学科分类
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59 个结果
  • 简介:Aconductionchannelmodelispropsedtoexplainthehighconductivitypropertyofnc-Si:H.Detailedenergybanddiagramisdevelopedbasedontheanalysisandcalculation,andtheconductivityofthenc-Si:Hwasthenanalysedonthebasisofenergybandtheory.Itisassumedthattheconductivityofthenc-Si:Hstemsfromtwoparts:theconductanceoftheinterface,wherethetransportmechanismisidentifiedasathermal-assistedtunnelingprocess,andtheconductancealongthechannelaroundthegrain,whichmainlydeterminedthehighconductivityofthenc-Si:H.Theconductivityofnc-Si:Hiscalculatedandcomparedwiththeexperimentdata.Thetheoryisinagreementwiththeexperiment.

  • 标签: 传导率 能带图 片状晶体硅
  • 简介:Inthispaper,anewcollocationBEMfortheRobinboundaryvalueproblemoftheconductivityequation▽(γ▽u)=0isdiscussed,wheretheγisapiecewiseconstantfunction.Bytheintegralrepresentationformulaofthesolutionoftheconductivityequationontheboundaryandinterface,theboundaryintegralequationsareobtained.Wediscussthepropertiesoftheseintegralequationsandproposeacollocationmethodforsolvingtheseboundaryintegralequations.Boththetheoreticalanalysisandtheerroranalysisarepresentedandanumericalexampleisgiven.

  • 标签: 分段常数 罗宾边界条件 边界积分方程 配置法
  • 简介:这研究的目的是用作为矩阵树脂作为传导性的fillers和修改环氧基树脂的organosilicone树脂经由solvothermal方法准备的银nanowires开发传导性的粘合剂。电的传导性的粘合剂和机械性质上的银nanowires/flakes的增加的效果被调查。与有银薄片fillers的常规传导性的粘合剂相比,有银nanowiresfillers的传导性的粘合剂的过滤阀值是10?%近似降低。然而,银nanowires的内容的进一步的上升没在传导性的粘合剂的电的传导性的改进上有明显的影响。传导性的粘合剂的传导性、机械的性质能由增加银nanowires是兼容的,哪个传统的银传导性的粘合剂reach.Graphical不能提炼银nanowires,舒适形态学经由alcohothermal准备了方法被介绍进传导性的粘合剂作文。它能被发现尽管存在,发现银nanowires在传导性的粘合剂相当被重叠crosslinking到某程度,然而,银nanowires不出现凝块的现象。有传导性的fillers能展出有利电、机械的性质的银nanowires的传导性的粘合剂。

  • 标签: 机械性质 传导性 粘合剂 电导率 矩阵树脂
  • 简介:Theanalyticaltechniqueofconductometrictitrationisusedtocharacterizepolymericmaterials.Thistechniqueallowsobtainingthepolymerdryweightcapacity(DWC)andtheextentofreactionandestablishingtheoptimalnumberofwatermoleculespersulfonicgroups.InthisparticularcasethepolymermaterialunderstudywasNafion?117.Twodifferentreactionsweremade:Neutralizationandexchange.Bothofthemallowobtainingthesameresult.Conductometrictitrationscouldbeconsideredasagoodmethodtostudytheneutralizationandexchangereactionsforpolymericmaterialsusedinfuelcellsorelectrolyzers.Theimplementationofthisanalyticaltechniqueallowsreducingoperationtimeofthosetypesofmaterials.Thewaitingtimebetweendeterminationspermitstosaythattheamountofreactantconsumedandproductsobtainedwerethesameaftereachadditionoftitrant.

  • 标签: CONDUCTIVITY CONDUCTOMETRIC TITRATION POLYMERIC membranes
  • 简介:Optimizationofcompositionandmicrostructureisimportanttoenhanceperformanceofsolidoxidefuelcells(SOFC)andlithium-ionbatteries(LIB).Forthis,theporouselectrodestructuresofbothSOFCandLIBaremodeledasabinarymixtureofelectronicandionicconductingparticlestoestimateefectivetransportproperties.Particlepackingsof10000spherical,binarysizedandrandomlypositionedparticlesarecreatednumericallyanddensifiedconsideringthediferentmanufacturingprocessesinSOFCandLIB:thesinteringofSOFCelectrodesisapproximatedgeometrically,whereasthecalenderingprocessandvolumechangeduetointercalationinLIBaremodeledphysicallybyadiscreteelementapproach.Acombinationofatrackingalgorithmandaresistornetworkapproachisdevelopedtopredicttheconnectivityandefectiveconductivityforthevariousdensifiedstructures.ForSOFC,asystematicstudyoftheinfluenceofmorphologyonconnectivityandconductivityisperformedonalargenumberofassemblieswithdiferentcompositionsandparticlesizeratiosbetween1and10.Incomparisontopercolationtheory,anenlargedpercolationareaisfound,especiallyforlargesizeratios.Itisshownthatincontrasttoformerstudiesthepercolationthresholdcorrelatestovaryingcoordinationnumbers.Theefectiveconductivityshowsnotonlyanincreasewithvolumefractionasexpectedbutalsowithsizeratio.ForLIB,ageneralincreaseofconductivityduringtheintercalationprocesswasobservedincorrelationwithincreasingcontactforces.Thepositiveinfluenceofcalenderingonthepercolationthresholdandtheefectiveconductivityofcarbonblackisshown.Theanisotropycausedbythecalenderingprocessdoesnotinfluencethecarbonblackphase.

