简介：SinceitserliestyearsofR&D[1],theGEANT4simulationtoolkithasbeendevelopedfollowingsoftwareprocessstandardswhichdictatedtheoverallevolutionoftheproject.Thecomplexityofthesoftwareinvolved,thewideareasofapplicationofthesoftwareproduct,thehugeamountofcodeandCategorycomplexity,thesizeanddistributednatureoftheCollaborationitselfareallingredientswhichinvolveandcorrelatetogetherawidevarietyofsoftwareprocesses.Althoughin"production"andavailabletothepublicsinceDecember1998,theGEANT4softwareproduct[1]includesCategoryDomainswhicharestillunderactivedevelopment.Thereforetheyrequiredifferenttreatmentalsointermsofimprovementofthedevelopmentcycle,system,testingandusersupport,ThisarticleismeanttodescribesomeofthesoftwareprocessesastheyareappliedinGEANT4forbothdevelopment,testingandmaintenanceofthesoftware.

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简介：一、典型试题分析试题一：2007年，法国科学家阿尔贝·费尔和德国科学家彼得·格林贝格尔因发现某些材料的巨磁电阻效应（微弱的磁场变化可以导致电阻大小的急剧变化）而共同获得诺贝尔物理学奖．根据这一发现，可以制成的产品是（）

简介：Vanadiumalloys(V-Cr-Tiseries)areimportantcandidatematerialsforblanketcomponentsoffusionreactorsduetotheirlowactivationandhighstrengthatelevatedtemperatures.Low-temperatureirradiationembrittlementdeterminestheoperationtemperaturelimitofVanadiumalloysfortheapplicationtostructuralmaterialsoffusionreactorsirradiationresponseofvanadiumalloysneedstobeclarifiedfortheirapplication.Inthepresentstudy,specimensoftwoalloys(V-4Cr-4TiandV-5Cr-5Ti)wereirradiatedwithenergeticHeionsandheavyionstounderstandhardeningofthealloysduetoheliumaccumulationandcascadedamageproduction.

简介：Inthispaper,AgBF4/[emim][BF4]supportedionicliquidmembranes(SILMs)werepreparedsuccessfullyforCO/N2separationusingnitrogenpressureimmobilizationprocedures.TheincorporationofAgBF4coulddecreasemembraneweightloss,improvethepressure-resistantability,andkeepthecriticalpressure(0.45MPa)oftheSILMs.ThehighviscosityandundissolvedAgBF4solidsinmembraneliquidwoulddisturbgasmoleculartransportthroughmembraneandgiverisetothegastransportresistance.Therefore,thegaspermeabilitydecreasedremarkablywithincreasingAgBF4carriercontentinthemembrane.WhenthemolarratioofAgBF4to[emim][BF4]increasedfrom0:1to0.3:1,theCO/N2selectivityoftheSILMsshowedagreatincreasefrom~1to~9at20°Cand0.4MPa,suggestingthatAgBF4wasaneffectivecarrierforCOfacilitatedtransport.ThepermeabilitiesofN2andCOincreasedathighertransmembranepressure,indicatingthatmoleculartransportwoulddominatethetransportprocessathighpressure.Thetemperature-dependentgaspermeabilityfollowedtheArrheniusequation.Moreover,thedifferencesbetweentheactivationenergiesofCOandN2becamelargerafterintroducingAgBF4,resultinginmoreobviousdecreaseintheCO/N2selectivityathigheroperatingtemperature.

简介：TheGAUDIsoftwareframeworkistobeusedforallevent-processingapplicationsintheLHCbexperiment.TheGEANT4toolkithasbeenintegratedintoGAUDItoformthebasisoftheLHCbsimulationprogramGAUSS.Thebenefitsofthisapproacharethatitpermitsre-useofbasicservices,suchaspersistency,interactivityanddatavisualization,aswellasphysicsalgorithmsthatwereoriginallydevelopedinthecontextofthereconstructionandanalysisprograms.FollowingtheGAUDIphilosophy,theintegrationhasbeenachievedbydevelopinganumberofserviceswithabstractinterfacesthatcanbepluggedinatrun-time.Wedescribetheoveralldesignanddetailsofthecomponentsforinterfacingthedetectorgeometry,theprimaryinteractionandtheoutputfromtrackingparticlesthroughthedetector.

