简介:PlasmaScienceandTechnology(ISSN1009-0630,CN34-1187/TL),anEnglishjournaloftheInstituteofPlasmaPhysics,theChineseAcademyofSciences(ASIPP)andtheChineseSocietyofTheoreticalandAppliedMeohanics,acceptspapersaboutnewachievementsandphaseresultsofplasmaphysics.Specificinterestareas
简介:Theplasmageneratedinthelow-altitudeatmosphereisofhighcollisionfrequencies.Inthispaper,thetransmissioncoefficientsofmillimeter(MM)wavesnormallyincidentupontheplasmawithhighcollisionfrequenciesarecalculatedandanalyzed.Theexperimentalresultsofreflectionandattenuationarepresentedfortheeight-millimeterwavespropagatingthroughtheplasma.BoththecalculatedexperimentalresultsindicatethattheMM-wavesconcernedareattenuatedsignificantlyandreflectedweakly,whenpropagatingthroughtheplasmaofhighcollisionfrequencies.
简介:Theelectrostaticsheathwithacylindricalgeometryinanion-electronplasmaisinvestigated.AssumingaBoltzmannresponsetoelectronsandcoldionswithbulkflow,itisshownthattheradiusofthecylindricalgeometrydonotaffectthesheathpotentialsignificantly.Wealsofoundthatthesheathpotentialprofileissteeperinthecylindricalsheathcomparedtotheslabsheath.Thedistinctfeatureofthecylindricalsheathisthattheiondensitydistributionisnotmonotonous.Thesheathregioncanbedividedintothreeregions,twoascendantregionsandonedescendantregion.
简介:Anexperimentandanalysisonremovalofgaseousbenzenebypulsecoronainducedplasmaispresentedinthisarticle.Importantparameterseffectingremovalefficiencyhavebeeninvestigated,suchaspulsepeakvoltage,pulsefrequency,gasinletconcentration,gasflowrateandreactortemperature.Theresultshowsthattheremovalefficiencyincreaseswiththeincreaseinpulsepeakvoltage,pulsefrequencyandreactortemperature,butdecreasesintheriseofgasinletconcentrationandgasflowrate.OntheconditionofVp=36kV,f=80Hz,C=1440mg/m^3andQ=640ml/min,thelargestremovalefficiencyis98%.Finally,thereactedproductsarequalitativelyanalysedandthereactionprocessesarededucedincombinationwithplasma-chemistrytheory.
简介:Inthiswork,resultsonthestudyofthestructureandphotoluminescence(PL)propertiesofSiOxNythinfilmsarepresented.Thefilmsweredepositedatroomtemperatureusingadual-ion-beamco-sputteringsystem.TheXRDandTEMresultsshowthatthedepositedfilmshaveanamorphousstructure.IntheXPSresult,wefindN1sspectraconsistofonesymmetricsinglepeakat397.8eV,indicatingthatthenitrogenatomsaremainlybondedtosilicon.ItisinagreementtotheresultofFTIR.InSiOxNyfilms,anintensesinglePLpeakat590nmisobserved.Furthermore,withtheincreaseoftheNcontentintheSiOxNyfilms,theintensityofthePLpeakat590nmincreasesalot.ThePLpeakof590nmissuggestedtooriginatefromN-relateddefects.
简介:Anewtwo-dimensionalstructuremodulationalongc-andb-axeshasbeendiscoveredinsuperconductingsinglecrystalsofBi2.13Sr1.87CuO6+δ(Bi2201)byx-rayscattering.Suchmodulationstructuredoesnotexistinnon-superconductingBi2201singlecrystals.Butinsteadlatticedistortionsareobservedinthea-b-plane.Thisphenomenonmayindicatethatbothstrainrelaxationandchargemodulationinthea-b-planeareimportanttotheoccurrenceofsuperconductivityinthecopperoxides.
简介:Geepilayersofdifferentthicknessesaregrownbymolecular-beamepitaxywithSbasasurfactantonSI(100)substrates,X-raydiffractionillustratesthattheseGethinfilmsarepartiallystrained.andthestrainsdecreasegraduallywithincreasingepilayerthickness,RamanspectrarevealadownwardshiftoftheGe-Gemodepeakastheepilayerthicknessincreases.Intheregionsofhighstrain,therelationshipbetweentheRamanshiftofthismodeandthestraininthepartiallyrelaxedsamplesisconsiderablydifferentfromthelinearrelationshipreportedbefore,whichismainlyattributedtothespatialconfinementeffectofphononsinananocrystal.
