学科分类
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227 个结果
  • 简介:Thedipole-length,velocityandaecelerationabsorptionoscillatorstrengthsforthe1s^22p-ls^2nd(3_<n<_9)transitionsofthelithium-likesystemswith2=11to20arecalculatedusingtheenergiesandthemulticonfiguratloninteractionwavefunctionsobtainedfromafullcorepluscorrelationmethod.Theagreementbetweenthef-valuescalculatedfromthelength,velocityandaccelerationformulaeisexcellent.Ourresultsagreecloselywiththeexperimentaldataavailableintheliterature.Combiningthesediscreteoscillatorstrengthswiththesingle-channelquantumdefecttheory,thediscreteoscillatorstrengthsforthetransitionsfrom1s^22pstatetohighlyexcitedstates(n_>10)andtheoscillatorstrengthdensitiescorrespondingtothebound-freetransitionsareobtained.

  • 标签: 类锂系统 振荡器 量子缺陷 电离化原子系统 原子物理学
  • 简介:Themagnetoresistanceeffectofap–njunctionunderanelectricfieldwhichisintroducedbythegatevoltageatroomtemperatureisinvestigatedbysimulation.Asauxiliarymodels,theLombardiCVTmodelandcarriergenerationrecombinationmodelareintroducedintoadrift-diffusiontransportmodelandcarriercontinuityequations.Alltheequationsarediscretizedbythefinite-differencemethodandtheboxintegrationmethodandthensolvedbyNewtoniteration.Takingadvantageofthosemodelsandmethods,anabruptjunctionwithuniformdopingisstudiedsystematically,andthemagnetoresistanceasafunctionofdopingconcentration,SiO_2thicknessandgeometricalsizeisalsoinvestigated.Thesimulationresultsshowthatthemagnetoresistance(MR)canbecontrolledsubstantiallybythegateandisdependentonthepolarityofthemagneticfield.

  • 标签: 磁电阻效应 电场控制 数值模拟 P-N结 连续性方程 栅极电压
  • 简介:ThepresolarSiCgrains[1]carrytheoriginalstellarnucleosynthesissignature.Theirisotopicanomaliescomparedtothesunarethestrongconstrainsinthesupernovae(SN)modelcalculations.The15N-excessinsomeSiC-ABgrains(12C/13C<10and14N/15N<272)isoneofthechallengesofcore-collapsesupernovae(CCSNe)models[2].Recently,PignataripointedoutthattheentrainmentofH-richmaterialintotheHeshellbeforetheSNexplosionallowsthecoproductionof13C,15Nand26Al,whichprovidesanewproductionscenarioforSiC-ABgrains[2].IntheHeshellnucleosynthesis,the13Cisproducedthrough12C(p,γ)13N(β+γ)13Creaction.The14Nissynthesizedthrough13N(n,γ)and13C(p,γ)reactions.

  • 标签: EXPERIMENTAL STRONG SIC SUN 15N He
  • 简介:Accordingtothegoodchargetransportingpropertyofperovskite,wedesignandsimulateap–i–n-typeall-perovskitesolarcellbyusingone-dimensionaldevicesimulator.Theperovskitechargetransportinglayersandtheperovskiteabsorberconstitutetheall-perovskitecell.Bymodulatingthecellparameters,suchaslayerthicknessvalues,dopingconcentrationsandenergybandsofn-,i-,andp-typeperovskitelayers,theall-perovskitesolarcellobtainsahighpowerconversionefficiencyof25.84%.Thebandmatchedcellshowsappreciablyimprovedperformancewithwidenabsorptionspectrumandloweredrecombinationrate,soweobtainahighJ_(sc)of32.47mA/cm~2.Thesmallseriesresistanceoftheall-perovskitesolarcellalsobenefitsthehighJ_(sc).Thesimulationprovidesanovelthoughtofdesigningperovskitesolarcellswithsimpleproducingprocess,lowproductioncostandhighefficientstructuretosolvetheenergyproblem.

  • 标签: 高效太阳能电池 钙钛矿型 仿真设计 n型 模拟器设计 P型
  • 简介:PD(X3?)相互作用潜力用CCSD(T)理论和基础集合被构造,aug-cc-pV5Z。用这个潜力,分光镜的参数是精确地坚定的。礼品,De,Re,e,ee,e,并且具有3.05699eV,3.16175eV,0.14239nm,1701.558厘米?1,23.6583厘米?1,0.08599厘米?1,和4.3963厘米?1,分别地它几乎完美地符合大小。当时,26个震动的状态的一个总数被预言J=0由解决光线的Schr?原子运动的dinger方程。完全的震动的层次,古典拐弯处点,起始的旋转和离心的失真常数什么时候J=0第一次被报导,它有利地同意实验。全部、各种各样的部分波浪的生气的节在1.0魄为在二个地面状态PD原子之间的有弹性的影响被计算吗??

