学科分类
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95 个结果
  • 简介:MesoporousLiFePO4/Ccompositescontaining80wt%ofhighlydispersedLiFePO4nanoparticles(4-6nm)werefabricatedusingbimodalmesoporouscarbon(BMC)ascontinuousconductivenetworks.TheuniqueporestructureofBMCnotonlypromisesgoodparticleconnectivityforLiFePO4,butalsoactsasarigidnano-confinementsupportthatcontrolstheparticlesize.Furthermore,thecapacitieswereinvestigatedrespectivelybasedontheweightofLiFePO4andthewholecomposite.Whencalculatedbasedontheweightofthewholecomposite,itis120mAh·g-1at0.1Cofthehighloadingelectrodeand42mAh·g-1at10Cofthelowloadingelectrode.TheelectrochemicalperformanceshowsthathighLiFePO4loadingbenefitslargetapdensityandcontributestotheenergystorageatlowrates,whiletheelectrodewithlowcontentofLiFePO4displayssuperiorhighrateperformance,whichcanmainlybeduetothesmallparticlesize,gooddispersionandhighutilizationoftheactivematerial,thusleadingtoafastionandelectrondiffusion.

  • 标签: LiFePO4 HIGH loading fast ion diffusion
  • 简介:Directconversionoffructose-basedcarbohydratesto5-ethoxymethylfurfural(EMF)catalyzedbyLewisacidinethanolwasinvestigated.ItwasfoundthatBF3(Et)2Owasfavorablefor5-hydroxymethylfurfural(HMF)etherificationtoEMF.BF3(Et)2OcombinationwithAlCl36H2Owiththemolarratioof1wasaneffectivecatalystsystemforsynthesisofEMFfromfructose-basedcarbohydrates.55.0%,45.4%and23.9%ofEMFyieldswereobtainedfromfructose,inulinandsucroseunderoptimizedconditions,respectively.

  • 标签: 碳水化合物 直接转换 酸催化 果糖 乙醇 羟甲基糠醛
  • 简介:Ultrafastfiberlasersareingreatdemandforvariousapplications,suchasopticalcommunication,spectroscopy,biomedicaldiagnosis,andindustrialfabrication.Here,wereportthehighlystablefemtosecondpulsegenerationfromaMXenemode-lockedfiberlaser.Wehavepreparedthehigh-qualityTi3C2Txnanosheetsviatheetchingmethod,andcharacterizedtheirultrafastdynamicsandbroadbandnonlinearopticalresponses.Theobviousintensity-andwavelength-dependentnonlinearresponseshavebeenobservedandinvestigated.Inaddition,ahighlystablefemtosecondfiberlaserwithsignal-to-noiseratioupto70.7dBandcentralwavelengthof1567.3nmhasbeendelivered.Thestudymayprovidesomevaluabledesignguidelinesforthedevelopmentofultrafast,broadbandnonlinearopticalmodulators,andopennewavenuestowardadvancedphotonicdevicesbasedonMXenes.

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  • 简介:Theresultsonadissociationbehaviorofpropanehydratespreparedfrom'drywater'andcontainedunreactedresidualwaterintheformoficeinclusionsorsupercooledliquidwater(watersolutionofgas)werepresentedfortemperaturesbelow273K.Thetemperaturerampingorpressurereleasemethodwasusedforthedissociationofpropanehydratesamples.Itwasfoundthatthemechanismofgashydratedissociationattemperaturesbelow273Kdependedonthephasestateofunreactedwaterinthehydratesample.Gashydratesdissociatedintoiceandgasiftheiceinclusionswereinthehydratesample.Thesamplesofpropanehydrateswithinclusionsofunreactedsupercooledwateronly(withouticeinclusions)dissociatedintosupercooledwaterandgasbelowthepressureofthesupercooledwater-hydrate-gasmetastableequilibrium.