简介:WereportonastudyofinterfacialstructureofGaNfilmsgrownonGaAs(001)substratesbyplasma-assistedmolecularbeamepitaxyusingx-raygrazing-anglespecularreflection.WeshowthatinterfaciallayerswithelectrondensitiesdifferingfromthoseofGaNandGaAswereformedupondepositionofGaN.Itisalsofoundthattheinterfacialstructureofoursystemsdependsstronglyonthecourseoftheinitiallayerdeposition.ThephasepurityoftheGaNfilmswasexaminedbyx-rayreciprocalspacemapping.Asimplekineticgrowthmodelsuggestedbyourresultshasbeenpresented.
简介:TheexperimentalapparatusofX-rayfluorescence(XRF)microprobeanalysisatBeijingSynchrotronRadiationFacility(BSRF)isdescribedUsingthebovineliverasthestandardreference.theminimumdetectionlimit(MDL)oftraceelementwasmeasuredtodeterminethecapabilityofbiologicalsampleanalysisbysynchrotronradiationXRFmicroprobe.TherelativechangeofthecontentofthemajorortraceelementinthenormalandtumorpartofhumanbonetissueslicewasinvestigatedTheexperimentalresultrelationtotheclinicalmedicinewasalsodiscussed.
简介:ThegrowthdetectsinNd:YCa4O(BO3)3(Nd:YCOB)crystalswereinvestigatedbytransmissionsynchrotrontopography.ItwasfoundthatgrowthstriationsweretheprimarydefectsinNd:YCOBcrystals.Grown-indislocations.mosaicblocksandinclusionswerealsoobseredinthecrystals.Theeffectoftemperaturefieldontheformationofgrowthdefectsinthecrystalswasdiscussed.
简介:Insituwhite-beamsynchrotronradiationtopographicobservationsunderanelectricfieldhavebeenmadeontheKTiOPO4(KTP)familyofcrystals.Theinvestigationshowsastrongenhancementofdiffractedintensityforhklreflections(l≠0)andtopographiccontrastintheformoffinestriationswhentheexternalelectricfieldisparalleltothepolaraxis.Severalkkindsofdopedandundopedsampleswithvariousgrown-indefects,suchasdomainboundaries.growthstriations,growth-sectorboundaries.dislocations.etc.,havebeenstudiedindetail.Theresultssuggestthatthesedefectshaveverylittleeffectonthefield-inducedstriations,ItisbelievedthatthemovementofK^+ionsdrivenbytheelectricfieldleadstoalocalaccumulationofchargesandalatticedistortion.Thestronlyanisotropicconductivityisagoverningfactorintheexplanationofthefield-relatedphenomenainthiskindofquasi-one-dimensionalconductor.
简介:ThetransientopticalpropertiesofnovelPbSnanoparticlescoatedwith2.6-O-diallyl-β-cyclodextrines(CDs)werestudiedbythefemtosecondpump-probetechnique.Theresultsshowthattheultrafasttransient-inducedabsorptionforthenovelcase.ComparedtothePbSnanoparticlesstabilizedwithpolyvinylalcohol(PVA),wefindthattheprocessforthenovelcaseisdifferentfromthePbS(PVA),WesuggestthattheCDssurfacemodificationcantrapholesonthesurfaceofPbSnanoparticles.ThiscaninduceanefficientchargeseparationbetweenthePbSnanoparticlesanditssurfaceandresultinanultrsafast-inducedabsorptionfornovelPbSnanoparticles.
简介:TheballmillingofFe-24MnandFe-24Mn-6Simixedpowdershasbeenperformedbythehighenergyballmillingtechnique.ByemployingX-raydiffractionandMoessbauermeasurements.Theccmpositionevolutionduringthemillingprocesshasbeeninvestigated.TheresultsindicatetheformationofparamagneticFe-MnorFe-Mn-Sialloyswithametastablefccphaseasfinalproducts.whichimplythattheFeandMnproceedaco-diffusionmeenanismthroughthesurfaceoffragmentedpowders.Thethermalstabilityandcompositionevolutionoftheas-milledalloyswerediscussedcomparingwiththebulkalloy,.
简介:Highsolid-solubilityCo15Cu35alloyshavebeenpreparedbymeltspinningandsubmittedtoisothermalandanisothermalannealingtoobtaingranularalloys.TheX-raydiffraction(XRD)patternsweremeasuredtoinvesugatethedecompositionofsupersaturatedsolidsolutioninducedbyannealing.Theatomicdiffusionandstructuralevolutionduringtheheattreatmentwereinvestigated.Inviewoftheproblemslimitingtheirappllcation.thehigh-fieldmagneazationcurvesweremeasured.Byafittothehigh-fieldmagnetizationcurves,thegranuiaralloysarefoundhardtobemagneticallysaturatedattheearlystageofnucleationandgrowth.Themagnetizationbehaviorwascorrelacedtotheannealed-inducedstructurealevolutionandalsotothemagnetoresistanceeffect.