  • 标签: 弹性碰撞 基态原子 低温度 横截面形状 大陆科学钻探 相互作用势
  • 简介:Inthispaper,normalincidenceverticalp-i-nphotodetectorsonagermanium-on-insulator(GOI)platformweredemonstrated.Theverticalp-i-nstructurewasrealizedbyion-implantingboronandarsenicatthebottomandtopoftheGelayer,respectively,duringtheGOIfabrication.Abruptdopingprofileswereverifiedinthetransferredhigh-qualityGelayer.Thephotodetectorsexhibitadarkcurrentdensityof~47mA∕cm~2at-1Vandanopticalresponsivityof0.39A/Wat1550nm,whichareimprovedcomparedwithstate-of-the-artdemonstratedGOIphotodetectors.Aninternalquantumefficiencyof~97%indicatesexcellentcarriercollectionefficiencyofthedevice.Thephotodetectorswithmesadiameterof60μmexhibita3dBbandwidthof~1GHz,whichagreeswellwiththeoreticalcalculations.Thebandwidthisexpectedtoimproveto~32GHzwithmesadiameterof10μm.ThisworkcouldbesimilarlyextendedtoGOIplatformswithotherintermediatelayersandpotentiallyenrichthefunctionaldiversityofGOIfornear-infraredsensingandcommunicationintegratedwithGeCMOSandmid-infraredphotonics.

  • 标签:
  • 简介:WereportonN-dopedp-typeZnOfilmswiththec-axisparalleltothesubstrate.ZnOfilmswerepreparedonana-Al2O3(0001)substratebysolid-sourcechemicalvapourdeposition(CVD),Zn(CH3COO)2.2H2OwasusedastheprecursorandCH3COONH4asthenitrogensource.Thegrowthtemperaturewasvariedfrom300℃to600℃,theas-grownZnOfilmdepositedat500℃showedp-typeconductionwithitsresistivityof42Ωcm,carrierdensity3.7×10^17cm^-3andHallmobility1.26cm^2V^-1.s^-1atroomtemperature,whicharethebestpropertiesforp-typeZnOdepositedbyCVD.Thep-typeZnOfilmpossessesatransmittanceofabout85%inthevisibleregionandabandgapof3.21eVatroomtemperature.

  • 标签: ZNO薄膜 固体源 化学蒸汽沉积
  • 简介:利用日本原子力研究机构串列加速器提供的能量为85和95MeV的28Si束流,通过重离子熔合蒸发反应76Ge(28Si,3n),布居了101Pd的高自旋激发态。根据标准在束核谱学实验测量结果,拓展了基于d5/2和1/2-[550]组态的能级纲图,新发现了1/2-[550]组态的非优惠旋称分支,完整观测到了101Pd原子核中正负宇称带的带交叉现象。根据系统性分析,将101Pd中观测到的带交叉现象归咎于g9/2质子顺排。

  • 标签: 高自旋态 带交叉 顺排
  • 简介:P-typenitrogen-dopedZnOfilmsarepreparedsuccessfullybyin-situthermaloxidationofZn_3N_2films.Thepreparedfilmsarecharacterizedbyx-raydiffraction,non-Rutherfordbackscattering(non-RBS)spectroscopy,xrayphotoelectronspectroscopy,andphotoluminescencespectrum.TheresultsshowthattheZn_3N_2filmsstarttotransformtoZnOat400°Candthetotalnitrogencontentdecreaseswiththeincreasingannealingtemperature.Thep-typefilmsareachievedat500℃withalowresistivityof6.33Ω·cmandahighholeconcentrationof+8.82×10~(17)cm~(-3),aswellasalowlevelofcarboncontamination,indicatingthatthesubstitutionalnitrogen(N_O)isaneffectiveacceptorintheZnO:Nfilm.ThephotoluminescencespectrashowclearUVemissionsandalsoindicatethepresenceofoxygenvacancy(V_O)defectsintheZnO:Nfilms.Thep-typedopingmechanismisbrieflydiscussed.

  • 标签: ZnO薄膜 薄膜制备 氮掺杂 热氧化 p型 原位
  • 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:Multimediastreamingservedthroughpeer-to-peer(P2P)networksisboomingnowadays.However,theend-to-endstreamingqualityisgenerallyunstableduetothevariabilityofthestateofserve-peers.Ontheotherhand,proxycachingisabandwidth-efficientschemeforstreamingovertheInternet,whereasitisasubstantiallyexpensivemethodneedingdedicatedpowerfulproxyservers.Inthispaper,wepresentaP2PcooperativestreamingarchitecturecombinedwiththeadvantagesofbothP2Pnetworksandmultimediaproxycachingtechniquestoimprovethestreamingqualityofparticipatingclients.Inthisframe-work,aclientwillsimultaneouslyretrievecontentsfromtheserverandotherpeersthathaveviewedandcachedthesametitlebefore.Inthemeantime,theclientwillalsoselectivelycachetheaggregatedvideocontentsoastoservestillfutureclients.Theassociateprotocoltofacilitatethemulti-pathstreamingandadistributedutility-basedpartialcachingschemearedetailedlydis-cussed.Wedemonstratetheeffectivenessofthisproposedarchitecturethroughextensivesimulationexperimentsonlarge,Inter-net-liketopologies.

  • 标签: 分布式高速缓存 P2P网络 流媒体服务 体系结构