简介:Byanalogueexperimentofexhaustgas,thesensitivecharacteristicsoftitaniatoair/fuelratiowasinvestigated.Theeffectsofsomeimpuri-tiesontheelectricconductivityofTiO2,thedeviationof(A/F)cfrom(A/F)sinnonequilibriumgassystemandtheself-catalyticoxidationofTiO2wereexplainedrespectively.Theeffectsofca-talyst,porosityandthicknessofsensorelementontheresponsetimewasalsoanalyzed.
简介:Samplesofacobalt-basedalloythatunderwentasurfacetreatmentwereevaluated.Thesamples,whichwereobtainedbycastingalloyASTMF75,weregroundandpolishedononesideuntilamirrorfinishwasobtained.Thesampleswereencapsulatedinwollastonite(W)usinguniaxialpressure,treatedat1220℃for1handsubsequentlytemperedinwater.Thecharacterisationofthesampleindicatedthatpartoftheceramicencapsulatingmaterialwasmechanicallyincorporatedonthemetallicsurfacebygrowthoftheoxidelayerofthealloy.Afterthermaltreatment,aseriesofspecimensweresubmergedinasolutionwith5-foldsimulatedbodyfluid(5SBF)for3,5and21days.Characterisationbyscanningelectronmicroscopy(SEM),energydispersivespectroscopy(EDS)andX-raydiffraction(XRD)indicatednucleationandgrowthofahomogenouslayerofapatite,beginningonthethirddaywhenthesamplewassubmerged.
简介:Thestatusandthevariationofelectricalresistanceofimpactedcarbonfiber/epoxy-matrixcompositeswerestudiedbyultrasonicF-scanandelectricalresistancemeasurementTheexperimentalresultsshowsthatimpactdamageenergythresholdvalueofcarbonfabric/epoxy-matrixcompositescandeterminebyusingultrasonicF-scan.Whentheimpactenergyexceedsthethresholdvalue,damageisgeneratedincomposites.Electricalresistanceofimpactedcompositesischangedowingtothecontactofeachcarbonfiberunitincomposites,whichcauseachangeoftheseries-parallelinconductors.Theveracityofdetectingimpactdamageincompositescanbeimprovedinthiscase.
简介:以KF、SbCl3和SnCl2为原料配制乙醇溶胶,通过在Ti基底上涂胶、干燥、预热处理和煅烧等工艺制备出了F—Sb-SnO2/Ti复合电极。以F—Sb—SnO2/Wi复合电极为阳极,镍片为阴极,施加恒电压观测甲基橙电解液的脱色变化,在正交设计试验基础上,考察溶胶涂层数、煅烧温度、掺杂F离子的浓度等因素对甲基橙降解率的影响,结果表明,固定电解参数电压3V,甲基橙浓度50mg/L,添加荆h(Ⅲ)浓度110mg/L,溶液pH=l,优化的溶胶涂层数9,煅烧温度为773K,溶胶中维持Sn/Sb摩尔比9/1时,优化的KF掺杂摩尔比为0.5时,电解75min,甲基橙的降解率达93%。
简介:采用HP-8510B微波矢量网络分析仪测试了3种不同管径碳纳米管(CNTs)的电磁参数,并对三者的电磁参数进行比较。结果表明CNTs的管径不同,其电磁性能也有所变化,随着CNTs管径增加,其复介电常数虚部不断增加,在10~18GHz高频段,管径为30~50nm的CNTs介电损耗角正切较大。根据电磁波传输线理论计算了3种碳纳米管的反射率曲线,厚度为2.0mm时,管径为30~50nm的CNTs的吸波性能最佳,模拟反射率峰值为-26.24dB;管径为20~30nm的CNTs模拟反射率峰值为-12.52dB;管径50~80nm的CNTs模拟反射率峰值为-24.1dB。