简介:Fibrestressofglassfibrereinforcedpolymericcopmositesonloadisdeterminedbyusingopticalfibreasmodelfiberandbymeansoflaserinterferencemethod.Inaddition,theoriginationoffibrestressduringmouldingprocessofcompositesandtherelationbetweenfiberstressofloadedcompositesandexternalstressareexamined.Theexperimentsshowthatfibrestressisrelatedtomolecularstructureofinterfacialmaterialsandstructureofinterfaciallayers.Whenstressistransferredfrommatrixtofibre,eachinterfaciallayerhasdifferentstressgradientanddeformability.Thispropertycanbecharacterizedbyintroducinganinterfacialstresstransfercoefficientktothetwo-phasemodel.
简介:Silicaaerogelmaterialsarewellrecognizedfortheirsuperinsulationperformanceandareregardedasoneofthehotcandidatestorevolutionizebuildinginsulation.Todate,highproductioncostrelatedtoexorbitantprecursorsaswellascumbrousmulti-stephydrophobizationprocesshasoftennarrowedthefieldofapplications.Inthiswork,granularsilicaaerogelmaterialsweresynthesizedbyextractingSiO2fromrecycledrichsiliconcoalgangue,followedbyone-stephydrophobizationandambientpressuredrying.Lightweight(about0.16g/cm3)andnanostructuralaerogelswereobtainedthroughthisroute.Theyexhibita3Dopenporousmicrostructurewitharound600cm2/gsurfaceareaand20nmoftheaverageporediameter,thermalconductivityof4-5mmpackedgranulesis20-25mW/(m·K),whichwasprovedbybothguardedhotplateandhot-wiretransientmethods.Thisstudyoffersanewfacilerouteforthesynthesisofsilicaaerogelfromrecycledsolidwastecoalgangueandsuggestsamethod,whichmayleadtoacostreductionintermsofindustrialproduction.
简介:AnewcompoundK6Ti0.67Nb15.33O42waspreparedforthefirsttimebysolidstatereactioninK2O-Ni2O3-Nb2O5ternarysystem.Thenewcompoundwascharacterizedbyelectronprobe,X-raypowderdiffractionandDTA.TheresultofX-raypowderdiffractionshowsthatK6Ti0.67Nb15.33O42crystallizesthehexagonalsystemwithunitcellparametersa=9.1341(5)A,c=12.090(1)A.andspacegroupP62/mcm(193).
简介:Nearlysingle-phaseandpolycrystallinecharge-density-wavecompoundK_(0.3)MoO_3havebeenpreparedbyusingasimplemethod.Inthiswork,K_2CO_3andMoO_3wereusedasstartingmaterialsandreactedbyhotisostaticpressing(HIP)sintering.TheproductisnearlysinglephaseK_(0.3)MoO_3determinedbyX-raypowderdiffraction(XRD)andenergydispersivespectroscopy(EDS).MeasurementoftemperaturedependenceofresistivityrevealsthatthetransportpropertyofpolycrystallineK_(0.3)MoO_3obviouslydiffersfromthatofsinglecrystalduetothegrainboundariesandtheanisotropicstructureinthiskindofcompound.
简介:AseriesofCd1-xZnxS/K2La2Ti3O10compositesweresynthesizedviaasimpleco-precipitationmethod.ThepreparedsampleswerecharacterizedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),X-rayenergydispersivespectroscopy(EDX),ultraviolet-visiblediffusereflection(UV-Vis),X-rayphotoelectronspectroscopy(XPS)andphotoluminescence(PL)measurements.ThecompositestructuresconsistedofCd1-xZnxSnanoparticlesevenlydistributedonthesurfaceofK2La2Ti3O10.TheabsorptionedgeofK2La2Ti3O10shiftedtothevisiblelightregionuponintroductionoftheCd1-xZnxSnanoparticles.Thephotocatalyticactivitiesofthecatalystswereevaluatedbyhydrogenproductionundervisiblelightirradiation.ThepreparedCd0.8Zn0.2S(30wt%)/K2La2Ti3O10exhibitedhigherphotocatalyticactivity,evolving6.92mmol/gH2undervisiblelightirradiationfor3h.ThepromotedphotocatalyticactivityofthecompositeswasattributedtothesynergisticeffectbetweenCd1-xZnxSandK2La2Ti3O10,whichresultedinenhancedseparationofphotogeneratedelectronsandholes.