学科分类
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485 个结果
  • 简介:雷纳兹应力(RS)上的积极偏爱的效果和它在边血浆的光线的狂暴的运输上的效果(r/a?=?0.9)并且在tokamak的血浆的擦去层(太阳)区域被调查。光线并且poloidal电场(Er,Ep)和离子浸透电流(我s)被多种用途的探查(MPP)测量。这根探针在IR-T1tokamak第次被制作并且构造。这根探针的大多数优点是Er和Ep能在单个射击在不同半径被测量。因此不同半径的信息能与高精确相比。偏爱电压在V偏爱?=?200V和它与在r/a被修理的limiter偏爱被使用了?=?0.9。而且,之间的阶段差别光线并且MPP检测的RS光谱的poloidal电场,和时间的进化被计算。边上的RS大小(r/a?=?0.9)多于它在太阳的价值(r/a?=?1.02)。与应用偏爱200V,RS和Er和Ep被增加,当光线的狂暴的运输同时被减少时。因此,RS影响光线的骚乱,这能被结束。RS光谱的时间的进化证明RS的频率在r/a被增加并且到达它的最高的价值?=?0.9面对偏爱。

  • 标签: 雷诺兹应力 外加偏压 多功能 托卡马克等离子体 探针 装置
  • 简介:Inatwocomponentfermionsystem,themismatchedFermisurfacespreventtheformationofCooperpairsbetweenthetwospicesneartheiraverageFermisurface.Ourpreviouswork[1]hasshownthattheangledependenceofthenons-wavepairinggapcanreducetheeffectofthedifferenceμbetweentheFermisurfacesoftwospicesinasymmetricnuclearmatter.Ontheotherhand,intheheavyfermionsuperconductors,suchasCeCoIn5pressuredCeRhIn5NpPd5Al2andTl-basedcuprates,mayhaveacoupleofcommonfeatures,forexample,thed-wavepairingandastrongparamagneticeffect(thedifferenceofthetwoFermisurfacesμ).Therefore,theangledependenceofthepairinggapmayhavesignificantinfluenceinthesesystems.

  • 标签: COMPONENT FERMION SYSTEM
  • 简介:Inthisarticle,wecalculatethecontributionfromthenonfactorizablesofthadronicmatrixelementtothedecayB~0→χc1~π~0withthelight-conequantumchromo-dynamic(QCD)sumrules.Thenumericalresultsshowthatitscontributionisratherlargeandshouldnotbeneglected.Thetotalamplitudesleadtoabranchingfractionwhichisinagreementwiththeexperimentaldatamarginally.

  • 标签: QCD求和规则 衰变 计算结果 强子矩阵元 实验数据 动力学
  • 简介:Ithasbeenproposedthatfusionreactionsbetweenneutron-richlightnuclei,forexample24C,24Oand28Ne,maycontributetoachievingtheignitiontemperatureforexplosivecarbonburningprocessduringsuperbusrsts[1,2].Studiesoffusionreactionsinvolvingneutron-richnucleiarebeyondordinaryexperimentaltechniques,sincetheintensityofradioactivebeambecomelowforthesemeasurements[3].TheactivetargettechniqueusingTPC(TimeProjectionChamber),withpropertiesofmulti-sampling,highefficiencyandlowbackground,isasuitablesolutiontotheproblem.

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  • 简介:Inthispaper,thevariableseparationapproachisusedtoobtainlocalizedcoherentstructuresofthe(2+1)-dimensionalgeneralizedDavey-Stewarsonequations:iqt+1/2(qxx+qyy)+(R+S)q=O,Rx=-σ/2|q|2ySy=-σ/2|q|2/x.ApplyingaspecialBacklundtransformationandintroducingarbitraryfunctionsoftheseedsolutions,anabundanceofthelocalizedstructuresofthismodelisderived.Byselectingthearbitraryfunctionsappropriately,somespecialtypesoflocalizedexcitationssuchasdromions,dromionlattice,breathers,andinstantonsareconstructed.

