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392 个结果
  • 简介:Muscovitemicasheetswithathicknessof12mwereirradiatedbyswiftheavyionsKrandBifromHeavyIonResearchFacilityinLanzhou(HIRFL).Theuencesrangefrom11010to11012ions/cm2.Theelectronicenergyloss(dE/dx)eincreasesfrom5.9to31.5keV/nm.ThevibrationalmodicationsinirradiatedmicawereinvestigatedbyFourier-transforminfraredspectroscopyandthelatenttrackswereobservedbytransmissionelectronmicroscope(TEM).Theinfraredspectrumshowsthatmotionsfromallatomtypesinthemuscovitemicastructurecouldbefoundinmodesforallvibrations.AsshowninFig.1,theintensityofallvibrationalmodesinmica,includingtheOHstretchmotionat3621cm??1,decreasedwiththeincreasing(dE/dx)e.Thesimilartendencyisfoundinsamplesirradiatedbyswiftheavyionswithincreasingionuence.Itisindicatedthatdefectsandstructuralmodicationsgeneratedduringswiftheavyionirradiation,andmoredefectsareintroducedbyirradiationwithhigherionuence.

  • 标签: TRACK VIBRATIONAL MUSCOVITE
  • 简介:Understandingthehealtheffectsofexposuretospaceradiationisofparticularimportancebecauseofthemountinginterestindeepspaceexploration.Heavyionssuchas56Fearemainradiationsourcesindeepspace,whichcouldposeasignificanthazardtospaceflightcrewsduringandaftermissions[1].ComparedtoX-rays,56FeionshasthemostdeleteriouseffectsonsurvivalandlevelsofDNAdamage[2].

  • 标签: FE ION RADIATION
  • 简介:采用并行时域有限差(PFDTD)和并行时域物理光学(PTDPO)相混合的方法对大口径反射面天线近轴区的辐射远场进行了模拟计算。以圆锥喇叭馈电的单反射面天线为例,给出了馈源及反射面网格剖的要求;根据此要求剖分网格,给出了卡塞格伦双反射面天线的时域算例,所得计算结果与CST软件的计算结果符合较好。该网格剖要求可用于PFDTDPTDPO混合方法中进行任意馈源馈电的大型反射面天线的瞬态模拟,包括馈源偏焦的情况。

  • 标签: 时域 反射面天线 并行时域有限差分 并行时域物理光学 网格剖分 近轴区
  • 简介:Nuclearmassisoneofthefundamentalquantityofatomicnucleus.Thetotalbindingenergyofanucleusderivedfromtherelatedmassvaluesreflectsalltheinteractionsamongtheconstitutingnucleons.Massesofshort-livedA=2Z+3nucleiof112SnprojectilefragmentshavebeenmeasuredattheexperimentalcoolerstorageringCSRe,employingtheIsochronousmassspectrometry(IMS).TheexperimentwasconductedattheHeavyIonResearchFacilityinLanzhouatthebeginningof2016.Theprimarybeamof112Sn35+wasaccumulatedinthesynchrotronCSRmandacceleratedto467.91MeV/u.Secondarybeamwereproducedbyimpingingthehighintensity112Sn35+beamontoa10mmberylliumtargetwhichwaslocatedattheentranceoftheradioactivebeamlineRIBLL2.Theprojectilefragmentsof112Snemergedfromthetargetwerethentransmitted,separatedinflightthroughRIBLL2andfinallyinjectedintoCSRe.

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  • 简介:AnewgeneralizedJacobiellipticfunctionmethodisusedtoconstructtheexacttravellingwavesolutionsofnonlinearpartialdifferentialequations(PDEs)inaunifiedway.Themainideaofthismethodistotakefulladvantageoftheellipticequationwhichhasmorenewsolutions.Morenewdoublyperiodicandmultiplesolitonsolutionsareobtainedforthegeneralized(3+1)-dimensionalKronig-Penny(KP)equationwithvariablecoefficients.Thismethodcanbeappliedtootherequationswithvariablecoefficients.

