简介:Amild,regioselective1,3-dipolarcycloadditionprotocolforthepreparationofphenylselenomethylisoxazolinesthroughsubstitutedallylphenylselenidesandnitrileoxideswasreported.
简介:Three—layerback—propagationneuralnetworkswereusedforprocessingtheinformationprovidedbytheultravioletspectraoffive—componentmixtures,affectingthesimultaneousdeterminationofthecomponentswithsatisfactoryresults.
简介:Poly(vinylidenefluoride)(PVDF)/multi-walledcarbonnanotube(MWCNT)nanocompositeswerepreparedbymeansofultrasonicdispersionmethod.X-raydiffraction(XRD)resultsindicatethatincorporatingMWCNTsintoPVDFcausedtheformationofβphase.Athermalannealingat130°Cconfirmedthattheβphasewasstableinthenanocomposites.Differentialscanningcalorimetry(DSC)resultsindicatethatthemeltingtemperatureslightlyincreasedwhiletheheatoffusionmarkedlydecreasedwithincreasingMWCNTcontent.ThetensilestrengthandmodulusofPVDFwereimprovedbyloadingtheMWCNTs.Thescanningelectronmicroscopy(SEM)observationsshowedthatMWCNTswereuniformlydispersedinthePVDFmatrixandaninterfacialadhesionbetweenMWCNTandPVDFwasachieved,whichwasresponsiblefortheenhancementinthetensilestrengthandmodulusofPVDF.
简介:Polyamide/acrylonitrile-butadiene-styrenecopolymer(PA/ABS)blendshavedrawnconsiderableattentionfrombothacademiaandindustryfortheirimportantapplicationsinautomotiveandelectronicareas.DuetopoormiscibilityofPAandABS,developinganeffectivecompatibilizationstrategyhasbeenanurgentchallengetoachieveprominentmechanicalproperties.Inthisstudy,wecreateasetofmechanicallyenhancedPA6/ABSblendsusingtwomulti-monomermelt-graftedcompatibilizers,SEBSg-(MAH-co-St)andABS-g-(MAH-co-St).Thedisperseddomainsizeissignificantlydecreasedandmeanwhiletheunique“softshell-encapsulating-hardcore”structuresforminthepresenceofcompatibilizers.Theoptimummechanicalperformancesmanifestanincreaseof36%intensilestrengthandanincreaseof1300%inimpactstrength,comparedwiththeneatPA6/ABSbinaryblend.
简介:Inthisworkamulti-objectivequantitativestructure-propertyrelationship(QSPR)analysisapproachwasreportedbasedonthestudyonthreepartitionpropertiesof50aromaticsulfur-containingcarboxylates.Heremulti-objectives(properties)weretakenasavectorforQSPRmodeling.Thequantitativecorrelationsforpartitionpropertiesweredevelopedusingage-neticalgorithm-basedvariable-selectionapproachwithquantumdescriptors,derivedfromAM1-basedcalculations.WiththeQSPRmodels,theaqueoussolubmty,octanol/waterpartitioncoefficientsandreversed-phaseHPLCcapacityfactorsofsulfur-contalningcompoundswereestimatedandpredicted.UsingGA-basedmultivariatelinearregressionwithcross-vali-dationprocedure,asetofthemostpromisingdescriptorswasselegtedfromapoolof28quantumchemicalsemi-empiricalde-scriptors,inclodingstericandelectronictypes,tointegrallybuildQSPRmodels.Theselectedmoleculardescriptorsinclud-edthenetchargesoncarboxylgroup(Qoc),the2ndpowerofnetehnrgesonnitrogenatoms(QN^2),thenetatomicchargeonthesulfuratoms(Qs),thevanderWaalsvolumeofmolecule(V),themostpositivenetatomicchargeonhydrogenatoms(QH)andthemeasureofpolarityandpolarizability(π),whichweremainfactorsaffectingthedistributionprocessesofthecompoundsunderstudy.ThestatisticallybestQSPRmodelsofsixdescriptorsweresimultaneouslyobtainedbyGA-basedlinearregressionanalysis.WiththeselecteddescriptorsandtheQSPRequations,mechanismsofpartitionactionoftheSulfur-containingcarboxylateswereabletobeinvestigatedandinter-preted.
简介:Inthiswork,acidfunctionalizedmulti-wallcarbonnanotubes(MWCNTs)weremodifiedwithimidazolium-basedionicliquids.Theselectiveoxidationofvariousalcoholswithhydrogenperoxidecatalyzedby[PZnMo_2W_9O_(39)]~(5-),ZnPOM,supportedonionicliquids-modifiedwithMWCNTs,MWCNTAPIB,isreported.Thiscatalyst[ZnPOM@APIB-MWCNT],wascharacterizedbyX-raydiffraction,scanningelectronmicroscopy(SEM)andFT-IRspectroscopicmethods.Thisheterogeneouscatalystexhibitedhighstabilityandreusabilityintheoxidationreactionwithoutlossofitscatalyticperformance.