学科分类
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184 个结果
  • 简介:p类型(100)上的HfO2电影的乐队排列磁控管劈啪作响种的InP底层被调查。化学状态和系统的结合的特征被X光检查光电子光谱学(XPS)描绘。结果证明没有Hf-P或Hf在里面的存在,有在2在接口的O3和InPO4。紫外分光光度计(UVS)被采用获得HfO2的乐队差距价值。在3d和Hf4f,核心级的系列和原子价系列被采用获得HfO2/InP的原子价乐队偏移量。试验性的结果出现(5.88??T

  • 标签: HFO2薄膜 INP衬底 排列 能带 p型 X射线光电子能谱
  • 简介:NanocrystallineMg2Ni-typealloyswithnominalcompositionsofMg20Ni10–xCux(x=0,1,2,3,4,massfraction,%)weresynthesizedbyrapidquenchingtechnique.Themicrostructuresoftheas-castandquenchedalloyswerecharacterizedbyXRD,SEMandHRTEM.Theelectrochemicalhydrogenstorageperformancesweretestedbyanautomaticgalvanostaticsystem.ThehydridinganddehydridingkineticsofthealloysweremeasuredusinganautomaticallycontrolledSievertsapparatus.Theresultsshowthatalltheas-quenchedalloysholdthetypicalnanocrystallinestructureandtherapidquenchingdoesnotchangethemajorphaseMg2Ni.Therapidquenchingsignificantlyimprovestheelectrochemicalhydrogenstoragecapacityofthealloys,whereasitslightlyimpairsthecyclingstabilityofthealloys.Additionally,thehydrogenabsorptionanddesorptioncapacitiesofthealloyssignificantlyincreasewithrisingquenchingrate.

  • 标签: 合金成分 快淬技术 储氢特性 高分辨透射电子显微镜 纳米晶 MG2NI
  • 简介:Cesiumcontentintheseawateris3.0910-4mg·L-1,andammonium-typemordenitewasusedtoexchangecesiumfromcesiumsource.K-typemordenitewasobtainedbyhydrothermalsynthesismethod.Afterammonium-modified,ionexchangepropertiessuchassaturatedionexchangecapacitiesandselectivitycoefficientsforalkalimetalionsweredetermined.Atthesametime,ionexchangeisothermalcurvesofammonium-typemordeniteforCs+andNH4+weredeterminedat25°C.Pitzerelectrolytesolutiontheorywasusedtoworkoutactivitycoefficientsofthesystem,andtheKiellanddiagramoftheionexchangesystemwasobtained.Thecalculatedequilibriumconstant(Ka)andionfreeenthalpy(DG0)ofmordeniteforCs+andNH4+are1.455and-930.3J·mol-1,respectively,indicatingthationexchangeprocessofammonium-typemordeniteforcesiumisaspontaneousprocess.

  • 标签: ION EXCHANGE THERMODYNAMICS MORDENITE CESIUM
  • 简介:Precipitationresponseofarecentlydevelopedb-typeTi–25Nb–2Mo–4Snalloy(wt%)duringagingwasinvestigatedindetail.Experimentalresultsindicatethatthemetastableωorequilibriumαphasecanformalternativelyevenunderthesameagingcondition,dependingontheconditionpriortotheaging,i.e.,solutiontreatmentorseverecoldrolling.Thisprovides,forthefirsttime,thedirectevidenceforthecompetitionbetweenωandαinagedβ-typeTialloys.Thispeculiaragingresponseisfoundtobecloselyrelatedtohigh-densitydislocationsandgrainboundarieswhichsuppresstheformationofωbutfavortheprecipitationoffineaphase.

  • 标签: 钛合金 竞争 证据 平衡 老年 亚稳态
  • 简介:在这,纸,脱臼的高密度,谷物边界和纳米规模猛抛包括严重冷滚动和短时间的退火处理通过一条thermo机械的途径被介绍给亚稳的Ti-36Nb-5Zr合金(wt%)。martensitic转变被延迟,并且有stabilizers的低内容的阶段在thermo机械的处理以后在房间温度被保留。作为结果,两低模量(57?GPa)并且高力量(950?MPa)被获得。结果显示通过微观结构优化控制martensitic转变开始温度而不是作文设计是可行策略,与制作低模量类型Ti合金的目的。