  • 标签: 椭圆方程 孤立解 行波解 非线性偏微分方程 计算数学
  • 简介:Menofreproductiveageundergoingradiotherapyareoftenconcernedaboutthepossibleeffectsonfertilityandfuturechildren[1].Inthisinvestigation,serumtestosteronewasmeasuredfollowingwhole-bodyirradiationwitha2Gycarbonionradiation(CIR),andimmunofluorescencewereusedtoinvestigateproteinlocalizationthatevaluatetheunderlyingtoxicologicalmechanismofacuteinjuryinducedbyCIRinpubertalmicetestes.

  • 标签: ACUTE INJURY INDUCED
  • 简介:TheDNA-dependentproteinkinasecatalyticsubunit(DNA-PKcs)playsamajorroleinDNAdamagesignalingandrepair,andisalsofrequentlyover-expressedintumormetastasis.WeusedisogeniccelllinesexpressingdifferentlevelsofDNA-PKcstoinvestigatetheroleofDNA-PKcsinmetastaticdevelopment.Interestingly,ourresultsshowedthatX-rayirradiationinducedthemetastasisofDNA-PKcspositive(M059K)butnotnegative(M059J)cells;however,genisteincouldsuppresstheradiation-inducedmetastaticpotentialofM059Kcells(Fig.1).Theconcretemechanismsunderlyingthisphenomenonwillbeinvestigatednextyear.

  • 标签: DNA-PKCS POSITIVE CELLS
  • 简介:Thispaperreportsthathexagonal-phaseLaF3:Yb30.20,Er30.02andLaF3:Yb30.20,Tm30.02nanocrystals(NCs)weresynthesizedviaahydrothermalmethod.Thetransmissionelectronmicroscopy,selectedareaelectrondiffraction,powderx-raydiffraction,andthermogravimetricanalysisareusedtocharacterizetheNCs.Under980nmexcitation,theYb3/Er3andYb3/Tm3codopedNCscolloidalsolutionspresentbrightgreenandblueupconversionfluorescence,respectively.TheseNCsshowefficientinfrared-to-violetandinfrared-to-visibleupconversion.TheupconversionfluorescencemechanismsofLaF3:Yb30.20,Er30.02andLaF3:Yb30.20,Tm30.02NCsareinvestigatedwitha980-nmdiodelaserasexcitationsource.

  • 标签: 可见红外线 荧光性 调查研究 RE离子
  • 简介:Thisworkpresentsthesaturableabsorption(SA)propertiesofCsPbBr3perovskitequantumdots(QDs).TheperovskiteQDsshowexcellentSAperformancewithanonlinearabsorptioncoefficientof-35×10-2cm∕GWandafigureofmeritof3.7×10-14esucm.Further,theiruseassaturableabsorbersinapassivelyQ-switchedvisiblesolid-statelaserforthegenerationofsolitonpulsesisdemonstrated.TheseresultsdemonstratethepotentialfortheperovskiteQDstoactassaturableabsorbers.

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  • 简介:Weperformfirst-principlecalculationsforthestudyoftheorthorhombicRb2Cd2(SO4)3structure.Electronicenergybands,totalandpartialdensitiesofstatesarereportedandanalysed.Itisfoundthatoxygenatomic2pelectronsstronglyhybridizewithRb/orCd4dandS2pstates,resultingintwo-typeionicgroupswithweakcouplings.Itisshownthatmacroscopicdomainwallsoriginatefromsuchweak-couplingionicgroups,arisingatthecellboundaries.Theasymmetriccationbonds(Rb-OandCd-O)andthesubsequentrotationsoftheS04tetrahedracanleadtothedrivingforceoftheferroelectricbehaviour.Thepredictedpyroelectriccurrenteffectsareobservedexperimentallyintheferroelectricphase.