  • 标签: 有效电导率 电极结构 细观力学模型 固体氧化物燃料电池 锂离子电池 粒状
  • 简介:Polyparaphenylene(PPP)ispreparedbyAlCl3-CuCl2catalystswithbenzeneasthemonomerandisdopedbychemicalmethodandN^+ionimplantation.Theinfluencesoftheconcentration,temperatureandtimeofchemicaldopingandthedose,energyandtemperatureofionimplantation,onPPPconductivityareinvestigated.TheresultsshowedthattheconductivityofPPPcanbeimproved4-5ordersofmagnitudebyionimplantationandtheconductivityofPPPcanreachabout0.11S·cm^-1bychemicaldoping.Thecomparisonofstabilityofthematerialconductivebehaviorbyusingthetwodopingmethodsispresented.Itshowsthationimplantationisbetterthanchemicaldopinginstabilizingtheelectricconductivebehaviorforthematerial.

  • 标签: 导电聚合物 离子注入 聚苯物 PPP 半导体
  • 简介:Asymmetrictree-likebranchednetworksareexploredbygeometricalgorithms.Basedonthenetwork,ananalysisofthethermalconductivityispresented.Therelationshipbetweeneffectivethermalconductivityandgeometricstructuresisobtainedbyusingthethermal-electricalanalogytechnique.Inallstudiedcases,aclearbehaviourisobserved,whereangle(δ,θ)amongparentbranchingextendedlines,branchesandparameterofthegeometricstructureshavestrongereffectsontheeffectivethermalconductivity.Whentheangleδisfixed,theopticaldiameterratioβisdependentonangleθ.Moreover,γandmarenotrelatedtoβ.Thelongerthebranchis,thesmallertheeffectivethermalconductivitywillbe.Itisalsofoundthatwhentheangleθ<δ/2,thehighertheiterationmis,thelowerthethermalconductivitywillbeandittendstozero,otherwise,itisbiggerthanzero.Whenthediameterratioβ1<0.707andangleδisbigger,theoptimalkoftheperfectratioincreaseswiththeincreaseoftheangleδ;whenβ1>0.707,theoptimalkdecreases.Inaddition,theeffectivethermalconductivityisalwayslessthanthatofsinglechannelmaterial.Thepresentresultsalsoshowthattheeffectivethermalconductivityoftheasymmetrictree-likebranchednetworksdoesnotobeyMurray'slaw.

  • 标签: 有效导热系数 网络 树形 几何结构 几何算法 行为观察
  • 简介:ThepreparationofconductingPPQfilmwasfirstreportedinthepreviouspaper.Itisveryinterestingthatthisfilmishighlysensitivetomoistureinair.ThehydrationanddehydrationofthefilmareaccompaniedbychangenotonlyincolorbutalsoinconductivityandUV-visiblespectrum.TheconductingPPQisreducedtoPPQandlosesitsconductivityafterbeingsoakedinwater.

  • 标签: POLYPHENYLQUINOXALINE ClO4- COMPLEX Electrical CONDUCTIVITY WATER
  • 简介:alloying,热处理,并且在Cu-Cr-Zr合金的表演上的塑料工作的影响被调查。猛抛的阶段作为Cr,Cu_(51)Zr_(14)和Cu_5Zr被描绘。Cu-Cr-Zr合金在答案处理,老化处理,和塑料变丑以后表明高力量和高电导率的联合性质。当增加Zrin时,Cr的Precipitationcourse是影响Cu-Cr-Zr合金的传导性的主要因素合金调整在Cr和矩阵之间的取向关系,并且趋于在变丑以后增加年老的Cu-Cr-Zr合金的传导性。

  • 标签: 铜铬锆合金 电导率 改进方法 合金化 热处理
  • 简介:Theeffectofpiezoelectricityonphononpropertiesandthermalconductivityofgalliumnitride(GaN)nanofilmsistheoreticallyinvestigated.TheelasticitymodelisutilizedtoderivethephononpropertiesinspatiallyconfinedGaNnanofilms.ThepiezoelectricconstitutiverelationinGaNnanofilmsistakenintoaccountincalculatingthephonondispersionrelation.Themodifiedphonongroupvelocityandphonondensityofstateaswellasthephononthermalconductivityarealsoobtainedduetothecontributionofpiezoelectricity.TheoreticalresultsshowthatthepiezoelectricityinGaNnanofilmscanchangesignificantlythephononpropertiessuchasthephonongroupvelocityanddensityofstates,resultinginthevariationofthephononthermalconductivityofGaNnanofilmsremarkably.Moreover,thepiezoelectricityofGaNcanmodifythedependenceofthermalconductivityonthegeometricalsizeandtemperature.TheseresultscanbeusefulinmodelingthethermalperformanceintheactiveregionofGaN-basedelectronicdevices.

