学科分类
/ 6
108 个结果
  • 简介:Low-energypartial-waveπNscatteringdataisreexaminedwiththehelpoftheproductionrepresentationofpartial-waveSmatrix,wherebranchcutsandpolesarethoroughlyunderconsideration.Theleft-handcutcontributiontothephaseshiftisdetermined,withcontrolledsystematicerrorestimates,byusingtheresultsofO(p^3)chiralperturbativeamplitudesobtainedintheextended-onmass-shellscheme.InSnandPuchannels,severediscrepanciesareobservedbetweenthephaseshiftdataandthesumofallknowncontributions.Statisticallysatisfactoryfitstothedatacanonlybeachievedbyaddingextrapolesinthetwochannels.WefindthataSnresonancepolelocatesat√zr=(0.895±0.081)—(0.164±0.023)iGeV,onthecomplexs-plane.Ontheotherhand,aFnvirtualpole,asanaccompanyingpartnerofthenucleonbound-statepole,locatesat√zv=(0.966±0.018)GeV,slightlyabovethenucleonpoleontherealaxisbelowthreshold.Physicaloriginofthetwonewlyestablishedpolesisexploredtothebestofoiirknowledge.ItisemphasizedthattheO(p^3)calculationgreatlyimprovesthefitqualitycomparingwiththepreviousO(p^2)one.

  • 标签: dispersion RELATIONS πN scatterings NUCLEON RESONANCE
  • 简介:Anenvironmentallyfriendlyprecursor,adenosine,hasbeenusedasadualsourceofCandNtosynthesizenitrogen-dopedcarboncatalystwith/withoutFe.Ahydrothermalcarbonizationmethodhasbeenusedandwateristhecarbonizationmedia.Themorphologyofsampleswith/withoutFecomponenthasbeencomparedbyHRTEM,andtheresultshowsthatFecanpromotethegraphitizationofcarbon.Furtherelectro-chemicaltestshowsthattheoxygenreductionreaction(ORR)catalyticactivityofFe-containingsample(C–FeN)ismuchhigherthanthatoftheFe-freesample(C–N).Additionally,theintermediatesofC–FeNformedduringeachsyntheticprocedurehavebeenthoroughlycharacterizedbymultiplemethods,andthefunctionofeachprocedurehasbeendiscussed.TheC–FeNsampleexhibitshighelectro-catalyticstabilityandsuperiorelectro-catalyticactivitytowardORRinalkalinemedia,withitshalf-wavepotential20mVlowerthanthatofcommercialPt/C(40wt%).Itisfurtherincorporatedintoalkalinepolymerelectrolytefuelcell(APEFC)asthecathodematerialandledtoapowerdensityof100mW/cm~2.

  • 标签:
  • 简介:传统的光子计数技术一般采用光电倍增管作为探测器。一般情况下,弱光信号在时间上较分散,因而由探测器输出的是离散电信号。针对这一特点,采用脉冲放、脉冲高度甄别和数字计数技术进行单光子计数。累计输出的脉冲计数即为探测到的光子。对于离散弱光信号,传统单光子计数方法较为可取。但由于存在甄别器死时间限制和倍增管输出脉冲堆积效应的缺陷,该方法在对脉冲微光光子计数时失去实用价值。

  • 标签: 单光子计数 计数方法 短脉冲 微光 光电倍增管 输出脉冲
  • 简介:Wetrytoapplyaconstituentquarkmodel(avarietychiralconstituentquarkmodel)andtheresonatinggroupapproachforthemulti-quarkproblemstocomputetheeffectivepotentialbetweentheNN-inS-wave(thequarksinthenucleonsNandN-,andthetwonucleonsrelativelyaswell,areinSwave)soastoseethepossibilityiftheremaybeatightboundstateofsixquarksasindicatedbyastrongenhancementatthresholdofpp-inJ/ψandBdecays.TheeffectivepotentialwhichweobtainintermsofthemodelandapproachshowsiftheexperimentalenhancementisreallycausedbyatightS-waveboundstateofsixquarks,thenthequantumnumberoftheboundstateisverylikelytobeI=1,JPC=0-+.