  • 标签: 轨道杂交 斜方晶结构 氧原子 电子状态 铁电物质 畴壁能量
  • 简介:研究了YBaCuO6~7超导催化剂上CO2的加氢制醇反应。考察了温度、压力和空速等条件对催化剂反应性能的影响。反应的主要产物是甲醇、CO和少量甲醚。利用XPS、XRD和AFM等技术对催化剂的结构、铜的存在状态和反应活性位进行表征发现,在反应过程中,YBa2CuO6~7由orthombic相转变为tetragonal相。反应活性位可能是Cu(I)物种。反应后催化剂颗粒的分散程度明显提高

  • 标签: CO2加氢 YBa2Cu3O6~7超导催化剂 结构 活性位
  • 简介:在这份报纸,我们在场一三维(3D)在为收音机频率的晶片水平的真空包装技术微机电的系统(RFMEMS)共鸣器,低损失的硅vias在被用来播送RF发信号。Au-Sn焊接结合被采用象电的导体一样提供真空封装。封装帽子的一个RF模型被建立评估包装的寄生效果,它提供3DRFMEMS封装的一个有效设计答案。与建议包装结构,24dB的signal-to-background比率(SBR)被完成,以及共鸣器的优秀因素(Q因素)在包装以后从8000~10400增加。包装共鸣器有线性频率温度(英尺)在在0楨?慰数?之间的一个温度范围特征?牵敶?牡?牰癯摩吗??

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  • 简介:AfacilehydrothermalmethodwasdevelopedforthepreparationofFe2O3@CnanocompositesusingFeCl3·6H2Oasironsourceandglucoseascarbonsourceunderalkalinecondition.Themorphologyandstructureoftheas-preparedproductwereidentifiedbytransmissionelectronmicroscopy(TEM),highresolutiontransmissionelectronmicroscopy(HRTEM),field-emissionscanningelectronmicroscopy(FESEM),X-raydiffraction(XRD),Ramanspectroscopy,FourierTransforminfraredspectroscopy(FTIR),andthermogravimetricanalysis(TGA).Theas-prepareα-Fe2O3@Cnanocompositeswereemployedforsupercapacitorelectrodematerial.Thesynergisticcombinationofcarbonelectricaldouble-layercapacitanceandα-Fe2O3pseudo-capacitanceestablishedsuchnanocompositesasversatileplatformforhighperformancesupercapacitors.Thesynthesismethoddevelopedhereisexpectedtoobtainothermetaloxide/carboncomposite.

  • 标签: Α-FE2O3 Carbon HYDROTHERMAL PSEUDOCAPACITOR
  • 简介:Inthispaper,weproposeahighlyautomaticapproachfor3Dphotorealisticfacereconstructionfromasinglefrontalimage.Thekeypointofourworkistheimplementationofadaptivemanifoldlearningapproach.Beforehand,anactiveappearancemodel(AAM)istrainedforautomaticfeatureextractionandadaptivelocallylinearembedding(ALLE)algorithmisutilizedtoreducethedimensionalityofthe3Ddatabase.Then,givenaninputfrontalfaceimage,thecorrespondingweightsbetween3DsamplesandtheimagearesynthesizedadaptivelyaccordingtotheAAMselectedfacialfeatures.Finally,geometryreconstructionisachievedbylinearweightedcombinationofadaptivelyselectedsamples.Radialbasisfunction(RBF)isadoptedtomapfacialtexturefromthefrontalimagetothereconstructedfacegeometry.Thetextureofinvisibleregionsbetweenthefaceandtheearsisinterpolatedbysamplingfromthefrontalimage.Thisapproachhasseveraladvantages:(1)Onlyasinglefrontalfaceimageisneededforhighlyautomaticfacereconstruction;(2)Comparedwithformerworks,ourreconstructionapproachprovideshigheraccuracy;(3)ConstraintbasedRBFtexturemappingprovidesnaturalappearanceforreconstructedface.

  • 标签: 三维人脸重建 单张正面像 自适应局部线性嵌入 RBF插值