简介:Fe2O3nanoparticlescoatedwithsodiumdodecylbenzenesulphonate(DBS)orcetyltrimethylammoniumbromide(CTAB)werepreparedbyusingamicroemulsionmethodinthesystemwater/toluene.Thenanoparticleswerecharacterizedbymeansoftransmissionelectronmicroscopyandaverageparticlesizesof5.0nmand6.0nmwerefoundforDBS-modifiedandCTAB-modifiednanoparticlesrespectively.Thelocalatomicstructuresoftheseiron(Ⅲ)oxidenanoparticleswereprobedbyusingtheextendedx-rayabsorptionfine-structuretechnique.FeKabsorptionspectrawerecollectedatbeamline4W1BofBeijingSynchrotronRadiationFacility.Astructurealmodelwasproposedfordescribingtheiratomicstructures.TheFe-ObondlengthatthesurfaceofDBS-coatedFe2O3nanoparticleswasfoundtobesimilartothatinbulkFe2O3.buttherewasabout0.04AexpansionfortheCTAB-coatedFe2O3nanoparticles.Onthebasisofthemodelproposedinthispaper,thethicknessesofthesurfacelayerswereestimatedtobe0.5nmand0.7nm.respectively,fortheDBS-coatedandCTAB-coatedFe2O3nanoparticles.Theanharmonicityoftheatomicvibrationandtheasymmetryofatom-pairdistributionwerefoundtobelargeratthesurfaceofthenanoparticlesthaninthebulkmaterial,whiletheDebye-Wallerfactorsarealmostthesameforthesurfaceandthecorepartsofthenanoparticles.Itcanbeconcludedthattheatomicstructureofthenanoparticlesurfaceisordered.buttheatom-paridistributionisasymmetric.
简介:Organicgermaniumcompoundshavebeenextensivelyappliedinmedicineastonics,Inthispaper,thelocalstructuresoftwoorganicgermaniumcompounds,carboxyethylgermaniumsesquioxideandpolymericgermaniumglutamate,weredeterminedbyEXAFS.Thestructureparametersincludingcoordinationnumbersandbondlengthswerereported,andpossiblestructurepatternswerediscussed.
简介:LocalstructuresofthemolybdenumsulfidespeciesinthesultidedRh-Mo-K/Al2O3catalystswithvariousrhodiumloadingshavebeeninvestigatedbyXAFS.Fromthefittingresults.theMo-Mocoordinationnumberforthesamplefreeofrhodium(ca.3.7)issimilartothatforthecrystallineMoS2,indicatingthatthesupportedsulfidedmolybdenumspeciesmainlypresentaslargepatechesofMoS2-likeslabs.Fortherhodium-modifiedsamples,however,theamplitudesoftheMo-SandMo-Mocoordinationshellsaresharplyreduced,revealingahighdispersionoftheMoS2-likespeciesinthecatalysts,TheschemeofthemicrostructuresofthesulfidedmolybdenumspeciesstabilizedonthealuminasupportisdiscussedbasedupontheanalysisoftheEXAFSdata.
简介:Photoconductivityspectrameasurementofpolymersatx-rayenergiesaroundtheZnandCoKedges,showsobviousx-rayabsorptionfinestructureoscillations.Thephotoconductivityspectraobtainedforgappedandsandwichedelectrodegeometricsamples,indicatethattheshapeofphotoconductivityspectrumdependsontheelectrodeconfigurationofthesamples.Thethicknessoftheconductionlayercanbeestimatedfromthephotoconductivityspectrum.
简介:Extendedx-ray-absorptionfine-structuremeasurements(EXAFS)wereperformedonnanocrystalline(nc)elementalSesampleswithgrainsizesrangingfrom13to60nm.Accompaniedwiththepreviousstudy,weconcludedthat,withtherefinementinnc.Se.theintrachainstructure(thebondlength,thecoordinationnumber)isunchangedwhiletheinterchainspacingisenlarged.ThegrainboundaryinthencSeisfoundtobeinalow-energyconfigurationthatisdifferentfromthedisorderedgaslikegrainboundarystructure.
简介:Thenanoparticlesγ-Fe2O3coatedwithsurfactants.DBS,STandCTAB.repsectively.weresynthesizedbymicroemulsionmethod.Thecoatedferricoxides.whichshowenhancednonlinearopticalpropertiescomparedwiththeirbulkcounterpart.wereprobedbyEXAFSinsolutionforms.Thex=-rayabsorptionspectraforFeKedgeweremeasuredatroomtemperaturebyhelpofsynchrotronradiationlightsource.Extendedx-rayabsorptionfinestructureanalysisshowsthatthecoatinglayersoforganicmoleculesinteractwithsurfaceatomsofnanopartices,theFe-Obondlengthwasextended.