简介：ThislettermainlyaimstoinvestigatethemechanicalbehaviorwithinshearbandsinregolithbothundertheEarthandtheMoonconditionsviathedistinctelementmethod,inwhichanovelcontactmodelconsideringinterparticlevanderWaalsforcesandrollingresistanceisemployed.Theresultsshowthatforregolithunderbothconditionsthestresspathsarealmostidenticalinsideandoutsidetheshearbandsbutvoidratio,averagepurerotationrate,andstrainpathsareratherdistinctwithdilation,particlerotationandthesecondinvariantofstraintensormainlyoccurringwithinthebands.However,theregolithundertheMoonconditionhashigherpeakstrengthandmoresignificantstrainlocalizationthanthoseundertheEarthcondition.更多还原

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简介：Thispaperreportsthathexagonal-phaseLaF3:Yb30.20,Er30.02andLaF3:Yb30.20,Tm30.02nanocrystals(NCs)weresynthesizedviaahydrothermalmethod.Thetransmissionelectronmicroscopy,selectedareaelectrondiffraction,powderx-raydiffraction,andthermogravimetricanalysisareusedtocharacterizetheNCs.Under980nmexcitation,theYb3/Er3andYb3/Tm3codopedNCscolloidalsolutionspresentbrightgreenandblueupconversionfluorescence,respectively.TheseNCsshowefficientinfrared-to-violetandinfrared-to-visibleupconversion.TheupconversionfluorescencemechanismsofLaF3:Yb30.20,Er30.02andLaF3:Yb30.20,Tm30.02NCsareinvestigatedwitha980-nmdiodelaserasexcitationsource.

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简介：Inthepresentstudy,weinvestigatedtheeffectofceriumanderbiumdopingofthezirconiumdioxidematrix.Wesynthesizeddopedsamplesusinghydrothermalprocess.Theamountsofdopantusedwere0.5%,1%and5%molar(rareearthoxideoverzirconiumdioxide)respectively.ThesampleshavebeenstudiedviaX-rayDiffractionmeasurementsforthestructuralcharacterization.UVvisiblediffusereflectancewasusedfortheopticalanalysis,Brunauer-Emmett-Teller(BET)modelforthemeasurementofthesurfacearea.Finallythesampleshavebeenanalysedviaelectronparamagneticresonance(EPR)fortheelectroniccharacterization.Thenwetestedthenewsynthetizedmaterialstodeterminetheirphotocatalyticactivityinthereactionofdegradationofmethyleneblueperformedunderirradiationbydiodes(LEDs)emittingexclusivelyvisiblelight.

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简介：Theoccurrencemodesofalkaliandalkaline-earthmetals(AAEMs)incoalrelatetotheirreleasebehaviorandashformationduringcombustion.TobetterunderstandthetransformationofAAEMs,thereleasebehaviorofwater-soluble,HCl-soluble,HCl-insolubleAAEMsduringShenmucoal(SMcoal)oxy-fuelcombustioninthepresenceofSO2andH2Oinadrop-tubereactorwasinvestigatedthroughserialdissolutionusingH2OandHClsolutions.TheresultsshowthatthereleaseratesofAAEMsincreasewithanincreaseintemperatureunderthethreeatmospheresstudied.ThehighreleaseratesofMgandCafromSMcoalaredependentonthehighcontentofsolubleMgandCainSMcoal.SO2inhibitsthereleaseratesofAAEMs,whileH2Opromotesthem.TheeffectsofSO2andH2OontheNaandKspeciesaremoreevidentthanthoseonMgandCaspecies.AllthreetypesofAAEMsincoalcanvolatilizeinthegasphaseduringcoalcombustion.TheW-typeAAEMsreleaseexcessively,whereasthereleaseratesofI-typeAAEMsarerelativelylower.DifferenttypesofAAEMmayinterconvertthroughdifferentpathwaysundercertainconditions.BothSO2andH2Opromotethetransformationreactions.TheeffectofSO2wasrelatedtosulfateformationandthepromotionbyH2OoccursbecauseofadecreaseinthemeltingpointofthesolidaswellasthereactionofH2O.

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