学科分类
/ 1
11 个结果
  • 简介:我们由在固定联合盒子中在LHC/ALICE使用颜色玻璃冷凝物动力学学习高精力Pb+Pb碰撞的强子复合的伪快分发。在包括pomeron循环在中央快完成控告的强子复合以后,它被发现那比浸透基于计算的为中央Pb+Pb碰撞是大约1500,它显著地小,[?]1700/2500并且与那兼容基于在破碎区域的复合的研究。[从作者抽象]

  • 标签: 大型强子对撞机 高能强子碰撞 POMERON 子环 重数
  • 简介:Asoneofcandidatesforthefuelcladdingorstructurematerialusedinfourthgenerationfissionandfusiondemonstratereactor,MAXphasehasthepropertiesofbothceramicandmetal,suchashighmeltingpoint,hightemperaturestability,gooderosionresistanceandradiation-damagetolerance[1;2].Maxphaseisaseriesofceramicsofnanolamellarandhexagonalstructure.Mrepresentstransitionelement.Arepresentsthethirdorfourthmaingroupelement.XrepresentNandC.Inthedesignoflead-cooledfastreactor,itisrequiredthatthematerialshouldendurethecorrosionofliquidPb-Bialloy.Therefore,understandingoftheoxidelayersandtheirgrowthmechanismsinLBEisfundamentallyimportantforthedevelopmentofcandidatematerials.

  • 标签: LIQUID Pb-Bi ALLOY
  • 简介:本文针对核辐射探测实验中所获取的实验数据量大、处理复杂的问题,提出了用实验教学软件通过计算机判断所获取的核辐射探测实验数据,为学生做实验时所获取的实验数据的正确与否做出直观、方便、快速的判断,从而提高实验教学质量.

  • 标签: 实验教学软件 核辐射探测 PB8.0 开发 实验数据 计算机判断
  • 简介:TheelectronicpropertiesandtopologicalphasesofThXY(X=Pb,Au,Pt,PdandY=Sb,Bi,Sn)compoundsinthepresenceofspin–orbitcoupling,usingdensityfunctionaltheoryareinvestigated.TheThPtSncompoundisstableintheferromagneticphaseandtheotherThXYcompoundsarestableinnonmagneticphases.Bandstructuresofthesecompoundsintopologicalphases(insulatorormetal)andnormalphaseswithingeneralizedgradientapproximation(GGA)andEngel–Voskogeneralizedgradientapproximation(GGAEV)arecompared.TheThPtSn,ThPtBi,ThPtSb,ThPdBi,andThAuBicompoundshavetopologicalphasesandtheotherThXYcompoundshavenormalphases.Bandinversionstrengthsandtopologicalphasesofthesecompoundsatdifferentpressurearestudied.Itisseenthatthebandinversionstrengthsofthesecompoundsaresensitivetopressureandforeachcompoundasecond-orderpolynomialfittedonthebandinversionstrengths–pressurecurves.

  • 标签: 结构拓扑 化合物 电子性质 PB AU BI
  • 简介:Usingfirst-principlescalculations,wesystematicallystudythedissociationsofO2moleculesondifferentultrathinPb(111)films.AccordingtoourpreviousworkrevealingthemolecularadsorptionprecursorstatesforO2,wefurtherexplorewhytherearetwonearlydegenerateadsorptionstatesonPb(111)ultrathinfilms,butnoprecursoradsorptionstatesexistingatallonMg(0001)andAl(111)surfaces.Thereasonisconcludedtobethedifferentsurfaceelectronicstructures.FortheO2dissociation,weconsiderboththereactionchannelsfromgas-likeandmolecularlyadsorbedO2molecules.WefindthattheenergybarrierforO2dissociationfromthemolecularadsorptionprecursorstatesisalwayssmallerthanthatfromO2gas.ThemostenergeticallyfavorabledissociationprocessisfoundtobethesameondifferentPb(111)films,andtheenergybarriersarefoundtobeinfluencedbythequantumsizeeffectsofPb(111)films.

  • 标签: 第一原理计算 超薄膜 氧分子 无铅 平面波 表面电子结构
  • 简介:Theelectronicstructures,dielectricfunctions,complexrefractiveindicesandabsorptionspectraforaperfectPbW04(PWO)crystalandthePWOcrystalscontainingleadvacancyV^2-pbhavebeencalculatedusingafull-potential(linearized)augmentedplane-wave(LAPW)+localorbitals(LO)methodwiththelatticestructureoptimized.Thepeaksoftheabsorptionspectracorrespondingtotheelectronictransitionshavebeenstudied.

