简介:Forthepurposesoffloodcontrol,conveyanceofsediment,andadequateutilizationofwaterresourcesintheLowerYellowRiver,theoperationschemeofsedimentregulationonperennialbasisisproposedfortheXiaolangdiReservoi.Waterandsedimentareretainedinthereserviorinnormalandlowwateryears,whileinyearswithabundanceofwater,theyareflushedoutinshortperiodsofreservoirdrawdowntoformhyperconcentratedfloods.TheseremouldthewideshallowreachaboveGaocunintoanarrowdeepchannel,throughwhichthesedimentmaybetransportedallthewaytothesea.Theresults?
简介:Asimpleroutetosynthesizethepolyaniline(PANI)nanofiberswithdiameterabout150nmwasreported.Inthisstrategy,thePANInanofiberswerefabricatedbyelectrochemicaldepositionbyusingtwo-electrodeconfigurationin0.01Manilineand0.01MH2SO4electrolytes.Theas-preparedmaterialswerecharacterizedbyscanningelectronmicroscopy(SEM),infraredspectroscopy(FTIR),Ramanspectroscopyandthermogravimetricanalysis(TGA).TheelectrochemicalpropertiesofthePANInanofiberselectrodeassupercapacitormaterialswereinvestigated.ThePANInanofiberselectrodeshowedhighcapacitanceof485F·g-1at0.1A·g-1,andthedecreaseinthespecificcapacitanceisabout3.5%in1000cycles.TheresultsindicatethatthePANInanofiberselectrodeshowshighstabilityandretainsitselectrochemicalcapacitancepropertyover1000cycles,suggestingPANInanofibershavepromisingapplicationsinhigh-performancesupercapacitors.
简介:Uniformdiamondfilmsarehighlydesirableforcuttingindustries,duetotheirhighperformanceandlonglifetimeusedoncuttingtools.Nevertheless,theyaredifficulttoobtainoncuttingtoolswithcomplicatedshapes,greatlylimitingtheapplicationsofdiamondfilms.Inthisstudy,anovelapproachofdepositionforuniformdiamondfilmsisproposed,oncircularsawbladesmadeofcementedcarbideusingreflectorsofbrasssheets.Diamondfilmsaredepositedusinghotfilamentchemicalvapordeposition(HFCVD).Anovelconcavestructureofbrasssheetsisdesignedandfabricated,improvingthedistributionoftemperaturefield,andovercomingthedisadvantagesoftheconventionalHFCVDsystems.ThisincreasestheenergyefficiencyofusewithoutchangingthestructureandincreasingthecostofHFCVD.Thegrainsarerefinedandtheintensitiesofdiamondpeaksarestrengthenedobviously,whichisconfirmedbyscanningelectronmicroscopyandRamanspectrarespectively.
简介:Amorphoussiliconfilmsarepreparedatlowertemperatureof350℃bynewcatalyticchemicalvapordepositionmethod.Inthemethod,materialgases(SiH4andH2)aredecomposedbycatalyticreactionatgiventemperature,soa-Sifilmsaredepositedonsubstrates.Itisfoundthata-Sifilmswithhighqualitycanbeobtain,suchashighphotosensitivityof10^6,lowspindensityof2.5×10^16cm^-3.
简介:Thediffusionandmasstransfer,reaction,integrationandgrowthprocessesofthemetalionsontheactivatedcarbonfibers(ACFs)arediscussed.Basedonthediffusionfilmtheory,thediiffusionandtheintegrationmodelaredevelopedtodescribethedepositionprocessesofmetalionsfromthesolutiontoACFsinthefiuidizedbeds.Themodelofheattransferofthisprocessisestablishedtoexpoundtheimportantrole-playedindepositionprocessesbytheinfluenceofthereactionheatreleasedatACFssurfaceandthenon-uniformtemperaturedistributioncausedbyhydrodynamics.
简介:TheDevoniansuccessioninSouthChinaiswell-knownforitscompletedevelopment,vari-fiedsedimentarytypes,remarkablelithofaciesvariationandabundantmineralresources.TheSouthChinaplatewasformedbythecollisionandcollageoftheYangtzeplateandtheCathaysianplate.ThecollisionbeganapproximatelyattheJinningianstageandthecollagewasnotfinalizeduntiltheGuangxianmovement.ItwasontheSouthChinaplatewithasomewhatdifferentnatureofthebasementthattheDevoniandepositionformed.