  • 标签: 非线性偏微分方程 Darey-Stewa-Son方程 相干孤子结构
  • 简介:MOS型功率场效应管具有大的脉冲开关电流(数十安培)、较高的漏源电压(达千伏)、小的导通内阻(欧姆量级)和较快的导通时间(数纳秒)。由于其输入输出电容大,故用其制作的脉冲源抗脉冲电磁干扰能力较强,也因此它的开关速度较慢。采用过驱动能提高MOS型功率场效应管的开关速度。就是使栅极驱动脉冲波形的前沿很快且上冲大大超过额定的栅源驱动电压。为此,在研制过程中,解决了用多个场效应管串、并联组合,形成具有纳秒级陡峭前沿的大电流开关;用多个脉冲变压器并联,对大电流开关输出的信号进行放大和成形;用脉冲变压器的技术解决了大功率脉冲功率合成等关键技术,采用稳定的开关器件等技术和工艺,解决低压电路抗高速高压强电干扰。实现了用固体器件—场效应管,替代国外氢闸流管部分用途的功能。

  • 标签: 场效应管 纳秒高压宽脉冲驱动源 漏源电压 电磁干扰
  • 简介:Thespectrumofisospin3/2Δ++(1232)excitedstatesisoneofthemostimportantissuesinhadronicphysicsandisattractingmuchattentionbecauseitisthemostexperimentallyaccessiblesystemcomposedofthreeidenticalvalencequarks.However,ourknowledgeontheseresonancesmainlycomesfromoldNexperimentsandisstillverypoor[1].Intheenergyregionaroundorabove2.0GeV,therearestillmanytheoreticalpredictionsofmissingΔstateswhichhavesofarnotbeenobserved.Searchingforthesemissingstatesfromotherproductionprocessesisnecessary.ApossiblenewexcellentsourceforstudyingtheseΔresonancecomprisesthe+p!K+Σ+(1385)andpp!nK+Σ+(1385)reactions,whichhaveaspecialadvantage,i:e:,thereisnocontributionsfromisospin1/2nucleonresonancesduetotheisospinandchargeconservations.

  • 标签: PP EXCELLENT ADVANTAGE source most is
  • 简介:说到课程改革,常挂嘴边的就是“更新观念”.点不错,“改革”是行为,“观念”是思想,行为受思想支配.要转变什么观念?不少人可以说出大串,但大都只是表达些陈述性的条文,而行动上却不完全是那么回事,甚至完全不是那么回事.在思考“课改已近十年,而现实教学却并未发生根本性改观”的原因时,我曾以为“咱们并不缺少新的理念,

  • 标签: 物理教学 教学目标 科学素养 立意 课程改革 更新观念
  • 简介:TheCMSCollaborationof2000scientistsinvolves150institutionsfrom31nationsspreadallovertheworld.CMSsoftwaresystemintegrationandreleasemanagementisperformedatCERN.CodemanagementisbasedonCVS,withreadorwriteaccesstotherepositoryviaaCVSserver,Softwareconfiguration,releasemanagementtools(SCRAM)arebeingdevelopedatCERN.Softwarereleasesarethendistributedtoregionalcenters,wherethesoftwareisusedbyalocalcommunityforawidevarietyoftasks,suchassoftwaredevelopmentdetectorsimulationandreconstructionandphysicsanalysis.Dependingonspecificapplication,thesystemenvironmentandlocalhardwarerequirements,differentapproachesandtoolsareusedfortheCMSsoftwareinstallationatdifferentplaces.Thispresentationdescribesconceptsandreactialsolutionsforavarietyofwaysofsoftwaredistribution,withanemphasisontheCMSexperienceatFermilab,Installationandusageofdifferentmodelsusedfortheproductionfarm,forcodedevelopmentandforphysicsanalysisaredescribed.

  • 标签: CMS实验 分布系统 设置系统
  • 简介:TheenigmaticchargedstatesZc(3900),Zc(4020),Zc(4050),Zb(10610),andZb(10650)arestudiedwithinacoupled-channelSchr¨odingermodel[1],whereradiallyexcitedquark-antiquark(qˉq)pairs,withthesameangularmomentaandisospinasthea1(1260)andb1(1235),arestronglycoupledtotheirOkubo-Zweig-Iizuka-allowedde-caychannelsDˉD+ˉDDandDˉD,orBˉB+ˉBBandBˉB,inSandD-wave.Poles,matchingtheexperimentalmassandwidthofalltheabovestates,arefoundbyvaryingonlytwofreeparameters.In

  • 标签: Radially EXCITED AXIAL
  • 简介:Themesonproductioninnucleon-nucleoncollisionsnearthresholdhasthepotentialtogaininformationonhadronpropertiesandalsoplaysanimportantroleinexploringthebaryonspectroscopy[1].Inrecentyears,theexperimentaldatabaseonthereactionofpp!ppK+Knearthresholdhasbeenexpandedsignificantly.Inadditiontothemeasurementsofthetotalanddifferentialcrosssections,belowthethresholdoftheproductionofthe?meson,performedexperimentallywithCOSY-11andANKEdetectorsatthecoolersynchrotronCOSYinGermany,invariantmassdistributionsofvarioussubsystemshavebeenobtainedatlowenergies.Unlikeabovethethresholdoftheproductionofthe?meson,inthelowenergyregion,wedonotneedtoseparatethenon-?fromthe?contribution,andduetothefactthatthedatawerespreadoverawiderangeofK+K??invariantmasses,ithasaspecialadvantagetoinvestigatethescalarmesonsa0(980)$andf0(980)whicharedynamicallygeneratedfromtheinteractionsofK ̄K,ππ,andπηtreatedascoupledchannelsinI=0andI=1,respectively.BothofthemcouplestronglytotheK ̄Kchannel.

