简介：CuO-CeO2catalystswerepreparedbyaureaprecipitationmethodfortheoxidativesteamreformingofethanolatlow-temperature.Thecatalyticperformancewasevaluatedandthecatalystswerecharacterizedbyinductivelycoupledplasmaatomicemissionspectroscopy,X-raydiffraction,temperature-programmedreduction,fieldemissionscanningelectronmicroscopyandthermo-gravimetricanalysis.OverCuOCeO2catalysts,H2withlowCOcontentwasproducedinthewholetestedtemperaturerangeof250–450C.Thenon-noblemetalcatalyst20CuCeshowedhigherH2productionratethan1%Rh/CeO2catalystat300–400Candtheadvantagewasmoreobviousafter20htestingat400C.TheseresultsfurtherconfirmedthatCuO-CeO2catalystsmaybesuitablecandidatesforlowtemperaturehydrogenproductionfromethanol.

简介：在这评论，我们在场拓扑的绝缘体(TI)和超导的nanowires和电影的一些最近的实验的一篇摘要。电子电子相互作用(EEI)，弱反本地化(WAL)和效果由运输大小在拓扑的绝缘体电影发现了的各向异性的磁致电阻(AMR)被报导。然后，在非超导的nanowires的超导的电影，桥和nanowires和最近效果的运输性质被描述。最后，在拓扑的绝缘体和超导体(SC)之间的相互影响也被讨论。

简介：Inthispaper,weinvestigateexcitedcharacteristicoftheweaklyinteractingquasi-one-dimensional(1D)andquasi-two-dimensional(2D)Bose–Einsteincondensation(BEC)inharmonicpotentialtrap.Theenergyspectrumandtheanalyticalexpressionofthesoundvelocityareobtainedandanalyzed.Comparedwith3-DimensionalhomogeneousBose-condensedgasoccasion,thesoundvelocityof2DBose-Einsteincondensationinharmonicpotentialtrapissmaller.

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简介：Thispaperdescribestheeffectsofnon-equilibriumairplasmageneratedbyadielectricbarrierdischarge（DBD）onthecombustionoflowheatingvaluefuels.TheexperimentalresultsindicatethatadditionofaverysmallamountofenergytotheairflowintheformofDBDsignificantlyimprovestheflamestability.Moreover,maincombustioncharacteristicssuchasflamepropagationspeed,combustionintensityandleanblow-offlimitsarealsoenhancedbytheeffectofplasma.SomeactiveradicalssuchasexcitedOatomandexcitedN2moleculeareobservedbyspectrographinthedischargearea.BasedontheresultsofnumericalinvestigationwecanconcludethattheseactiveradicalsgeneratedindischargeareacanacceleratetheproductionrateofactiveOHradicalwhichplaysakeyroleintheoxidationprocessoflowheatingvaluefuel,andthusthewholecombustionprocessisaccelerated.

简介：Anumericalinvestigationonover-shroud&inter-shroudleakageflowhasbeencarriedouttoexploretheunderneathflowphysicsatthestageofshroudedLowPressure(LP)turbine.ComparedwiththeNointer-Shroudgap'sLeakageflowModel(NSLM)andWithinter-Shroudgap'sLeakageflowModel(WSLM),theaerodynamiccharacteristicsandtheheattransferperformancehavebeenstudied.Throughtheaerodynamicpointofview,itisconcludedthatduetothepressuredifferencebetweentherotor'spassageandtheover-shroudcavity,inthestream-wisedirection,flowstructurehasbeenmodified,andtheinter-shroudleakageflowmayevencauseflowseparationinthevicinityofthebladepassage'sthroat.Inthecircumferentialdirection,separationflowsappearovertherotor'sshroudsurface(upperplatformoftheshroud).Meanwhile,fromthepointofviewofheattransfer,furtherprovisiononcontourmapsofthenon-dimensionalNusseltnumberrevealsthatthereattachmentofleakageflowwouldenhancetheheattransferratesandendangertherotor'slabyrinthfinsovertheshroud.However,duetothelimitedamountofinter-shroudleakageflow(currentcomputationalmodel),temperaturedistributionvariationalongthebladesurface(neartherotor'stipsection)seemstohaveonlyminorinsignificantdifferences.Attheendofthepaper,theauthorputsforwardsomerecommendationsforthepurposeoffuturesuccessfulturbinedesign.

简介：Adirectsynthesisofmethyllevulinatefromcellulosealcoholysisinmethanolmediumundermildcondition(180210C)catalyzedbyextremelylowconcentrationsulfuricacid(0.01mol/L)andtheproductisolationweredevelopedinthisstudy.Effectsofdifferentprocessvariablestowardsthecatalyticperformancewereperformedasafunctionofreactiontime.Theresultsindicatedthatsulfuricacidconcentration,temperatureandinitialcelluloseconcentrationhadsignificanteffectsonthesynthesisofmethyllevulinate.Anoptimizedyieldofaround50%wasachievedat210Cfor120minwithsulfuricacidconcentrationof0.01mol/Landinitialcelluloseconcentrationbelow100g/L.Theresultingproductmixturewasisolatedbyadistillationtechniquethatcombinesanatmosphericdistillationwithavacuumdistillationwheren-dodecanewasaddedtohelpdistilltheheavyfraction.Thelightfractionincludingmainlymethanolcouldbereusedasthereactionmediumwithoutanysubstantialchangeintheyieldofmethyllevulinate.ThechemicalcompositionandstructuraloflowerheavyfractionwerecharacterizedbyGC/MS,FTIR,1H-NMRand13C-NMRtechniques.Methyllevulinatewasfoundtobeamajoringredientoflowerheavyfractionwiththecontentover96%.Thispathwayisefficient,environmentallybenignandeconomicalfortheproductionofpurelevulinateestersfromcellulose.