简介:Inordertoevaluatethevalidityofcommonlyusedformulaedescribingerosionanddepositionofcohesivesedimentsfortheirapplicationwithinnumericalsimulations,acombinedexperimentalandnumericalinvestigationiscarriedout.Anannularflumeisusedforexperimentsonerosionanddepositionofreservoirmuds.Theresultsoftheseexperimentsserveasvalidationdatafortheformulaeinconsideration.Forthisvalidation,theexperimentsarereproducedwithinanumericalsimulation,whichconsistsoftwoparts:Inafirststep,theflowintheannularflumeissimulatedwithina3Dlargeeddysimulation.Theflowfieldsobtainedinthesesimulationsthenserveasinputforthesecondstep,adecoupled2DVsimulationoferosionanddepositionprocessesduringtheexperiments.TheinvestigatedformulaearethoseofPartheniadesandParchure&MehtaconcerningerosionandofKroneandRichardson&Zakiconcerningdeposition.
简介:TheTm-Ni-Coalloyfilmshavebeenpreparedbythesweeppotentialdepositiontechnique.ThesurfaceappearanceofTm-Ni-Coalloyfilmswassilver,smoothandadhesive.ThesurfacesofTm-Ni-Coalloyfilmsobservedbyscanningelectronmicroscope(SEM)wereuniform,adhesiveandcompact.Thesizesofmetallicgrainswereabout80-100nm,100-200amorphousasprovenbytheX-raydiffraction(XRD).
简介:Depositionofamorphousparticles,asaprevalentproblemparticularlyinthespraydryingoffruitandvegetablejuices,isduetolow-molecular-weightsugarsandisstronglydependentontheconditionoftheparticlesuponcollisionwiththedryerwall.Thispaperinvestigatestheconditionoftheamorphousparticlesimpactingthewallatdifferentdryingconditionswiththeaimofelucidatingthedepositionmechanismandphysicalphenomenainthedryingchamber.Amodelsucrose-maltodextrinsolutionwasusedtorepresentthelow-molecular-weightsugar.Particledepositswerecollectedonsamplingplatesplacedinsidethedryerforanalysesofmoisturecontent,particlerigidity(usingSEM)andsizedistribution.Moisturecontentwasadoptedasageneralindicatorofstickiness.Productparticlescollectedatthebottomoftheexperimentaldryerwerefoundtohavehighermoisturethanparticledepositsonsamplersinsidethedryer.Moisturecontentprofileinthedryershowsthatapartfromtheatomizerregion,whereparticlesarerelativelywet,particledepositsatotherregionsexhibitsimilarlowermoisturecontent.Atthehighesttemperatureadoptedintheexperiments,particlesbecamerubberysuggestingliquid-bridgeformationasthedominantdepositionmechanism.Furtheranalysisonparticlessizedistributionrevealsaparticlesegregationmechanismwherebysmallerparticlesfollowpreferentiallytothecentralairstreamwhilelargerparticlestendtore-circulateinthechamber,aspredictedinpastCFDsimulation.ThefindingsfromthisworkwillformthebasisandprovidevalidatingdataforfurthermodelingofwalldepositionofamorphousparticlesinspraydryingusingCFD.
简介:Thepiezoelectricfilmelectro-depositionforopticalfibersensorwithZnOcoatingisstudied.Thezincoxideplatingfilmismadeonthecoppersurfacedirectlybycathodicelectro-depositionintheZn(NO_3)_2singlesaltaqueoussolutionsystems.TheinfluencesofmainexperimentalconditionsonthepropertiesofZnOthinfilmintheelectro-depositionprocessesareanalyzedandastable,practicalandeconomictechniqueisobtained.
简介:DedicatedexperimentsintheHT-7tokamakwereperformedtoinvestigatethein-fluenceoferosionanddepositiononthemirrorsamples.Thefirstmirror(FM)samplesmadeofpolycrystalline(PC)stainlesssteel(SS),molybdenum(Mo)andtungsten(W)werefixedonaholderatanangleof45withrespecttothehorizontalplaneandsetatdifferentlocationswithdifferentconnectionlengthsalongthemagneticfield.Theopticalreflectivityofthefirstmirrorwasmeasuredbyaspectrophotometerbeforeandafterplasmaexposure.Itwasfoundthatthesurfacemorphologyandspecularreflectivityofthemirrorsamplesaftertheexposureweredifferentwithrespecttothedifferentdistancesfromthemirrorsurfacetothelastclosedfluxsurface(LCFS)oftheplasmainthetokamak.Itwasalsofoundthatshorteningtheconnectionlengthbeforethemirrorsurfacewouldweakentheinfluenceoftheplasmaerosionandimpuritydepositiononthemirrorsurface.Inordertomaintaintheopticalcharacteristicsofthemirrorsurface,itisnecessarytoadoptthein-situcleaningandmirrorprotectiontechniques.