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150 个结果
  • 简介:ThebacteriausedintheexperimentareThiobacillusFerrooxidansseparatedfromacidicminewaterinsulphidedeposits.Thechemoautotrophicbacteriacanactdirectlyonsulphidesandacceleratetheoxidationofsulphides.Theexperimentshowsthatthebacteria,asanimportantmicrobialfactorofgold’ssupergenousenrichmentwithintheoxidizedzonesofsulphidedeposits,arehelpfultodissolvegoldandsilverinferricsulphate.Inthebacterialoxidationprocess,theprecipitationofgoethiteisconcernedbothwiththeloweractivityofferricionsandwiththeexistenceofcarbonatesinsolution.Meanwhile,theacid-resistingandoxidizingabilityofthebacteriawillcertainlyleaduptoamicrobialwayoftreatingtheacidicminewater.

  • 标签: SULPHIDES BACTERIAL OXIDATION SUPERGENE ENRICHMENT of
  • 简介:Carbon-containingrefiactoriesareeasilyoxidizedathightenperature,thusmakingserviceliferapidlydrop.Theanti-oxidationmethods,suchasimpregnationandaddinganti-oxidatonagents,can'tmeettherequire-mentsofindustry'sdevelopmentandsomespecialcases,Byanalyzingthecharcteristicsofseveraloxidesandnon-oxidesrawmaerials,theoxidationresistantmechanismoftherefractoryanti-oxidationcoatings(RAOC),whichpossessthecharacteristcofself-healingathighttemperature,isdiscussed.

  • 标签: 耐火材料 抗氧化机理 制备 碳化物 原料 氧化硅
  • 简介:Oxidationprocessoflanthanumhexaboride(LaB6)ceramicpowderwasinvestigated.TheLaB6powdersampleswereheatedcontinuallyfromroomtemperatureto1473Kataheatingrateof10K/minbydifferentialscanningcalorimetry.Theoxidationtestswereconductedatdifferentexposuretemperatures.ThephasesandmorphologiesofthesamplesbeforeandafterexposurewereanalyzedbyXRDandSEM.Itwaspointedoutthatbefore1273K,LaB6hashighoxidationresistantability,whichwasduetothattheoxidelayerhinderstheoxygendiffusionfromoutertothesurfaceofLaB6grains.Theoxidelayerwascomposedofthetransitionphases,whichwerecomposedofLa2O3andB2O3formedfromtheinitialoxidation;whentheoxidationtemperatureexceeded1273K,protectivelayerwasdestroyedduetothevaporizationofliquidB2O3.BasedontheresultsofX-raydiffractionanalysis,oxidationprocessofLaB6ceramicpowdercanbedescribedasfollows:Before1273K,lanthanumborate,La(BO2)3wasformedonthesurfaceofsamples,thenlanthanumoxide(La2O3)andboronoxide(B2O3)werepresentonthesurfaceofsamplesoxidizedwhenthetemperaturereachedto1473K.

  • 标签: 六溴化镧 氧化 陶瓷 稀土 XRD 高温结构材料
  • 简介:Theoxidationbehaviorofthreebiodieselsofdifferentorigins,viz.rapeseedoilderivedbiodiesel,soybeanoilderivedbiodieselandwasteoilbasedbiodiesel,weretestedonanoxidationtester.Thechemicalcompositionsofthebiodieselswerecharacterizedbygaschromatography.Thereafter,thestructuraltransformationoffattyacidmethylester(FAME)ofthebiodieselswasanalyzedbyaninfraredspectrometerandanultravioletabsorptionspectrometer.TheresultsdemonstratedthattheoxidationbehaviorofbiodieselsofdifferentoriginswascloselyrelatedtothecompositionanddistributionofFAMEs.HigherconcentrationofunsaturatedFAMEwithmulti-doublebondsexhibitedpooreroxidationresistance.Furthermore,cis-transisomerizationtransformationoccurredintheunsaturatedFAMEmoleculesandconjugateddouble-bondproducedduringtheoxidationprocessofbiodiesel.Greatercis-transvariationscorrespondedtodeeperoxidationdegree.ThehigherthecontentofunsaturatedFAMEwithmulti-doublebondsinabiodiesel,themoretheconjugateddoublebondswasformed.

