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192 个结果
  • 简介:Inthecontemporarylargetokamak,thedisruptiveterminationofadischargewillreducethelifetimeofthefirstwallmaterialswiththeintenseheatfluxattheenergyquenchandtheintenserunawayelectronsduringthecurrentquench,andgeneratehighelectronmagneticforcesonvacuumvesselcomponentswithintenseeddycurrentatthecurrentquench.Thus,avoidanceandsofteningoftheenergyquenchandthecurrentquenchandcontrollinganexpecteddisruptionoremergencyshutdownmustbeestablishedinthepresenttokamakmachines.

  • 标签: 高Z杂质 HL-1M 激光吹气 等离子体 破裂放电 安全终止
  • 简介:寻求新无限的顺序象soliton一样非线性的进化方程的准确答案(旧姓)由在辅助方程方法上开发建设和机械化的二个特征,秒种椭圆形的方程高度被学习并且新类型答案和B?cklund转变被获得。(2+1)然后,维的碎soliton方程作为一个例子和它的无限的顺序被选象soliton一样准确解决方案在符号的计算系统Mathematica的帮助下被构造,它包括无限的顺序Jacobi椭圆形的类型的光滑的象soliton一样解决方案,Jacobi椭圆形的类型的无限的顺序协议soliton解决方案和指数的函数类型和三角形的功能的无限的顺序山峰soliton解决方案打字。

  • 标签: 破裂孤子方程 无限序列 精确解 Mathematica BACKLUND变换 Jacobi
  • 简介:用特殊Painleve-Baecklund转变以及扩大印射的途径和线性重叠定理,我们获得的可变分离答案的新家庭(2+1)维的概括Broer-Kaup(GBK)系统。基于导出的准确答案,我们揭示局部性的刺激的一些新奇进化行为,即分裂和熔化现象在(2+1)维的GBK系统。

  • 标签: GBK系统 变量分离解 局部激发 裂变 聚变
  • 简介:Extractionofthein-mediumpropertiesofstrangeparticlesfromheavy-ioncollisionsisverycomplicated,sincehenucleardensityvariesintheevolutionofnucleus-nucleuscollisions.Toavoidtheuncertaintiesofthebaryonensitiesduringthestageofstrangeparticleproduction,onecaninvestigateproton-nucleuscollisionswheretheucleardensityisdefinitearoundthesaturationdensity.DynamicsofstrangeparticlesproducedintheprotoninduceduclearthereactionsnearthethresholdenergieshasbeeninvestigatedwithintheLanzhouquantumoleculardynamics(LQMD)transportmodel.Thein-mediummodificationsonparticleproductionindensenuclearmatterareconsideredthroughthecorrectionstotheelementarycrosssectionsviatheeffectivemassandhemean-fieldpotentials[1].

  • 标签: STRANGE PARTICLES In-medium
  • 简介:Parametersforthe3W1sourceatBSRFweredeterminedinboththededicatedandparasiticmodeandtheirsuitabilityforproteincrystallographybeamlineatBSRFwererealized.Itisdiscussedthatthephysicsmotivationandthedesignofthe3W1iscomparedwithsimilarexperimentalstationsattheBrazilianLightSourec(1.37Gev)andMax-IIinSweden(1.5GeV).Thephotonfluxfromthe3W1sourcdisabout2×10^11photon/smAinthewavelengthrangeof2.0-0.9Ainparasiticmodeand50-80timeshigherinthededicatedmode.Boththededicatedandparasiticmodesaresuitableformacromolecularstructureexperiments.2001ElsevierScienceB.V.Allrightsreserved.

  • 标签: BSRF 北京同步辐射装置 蛋白质 生物化学 结构分析 结晶学
  • 简介:Thermodynamicpropertiesandphasediagramsofamixedspin-(1,2)Isingferrimagneticsystemwithsingleionanisotropyonhexagonalnanowirearestudiedbyusingeffective-fieldtheorywithcorrelations.Thesusceptibility,internalenergyandspecificheatofthesystemarenumericallyexaminedandsomeinterestingphenomenainthesequantitiesarefound.TheeffectoftheHamiltonianparametersonphasediagramsareexaminedindetail.Besidessecond-orderphasetransition,linesoffirst-ordertransitionandtricriticalpointsarefound.Inparticular,wefoundthatforsomenegativevaluesofsingle-ionanisotropies,thereexistfirst-orderphasetransitions.

  • 标签: HEXAGONAL ISING NANOWIRE mixed spin-(1 2)
  • 简介:Usingasimpletwo-parameterwavefunction,wecalculatevariationallythebindingenergyofpositivelyandnegativelychargedexcitonsinGaAs/AlxGa1-xAsquantumwellsforwellwidthsfrom10to300A.Weconsidertheeffectofeffectivemass,dielectricconstantmismatchinthetwomaterials,andthewholecorrelationamongtheparticles.Theresultsarediscussedandcomparedindetailwithpreviousexperimentalandtheoreticalresults,whichshowfairagreementwiththem.