  • 标签: 核子-反核子效应 多夸克系统 夸克成分模型 BES 高能物理学
  • 简介:方案1:“窝里K”成本:一部CD机,一副嗓子总需经费:CD机+唱片卡担是条狗,当钱包开始瘪的时候,我们开始强烈赞同冯大导演这句话。个人演唱会不是明星的专利啊,

  • 标签: 穷开心方法
  • 简介:ThenucleiaroundmagicnumberN=126areinvestigatedinthedeformedrelativisticmeanfield(RMF)modelwitheffectiveinteractionsTMA.WefocusinvestigationsontheN=126isotonicchain.TheN=126shellevolutionisstudiedbyanalyzingthevariationsoftwo-neutron(proton)separationenergies,quadrupledeformations,singleparticlelevelsetc.Thegoodagreementoftwo-neutronseparationenergiesbetweenexperimentaldataandcalculatedvaluesisreached.TheRMFtheorypredictsthatthesizesofN=126shellbecomesmallerandsmallerwiththeincreasingofprotonnumberZ.However,theN=126shellexistsinourcalculatedregionallalong.Accordingtothecalculatedtwo-protonseparationenergies,theRMFtheorysuggests~(220)Puisatwo-protondrip-linenucleusintheN=126isotonicchain.

  • 标签: 相对论平均场理论 演变 壳牌 质子数 分离能 计算值
  • 简介:AlineararrayofNmutuallycoupledsingle-modelasersisinvestigated.ItisshownthattheintensitiesofNlasersarechaoticallysynchronizedwhenthecouplingbetweenlasersisrelativelystrong.Thechaoticsynchronizationofintensitiesdependsonthelocationofthelasersinthearray.Thechaoticsynchronizationappearsbetweentwooutmostlasers,thesecondtwooutmostlasers,etc.Thereisnosynchronizationbetweennearestneighborsofthelasers.IfthenumberofNisodd,themiddlelaserisneversynchronizedbetweenanylasers.ThechaoticsynchronizationofphasesbetweennearestlasersinthearrayisexaminedbyusingtheanalyticsignalandtheGaussianfiltermethodsbasedonthepeakofthepowerspectrumoftheintensity.Itcanbeseenthatthemessageofchaoticintensitysynchronizationisconveyedthroughthephasesynchronization.

  • 标签: 混沌同步 密度相位 线性排列 固体激光器 非线性耦合
  • 简介:1-17 Vibrational Properties of Na_1-17VibrationalPropertiesofNa_¥ZhangFengsllou;E.SuraudlandR.GlowinskiZItisknownthatsmallso...

  • 标签:
  • 简介:N阶电阻网络等效电阻进行了研究,应用虚拟电流法给出了这类问题的两个普适规律,并将所得结果与其它相关结果进行了比较

  • 标签: N阶 电阻网络 虚拟电流 等效值
  • 简介:在低仰角条件下,对脉冲微波传播中出现的遮挡、多径到达和天线波束分裂现象进行了分析,分别应用透波屏模型、Fresnel半径模型和两路径模型描述这三种现象,结合工程实践估算其产生的影响,并提出了应对措施。

  • 标签: 低仰角 短脉冲微波 近地传播
  • 简介:AschemeforcontrolledteleportationofanunknownN-qubitentangledGHZstatefromthesenderAlicetothedistantreceiverBobisproposed.Andm-qubitGHZstateissufficientforthetaskofcontrolbymspatially-separatedsupervisors.Conditionedonthelocaloperationsexecutedbyallparticipants,Bobcanfaithfullyrestoretheoriginalstatebyperformingrelevantunitarytransformationswiththeaidofsomeclassicalmessageaboutmeasurementresults.Anyone'sabsencewillabsolutelyleadtothefailureofteleportation.

  • 标签: 量子隐形传态 未知N-量子位 量子纠缠 GHZ态 BELL态测量
  • 简介:Inthepresentwork,theLEDchipwasirradiatedbyusing59.6MeVNionsinaterminalchamberoftheSector-focusedcyclotron(SFC)intheNationalLabortaryofHeavy-ionAcceleratorsinLanzhou.The63MeVNionspenetratedthroughagoldfoilandscatteredinalargearea.Theenergyofionwasreducedto59.6MeVafterscatteringofthegoldfoil.TheLEDwasprovidedbytheSemiconductorLightingCenterinInstituteofSemiconductorinBeijing.TheluminencesoftheLEDbefore/afterirradiationweretestedthroughaintegratingsphereinSemiconductorLightingCenterinInstituteofSemiconductorinBeijing.Theluminancewastestedunderacurrentof350mA.Fig.1showstherelationshipbetweentheluminencesandtheirradiationfluences.Theirradiationledto

  • 标签: CHARACTERISTICS LUMINESCENCE IRRADIATED