简介：ConsideringthatKBe2BO3F2(KBBF)isanoutstandingdeepultravioletcrystalwhichcangeneratetheshortestwavelengthsinsecondharmonicgenerationandsum-frequencygeneration,wereportthedeterminationofthenonlinearopticalcoefficientsoftheKBBFcrystal.Thed11coefficientwasdeterminedtobe0.49pm/VbytheMakerfringesmethodatthewavelength1064nm,whichisinagreementwellwiththetheoreticalvalue.
简介：Theeffectofbismuth（Bi）forbothVO2+/VO2+andV3+/V2+redoxcouplesinvanadiumflowbatteries（VFBs）hasbeeninvestigatedbydirectlyintroducingBionthesurfaceofcarbonfelt（CF）.TheresultsshowthatBihasnocatalyticeffectforVO2+/VO2+redoxcouple.Duringthefirstchargeprocess,BiisoxidizedtoBi3+（neverreturnbacktoBimetalinthesubsequentcycles）duetothelowstandardredoxpotentialof0.308V（vs.SHE）forBi3+/BiredoxcouplecomparedwithVO2+/VO2+redoxcoupleandBi3+exhibitno（orneglectable）electro-catalyticactivity.Additionally,therelationshipbetweenBiloadingandelectrochemicalactivityforV3+/V2+redoxcouplewasstudiedindetail.2wt%Bi-modifiedcarbonfelt（2%-BiCF）exhibitsthehighestelectrochemicalactivity.Usingitasnegativeelectrode,ahighenergyefficiency（EE）of79.0%canbeachievedatahighcurrentdensityof160mA/cm2,whichis5.5%higherthanthepristineone.Moreover,theelectrolyteutilizationratioisalsoincreasedbymorethan30%.Eventhecelloperatedat140mA/cm2forover300cycles,theEEcanreach80.9%withoutobviousfluctuationandattenuation,suggestingexcellentcatalyticactivityandelectrochemicalstabilityinVFBs.
简介：Inthiswork,theinfluenceofCO2onthestructuralvariationandcatalyticperformanceofNa2WO4/Mn/SiO2foroxidativecouplingofmethanetoethylenewasinvestigated.ThecatalystwaspreparedbyimpregnationmethodandcharacterizedbyXRD,RamanandXPStechniques.AppropriateamountofCO2inthereactantgasesenhancedtheformationofsurfacetetrahedralNa2WO4speciesandpromotedthemigrationofOinMOx,Na,Wfromthecatalystbulktosurface,whichwerefavorableforoxidativecouplingofmethane.WhenthemolarratioofCH4/O2/CO2was3/1/2,enrichedsurfacetetrahedralNa2WO4speciesandhighsurfaceconcentrationofOinMOx,Na,Wweredetected,andthenhighCH4conversionof33.1%andhighC2H4selectivityof56.2%wereobtained.WithfurtherincreaseofCO2inthereagentgases,thecontentofactivesurfacetetrahedralNa2WO4speciesandsurfaceconcentrationofOinMOx,Na,Wdecreased,whilethatofinactivespecies(MnWO4andMn2O3)increaseddramatically,leadingtolowCH4conversionandlowC2H4selectivity.ItcouldbespeculatedthatNa2WO4crystalwastransformedintoMnWO4crystalwithexcessiveCO2addedunderthereactionconditions.PretreatmentofNa2WO4/Mn/SiO2catalystbymoderateamountofCO2beforeOCMalsopromotedtheformationofNa2WO4species.
简介：Asimplemethodisappliedtocalculatingtheisotopeshifts(ISs)on5S1/2→4D3/2,5/2transitionsof87,88Sr+.FirstwehavecalculatedtheISsoflowertransitionsonaseriesofalkali-likesystemssuchasB2+,Ca+andBa+,whichareinagreementwithotherworks.ThentheISson5S1/2→4D3/2,5/2transitionsof87,88Sr+,whichareusefultostudytheSr+opticalfrequencystandard,areevaluated.
简介：Takingadvantageofthelargeγ-detectorarrayGammasphereandtherecoilmassseparatorFMA,highspinstatesin117Bawereinvestigatedthroughtherecoil-β-delayedprotondecaytaggingtechniqueviatheheavy-ioninducedfusion-evaporationreaction64Zn(58Ni,2p3n)117Ba,atabeamenergyof305MeV.Promptγraysbelongingto117Bahavebeenidentifiedfurthermore,arotationalbandhasbeenidentifiedforthefirsttimeandpresentedasbandAinFig.1.
简介：Anewmethodforfabricatingorderedporoussiliconisreported.Atwo-dimensionalsilicananospherearrayisusedasatemplatewithahydrofluoricacid-hydrogenperoxidesolutionforetchingthenanospheres.Theinitialdiameteranddistributionoftheholesintheresultingporoussiliconlayeraredeterminedbythesizeanddistributionofthesilicananospheres.Thecorrosiontimecanbeusedtocontrolthedepthsoftheholes.ItisfoundthatthepresenceofaSiO_2layer,formedbytheoxidationoftheroughinternalsurfaceofthehole,istheprimaryreasonallowingthecorrosiontoproceed.Ultravioletreflectionandthermalconductivitymeasurementsshowthatthediameteranddistributionoftheholeshaveagreatinfluenceonpropertiesoftheporoussilicon.