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简介：Thearomatizationoflightalkenesinliquefiedpetroleumgas(LPG)withandwithoutdimethylether(DME)additioninthefeedwasinvestigatedonamodifiedZSM-5catalyst.Theresultsshowedthatunderthegivenreactionconditionstheselectivityofalkenestohigh-octanegasolineblendingcomponentswasmarkedlyenhancedandtheformationofpropaneandbutaneswasgreatlysuppressedwiththeadditionofDME.ItwasalsofoundthatthedistributionofC5+componentswaschangedalotwithDMEadditionintotheLPGfeed.Theformationofbranchedhydrocarbons(mainlyC6C8i-paraffin)andmulti-methylsubstitutedaromatics,whicharehighoctanenumbergasolineblendingcomponents,waspromotedsignificantly,whilethecontentofn-paraffinsandolefinsinC5+componentswasdecreasedobviously,indicatingthatinadditiontotheoligomerization,cracking,hydrogen-transferanddehydrogenation-cyclizationofalkenes,themethylationoftheformedaromaticsandolefinsintermediatesalsoplaysanimportantroleindeterminingtheproductdistributionduetothehighreactivityofsurfacemethoxygroupsformedbyDME.Andthisprocess,incombinationwiththesyngas-to-methanol/DMEtechnology,providesanalternativewaytotheproductionofhigh-octanegasolinefromcoal,naturalgasorrenewablerawmaterials.

简介：Cold-stretchedpressurevesselsfromausteniticstainlesssteels(ASS)arewidelyusedforstorageandtransportationofliquefiedgases,andhavesuchadvantagesasthinwallandlightweight.Fatigueisanimportantconcerninthesepressurevessels,whicharesubjectedtoalternativeloads.Eventhoughseveralcodesandstandardshaveguidelinesonthesepressurevessels,therearenorelevantdesignmethodsonfatiguefailure.TounderstandthefatiguepropertiesofASS1.4301(equivalentsincludeUNSS30400andAISI304)insolution-annealed(SA)andcold-stretchedconditions(9%strainlevel)andtheresponseoffatiguepropertiestocoldstretching(CS),low-cyclefatigue(LCF)testswereperformedatroomtemperature,withtotalstrainamplitudesrangingfrom-.4%to-.8%.Martensitetransformationsweremeasuredduringthetests.Comparisonsoncyclicstressresponse,cyclicstress-strainbehavior,andfatiguelifewerecarriedoutbetweenSAandCSmaterials.ResultsshowthatCSreducestheinitialhardeningstage,butprolongsthesofteningperiodinthecyclicstressresponse.Martensitetransformationhelpsformastableregimeandsubsequentsecondaryhardening.Thestressesofmonotonicandcyclicstress-straincurvesareimprovedbyCS,whichleadstoalowerplasticstrainandamuchhigherelasticstrain.ThefatigueresistanceoftheCSmaterialisbetterthanthatoftheSAmaterial,whichisapproximately1?03to2?04cycles.TheS-NcurveoftheASMEstandardforASSiscomparedwiththefatiguedataandisjustifiedtobesuitableforthefatiguedesignofcold-stretchedpressurevessels.However,consideringtheCSmaterialhasabetterfatigueresistance,theS-Ncurvewillbemoreconservative.ThepresentstudywouldbehelpfulinmakingfulluseoftheadvantagesofCStodevelopanewS-Ncurveforfatiguedesignofcold-stretchedpressurevessels.

简介：Solidoxidefuelcells(SOFCs)offerhighenergyconversion,lownoise,lowpollutantemission,andlowprocessingcost.Despitemanyadvantages,SOFCsfaceamajorchallengeincompetingwithothertypesoffuelcellsbecauseoftheirhighoperatingtemperature.ThenecessitytoreducetheoperationaltemperatureofSOFCshasledtothedevelopmentofresearchintothematerialsandfabricationtechnologyoffuelcells.Theuseofcompositecathodessignificantlyreducesthecathodepolarizationresistanceandexpandsthetriplephaseboundaryareaavailableforoxygenreduction.Powderpreparationandcompositecathodefabricationalsoaffecttheoverallperformanceofcompositecathodesandfuelcells.Amongmanytypesofcathodematerials,lanthanum-basedmaterialssuchaslanthanumstrontiumcobaltferrite(La1-xSrxCo1-yFeyO3-haverecentlybeendiscoveredtooffergreatcompatibilitywithceria-basedelectrolytesinperformingascompositecathodematerialsforintermediate-tolow-temperatureSOFCs(IT-LTSOFCs).Thispaperreviewsvariousceria-basedcompositecathodesforIT-LTSOFCsandfocusesontheaspectsofprogressandchallengesinmaterialstechnology.