  • 标签: PP ADVANTAGE total range has COSY
  • 简介:TN1595010522光电器件近年来的发展趋向=Reviewofrecentdevelopmentinoptoelectronicdevices[刊,中]/缪家鼎(浙江大学.浙江,杭州(310027))//半导体光电.—1994,15(1).—1—6文章从光电器件的单元技术、成像器件和垂直腔面发射半导体激光器三方面评述了光电器件的进展,说明它是个充满活力的研究领域。图12表1参2(任延同)TN1595010523光学器件与光计算机=Opticaldeviceandopticalcomputer[刊,中]/张桂萍(河北大学电子系,

  • 标签: 光电器件 垂直腔面发射半导体激光器 发展趋向 成像器件 光学器件 光计算机
  • 简介:次函数是初中学生学习函数的第个阶段,其基础性和重要性不言而喻,中考对函数的考查属重头戏,对次函数的考查十分关注.通过题多变把次函数的有关基础知识横纵向联系,把以前学习的方程(组)、不等式(组)等统起来认识,逐步达到新旧知识的融会贯通,从而进步体会次函数的重要性,通过题多变能更全面、更快捷地掌握知识和技能.

  • 标签: 一次函数 一题多变 轻负高质
  • 简介:InfluenceoftheeffectivefermionhexadecapoleforcenewlyincorporatedinamicroscopicsdgIBM-1onspectra,reducedE2andE4transitionmatrixelements(T(E2)sandT(E4)s)intheeven-evenplatinumisotopes(A=192,194,196,198)isinvestigatedintermsofnumericalcalculations.ItisfoundthattheintroducedinteractioncausesonlylimitedmodificationtothespectrumandT(E2)s,apartfromafewexceptions.However,itplaysanessentialroleindescribingE4transitions.Thusinthecasethattheinteractionisincorporatedwithcertainstrength,areasonabledescriptionofalltheE4transitionsintheplatinumisotopesisreachedinthemicroscopicsdgIBM-1incomparingbothtoexperimentaldataandtheresultscalculatedinphenomenologicalbosonmodel.``

  • 标签: 相互作用介子模型 铂同位素
  • 简介:Weproposeandexperimentallydemonstratecompacton-chip1×2wavelengthselectiveswitches(WSSs)basedonsiliconmicroringresonators(MRRs)withnestedpairsofsubrings(NPSs).OwingtotheresonancesplittinginducedbytheinnerNPSs,theproposeddevicesarecapableofperformingselectivechannelroutingatcertainresonancewavelengthsoftheouterMRRs.SystemdemonstrationofdynamicchannelroutingusingfabricateddeviceswithoneandtwoNPSsiscarriedoutfor10Gb∕snon-return-to-zerosignal.Theexperimentalresultsverifytheeffectivenessofthefabricateddevicesascompacton-chipWSSs.

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  • 简介:Atheoreticaldesignispresentedfora1×Mwavelength-selectiveswitch(WSS)thatroutesanyoneofNincomingwavelengthsignalstoanyoneofMoutputports.Thisplanaron-chipdevicecomprisesofa1×Ndemultiplexer,agroupofNswitching'trees'actuatedbyelectro-opticalorthermo-opticalmeans,andanM-foldsetofN×1multiplexers.Treesutilize1×2switches.TheWSSinsertionlossisproportionalto(log2(M+N+1))Alongwithcrosstalkfromtrees,crosstalkispresentateachcross-illuminatedwaveguideintersectionwithintheWSS,andthereareatmostN-1suchcrossingsperpath.TheselossandcrosstalkpropertieswilllikelyplaceapracticallimitofN=M=16upontheWSSsize.Byconstrainingthe1×2switchingenergyto1fJ∕bit,wefindthatresonant,narrowband1×2switchesarerequired.The1×2devicesproposedherearenanobeamMach–Zehndersandasymmetriccontra-directionalcouplerswithgratingassistance.

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