  • 标签: GAN薄膜 声子 性质 导电 压电效应 纳米薄膜
  • 简介:Poly(β-carboxyethylmethylsiloxane)-LiClO4andpoly(β-alkoxylethylmethylsiloxane)-LiClO4crosslinkedfllmshavebeenprepared.Theionicconductivityofthefilmsdependsonthepolymerspecies,concentrationoflithiumperchlorate,temperatureandcontentofcrosslinkingagent.Theeffectofhighpolarorganicsolvent1,4-butyrolactoneontheionicconductivityandmechanicalpropertiesofpoly(β-carhoxyethylmethylsiloxane)-LiClO4systemwasalsoinvestignied.

  • 标签: IONIC conductivity: Poly(β-alkoxycarbonylethylmethylsiloxane)- LITHIUM Complex 1
  • 简介:土壤的理解在野火或控制灼伤以后的热电导率是重要的打管理和火以后的恢复努力。尽管玷污热电导率很好被学习了因为非火加热了土壤,全面数据评估在土壤上的从火的极端加热的长期的效果热电导率被限制。这研究的目的是由直接比较在土壤的有效热传导性上评估火的长期的影响加热火的,没有火控制通过一系列实验室研究玷污。热传导性在Manitou试验性的福雷斯特,以内从二个地点为十件土壤样品被测量科罗拉多,美国,为到浸透的剩余度的从浸透的水内容的一个范围。测量的热传导性与用文学用三个实验模型做的独立估计相比,包括坎贝尔等。(1994),C?t???????$

  • 标签: 土壤有效 森林火灾 热导率 实验室 模拟 经验模型
  • 简介:作为一个参数,那把岩石的热传播性质描述,热电导率为学习沉积的盆的热政体是不可缺少的,并且检索热电导率的高质量的数据是地热的相关研究的基础。光扫描方法这里被使用从Tarim盆,有在中国的丰富的烃潜力的最大的intermontane盆,和修正为可变的孔的碎屑状的岩石样品被做的水浸透测量745件练习核心样品的热传导性。所有测量的值,在这个区域与以前出版的数据结合了,是综合的讨论控制在盆影响岩石的热传导性的因素的分发特征和专业。我们的结果证明岩石的热电导率的价值通常从1.500~3.000W/m?8

  • 标签: 塔里木盆地 中国西北地区 岩石类型 测量值 热导率 导热系数
  • 简介:Theeffectofnanoparticleaggregationonthethermalconductivityofnanocompositesornanofluidsistypicallynonnegligible.Auniversalmodel(Maxwellmodel)includingnanoparticleaggregationismodifiedinordertopredictthethermalconductivityofnanocompositesmoreaccurately.Thepredictedthermalconductivitiesofsilicaandtitaniananoparticlepowdersarecomparedfirstwiththatmeasuredbyahot-wiremethodandthenwiththoseinpreviousexperimentalworks.Theresultsshowthatthereisgoodagreementbetweenourmodelandexperiments,andthatnanoparticleaggregationinananocompositeenhancesthethermalconductivitygreatlyandshouldnotbeignored.Becauseitconsiderstheeffectofaggregation,ourmodelisexpectedtoyieldprecisepredictionsofthethermalconductivityofcomposites.

  • 标签: 纳米复合材料 通用模型 聚集作用 热导率 复合纳米粒子 二氧化钛纳米粉
  • 简介:Thetwo-dimensionalRayleigh-Taylorinstabilityproblemissimulatedwithamultiple-relaxation-timediscreteBoltzmannmodelwithagravityterm.Viscosity,heatconductivity,andPrandtlnumberef-fectsareprobedfrommacroscopicandnonequilibriumviewpoints.Inthemacrosense,bothviscosityandheatconductionshowasignificantinhibitoryeffectinthereaccelerationstage,whichismainlyachievedbyinhibitingthedevelopmentoftheKelvin-Helmholtzinstability.Beforethis,thePrandtlnumbereffectisnotsensitive.Viscosity,heatconductivity,andPrandtlnumbereffectsonnonequilib-riummanifestationsandthedegreeofcorrelationbetweenthenonuniformityandthenonequilibriumstrengthinthecomplexflowaresystematicallyinvestigated.

  • 标签: discrete BOLTZMANN model/method multiple-relaxation-time RAYLEIGH-TAYLOR instability nonequilibrium