  • 标签: 优化控制 低模量 类型 设计 合金 制造
  • 简介:Theeffectsoflow-CoAB5typehydrogenstoragealloyspreparedbyquenchingandannealingontheperformancesofMH-Nibatterieswereinvestigated,andthecharacteristicsofthelow-CoAB5typehydrogenstoragealloyswerecomparedwiththoseofthehigh-CoAB5typehydrogenstoragealloyaswell.Theresultsshowedthatthefasterthecoolingofthelow-Cohydrogenstoragealloyis,thebetterhomogeneityofthechemicalcompositionforthealloyandthelongercyclelifeofthebatteryare,buttheelectrochemicaldischargecapacityandhigh-ratedischargeabilityarereduced.Thehigh-ratedischargeabilityandchargeretentionofMH-Nibatteriesfortheconventionalas-castannealedlow-Cohydrogenstoragealloyweresuperiortothosefortherapidlyquenchedlow-Cohydrogenstoragealloyandthehigh-Cohydrogenstoragealloy,butalittleinferiorinthecyclelife.

  • 标签: 热处理 MH-NI电池 能量储存 低-Co-AB5氢储存合金 制备 淬火
  • 简介:SiliconEpitaxialWaferforXBandDoubleRead-typeDDRIMPATTDiodesbyAtmosphere/LowPressureGrowthTechniqtWangXiangwuandLuChunyi王向武,陆春...

  • 标签: Si EPITAXY Multilayer X BAND DDR
  • 简介:TiO2nanoparticleswithdifferentphasesarepreparedbyhydrolysisoftitaniumtetrabutoxideinthepresenceofHCl.ThecompositionandmicrostructureoftheresultingsamplesarestudiedbyXRDandTEM.TheseresultsshowthattherangeofparticlesizeofTiO2isfrom20to30nm.ThemechanismofTiO2photocatalysisreactionhasbeendiscussedextensively.PhotocatalyticactivitiesofnanometerTiO2arealsoevaluatedbydegradationofthecrystalvioletsolution.ExperimentalresultsindicatethatthesynergisticactionofH2O2andultrasonicwavegreatlyenhancesphoto-catalyticreactionofTiO2.

  • 标签: TIO2 二氧化钛 超声波 H2O2 双氧水 晶体
  • 简介:Iron(Ⅲ)-dopednanostructureTiO2-coatedSiO2(TiO2/SiO2)particleswerepreparedusingthelayer-by-layeras-semblytechniqueandtheirphotocatalyticpropertywasstudied.TiO2colloidsweresynthesizedemployingthesol-gelmethodwithTiCl4asaprecursor.ThesampleswerecharacterizedbyFouriertransforminfraredspectroscopy(FTIR),SEM,EDS,XPS,andXRD.TheexperimentalresultsshowthatTiO2nanopowdersonthesurfaceofSiO2particlesarewelldistributed,theamountofTiO2isincreasedwiththeaddingofcoatinglayers,thepureanatase-TiO2coatinglayersaresynthesizedat500°C,andthephotocatalyticactivityofFe3+-dopedTiO2/SiO2ishigherthanthatofundopedTiO2/SiO2.

  • 标签: 氧化钛覆盖层 氧化硅颗粒 纳米构造 掺杂
  • 简介:Nb-24Ti-18Si-2Al-2Hf-4CrandNb-24Ti-18Si-2Al-2Hf-8Cralloyswerepreparedbyarcmeltinginawater-cooledcrucibleunderargonatmosphere.Microstructuralcharacteristicsandoxidationresistanceofthealloysat1250℃wereinvestigated.Theresultsshowthat,whentheCrcontentis4at%,themicrostructuresconsistof(Nb,Ti)_(ss)andNb_5Si_3;asCrcontentincreasesto8at%,C14LavesphaseCr_2Nbisformed.Theisothermaloxidationtestsshowthattheoxidationkineticsofthetwoalloysfollowsimilarfeatures.Theweightgainsofthetwoalloysafteroxidationat1250℃for100hare235.61and198.50mg·cm~(-2),respectively.Duringoxidation,SiO_2,TiO_2,Nb_2O_5andCrNbO_4areformedatfirst.Then,Ti_2Nb_(10)O_(29)isformedafteroxidationfor20minandbeginstochangeintoTiNb_2O_7astheoxidationproceeds.SiO_2isformedassolidstateatfirstbutlaterevolvesintoglassystatetoimprovethecohesionofthescale.Afteroxidationfor100h,oxidationproductsconsistofSiO_2,TiNb_2O_7,Nb_2O_5andCrNbO_4.

  • 标签: 过共晶合金 氧化行为 NB2O5 LAVES相 显微组织 SiO2
  • 简介:ElectrocrystallizationMechanismofTungsteninMoltenKF-B_O_3-K_WO_4WenZhenhuanandLiGuoxun文振环,李国勋(GeneralResearchInstiiuteforNo...

