简介:根据伊朗德黑兰地铁正线轨道电路的调试具体情况,简单介绍T121-M无绝缘轨道电路的调试方案。
简介:ThehotrollingexperimentinvestigatesintotherelationshipbetweenthemicrostructuresandthemechanicalpropertiesofNb-TimicroalloyedsteelswithvariousTicontents.TheresultsindicatethattheeffectofthebainitefractionofNb-TimicroalloyedsteelsontheyieldstrengthofthesteelsisnotrelatedtoTicontent,whiletheslopeoftheHall-PetchrelationshipdecreaseswiththeincreaseofTicontent.Accordingly,theMisramodelfortheyieldstrengthofNb-Timicroalloyedsteelsismodified,andthefactorswhichcausethechangeintheslopeofHall-Petchrelationshiparediscussed.
简介:ThemorphologiesevolutionofvarioustypesofinclusionsinTi-IFsteelwereobservedbyaspecialdeptherosionmethod,andtheformationandevolutionprocesswerediscussed.TheresultsshowedthatthemaininclusionswereFeO·xMnObeforeAldeoxidizationandtheratioofintegratedoxygenandfreeoxygenwasinrangedof0.3to0.4.Inpresentstudy,themaineffectfactorsonthemorphologiesofAl2O3inclusionswere[Al]/[O]Free(solublealuminumdividefreeoxygen)andinitialfreeoxygen;clusterAl2O3wasformedeasilywithhighfreeoxygen([O]Free)andlow[Al]/[O](blew3inpresentstudy).Otherwise,thedendriticAl2O3wasformed;coral-likeAl2O3wasthemixtureofthedendriteAl2O3andsphericalAl2O3.SomeAl2O3·TiOxinclusionsappearedbecauseahigh[Ti]concentrationregionexistedaround70TiFe(containing70percenttitanium)particlesafter70TiFeaddition.ThemaximumsizesofAl2O3reached800μmwhen3minaluminumwasadded;asthetimepast,thelargesizeAl2O3decreasedsignificantly;themaximumsizeofAl2O3wasblew100μmand50μmincalmingsampleandtundishsamplerespectively.
简介:用密度泛函理论研究了气相中过渡金属硫化物阳离子(Msn+,M=Se,Ti,n=1,2,3).获得了各种离子的几何结构、电子结构、光谱性质及热力学数据,确定了其基态结构,并和已有实验数据作了对比.根据我们的理论计算,ScS+,TiS+的基态分别为1∑+,2△.其主要电子组态分别为1σ2σ21π4,1σ^22σ2141δ.MS2+的各种离子基态结构是三元环型结构,ScS2+,TiS2+的基态分别为1A’,2A’,MS3+的可能结构有直线型结构、三角锥型结构和以M+为中心的平面结构.经过反复计算,优化各种结构并对每一结构做振动频率分析,得到scS3+,TiS3+基态分别为:3A″,2A″。
简介:MicrostructuralevolutionofinfraredvacuumbrazedCP-TiusingtwoTi-basedbrazealloys,Ti-15Cu-15NiandTi-15Cu-25Ni,hasbeeninvestigated.TheinfraredbrazedjointconsistedofeutecticTi2Cu/Ti2NiintermetalliccompoundsandTi-richmatrix.TheeutecticTi2Cu/Ti2Niintermetalliccompoundsdisappearedfromthejointafterbeingannealedat900Cfor1h.Incontrast,thedepletionrateofbothCuandNifromthebrazealloyintoCP-Tisubstrateat750Cannealingwasgreatlydecreasedascomparedwiththatannealedat900C.BlockyTi2Cu/Ti2Niphaseswereobservedevenifthespecimenwasannealedat750Cfor15h.BecausetheNicontentoftheTi-15Cu-25NibrazealloyismuchhigherthanthatoftheTi-15Cu-15Nialloy,theamountofeutecticTi2Cu/Ti2NiphasesinTi-15Cu-25NibrazedjointismorethanthatinTi-15Ci-15Nibrazedjoint.However,similarmicrostructuralevolutioncanbeobtainedfromtheinfraredbrazedjointannealedatvarioustemperaturesand/ortimeforbothfillermetals.
简介:TheeffectoftitaniumadditiononthemicrostructureandmechanicalpropertiesofbrassCu40Znhasbeenstudiedviathepowdermetallurgy(P/M)route.Thewater-atomizedCu40Zn—1.0wt%Tialloypowderwasconsolidatedatdifferenttemperaturesintherangeof400—600℃usingsparkplasmasintering(SPS)andhotextrusionsubsequently.Resultsshowthatthesuper-saturatedsolidsolutiontitaniumelementinrapidlycooledbrassCu40Znpowdercreatedhighchemicalpotentialforaprecipitatereaction,showingsignificantgrainrefinementeffectsontheconsolidatedCu40Znmatrix.Consequently,excellentmechanicalpropertieswereobtainedbyprecipitationhardeningandworkhardeningaftersinteringandextrusion,withyieldstrengthof390MPa,ultimatetensilestrengthof617MPa,andVickersmicro-hardnessof192HV,whichare28.7%,23.4%,and23.9%highervaluesthanthoseofextrudedCu40Znbrass,respectively.
简介:1.IntroductionRecently,singleserverqueueswithvacationshavebeenstudiedextensivelyfromtheirowntheoreticalinterestaswellastheirapplicationstomanyengineeringsystemssuchascomputers,communicationnetworksandmanufacturingsystems.FOrtheM/G/lqueueingsystemswit...