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简介：Thispaperinvestigatesthetemperaturefielddistributionandthermalfocallengthwithinalaserdiodearray(LDA)end-pumpedYVO4/Nd:YVO4rectangularcompositecrystal.AgeneralexpressionofthetemperaturefielddistributionwithintheNd:YVO4rectangularcrystalwasobtainedbyanalysingthecharacteristicsoftheNd:YVO4crystalandsolvingthePoissonequationwithboundaryconditions.ThetemperaturefielddistributionsintheNd:YVO4rectangularcrystalfortheYVO4/Nd:YVO4compositecrystalandtheNd:YVO4singlecrystalareresearchedrespec-tively.CalculatingthethermalfocallengthwithintheNd:YVO4rectangularcrystalwasdonebyananalysisoftheadditionalopticalpathdifferences(OPD)causedbyheat,whichwasveryidenticalwithexperimentalresultsinthispaper.ResearchresultsshowthatthemaximumrelativetemperatureontherearfaceoftheNd:YVO4crystalinthecompositecrystalis150Kandthethermalfocallengthis35.7mmwhentheoutputpoweroftheLDAis22W.Inthesamecircumstances,theexperimentalvalueofthethermalfocallengthis37.4mm.Sotherelativeerrorbetweenthetheoreticalanalysisandtheexperimentalresultisonly4.5%.Withthesameconditions,thethermalfocallengthoftheNd:YVO4singlecrystalis18.5mm.SotherelativerateofthethermalfocallengthbetweentheYVO4/Nd:YVO4crystalandtheNd:YVO4crystalis93%.So,thethermalstabilityoftheoutputpowerandthebeamqualityoftheYVO4/Nd:YVO4laserismoreadvantageousthanthelaserwithNd:YVO4singlecrystal.

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简介：AKerr-lens,mode-lockedYVO4∕Nd:YVO4lasercoupledwithanacousto-opticmodulator（AOM）Q-switchingnear1064nmwasemployedtopumpanintracavityKTiOPO4（KTP）opticalparametricoscillator.Asubnanosecondsignalwavenear1572nmwithlowrepetitionratewasrealized.AtanAOMrepetitionrateof8kHz,themaximumoutputpowerwas165mW.Thehighestaveragepulseenergy,theshortestduration,andthehighestpeakpowerofamode-lockingsignalpulsewereestimatedtobe～10.3μJ,～120ps,and～82kW,respectively.

简介：Geant4LowEnergyElectromagneticpackageProvidesaprecisetreatmentofelectromagneticinterationsofparticleswithmatterdowntoverylowenergies(250oVforelectronsandphotons,<1keVforhadronsandions),Itincludesaverietyofmodelsfortheelectromagneticprocessesofelectrons,photons,hadronsandions,takingintoaccountadvancefeatures,suchasshelleffectsandeffectsduetochargedependence.Thecomprehensivesetofparticletypesitcanhandle,thevarietyofmodelingapproachesandtheextendedcoverageofenergyrangemakethispackageauniquetoolamongMonteCarlocodesonthemarket,andofrelevancetoserveralexperimentaldomainsinHIEP,astroparticlephysics,spacescienceandbiomedicalstudies.

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简介：丽丝·迈特纳于1878年11月7日出生于奥地利首都维也纳一个有犹太血统的家庭，父亲是律师，青少年时期，她腼腆害羞，勤奋好学，当时正值世纪之交，放射性现象以及电子被发现，而且现代物理学的基础——相对论和量子论的理论框架及其应用亦取得了令人鼓舞的进展，

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简介：在课堂教学中，教师要把教学过程变成学生发现知识的过程，而不是简单获取知识的过程．这就要求教师充分利用学生在课堂学习中的心理因素，调动学生的积极性，抑制和化解学生学习中的消极因素，把学生引入和谐、自然、轻松、愉快的学习境界，既让学生掌握丰富的科学知识，又培养学生的创新思维能力．

简介：科学探究是一个充满创造性思维的过程，是一个发挥潜能、克服困难、艰辛探索、不断实践、追求真理的过程，是培养创新能力和实践能力的最有效途径。通过科学探究能加深对科学知识的理解，促使学生主动建构具有个体意义的科学知识和技能，使学生的思维厅法和能力得到提高，体验科学思想。

简介：用多光子光电效应理论简要分析了多光子光电效应实验,指出多光子光电效应满足nhν=12mv20+φ(hν0)且nν/ν0=4/3。同时用微扰法及单光子光电效应理论分析了H原子电离问题,结果表明也是当ω/ω0=4/3时电离几率最大

简介：本文用少体方法对Ａ≤４的Ｓ壳超核动力学结构进行系统研究，同时研究Ａ≤３的普通原子核的结构，通过比较，看到了超子进入核内使结构产生变化，超子的加入，造成壳心核的缩聚，核子间均方根距离缩短，超子在核内起胶粘凝聚作用。对这些核体系内部结构的研究表明．粒子间相对运动主要处于Ｏｓ轨道。

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简介：一个学期的物理双语课已经结束了，今后也将没有这门课，但这门课对于我们的意义却不止如此。第一次接触双语课，这对于这些一直只能在英语课上才能有机会感受双语的我们来说既是有一份憧憬、喜悦，又不乏些许心悸。而报告做报告的形式对于我们也是前所未有的体验。