  • 标签: ELECTROCRYSTALLIZATION mechanism TUNGSTEN Electrodeposition Mol-ten KF-B2O3-K2WO4
  • 简介:介绍一种金属/合金的生产方法,用于恒电流和恒电位条件下由混合硫化物(Cu2S,NiS)生产Cu-Ni合金,称为直接电化学还原(DER)。研究槽电压和槽电流等工艺参数对还原得到的化合物组成的影响,以生产工业所需的CuNi10,CuNi20和CuNi30等合金。在1200°C下采用循环伏安法(CV)考察Cu2S和NiS在CaCl2熔体中的电化学行为。根据CV研究结果,Cu2S的阴极还原是一步完成的,即Cu2S?Cu;NiS的阴极还原则分两步进行,即NiS?Ni3S2?Ni。恒电流研究表明,在10A电流下电解15min,可制备出最高硫含量为320×10-6的高纯CuNi10合金。扫描电子显微镜以及能量色散X射线能谱和光学发射光谱(OES)测试结果表明,在2.5V电压下直接电化学还原15min,可制备出杂质含量低(即硫含量小于60×10-6)的所选成分的Cu-Ni合金。

  • 标签: 熔盐电解 电还原 铜提取 硫化铜 硫化镍 CU-NI合金
  • 简介:本文采用磁粉、X射线、CT和超声等无损检测和金相分析等方法对40CrNi2Si2,MoVA钢制零件的磁痕显示进行了系统分析。研究认为,40CrNi2Si2MoVA钢制零件的磁痕显示为显微成分沿变形方向偏析导致的马氏体转变点Ms差异所致。显微成分偏析是钢锭结晶过程中不可避免的,但可通过优化熔炼工艺参数降低显微偏析的程度。本文还分析了四种磁痕显示的类型及其判别方法。

  • 标签: 40CrNi2Si2MoVA 磁痕显示 显微偏析
  • 简介:Themetal-organicchemicalvapordeposition(MOCVD)techniqueisapromisingprocessforhigh-temperaturesuperconductorYBa2Cu3O7-δ(YBCO)preparation.Inthistechnique,itisachallengetoobtainbariumprecursorswithhighvolatility.Inaddition,thepurity,evaporationcharacteristics,andthermostabilityofadoptedprecursorsinwholeprocesswilldecidethequalityandreproducibleresultsofYBCOfilm.Inthepresentreport,bis(2,2,6,6-tetramethyl-3,5-heptanedionato)barium(Ⅱ)(Ba(TMHD)2)wassynthesized,anditsstructurewasidentifiedbyFTIR,1HNMR,13CNMR,andESI-MSspectroscopy.Subsequently,thethermalpropertiesandthekineticsofdecompositionweresystematicallyinvestigatedbynonisothermalthermogravimetricanalysismethods.BasedontheaverageapparentactivationenergyevaluatedbytheOzawa,Kissinger,andFriedmanmethods,thevolatilizationprocesswasdiscussed,andallresultsshowthatBa(TMHD)2isunstableandhighlysensitivetothechangeoftemperatureduringthewholeevaporationprocess.Therefore,itisveryimportanttochoosesuitablevolatilizationtechnologyandconditionsforavoidingBa(TMHD)2break-down(orthermalaging)duringMOCVDprocess.Subsequently,thepossibleconversionfunctionisestimatedthroughtheCoats-Redfernmethodtocharacterizetheevaporationpatternsandfollowsaphaseboundaryreactionmechanismbythecontractingsurfaceequationwithaverageactivationenergyof118.7kJ.mol-1.

  • 标签: 热稳定性 四甲基 合成 YBCO薄膜 MOCVD 表观活化能
  • 简介:在这份报纸,纺纱冰上的无磁性的Y离子的冲淡效果加重Dy2Ti2O7由红外线并且拉曼系列和磁化大小被调查。与温度弄软减少的异常声子在父母被发现并且冲淡除了之外,做的混合物,和Y能放松弄软声子233附近的红外模式?厘米<啜class=“a-plus-plus”>显示在纺纱冰材料联合的强壮的phononphonon的1,。当冲淡的水平不很高时,磁化大小表明无磁性的杂质严重地不处于扎根的状态影响纺纱冰规则。然而,大量冲淡提高混乱并且因为集体旋转扭动簇不再是可得到的,打破纺纱冰状态。