  • 标签: 电子结构 光学性质 钨酸铅晶体 V^2-pb 线性平面波法
  • 简介:建立了非线性热力学模型,定性分析了外加应力和外加温度对外延生长在正交基底上的Pb(Zr1-xTix)O3(PZT)薄膜相变的影响。在外力场下,固定其中一个方向失配应变e1=0.005,模拟得到了不同组分的PZT薄膜的失配应变一外加应力的相图。研究发现,随着Ti组分的减少,出现了新相正交a1c相和四方相a1相,且新相区域也会随Ti组分的不同而变化。在外加拉应力下,c相是薄膜较易出现的相,而在外加压应力下薄膜易处于a1a2相。在不同温度场下,模拟非等轴失配应变的PZT薄膜得到不同组分的PZT薄膜的失配应变一外加温度相图。当组分x≤0.7时,相图中出现了正交a1c相,由于非等轴失配应变的存在,使得从顺电相向r相发生相变的过程中,多出了正交a1a2相;同时另一新的四方a1相也出现在沿失配应变正方向e2被拉伸的区域。随着Ti组分的增加,单斜r相的面积缩小且位置下移。之前存在的四相点也变为了三相点,而正交相a1a2相则向相图的中心位置移动。模拟结果对研究外场下铁电薄膜微器件的性能变化具有一定的指导意义。

  • 标签: 非等轴失配应变 外加应力 外加温度 相图
  • 简介:Basedonloadseparationtheory,theloadseparationparameterSpbmethodisaneffectiveapproachforestimatingtheJ-resistancecurvefromrecordsofloadversusdisplacementdirectly,usingonesharpcrackedspecimenandanadditionalreferencebluntcrackedspecimen.However,theeffectofthereferencebluntcrackedspecimenonJ-resistancedeterminationwasnotexplicitlyconsideredinpastwork.Inthispaper,amodifiedloadseparationparameterSpbmethodwasdevelopedtoeliminatethiseffect,andthenauniqueestimationofinstantaneouscracklengthforonesharpcrackedspecimencouldbeobtained.Furthermore,aforcedbluntingcalibrationmethodwasalsoadoptedtodeterminetheinstantaneouscracklengthintheloadinseparableregion,referringtoanormalizationmethod.ExperimentsonsteamturbinerotatorsteelCr2Ni2MoVwerecarriedouttoestimateJ-resistancecurvesusinganunloadingcompliancemethod.Byremovingunloadandreloaddatafromload-displacementrecords,theJ-resistancecurveforthesamesharpcrackedspecimenwasestimatedusingthemodifiedseparationparameterSpbmethod.TheresultsindicatethatthemodifiedSpbmethodcompletelyeliminatestheeffectofthereferencebluntcrackedspecimenontheinstantaneouscracklengthdeterminationofthesharpcrackedspecimen.However,differentJ-resistancecurvesinasmallrangeofcrackextensionarepresentwhendifferentbluntingcoefficientsareusedinthebluntinglineequation.TheJ-resistancecurveobtainedfromthemodifiedSpbmethodagreeswellwiththatobtainedfromthecompliancemethod.

  • 标签: 汽轮机转子钢 阻力曲线 修改 估计 卸载柔度法 分离参数法
  • 简介:Temperature-dependentphotoluminescencecharacteristicsoforganic-inorganichalideperovskiteCH3NH3PbI3-xClxfilmspreparedusingatwo-stepmethodonZnO/FTOsubstrateswereinvestigated.Surfacemorphologyandabsorptioncharacteristicsofthefilmswerealsostudied.Scanningelectronmicroscopyrevealedlargecrystalsandsubstratecoverage.Theorthorhombic-to-tetragonalphasetransitiontemperaturewas140K.Thefilms’excitonbindingenergywas77.6±10.9meVandtheenergyofopticalphononswas38.8±2.5meV.TheseresultssuggestthatperovskiteCH3NH3PbI3-xClxfilmshaveexcellentoptoelectroniccharacteristicswhichfurthersuggeststheirpotentialusageinperovskitebasedoptoelectronicdevices.

  • 标签: 金属卤化物 有机-无机 光致发光 钙钛矿 氧化锌 两步法