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简介：Amodelisproposedtocorrelatethecrackgrowthrateandstressratiocontainingveryhighcyclefatigueregime.Themodelisverifiedbytheexperimentaldatainliterature.Thenaformulaisderivedfortheeffectofmeanstressonfatiguestrength,anditisusedtoestimatethefatiguestrengthofabearingsteelinveryhighcyclefatigueregimeatdifferentstressratios.TheestimatedresultsarealsocomparedwiththosebyGoodmanformula.

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简介：Veryhighcyclefatiguebehaviorsoftwobainite/martensitedual-phasesteelswereinvestigated.Oneofthesteelswascyclicrapidheattreatedanditsmicrostructureswererefined.Fatiguestrengthofthesteelis225MPahigherthanthatwithoutrefining.Observationoffracturesurfacesshowthatthefatiguecracksinitiateatbainitesfornon-refinedsteelandatnon-metallicinclusionsfortherefinedsteel.Thesizeofinclusionsismuchsmallerthanthatofbainiteswhichresultsintheimprovementoffatiguestrength.

简介：锁泉华的microfibrous网络由8m(dia)的3vol.%组成镍microfibers被利用了骗诱100200mdia的30vol.%。多孔的Al2O3。ZnO和CaO然后被早期的湿受精方法高度驱散到骗诱的Al2O3的毛孔表面上。由于表面区域，毛孔尺寸/粒子尺寸，热传导性，和空体积的唯一的联合，当在甲醇蒸气改过使用了时，产生microfibrous催化剂composites提供了催化的床反应和利用效率的重要改进。粗略地甲酸盐的260mL/min，包括>70%H2，<5%公司和踪迹CH4，与>97%甲醇变换，能在我们骗诱的新奇microfibrous的1cm3床卷被生产在470湩瑡潩?潰祬敭r合成的ZnO-CaO/Al2O3催化剂?鑈я鑈я8

简介：Anoveltwo-stagereductionprocessforsynthesisofultrafinenickelpowderwithahighpurityandlowdensityinafluidizedbedreactorhasbeendevelopedinthiswork.TherawultrafineNiOparticlesarefirstpre-reducedusinghydrogenatlowertemperatures(340-400℃),followedbyfurtherreductionathighertemperatures(500-600℃).Theself-agglomerationofNiparticlesformedduringlow-temperaturereductiondecreasesthesinteringactivityofthenewlyformedultrafineNiparticles,leadingtogoodfluidizationquality,evenforthesubsequenthigh-temperaturereductionprocess.TheagglomeratedNiparticleshaveahighNicontent(above99wt%),alowdensity(0.78g/cm~3)andauniformparticlesize(approximately100μm).Aconceptdesignforanoveltwo-stagefluidizedbedreactorprocessusedtoproducehigh-purityNipowderwasalsoproposed.Thisapproachmaybeextendedtothesynthesisofotherultrafine/nanosizedmetalsormetaloxidesthroughafluidizationmethod.

简介：Ultra-puremesoporoussilicamicrosphereswithgoodmonodispersityweresynthesizedintwosteps:nanometer-sizedsilicasolwasproducedbythesol-gelprocess,thenmicrometer-sizedsilicamicrospheresweresynthesizedbypolymerization-inducedcolloidaggregationofthesilicasol.Thetotalmetalcontentofthemicrosphereswasextremelylow,whicheliminatedthetailingofchromatographicpeaksbychelatingreagents.Theporestructureofthesilicamicrospherescouldbecontrolledbyalteringthesol-gelconditions.Thesilicamicrosphereparticlesizecouldbeadjustedbyusingdifferentpolymerizationinducedcolloidaggregationconditions.

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简介：BSTOdielectricceramicwaspreparedfromSrTiO3andBaTiO3powderssynthesizedbyhydrothermalmethod,aswellasfromBa0.6Sr0.4TiO3powdersynthesizedbyconventionalsolid-statereaction.Theformercanbesinteredatarelativelylowtemperatureof1120℃.CharacterizationbySEMshowedthatthegrainshapesofbothceramicsarecubical,thoughthegrainsizeoftheformerismuchsmaller.Dielectricconstantsmeasuredat20℃wereshowntovarywithfrequencyintherangefrom1kHzto2MHzanddcbiasfield,andfurtherthatthedielectriclossoftheformertobelessthan2×10-3inthefrequencyrangeof20kHzto1MHz,muchsmallerthanthatofthelattersample.Fortheformer,temperaturedependenceofdielectricconstantismuchflatterandthereexistsanextendedphasetransitiondiffusioncoveringawidetemperaturerangeofCurietemperatureTc.Thesmallergrainsizeoftheformerdepressesthedcbiaselectricalfielddependenceofdielectricconstant.Thetunabilityis7%underabiasfieldof0.6kV/mmdc.

简介：Ammoniumsulfateresidueisaparticulatesolidandisproducedduringthemanufactureofammoniumsulfatefertilizer.Theresidueusedinthisstudycontainedalargeportionofcalciumcarbonate,fromwhichactivelime（CaO）wasrecoveredviathermaldecomposition.Weusedapurpose-builtdevicetodecomposetheresidueinasemi-suspensionstate.WefoundthatCaOhadthehighestactivitywhenresiduewasdecomposedat850-900℃.OurexperimentsindicatedthatammoniumsulfateresidueshouldbedecomposedinasuspensionstatetoproduceactiveCaO.Basedonourlaboratorytestfindings,anindustrial-scaleproductionlinewithahighsolid/gasratioinasuspensionstatewasdevised.TheoptimaloperatingconditionsforthedecompositionoftheammoniumsulfateresiduetoproducehighqualityCaOwerealsoinvestigated.WefoundthattheCaCO3decompositionratewashighandtheCaOproductwashighlyactive,averaging170sbythecitricacidmethod.MorphologymeasurementsshowedthattheCaOproducthadaporousstructureandalargespecificsurfaceensuringhighactivity.

简介：TiO2nanoparticlesweresynthesizedbyahomogeneouscontrolledprecipitationmethodusingindustrialtitaniumsulfate(Ti(SO4)2).TheobtainedpowderswerecharacterizedbyX-raydiffraction(XRD),transmissionelectronmicroscope(TEM),Fouriertransforminfraredspectroscopy(FTIR)andICPplasmaspectrometer.EDTAwasusedascomplexingagenttoimprovethepurityandtheformationofTiO2nanoparticles.Experimentalresultsindicatedthatthehigh-purityTiO2nanoparticleswere20nminmeansizeandnearlymonodispersed.

简介：Fastsolvinglarge-scalelinearequationsinthefiniteelementanalysisisaclassicalsubjectincomputationalmechanics.Itisakeytechniqueincomputeraidedengineering(CAE)andcomputeraidedmanufacturing(CAM).Thispaperpresentsahigh-efciencyimprovedsymmetricsuccessiveover-relaxation(ISSOR)preconditionedconjugategradient(PCG)method,whichmaintainstheconvergenceandinherentparallelismconsistentwiththeoriginalform.Ideally,thecomputationcanbereducednearlyby50%ascomparedwiththeoriginalalgorithm.Itissuitableforhigh-performancecomputingwithitsinherentbasichigh-efciencyoperations.Bycomparingwiththenumericalresults,itisshownthattheproposedmethodhasthebestperformance.