  • 标签: 稀释效应 声子振动 磁化 基态自旋 冰物质 高温软化
  • 简介:起落架40CrNi2Si2MoVA钢螺桩在安装一段时间后发生了断裂。为确定螺桩断裂的原因,对断裂螺桩断口宏微观形貌、断裂螺桩及对比件的氢含量、材料的性能以及表面损伤等因素进行了检查,并对电镀工艺进行了评定。结果表明,裂纹主要起源于第一螺纹根部的机械损伤部位,源区以沿晶断裂特征为主,断裂件含氢量较高。综合分析认为。螺桩断裂性质为氢致延迟断裂,表面机械损伤对氢吸收和扩散的促进作用和40CrNi2Si2MoVA钢材料高强度所致的高氢脆敏感性是导致断裂的主要原因。

  • 标签: 螺栓 40CrNi2Si2MoVA钢 机械损伤 氢脆断裂
  • 简介:通过基于密度泛函理论的第一性原理计算方法,对MgCu2,Mg2Ca和MgZn2的力学性能和电子结构进行计算,计算所得晶格参数与实验值和文献值相吻合。合金形成热和结合能的计算结果表明,MgCu2具有最强的合金形成能力和结构稳定性。计算了MgCu2,Mg2Ca和MgZn2的弹性常数,推导了体模量、剪切模量、弹性模量和泊松比。结果表明,MgCu2、Mg2Ca和MgZn2均为延性相,MgCu2的刚度最大,MgZn2的塑性最好。通过对结合能和弹性常数的计算,预测了MgCu2、Mg2Ca和MgZn2的熔点。通过对态密度(DOS)、Mulliken布居数、电子占据数和差分电荷密度的计算,分析了MgCu2、Mg2Ca和MgZn2的结构稳定性和力学性能机制。最后,计算和讨论了3种金属间化合物的Debye温度。

  • 标签: 镁合金 MgCu2 Mg2Ca MgZn2 LAVES相 电子结构
  • 简介:InordertoimprovetheelectrochemicalcyclestabilityofLa-Mg-Nisystem(PuNi3-type)hydrogenstoragealloy,NiinthealloyswaspartiallysubstitutedbyM(M=Cu,Al,Mn).AnewLa-Mg-NisystemelectrodealloysLa0.7Mg0.3Ni2.55-xCo0.45Mx(M=Cu,Al,Mn;x=0,0.1)werepreparedbycastingandrapidquenching.Theeffectsofelementsubstitutionandrapidquenchingonthemicrostructuresandelectrochemicalperformancesofthealloyswereinvestigated.TheresultsbyXRD,SEMandTEMshowthatthealloyshaveamultiphasestructure,includingthe(La,Mg)Ni3phase,theLaNi5phaseandtheLaNi2phase.Therapidquenchingandelementsubstitutionhaveanimperceptibleinfluenceonthephasecompositionsofthealloys,butbothchangethephaseabundanceofthealloys.Therapidquenchingsignificantlyimprovesthecompositionhomogeneityofthealloysandmarkedlydecreasesthegrainsizeofthealloys.TheCusubstitutionpromotestheformationofanamorphousphaseintheas-quenchedalloy,andareversalresultbytheAlsubstitution.Theelectrochemicalmeasurementindicatesthattheelementsubstitutiondecreasesthedischargecapacityofthealloys,whereasitobviouslyimprovesthecyclestabilityofthealloys.ThepositiveinfluenceofelementsubstitutiononthecyclelifeofthealloysisinsequenceAl>Cu>Mn,andnegativeinfluenceonthedischargecapacityisinsequenceAl>Mn>Cu.Therapidquenchingsignificantlyenhancesthecyclestabilityofthealloys,butitleadstoadifferentextentdecreaseofthedischargecapacityofthealloys.

  • 标签: element SUBSTITUTION rapid QUENCHING La-Mg-Ni system
  • 简介:ItiswellknownthatthephotocatalyticactivityofTiO2thinfilmsstronglydependsonthepreparingmethodsandpost-treatmentconditions,sincetheyhaveadecisiveinfluenceonthechemicalandphysicalpropertiesofTiO2thinfilms.Therefore,itisnecessarytoelucidatetheinfluenceofthepreparationprocessandpost-treatmentconditionsonthephotocatalyticactivityandsurfacemicrostructuresofthefilms.ThisreviewdealswiththepreparationofTiO2thinfilmphotocatalystsbywet-chemicalmethods(suchassol-gel,reversemicellarandliquidphasedeposition)andthecomparisonofvariouspreparationmethodsaswellastheiradvantageanddisadvantage.Furthermore,itisdiscussedthattheadvancementofphotocatalyticactivity,super-hydrophilicityandbactericidalactivityofTiO2thinfilmphotocatalystinrecentyears.

  • 标签: TIO2薄膜 光催化剂 光催化活性 溶胶-凝胶方法 液相沉积方法 亲水性