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500 个结果
  • 简介:TheNd2O3nanoparticleswhichmodifiedbyAOTwaspreparedusingmicrioemulsionmethodinthesystemofwater/xylene.L3edgeXAFSwasusedtodeterminethedifferenceofthelocalstructurearundNd^3+ionandtheelectricalstructurebetweenthenanocystallineNd2O3andthecoarsebulkmicrocrystallineNd2O3.ItwasfoundthatNd-Odistanceincreasedwiththeformofnanocrystalliteandtheintensityofabsorptionedgealsoenhancedatthesametime.

  • 标签: EXAFS研究 ND2O3 毫微米粒子
  • 简介:Tungstendisulfide(WS2)isatypeofanisotropic-layeredcompoundandhasbroadbandsaturableabsorptionfeaturesassaturableabsorbers(SAs).WithWS2-basedSAs,darksolitonsinerbium-dopedfiber(EDF)lasersarefirstobtained.Forthegenerateddarksolitons,thecenterwavelengthismeasuredtobe1530nm,andtherepetitionrateisabout116.5MHz.Aseriesofopticalspectraisexhibited.Theelectricalsignal-to-noiseratioisbetterthan94dB.ResultsinthispaperdemonstratethatWS2-basedSAsarethepromisingSAsforgeneratingdarksolitonsinEDFlasers.

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  • 简介:TheCasimireffecthasbeenstudiedforvariousquantumfieldsinbothfiatandcurvedspacetimes.Asafurtherstepalongthisline,weprovideanexplicitderivationofCasimireffectformasslessspin-3/2fieldwithperiodicboundaryconditionimposedinfour-dimensionalMinkowskispacetime.ThecorrespondingresultswithDirichletandNeurnannboundaryconditionsarealsodiscussed.

  • 标签: CASIMIR效应 无质量自旋 MINKOWSKI空间 边界条件
  • 简介:TheHL-2ANBIdesignparametersarehydrogenbeamenergy60keY,thepulsedurationof2s,consistoftwobeamlinesandinjectedalongtangentialdirection.Theneutralbeampowerwillarrive4MWinthefuture.Thefirststepisonebeamlineandtwoionsources.Thevacuumvesselconsistsofmajorchamber,minorchamberandionsourcechamberanddriftduct.Weneedavacuumsystem,whichcapacityissufficientandtherelativelylowcostsofit.

  • 标签: 中性束注入器 钛吸附泵 HL-2A 等离子体 设计思路
  • 简介:Amine-silicacompositematerialsforpost-combustionCO2capturehaveattractedconsiderableattentionbecauseoftheirhighCO2uptakeatlowCO2concentrations,excellentCO2captureselectivityinthepresenceofmoisture,andlowerenergyrequirementsforsorbentregeneration.Thisreviewdiscussestherecentadvancesinamine-silicacompositesforCO2capture,includingadsorbentpreparationandcharacterization,CO2captureunderdryandmoistureconditionsatdifferentCO2partialpressures,sorbentregeneration,andstabilityaftermanycyclicsorption-desorptionruns.

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  • 简介:我们综合了一系列Nb2Pd1xRuxS5多晶的样品由一固态反应方法并且系统地由运输和磁性的大小在超导性上调查了做Ru效果。超导性被提高,Ru做并且在混乱之上是相当柔韧的,这被发现。霍尔系数大小显示费用运输被类似于做的红外的案例的洞类型费用搬运人统治,建议多乐队超导性。在Ru或红外做之上,Hc2/Tc展出重要改进,超过泡利不相容原理由约4的一个因素的顺磁的限制价值。Tc和上面的关键字段的比较(在Pd地点上的不同的做元素之中的Hc2),揭示联合的纺纱轨道的一个重要角色。

