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简介:P-typenitrogen-dopedZnOfilmsarepreparedsuccessfullybyin-situthermaloxidationofZn_3N_2films.Thepreparedfilmsarecharacterizedbyx-raydiffraction,non-Rutherfordbackscattering(non-RBS)spectroscopy,xrayphotoelectronspectroscopy,andphotoluminescencespectrum.TheresultsshowthattheZn_3N_2filmsstarttotransformtoZnOat400°Candthetotalnitrogencontentdecreaseswiththeincreasingannealingtemperature.Thep-typefilmsareachievedat500℃withalowresistivityof6.33Ω·cmandahighholeconcentrationof+8.82×10~(17)cm~(-3),aswellasalowlevelofcarboncontamination,indicatingthatthesubstitutionalnitrogen(N_O)isaneffectiveacceptorintheZnO:Nfilm.ThephotoluminescencespectrashowclearUVemissionsandalsoindicatethepresenceofoxygenvacancy(V_O)defectsintheZnO:Nfilms.Thep-typedopingmechanismisbrieflydiscussed.
简介:Wehavereportedthemassmeasurementsofneutron-deficientnuclides79Y,81;82Zr,83;84Nbinthisyear’sAnnualReport.However,fortheN=ZnuclidesclosetoA=80,theyieldismuchlowerandeveniftheycanbeproduced,thereisstillgreatdifficulttoidentifythembecauseoftheirquitesimilarmass-to-chargeratioandrevolutiontimes.However,theirmassareextremelyimportantforrapidprotoncaptureprocess,forexample,80Zrand84Moarewaitingpointsofrp-process.Theirmassescangreatlyeffectthereactionflowofprotoncaptureonthemandthentheabundanceoftheheaviernuclides.Inaddition,theseparationenergyof84Mo(determinedbythemassof80Zrand84Mo)hasastrongimpactonthe83Nb(p,α)reactionrateandplaysakeyroleintheformationofZr-NbFig.
简介:InthispaperweusedMOF-5andCu3(BTC)2toseparateCO2/CH4andCH4/N2mixturesunderdynamicconditions.Bothmaterialsweresynthesizedandpelletized,thusallowingforameaningfulcharacterizationinviewofprocessscale-up.ThematerialswerecharacterizedbyX-raydiffraction(XRD)andscanningelectronmicroscopy(SEM).Byperformingbreakthroughexperiments,wefoundthatCu3(BTC)2separatedCO2/CH4slightlybetterthanMOF-5.BecausethecrystalstructureofCu3(BTC)2includesunsaturatedaccessiblemetalsitesformedviadehydration,itpredominantlyinteractedwithCO2moleculesandmoreeasilycapturedthem.Conversely,MOF-5withasuitableporesizeseparatedCH4/N2moreefficientlyinourbreakthroughtest.
简介:Theequilibriumgeometries,relativestabilities,andelectronicpropertiesofMnAgm(M=Na,Li;n+m≤7)aswellaspureAgn,Nan,Lin(n≤7)clustersaresystematicallyinvestigatedbymeansofthedensityfunctionaltheory.Theoptimizedgeometriesrevealthatfor2≤n≤7,therearesignificantsimilaritiesingeometryamongpureAgn,Nan,andLinclusters,andthetransitionsfromplanartothree-dimensionalconfigurationsoccuratn=7,7,and6,respectively.Incontrast,thefirstthree-dimensional(3D)structuresareobservedatn+m=5forbothNanAgmandLinAgmclusters.Whenn+m≥5,astrikingfeatureisthatthetrigonalbipyramidbecomesthemainsubunitofLinAgm.Furthermore,dramaticodd-evenalternativebehavioursareobtainedinthefragmentationenergies,secondorderdifferenceenergies,highestoccupiedandlowestunoccupiedmolecularorbitalenergygaps,andchemicalhardnessforbothpureanddopedclusters.Theanalyticresultsexhibitthatclusterswithanevenelectronicconfiguration(2,4,6)possesstheweakestchemicalreactivityandmoreenhancedstability.
简介:Thesuppressionoftherecombinationofelectronsandholes(e–h)andtheenhancementofthelightabsorptionofsemiconductorsaretwokeypointstowardefficientphotocatalyticdegradation.Here,wereportafew-layerg-C3N4/α-MoO3nanoneedles(flg-C3N4/α-MoO3NNs)all-solid-stateZ-schememechanismphotocatalystsynthesizedviaatypicalhydrothermalmethodinacontrolledmanner.Therecombinationofthephoto-inducede–hpairscouldbeeffectivelyrestrainedbytheZ-schemepassagewaybetweentheflg-C3N4andα-MoO3NNsinthecomposite,whichcouldalsopromiseahighredoxabilitytodegradepollutants.Anditbecamepossibleforthepreparedphotocatalysttoabsorblightinawiderangeofwavelengths.Thedetailedmechanismwasstudiedbyelectronspin-resonancespectroscopy(ESR).Thelow-dimensionalnanostructureofthetwoconstituents(α-MoO3NNswithone-dimensionalstructureandflg-C3N4withtwo-dimensionalstructure)endowedthecompositewithvarietiesofexcellentphysicochemicalproperties,whichfacilitatedthetransferanddiffusionofthephotoelectronsandincreasedthespecificsurfaceareaandtheactivesites.The10wt%flg-C3N4/α-MoO3NNsshowedthebestphotocatalyticperformancetowardRhBdegradation,therateofwhichwas71.86%,~2.6timeshigherthanthatofα-MoO3NNs.