thedissolutionkineticswascontrolledbythechemicalreactionatthesurfacewiththeestimatedactivationenergyof43.46kJ·mol-1.Thel...

简介：

简介：

简介：

简介：

简介：

简介：Vanadiumnitridewassynthesizedbyone-stepmethodusingV2O5andcarbonblackasrawmaterialsinnitrogenatmosphere.ThephasesofdifferentreactionproductspreparedindifferentreactiontemperatureswereanalyzedbyX-raydiffraction(XRD),andthedynamicbehavioroftheprocessofsynthesizingvanadiumnitride(VN)byone-stepmethodwasstudiedwithnon-isothermalthermogravimetry.Themechanismfunctionandkineticparametersofreactionprocesswerecalculatedbythermalgravimetricanalyses(TGA),andthereactionrateequationwasestablished.TheXRDresultsshowthatforthesamplestestedwithminimalVNafterholdingfor4hat1273K,themainphaseofproductsisVNat1476K,whilesomevanadiumnitridestransformintovanadiumcarbidesagainover1573K.ItisfoundthatN2isbeneficialtostimulatereductionandproceedcarbonizationreaction,andthereductionandnitridationreactioncanoccursimultaneously.TheactivationenergyofpreparingVNbyone-stepmethodis104.005kJ·mol-1,andthefrequencyfactoris470.52at1280–1358K,and150.052kJ·mol-1and2.359104at1358–1426K,respectively.

简介：Carbonclothmodifiedbyhydrothermaltreatmentinammoniawaterisdevelopedasthepositiveelectrodewithhighelectrochemicalperformanceforvanadiumredoxflowbatteries.TheSEMshowsthatthetreatmenthasnoobviousinfluenceonthemorphologyofcarboncloth.XPSmeasurementsindicatethatthenitrogenousfunctionalgroupscanbeintroducedonthesurfaceofcarbonclothsuccessfully.TheelectrochemicalperformanceofV（IV）/V（V）redoxcoupleonthepreparedelectrodeisevaluatedwithcyclicvoltammetryandlinearsweepvoltammetrymeasurements.TheN-dopedcarbonclothexhibitsoutstandingelectrochemicalactivityandreversibilitytowardV（IV）/V（V）redoxcouple.TherateconstantofV（IV）/V（V）redoxreactiononcarbonclothcanincreaseto2.27×10-4cm/sfrom1.47×10-4cm/safternitrogendoping.ThecellusingN-dopedcarbonclothaspositiveelectrodehaslargerdischargecapacityandhigherenergyefficiencycomparedwiththecellusingpristinecarboncloth.TheaverageenergyefficiencyofthecellusingN-dopedcarbonclothfor50cyclesat30mA/cm2is87.8%,4.3%largerthanthatofthecellusingpristinecarboncloth.ItindicatesthattheN-dopedcarbonclothhasapromiseapplicationprospectinvanadiumredoxflowbatteries.

简介：Ultrathinfree-standingelectrospuncarbonnanofiberweb（ECNFW）usedfortheelectrodesofthevanadiumflowbattery（VFB）hasbeenfabricatedbytheelectrospinningtechniquefollowedbythecarbonizationprocessinthisstudytoreducetheohmicpolarizationoftheVFB.Themicrostructure,surfacechemistryandelectrochemicalperformanceofECNFWcarbonizedatvarioustemperaturesfrom800to1400°Chavebeeninvestigated.TheresultsshowthatECNFWcarbonizedat1100°CexhibitsthehighestelectrocatalyticactivitytowardtheV2+/V3+redoxreaction,anditselectrocatalyticactivitydecreasesalongwiththeincreaseofcarbonizationtemperatureduetothedroopingofthesurfacefunctionalgroups.WhilefortheVO2+/VO2+redoxcouple,theelectrocatalyticactivityofECNFWcarbonizedabove1100°Cbarelychangesasthecarbonizationtemperaturerises.ItindicatesthatthesurfacefunctionalgroupscouldfunctionasthereactionsitesfortheV2+/V3+redoxcouple,buthavenotanycatalyticeffectfortheVO2+/VO2+redoxcouple.AndthesinglecelltestresultsuggeststhatECNFWcarbonizedat1100°CisapromisingmaterialastheVFBelectrodeandtheVFBwithECNFWelectrodesobtainsasuperlowinternalresistanceof250mΩcm2.

简介：