  • 标签: 生物柴油 氧化行为 结构转变 光谱分析 脂肪酸甲酯 共轭双键
  • 简介:Inordertofurtherreducethesulfurcontentingasoline,anewdesulfurizationprocesswasproposedbyusingcatalyticoxidationandextractionrealizedinanelectrochemicalfluidizedreactor.Thefluidizedlayerofloadedcatalystparticlesconsistedofleaddioxide(PbO2)supportedonactivatedcarbonparticles(PbO2/C)andtheelectrolytewasaqueousNaOHsolution.ThePbO2/Cparticleanodescouldremarkablyacceleratetheelectrochemicalreactionrateandpromotetheelectrochemicalcatalysisofsulfurcompounds.Thesulfurcompoundswereatfirstoxidizedtosulfonesorsulfoxides,whichwerethenremovedafterextraction.Theexperimentalresultsindicatedthattheoptimaldesulfurizationconditionswereasfollows:Thecellvoltagewas3.2V,theconcentrationofhydroxylionsinelectrolytewas0.12mol/L,andthefeedratewas300mL/min.Undertheseconditionstheconcentrationofsulfuringasolinewasreducedfrom310ppmto70ppm.Basedontheseexperimentalresults,amechanismofindirectelectrochemicallycatalyticoxidationwasproposed.

  • 标签: GASOLINE electrochemically CATALYTIC OXIDATION DESULFURIZATION
  • 简介:Anincubationexperimentwascarriedoutinlaboratorytostudytheeffectoftemperature,moisture,phosphorus,organicmatter,croppingandpreviouselementalsulfurapplicationonelementalsulfuroxidationinfourselectedsoils,fluvo-aquicsoil,blacksoil,yellow-brownsoilandredsoil,Inallthesoilstested,sulfuroxidationratewasinfluencedbytemperatureandthetemperaturecoefficient(Q10)valuesattherangefrom10to30℃were4.41,,6.19and3.71forthefoursoils,respectively.Therateofsulfuroxidationwasparabolicallyrelatedtosoilwatercontent.Theoptimummoisturecontentforthemaximumoxiationratewasdifferentamongsoils,Phosphorusincreasedtheoxidationrateofelementalsulfurby57.7%,33.1%,21.7%and26.4%fortheabovefoursoils,respectively,comparedwiththecontrol(nophosphorusapplied).Organicmaterialofcornstrawwhichwasgoundandpassedthrougha0.5-mmsievealsoincreasedthoxidationrateofelementalsulfurinthefoursoilsby59.8%,7.8%,39.2%and540.4%,respectively.Elementalsulfurwhichwasappliedpreviouslytosoilssignificantlyenhancedtheoxidationofelementalsulfursubsequentlyaddedandincreasedsulfur-oxidizingpopulationssuchasautotrophicelementalsulfuroxidizerswithpHoptimum6.8,autotrophicthiosufateoxidizerswithpHoptimum6.8,heterotrophicthiosulfateoxidizersandheterotrophicsulfateproducers.Croppinghadlittleeffectonelementalsulfur-oxidizingpotentialityofsoils.

  • 标签: 土壤 元素硫 氧化作用 黄褐土 黑土 红壤
  • 简介:Thispaperstudiestheretardationprocessforphotosensitizedoxidationof9,10-diphenylanthracene(9,10-DPA)inducedbyhypocrellinA(HA)asasensitizerinthepresenceofpraseodymiumion(Pr3+).ExperimentalresultshowsthatthepromptfluorescenceofHAcanbequenchedbyPr3+inmethanol.Measurementoffluorescencelifetimerevealsthatitremainsconstantwithincreasingcon-centrationofPr3+,thusastaticquenchingcharacterisindicated.ThethermallyinduceddelayedfluorescenceofHAcanalsobequenchedeffectivelybythePr3+-HAcomplex.Thedelayedfluorescencelifetimeisre-ducedfrom1744±50nsto700±50nsand500±50nsinthepresenceofoxygenandPr3+respectively,thusthequenchingofdelayedfluorescenceisofdynamiccharacter.Ascomparedwiththedoublereciprocalrela-tionshipofconcentrationbetweentheoxidationproductderivedfromsingletoxygenandthereactant,itshowsthatthePr3+-HAcomplexcanquenchnotonlytheexcitedtripletofHAbutalsothesingletoxygenandthereforethephotosensitizedoxidationof9,10-DPAisretardedefficiently.