  • 标签: 天然气水合物 分解机制 分解行为 水分解 残留水 反应
  • 简介:氧化铝弥散强化铜合金是国际热核实验堆(ITER)的备选热沉材料之一,氘在其中的渗透滞留行为关系到ITER运行的安全性。通过气体驱动渗透平台测定了实验温度621~803K时氘气在氧化铝弥散强化铜合金中的渗透参数;通过热脱附谱实验平台记录了2种氧化铝弥散强化铜合金以及CuCrZr的热脱附曲线。结果表明:在相同温度区间内,氘气在氧化铝弥散强化铜合金中的渗透系数与纯铜及CuCrZr接近,说明氧化铝弥散相对氘气在氧化铝弥散强化铜合金中的渗透系数基本没有影响,而扩散系数比在纯铜和CuCrZr中都低,且在低温时显著降低;2种氧化铝弥散强化铜合金均有3个脱附峰,而CuCrZr合金只有1个脱附峰。

  • 标签: 渗透 滞留 弥散铜 热脱附
  • 简介:Thesuppressionoftherecombinationofelectronsandholes(e–h)andtheenhancementofthelightabsorptionofsemiconductorsaretwokeypointstowardefficientphotocatalyticdegradation.Here,wereportafew-layerg-C3N4/α-MoO3nanoneedles(flg-C3N4/α-MoO3NNs)all-solid-stateZ-schememechanismphotocatalystsynthesizedviaatypicalhydrothermalmethodinacontrolledmanner.Therecombinationofthephoto-inducede–hpairscouldbeeffectivelyrestrainedbytheZ-schemepassagewaybetweentheflg-C3N4andα-MoO3NNsinthecomposite,whichcouldalsopromiseahighredoxabilitytodegradepollutants.Anditbecamepossibleforthepreparedphotocatalysttoabsorblightinawiderangeofwavelengths.Thedetailedmechanismwasstudiedbyelectronspin-resonancespectroscopy(ESR).Thelow-dimensionalnanostructureofthetwoconstituents(α-MoO3NNswithone-dimensionalstructureandflg-C3N4withtwo-dimensionalstructure)endowedthecompositewithvarietiesofexcellentphysicochemicalproperties,whichfacilitatedthetransferanddiffusionofthephotoelectronsandincreasedthespecificsurfaceareaandtheactivesites.The10wt%flg-C3N4/α-MoO3NNsshowedthebestphotocatalyticperformancetowardRhBdegradation,therateofwhichwas71.86%,~2.6timeshigherthanthatofα-MoO3NNs.

  • 标签: Flg-C3N4 α-MoO3 NANONEEDLES ALL-SOLID-STATE Z-scheme mechanism
  • 简介:Throughournewly-developed'chemicalvapordepositionintegratedprocess(CVD-IP)'usingcarbondioxide(CO2)astherawmaterialandonlycarbonsourceintroduced,CO2couldbecatalyticallyactivatedandconvertedtoanewsolid-formproduct,i.e.,carbonnanotubes(CO2-derived)ataquitehighyield(thesingle-passcarbonyieldinthesolid-formcarbon-productproducedfromCO2catalyticcaptureandconversionwasmorethan30%atasingle-passcarbon-base).Forcomparison,whenonlypurecarbondioxidewasintroducedusingtheconventionalCVDmethodwithoutintegratedprocess,nosolid-formcarbon-materialproductcouldbeformed.IntheadditionofsaturatedsteamatroomtemperatureinthefeedforCVD,thereweremuchmoreend-openingcarbonnano-tubesproduced,ataslightlyhighercarbonyield.Theseinspiringworksopenedaremarkableandalternativenewapproachforcarbondioxidecatalyticcapturetosolid-formproduct,comparingwiththatofCO2sequestration(CCS)orCO2mineralization(solidification),etc.Asaresult,therewasmuchlessbodyvolumeandalmostnogreenhouseeffectforthissolid-formcarbon-materialthanthoseofprimitivecarbondioxide.

  • 标签: 二氧化碳 集成工艺 CVD 碳材料 体形 催化
  • 简介:在未采取预电离措施的情况下,研究了纯sf6气体及sf6/h29sf6/c2h6两种混合气体激光介质脉冲放电特性。实验结果表明,无预电离时SF68其混合气体介质可以实现自引发体放电,气体介质体放电维持电压主要由SF,;含量决定,C2H6具有抑制电弧的作用,可以有效延长体放电维持时间。分析认为,sf66体高折合场强E/P导致的放电通道电流密度受限和高电负度■引起的放电通道中负离子分解产生二次电子,是介质实现自引发体放电的重要机理。

  • 标签: HF激光 自引发 体放电 电弧放电