简介:通过理论推导提出了一种评价高速流动PIV示踪粒子随流能力的松弛特性分析模型,在法向Mach数大于1.4时具有良好的适用性.将新模型应用于试验测量,发展了高速流动PIV系统和示踪粒子布撒技术,验证了高速流动PIV的定量化测量能力.针对空间发展的二维超声速气固两相混合层,数值模拟了不同Stokes数和对流Mach数(M_c)下的粒子跟随性以及弥散和迁徙运动,结果表明:相同对流Mach数,粒径越小的示踪粒子跟随性越好,Stokes数在[1,10]范围内的粒子有最大扩散距离.示踪粒子的直径大小决定其在超声速混合层大涡拟序结构中的分布特征,且粒径越小,气体与粒子的掺混越剧烈.相同粒径的粒子,对流Mach数越大跟随性越差.
简介:TheLaboratoryforIntenseLasers(L2I)isaresearchcentreinopticsandlasersdedicatedtoexperimentalresearchinhighintensitylaserscienceandtechnologyandlaserplasmainteraction.Currentlythelaboratoryisundergoinganupgradewiththegoalofincreasingtheversatilityofthelasersystemsavailabletotheusers,aswellasincreasingthepulserepetitionrate.Inthispaperwereviewthecurrentstatusofthelaserresearchanddevelopmentprogrammeofthisfacility,namelytheupgradedcapabilityandtherecentprogresstowardstheinstallationofanultrashort,diode-pumpedOPCPAlasersystem.
简介:建立了单粒子多位翻转的测试方法和数据处理方法,在此基础上开展了体硅90nmSRAM重离子单粒子多位翻转的实验研究。通过分析单粒子多位翻转百分比、均值、尺寸等参数随线性能量转移(linearenergytransfer,LET)的变化关系,表明了纳米尺度下器件单粒子多位翻转的严重性,指出了单粒子多位翻转对现有重离子单粒子效应实验方法和预估方法带来的影响。构建了包含多个存储单元的全三维器件模型,数值模拟研究了不同阱接触布放位置对单粒子多位翻转电荷收集的影响机制,表明阱电势扰动触发多单元双极放大机制是导致单粒子多位翻转的主要因素,减小阱接触与存储单元之间的距离是降低单粒子多位翻转的有效方法。
简介:在数字方法的帮助下,在旋转的洞以内的流动地和它的伴随的损失机制在1二的st部分分开纸。便于比较,旋转洞进一步作为转子定子洞案例和转子转子洞被分类大小写。除了流动近围之外,结果作为inviscid流动在两种洞行为以内显示那流动,附近更低的G区域并且在旋转的孔的附近。在除了如此的inviscid-flow-dominate领域的区域,理论核心旋转因素能安全地被用来在洞以内预言swirl比率。当详细流动模式被考虑时,Ekman类型流动在在哪儿的表面边界层的圆周附近存在粘滞效果是非可以忽略的。由于模仿的洞案例的复杂侧面,然而,旋涡结构在洞以内被改变。由比较,打漩比率能被用来预言损失的大小。由于转子转子洞的相对明显的旋转效果,打漩比率甚至在当前的模型增加到1.4,它比包围圆盘快意味着那流动是动人的。进一步的调查发现这种高度旋转的流动伴有严肃的不受欢迎的压力损失。不同于它的对应物,插句地打漩当液体通过转子定子洞时,超过1.0的比率不发生。如此的结构设计什么时候是不可避免的,因此被建议有附加里面的throughflow的转子转子流动洞应该在引擎设计被避免或某些大小应该被提供。自从这些维的参数在state-of-art的设计是典型的,在当前的纸做的模拟是有意义的。Re和Cw的相对更低的范围没在二部分糊的水流被考虑。
简介:Accordingtothegoodchargetransportingpropertyofperovskite,wedesignandsimulateap–i–n-typeall-perovskitesolarcellbyusingone-dimensionaldevicesimulator.Theperovskitechargetransportinglayersandtheperovskiteabsorberconstitutetheall-perovskitecell.Bymodulatingthecellparameters,suchaslayerthicknessvalues,dopingconcentrationsandenergybandsofn-,i-,andp-typeperovskitelayers,theall-perovskitesolarcellobtainsahighpowerconversionefficiencyof25.84%.Thebandmatchedcellshowsappreciablyimprovedperformancewithwidenabsorptionspectrumandloweredrecombinationrate,soweobtainahighJ_(sc)of32.47mA/cm~2.Thesmallseriesresistanceoftheall-perovskitesolarcellalsobenefitsthehighJ_(sc).Thesimulationprovidesanovelthoughtofdesigningperovskitesolarcellswithsimpleproducingprocess,lowproductioncostandhighefficientstructuretosolvetheenergyproblem.
简介:Inthispaper,normalincidenceverticalp-i-nphotodetectorsonagermanium-on-insulator(GOI)platformweredemonstrated.Theverticalp-i-nstructurewasrealizedbyion-implantingboronandarsenicatthebottomandtopoftheGelayer,respectively,duringtheGOIfabrication.Abruptdopingprofileswereverifiedinthetransferredhigh-qualityGelayer.Thephotodetectorsexhibitadarkcurrentdensityof~47mA∕cm~2at-1Vandanopticalresponsivityof0.39A/Wat1550nm,whichareimprovedcomparedwithstate-of-the-artdemonstratedGOIphotodetectors.Aninternalquantumefficiencyof~97%indicatesexcellentcarriercollectionefficiencyofthedevice.Thephotodetectorswithmesadiameterof60μmexhibita3dBbandwidthof~1GHz,whichagreeswellwiththeoreticalcalculations.Thebandwidthisexpectedtoimproveto~32GHzwithmesadiameterof10μm.ThisworkcouldbesimilarlyextendedtoGOIplatformswithotherintermediatelayersandpotentiallyenrichthefunctionaldiversityofGOIfornear-infraredsensingandcommunicationintegratedwithGeCMOSandmid-infraredphotonics.
简介:Temperature-dependentphotoluminescencecharacteristicsoforganic-inorganichalideperovskiteCH3NH3PbI3-xClxfilmspreparedusingatwo-stepmethodonZnO/FTOsubstrateswereinvestigated.Surfacemorphologyandabsorptioncharacteristicsofthefilmswerealsostudied.Scanningelectronmicroscopyrevealedlargecrystalsandsubstratecoverage.Theorthorhombic-to-tetragonalphasetransitiontemperaturewas140K.Thefilms’excitonbindingenergywas77.6±10.9meVandtheenergyofopticalphononswas38.8±2.5meV.TheseresultssuggestthatperovskiteCH3NH3PbI3-xClxfilmshaveexcellentoptoelectroniccharacteristicswhichfurthersuggeststheirpotentialusageinperovskitebasedoptoelectronicdevices.