  • 标签: reactant LIFETIME thermally PROMPT QUENCHING SINGLET
  • 简介:Methaneoxidationbypaddysoilsinaclosedsystemcouldbesimulatedbytheequationx=k1xo/(k1+k2x0)exp(k2t)-k2x0wherex0andxaretheCH4concentrationsattimezeroandt,respectively;k1andk2areconstantsrelatedtotheconstantoffirst-order-kinetics.AccordingtotheequationthechangeofsoilabilitytooxidizeCH4couldbeestimatedbytheequationAc=k2/k1(x0-x)x0k2/k1-1.TheresultsshowedthatthesoilabilitytooxidizeCH4varied,dependingontheinitialCH4concentration.HighinitialCH4concentrationstimulatedsoilabilitytoconsumeCH4,whilelowconcentrationdepressedtheablility.Thischaracteristicofpaddysoilseemedtobeofconsiderablesignificancetoself-adjustingCH4emissionfromfloodedricefieldsifthereexistoxicmicrositesinthesoil.

  • 标签: 封闭生态系统 甲烷氧化 模拟 水稻土 甲烷释放量
  • 简介:Vanadiumalloyisoneofthemostimportantcandidatestructuralmaterialsforafusionreactor.Itsmainadvantagesoverothercandidatesareitslowactivityfeatureandfeasiblepropertiesathightemperature.However,vanadiumiseasilyoxidizedathightemperaturetoformanon-protectivesurfacefilmofV2O5.Oxygenconcentrationwouldthusgethighandthepropertiesgetworseinnotonlythelossoftheductilitybutalsotheenhancedhydrogenembrittlementbytheoxidation.

  • 标签: 钒合金 氧化反应 氧化温度 放射性特征
  • 简介:Thecatalyticwetairoxidation(CWAO)ofHacidandphenolwasinvestigatedinthepresenceofCuorFedopedCeO2solidsolutions,whichwereobtainedbysol-gelmethod.TheexperimentresultsshowedthattheincorporationofCuorFeintothefluoritelatticeofCeO2stronglyenhancedtheoxidationactivityofthecatalyst.At90℃and0.1MPa,Hacidconversionwas70%fortheCe0.9Fe0.1O2-δand60%fortheCe0.9Cu0.1O2-δcatalyst.Forphenolremoval,theconversionwas70%fortheCe0.9Cu0.1O2-δcatalyst,whilefortheCe0.9Fe0.1O2-δtheconversionwas30%.TheresultsindicatedthatCe0.9Cu0.1O2-δwassuitableforthetreatmentoforganicwastewaterswhileCe0.9Fe0.1O2-δwassuitablefortheremovalofHacid.The70%phenolremovalratewithCe0.9Cu0.1O2-δcatalystwasmarkedlyincreasedto90%withCe0.8Cu0.2O2-δcatalyst.However,thephenolremovalreducedfrom30%to15%withFecontentincreasingfrom10%to20%.FortheHacid,theincreaseofthecontentofCuorFetendedtoobviouslyincreasetheoriginalreactionratewhiletheCODremovalchangedlittle.

  • 标签: H acid PHENOL COD removal rate
  • 简介:NexttoCO2,methane(CH4)isthesecondimportantcontributortoglobalwarmingintheatmosphereandglobalatmosphericCH4budgetdependsonbothCH4sourcesandsinks.UnsaturatedsoilisknownasauniquesinkforatmosphericCH4interrestrialecosystem.ManycomparisonstudiesprovedthatforestsoilhadthebiggestcapacityofoxidizingatmosphericCH4invariousunsaturatedsoils.However,uptonow,thereisnotanoverallreviewintheaspectofatmosphericCH4oxidation(consumption)inforestsoil.ThispaperanalyzedadvancesofstudiesonthemechanismofatmosphericCH4oxidation,andrelatednaturalfactors(Soilphysicalandchemicalcharacters,temperatureandmoisture,ambientmaingreenhousegasesconcentrations,treespecies,andforestfire)andanthropogenicfactors(forestclear-cuttingandthinning,fertilization,exogenousaluminumsaltsandatmosphericdeposition,addingbiocides,andswitchofforestlanduse)inforestsoils.ItwasbelievedthatCH4consumptionratebyforestsoilwaslimitedbydiffusionandsensitivetochangesinwaterstatusandtemperatureofsoil.CH4oxidationwasalsoparticularlysensitivetosoilC/N,AmbientCO2,CH4andN2Oconcentrations,treespeciesandforestfire.Inmostcases,anthropogenicdisturbanceswilldecreaseatmosphericCH4oxidation,thusresultingintheelevatingofatmosphericCH4.Finally,theauthorpointedoutthatourknowledgeofatmosphericCH4oxidation(consumption)inforestsoilwasinsufficient.InordertoevaluatethecontributionofforestsoilstoatmosphericCH4oxidationandtheroleofforestplayedintheprocessofglobalenvironmentalchange,andtoforecastthetrendsofglobalwarmingexactly,moreresearchersneedtostudiesfurtheronCH4oxidationinvariousforestsoilsofdifferentareas.