  • 标签: 掺杂效应 超导电性 空穴 电荷输运 固相反应法 多晶样品
  • 简介:Nanostructuredγ-Al2O3withhighsurfaceareaandmesoporousstructurewassynthesizedbysol-gelmethodandemployedascatalystsupportfornickelcatalystsinmethanereformingwithcarbondioxide.ThepreparedsampleswerecharacterizedbyXRD,N2adsorption-desorption,TPR,TPO,TPH,NH3-TPDandSEMtechniques.TheBETanalysisshowedahighsurfaceareaof204m2g-1andanarrowpore-sizedistributioncenteredatadiameterof5.5nmforcatalystsupport.TheBETresultsrevealedthatadditionoflanthanumoxidetoaluminumoxidedecreasedthespecificsurfacearea.Inaddition,TPRresultsshowedthatadditionoflanthanumoxideincreasedthereducibilityofnickelcatalyst.Thecatalyticevaluationresultsshowedanincreaseinmethaneconversionwithincreasinglanthanumoxideto3mol%andfurtherincreaseinlanthanumcontentdecreasedthecatalyticactivity.TPOanalysisrevealedthatthecokedepositiondecreasedwithincreasinglanthanumoxideto3mol%.SEMandTPHanalysesconfirmedtheformationofwhiskertypecarbonoverthespentcatalysts.AdditionofsteamandO2todryreformingfeedincreasedthemethaneconversionandledtocarbonfreeoperationincombinedprocesses.

  • 标签: 甲烷二氧化碳重整 镍催化剂 纳米结构 氧化镧 合成气 NH3-TPD
  • 简介:Thenextgenerationofadvancedlightsourcesrequiresphotonswithlargeaveragefluxandhighbrightness,whichneedsadvancedelectrongunmatchedwithexcellentphotocathodematerials.K2CsSbphotocathodehastheadvantagesofhighquantumefficiency,longlifetimeandinstantaneousresponse.ThisstudyintroducesthedesignofasetofK2CsSbphotocathodepreparationsystemsanddetailedpreparationprocessofK2CsSbphotocathodes,includingsequentialdepositionprocessandco-depositionprocess,andfinallydevelopsaK2CsSbphotocathode.Theinfluenceoflaserpoweronthequantumefficiencyisalsoinvestigated.

  • 标签: CS SB St DEVELOPMENT of PREPARATION
  • 简介:Aquantumdynamiccalculationonafive-dimensionalO2/LiF(001)modelsystemisperformedusingthemulti-configurationtime-dependentHartreemethod.Theobtainedresultsshowthatthemechanismofrotationalanddiffractiveexcitationindetails:Comparisonwiththerotationalexcitedstate,theinitiallynon-rotationalstateisseentofavortheinelasticscatteringintherotationalexcitationprocess.Thesurfacecorrugationcandampthequantuminterferencesandproduceagreateramountofrotationalinelasticscatteringattheexpenseoftheelasticprocessintherotationalexcitationprocess.Thediffractionprocessandtheaverageenergytransferredintotherotationalanddiffractivemodearealsodiscussed.

  • 标签: 非弹性散射 旋转状态 衍射过程 表面波纹 氟化锂 氧气
  • 简介:Thedevelopmentofthehydrogenelectrodeisvitalfortheapplicationofalkalinepolymerelectrolytefuelcells(APEFCs).Inthisstudy,aseriesofNi(OH)2decoratedNi/Ccatalysts(Ni(OH)2-Ni/C)werepreparedbyathree-stepelectrochemicaltreatmentofNi/C.TheexistenceofNi(OH)2wasdemonstratedbyX-rayphotoelectronspectroscopy(XPS),andthesurfacemolarratioofNi(OH)2/Niofthesampleswasestimatedviaanelectrochemicalmethod.TheHORcatalyticactivityofthecatalystswasevaluatedbyarotationdiskelectrode(RDE)method,anda'volcanoplot'wasestablishedbetweentheHORexchangecurrent(j0)andthesurfacemolarratioofNi(OH)2/Ni.Ontopofthe'volcano',thesurfacemolarratioofNi(OH)2/Niis1.1:1,thej0ofwhichwas6.8timesofthatofNi/C.ThestabilityofthesamplestowardHORwasevaluatedtobegood.OurstudyaddedasystematicexperimentalevidencetotheHORresearch,showingthattheHORcatalyticactivityofNicanbedeliberatelycontrolledviadecorationofNi(OH)2,whichmayhelpunderstandingtheHORmechanismonNi.

  • 标签: Hydrogen oxidation reaction FUEL CELLS Alkaline