简介：我们揭示并且解释thermopowerS/T的可伸缩的行为展出了由典型重费米子(HF)金属YbRh2在在温度T的磁场B的申请下面的Si2。我们证明一样的可伸缩被不同HF混合物例如表明?-YbAlB4和强烈相关的分层的钴氧化物[BiBa0.66K0.36O2]CoO2。用YbRh2是的Si2一个例子，，我们证明S/T的可伸缩的行为在antiferromagnetic阶段转变被违背剩余抵抗力0和状态的密度，N，经验在阶段转变跳，引起thermopower做二跳并且改变它的符号。我们的说明基于深刻地影响0和N的单个粒子的光谱变平。描绘S/T行为的主要特征，我们构造TBYbRh2Si2。我们为HF混合物的计算S/T在对试验性的事实的好同意并且支持我们的观察。
简介：Twofamiliesofcatalysts,basedonPdnanoparticlessupportedonceramicasymmetrictubularaluminamembranes,arestudiesinthedirectsynthesisofH_2O_2.TheyarepreparedbydepositingPdintwoways:(i)reductionwithN_2H_4inanultrasonicbathand(ii)byimpregnation-deposition.Thefirstpreparationleadstolargerparticles,withaveragesizeofaround11nm,whilethesecondpreparationleadstosmallerparticles,withaveragesizearound4nm.Thecatalyticmembranesweretestedasprepared,afterthermaltreatmentinairandafterfurtherpre-reductionwithH_2inmild(100℃)conditions.SampleswerecharacterizedbyTEM,CO-chemisorptionmonitoredbyDRIFTSmethodandTPR,whilecatalytictestshavebeenperformedinasemi-batchrecirculationmembranereactor.Experimentalcatalyticresultswereanalysedusingtwokineticsmodelstoderivethereactionconstantsfortheparallelandconsecutivereactionsofthekineticnetwork.SmallerparticlesofPdshowlowerselectivityduetothehigherrateofparallelcombustion,evenifthebetterdispersionofPdandthushighermetalsurfaceareainthesampleleadtoaproductivityinH_2O_2similarorevenhigherthanthesamplewiththelargerPdparticles.IndependentlyonthepresenceofsmallerorlargerPdnanoparticles,anoxidationtreatmentleadstoasignificantenhancementintheproductivity,althoughthecatalystprogressivelyreducesduringthecatalyticprocess.Theinhibitionoftheparallelcombustionreaction(towater)inducedfromthecalcinationtreatmentremainsafterthein-situreductionoftheoxidizedPdspeciesformedduringthepre-treatment.Thisislikelyduetotheeliminationofdefectsiteswhichdissociativelyactivateoxygen,andtentativelyattributedtoPdsitesabletogivethree-andfour-foldcoordinationofCO.
简介：WeinvestigateindetailtheeffectsofR-parityleptonnumberviolationonthedecay~↑b1→b~↑x1^0intheR-parityviolatingminimalsupersymmetricstandardmodel(Rp-MSSM)underthepresentexperimentalconstraintsonRpparameters.Inournumericalcalculationsweconsidertwocasesofinputparametersofthesquarkandsleptonsectors,MsquarkMslepton,forcomparison.TheresultsshowthattherelativeR-parityviolatingcorrectionisnotverysensitivetothemassofthelightestneutralino-0↑x1andthedegenerateR-parityviolatingcouplingparameterλ2′,butstronglydependsonMsquark,Mslepton,tanβandthedegenerateR-parityviolatingcouplingparameterλ1′.Therelativecorrectionisabout-4～3%andcanexceed-6%insomeregionofparameterspace.Therefore,preciseexperimentanalysesonthedecay~↑b1→b~↑x1^0mayprovideaprobeoftheR-parityviolation.
简介：Aseriesofoxygenpermeabledual-phasecompositeoxides60wt%Ce0.8Gd0.2O2-δ-40wt%LnBaCo2O5+δ(CGO-LBCO,Ln=La,Pr,Nd,Sm,GdandY)weresynthesizedthroughasol-gelrouteandeffectsoftheLn3+cationsontheirphasestructure,oxygenpermeabilityandchemicalstabilityagainstCO2wereinvestigatedsystemicallybyXRD,SEM,TG-DSCandoxygenpermeationexperiments.XRDpatternsrevealthatthelargerLn3+cations(La3+,Pr3+andNd3+)successfullystabilizedthedouble-layeredperovskitestructureofsinteredLBCO,whilethesmallerones(Sm3+,Gd3+,andY3+)resultedinthepartialdecompositionofLBCOwithsomeimpuritiesformed.CGO-PBCOyieldsthehighestoxygenpermeationflux,reaching2.8×10-7mols-1cm-2at925?Cwith1mmthicknessunderair/Hegradient.TheTG-DSCprofilesin20mol%CO2/N2andoxygenpermeabilityexperimentswithCO2assweepgasshowthatCGO-YBCOdemonstratesthebestchemicalstabilityagainstCO2,possiblyduetoitsminimumbasicity.ThestableoxygenpermeationfluxofCGO-YBCOunderCO2atmosphererevealsitspotentialapplicationintheoxy-fuelcombustionrouteforCO2capture.
简介：HL-2AisthefirsttokamakwithdivertorinChina.TheobjectivesofHL-2Aaretoproducemoreadaptabledivertorconfigurationstostudyenergyexhaustandimpuritycontrol,andtostudyenhancedcoreplasmaconfinementbyprofilecontrolandmoderateplasmashaping.HL-2Ahaswelloptimizedoperationalflexibilityandexcellentaccessi-bilityforthediagnosticsystemstofacilitatevariousplasmaexperiments.
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![双金属化合物[Ni（en）<b style='color:red'>2</b>]3[Fe（CN）6]<b style='color:red'>2</b>·<b style='color:red'>2</b>H<b style='color:red'>2</b>O的变温穆斯堡尔谱研究](/image/thesis4 "双金属化合物[Ni（en）<b style='color:red'>2</b>]3[Fe（CN）6]<b style='color:red'>2</b>·<b style='color:red'>2</b>H<b style='color:red'>2</b>O的变温穆斯堡尔谱研究")