  • 标签: 森林土壤 氧化 大气甲烷 全球变暖 土壤碳氮比 土壤水分
  • 简介:Sprayingtestwereconductedtwicebeforesteelslabswereputintothefurnaceandtheeffectsoftheoxidationresistancecoatingwereinvestigatedandverified.Bycomparingthechangeofslabweight,rollingforceoftheroughingmill&finishingmill,thicknessofoxidefilmonthesurfaceslabsbyanXL-30SEMandacidpicklingspeedofslabswithandwithoutcoating,itwasfoundthattheoxidizationwasteinthefurnacedecreasedby40percentwiththeuseofthecoatingandthecorrespondingyieldcapacitycouldincreaseby0.2percentatleast.Besides,thethicknessofoxidescalefilmonhotrolledproductswasreducedby1.44micrometersandtheacidpicklingtimewasshortenedby6swiththecoatingtechnology,whilethetotalrollingforceofRM&FMdidnotchanged.Furthermore,theapplicationprospectofthistechnologywasalsodiscussedinthispaper.

  • 标签: 工业性试验 涂层技术 耐氧化性 喷雾试验 轧制力 粗轧机
  • 简介:<正>TheDalianInstituteofChemicalPhysicsofCAShasmadegreatstridesinselectiveoxidationstudiesafterhavingperformedsuccessfulcommercialtestingofthenovelcatalystforoxidationofparaxyleneinthe100kt/ascale.

  • 标签: XYLENE DALIAN manufacture CONDUCT RESTING calibrat
  • 简介:血浆nitrocarburizing和血浆氧化处理被执行改进wear和SKD61钢的腐蚀抵抗。血浆nitrocarburizing在生产epsilon-Fe2_3的氮,氢和甲烷空气在540°C为12h被进行(N,C)血浆nitrocarburising生产的phase.The混合物层主要由电子阶段组成,与gamma'-Fe4的一个小比例(N,C)复合的层和扩散层的phase.The厚度是大约10亩m和大约200/^m,respectively.Plasma柱子氧化为1h.The在500°C的经常的温度与各种各样的氧/氢比率在nitrocarburized样品上被执行在在复合的层上的厚度的1-2亩m的很薄的磁铁矿(Fe3O4)层被获得。阳极极化测试表明那个血浆nitrocarburizing过程贡献了SKD61钢的腐蚀抵抗的重要改进。然而,nitrocarburized混合物层的腐蚀特征被氧化处理败坏。

  • 标签: 等离子体 氧化处理技术 防腐措施
  • 简介:IntheprocessofinvestigationondomesticPTAprojecttheResearchInstituteofSINOPECYangziPetrochemicalCompanyundertakestoperform“AnalysisandprocessoptimizationofAmocohigh-temperatureoxidationtechnology”,“DevelopmentandcommercializationstudyonnovelcatalystforsynthesisofPTA”,“StudyonPTAoxidationreaction”,and

  • 标签: PTA PX SINOPEC
  • 简介:Nanofibrous碳的材料(NFC)作为有许多应用的材料的一个新班,能催化H2S的选择氧化到硫。在在H2S氧化的NFC结构和它的活动和选择之间的关联是坚定的。如果有更多的订的结构的NFC被综合,在碳的原来的催化剂的部分被增加在催化剂积累的碳减少,选择能被改进,这被表明。

  • 标签: 纳米结构 碳纳米纤维 碳纳米管 碳产率 氧化选择 硫化氢
  • 简介:离子的液体的一种新类型支持了硒试剂被综合并且发现了面对30%H2O2是在到醛和酉同类的白酒的氧化的优秀催化剂。离子的液体的可预言的溶解度从反应混合允许氧化产品的容易的分离。而且,当溶剂,和离子的支持液体的硒试剂能被再循环并且在催化性能与小减少在四次使用了,氧化反应能用离子的液体被执行。

  • 标签: 离子液体 过氧化氢 硒试剂 酮类 醛类