简介:用EXAFS方法研究了重金属Zn(Ⅱ)在δ-MnO2上吸附的微观结构及吸附机制。在pH5.50,0.1M硝酸钠介质中,吸附-解吸实验表明Zn(Ⅱ)在δ-MnO2上的吸附可逆性很高.EXAFS结果表明,δ-MnO2表面上吸附态Zn2+以六配位的水合离子八面体形式存在。八面体的水合Zn^2+离子与δ-MnO2的结构单元MnO6八面体通过共用O原子结合,形成角-角结合的弱吸附.Zn-O平均原子间距为2.071A,Zn-Mn平均原子间距为3.528A。同一条等温线上随着吸附量增加,角-角结合的弱吸附形式基本上没有变化。Zn(Ⅱ)在δ-MnO2上较高的吸附可逆性是由于吸附态Zn(Ⅱ)与δ-MnO2以弱吸附的角-角形式结合所导致的。
简介:Anew140GHz/2MW/3selectroncyclotronresonanceheating(ECRH)systemcomposedoftwounitsisnowbeingconstructedonHL-2A.Asapartofthesystem,twotransmissionlinesmarkedNo.7&8playtheroleofcarryingmicrowavepowerfromtwogyrotronstothetokamakport.Basedontheoversizedcircularcorrugatedwaveguidetechnology,anevacuatedtransmissionsystemwithhighpowercapabilityandhightransmissionefficiencyisdesigned.Detailsarepresentedforthedesignofthecorrugatedwaveguide,thelayoutoftheproposedlinesandthevacuumpumpingsystem.Thenmodeconversionlossesduetocoupling,misalignment,bendsandgapsarediscussedtoserveasareferenceforanalyzingthetransmissionefficiencyandalignment.Finally,adual-modespropagationcaseconsistingoftheHEnandLPnevenmodesisdiscussed
简介:StableoperatingregionintheHL-1Mtokamakhasbeenextendedbymeansofwallconditioning,corefuellingandcurrentcontroltechniques.Themechanismsoftheextensionareanalyzedinthispaper.Lithiumizationdiminishestheimpuritiesandhydrogenrecyclingtothelowestlevel.Afterlithiumizationahighdensityupto7×1019m-3wasobtainedeasilybystronggaspuffingwithordinaryohmicdischargealone.MoreattractivelywefoundthatmetalLi-coatingexhibitedtheeffectsofwallstabilization.Thelowqalimitwithhigherdensitywasextendedbyafactorof1.5~2incomparisonwiththatforboronization,and1.2forsiliconization.Siliconizationnotonlyextendedstableoperatingregionsignificantlybyitself,butalsoprovidedagoodtargetplasmaforotherexperimentsofraisingdensitylimit.Corefuellingschemesarefavourableespeciallyforsiliconizedwallwithahigherlevelofmedium-Zimpurity(Z=14).Aftersiliconizationthemaximumdensitynearto1020m-3wasachievedbyacombinationofsupersonicmoleculebeaminjectionandmultipelletinjection.ThenewdefinedslopeofHugilllimitillustratingmoreclearlythesituationunderlowqaandhighnedischargeswascreatedtoindicatethenewregionextendedbycombiningIpramp-upwithcorefuelling.TheslopewithalargeMurakamicoefficientincreasedbyafactorof50~60%.
简介:ThispaperpresentsabriefoverviewofCO2reformingofCH4(CRM)byvariousformsof'arc'plasma,whichismoresuitabletoCRM,andtheenergyefficiencyisusedtoevaluatedifferentplasmaprocessesspecifically.Accordingtothereportedresults,thearcthermalplasmawithbinodeexhibitedbetterperformance.Moreover,theplasmaCRMprocesswascomparedwiththereportedplasmasteamreformingofCH4(SRM)process,andtheresultsshowedthattheformerprocesshasadvantagesonenergyefficiencyandCH4consumption.Additionally,itisbelievedthattheplasmaCRMprocesswouldbecompetitivewiththeconventionalSRMprocessinbothenergyefficiencyandCO2emissiononcetheheatmanagementisemphasizedandtherenewablepowerisused.Finally,aconceptofplasmareactorforindustrialapplicationisproposed.
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简介:PhotocatalystwaspreparedbyimmobilizingTiO_2onglassbeadsusingthetradi-tionalsol-gelmethod.Ultravioletlight(UV)producedbypulsedstreamerdischargewasthenusedtoinducephotocatalyticactivityofTiO_2photocatalyst.Decolourationefficiencyoftherep-resentativeazodye(acidorange7,AO7)wasinvestigatedusingthesynergisticsystemofpulsedstreamerdischargeplasmaandTiO_2photocatalysis.Theobtainedresultsshowedthatthede-colourationrateofAO7couldbeincreasedby16.7%undertheconditionofaddingsupportedTiO_2inthepulsedstreamerdischargesystem,comparedtothatinthesolepulsedstreamerdischargeplasmasystem,duetothesynergisticeffectofpulsedstreamerdischargeandTiO_2photocatalysisinducedbypulsedstreamerdischarge.ThesynergisticsystemofpulsedstreamerdischargeandTiO~photocatalystwasfoundtohavemorereactiveradicalsfordegradationoforganiccompoundsinwater.
简介:Theoreticalcalculationandexperimentalresultsforapolarizerwithsinusoidalgroovesusedintheelectroncyclotronresonanceheating(ECRH)systemoftheHL-2Atokamakarepresented.Thecalculationisbasedonanintegralmethoddevelopedinthevectortheoryofdiffractiongratings,andthepolarizationcharacteristicsobtainedwithalow-powertestareingoodagreementwiththenumericalcalculatedresults.WiththepolarizerassembledinamiterbendintheECRHtransmissionline,pureordinarymode(O-mode)andextraordinarymode(X-mode)polarizedwavesarealsoexpectedinthehigh-powerexperiment,dependingonthepolarizerrotationangleandthetoroidalinjectionangleoftheelectroncyclotron(EC)wavebeam.Second-harmonicX-modeexperimentsweresuccessfullyexploredinHL-2A.Experimentalresultrevealedthattheelectrontemperatureincreasedfrom0.8keV(Ohmicheatingphase)to1.5keV(secondX-modeheatingphase).
简介:Thepreliminarydesignofamulti-barrelspelletinjectorwithcyclerefrigeratorasanadvancedplasma-fuellingtoolforHL-2Atokamakhasbeenproposed.Thedesignaimsatprecisetemperaturecontrol,easyoperation.withhighreliabilityandhighflexibility.GM-cyclerefrigeratorandpipe-gunStructurehavebeenemployedtoproduce25pelletsin25gunbarrelssimultaneouslyandthedesignaims.havebeenaccomplished.Primedesignprinciple,engineeringparameters,structureandlayoutofthecryostatcomponentsaswellascalculationofheatloadforthecryostatarepresented.