  • 标签: 量子力学 带电激子 GAAS/ALXGA1-XAS 最子阱
  • 简介:Ageneralmappingdeformationmethodispresentedandappliedtoa(2+1)-dimensionalBoussinesqsystem.Manynewtypesofexplicitandexacttravellingwavesolutions,whichcontainsolitarywavesolutions,periodicwavesolutions,JacobianandWeierstrassdoublyperiodicwavesolutions,andotherexactexcitationslikepolynomialsolutions,exponentialsolutions,andrationalsolutions,etc.,areobtainedbyasimplealgebraictransformationrelationbetweenthe(2+1)-dimensionalBoussinesqequationandageneralizedcubicnonlinearKlein-Gordonequation.

  • 标签: 三维Boussinesq方程 行波解 广义图分形理论 周期波解 孤波解 数学物理方法
  • 简介:针对红外探测器在空间应用中受高能粒子辐照后性能衰退的问题,利用电子束辐照实验,开展了位移损伤对HgCdTe材料红外透射光谱影响的研究.通过对比辐照前后材料的性能变化,结合光在材料中的传播过程及半导体辐射效应理论,分析了位移损伤对HgCdTe材料红外透射光谱的影响机制.结果表明:HgCdTe材料经电子辐照后,红外透射光谱发生衰退,衰退的幅度随辐照注量的增大而增大,且短波方向上的衰退幅度大于长波方向上的衰退幅度.该工作可为深入开展HgCdTe红外探测器辐射损伤效应及损伤机理的研究提供参考.

  • 标签: HGCDTE材料 红外透射光谱 电子辐照 位移损伤
  • 简介:Veryrecently,BelleannouncedtheirobservationofΥ(5S)!bJ!(J=0;1;2),indicatingthattheΥ(5S)!bJ!decaysalsohavelargedecaywidths,i.e.,themeasuredbranchratiosofΥ(5S)!bJ!are<3:410??3,(1:640:23+0:30??0:22)10??3,and(0:570:220:07)10??3withJ=0;1;2,respectively[1].ItshouldbenoticedthateventhoughthetreelevelcontributionstoΥ(5S)!bJ!(J=0;1;2)shouldbestronglysuppressedduetotheOkubo-Zweig-Iizuka(OZI)rule,suchlargedecaywidthsareobserved,whichagaininspiresourinterestinunderstandingsuchquantities.Inthiswork,weproposethatthecontributionfromthehadronicloopshouldbeconsideredinstudyingΥ(5S)!bJ!.

  • 标签: LOOP LOOP BE OUR IT
  • 简介:RecentexperimentalresultsofHL-1MtokamakandprogressofHL-2Aprojectarepresented.Strongfishboneinstabilitywasobservedduringoff-axisECRH.ThisisfirstobservationofthefishboneinstabilitypurelydrivenbyenergeticelectronsproducedbyECRH.TheMBIwasfirstproposedanddemonstratedonHL-1M.RecentlynewresultsofMBIexperimentwereobtainedbyincreasingthepressureofgas.Astair-shapedensityincrementwasobtainedwithhigh-pressuremulti-pulseMBIjustlikethedensityevolutionbehaviorduringthemultipelletinjection.Itisshown

  • 标签: HL-1M HL-2A 实验数据 托卡马克装置 等离子体物理学
  • 简介:YbxY1-xAl3(BO3)4(x=0.1,0.07and0)crystalshavebeengrownbythefluxmethod.ThegrowthdefectsofYbxY1-xAl3(BO3)4crystalsweredetectedbyX-raytopography.ItisfoundthattheperfcetionofYbYABcrystalwithlowYbdopantisbetterthanthatwithhighYbdopant.InYb0.1Y0.9Al3(BO3)4crystal,growhtbands,growthboundaries,grown-indislocationsandinclusionswereobserved.Howver,thedensitiesofgrowthdefectsforYb0.07Y0.93Al3(BO3)4andYAl3(BO3)4arelowandnoobviousinclusionsareobservedinthesecrytals.Inaddition,growthtwinswrerdetectedinYbxY1-xAl3(BO3)4crystalbyusingthechemicaletchingmethod.ItisfoundthatthegrowthtwinsoccurfrequentlyinYb0.01Y0.9Al3(BO3)4crystalwhereasnogrowthtwinappearsinYAl3(BO3)4crystal.Basedontheexperimentalobservations,theformationmechanismofgrowthtwinsisdiscussed.Inthemeantime,theeffectivemeasuresforreducingthegrowthtwinsanddefectsareproposed.2001ElsevierScienceB.V.Allrightsreserved.

  • 标签: YbxY1-xAl3(BO3)4晶体 晶体生长 结构缺陷 硼酸盐晶体 形貌学 X射线
  • 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第一次被制作并且构造。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.

  • 标签:
  • 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