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84 个结果
  • 简介:Theoreticalmodelsofstellarevolutionpredictnegligiblequantitiesof6Li,9Be,and11Binthehydrogenburningphasesofastar’sevolution[1].TheprimordialBig-Bangnucleosynthesis(BBN)modelmightbemoregenerousinitsproductionoftheseelements[2].Theradiative-capturecrosssectionforprotoncaptureon11Bleadingto12CissmallatastrophysicallyinterestingenergiesbecauseofthelargeCoulombbarrier.

  • 标签: FACTORS LOW ENERGIES
  • 简介:ThispaperreportsthePVTxpropertiesofR22/R152asystemintherangesoftemperaturefrom298.15Kto353.15Kandpressurefrom0.288MPato1.288MPa,SixtysevenPVTxmeasurementsforthreecompositions,i.e.0.2712,0.4094and0.7911molefractionofR22,havebeenmeasuredalong16isotherms.Theuncertaintiesoftemperatureandpressuremeasurementsarelessthan0.01Kand±500Parespectively.ThereliabilityoftheexperimentalmeasurementsisconfirmedbyusingREFPROPprogram,acomputerprogramsuggestedbyMorrisonetal^[4].

  • 标签: 致冷物质 R22/R152a Burnett方法
  • 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
  • 简介:当branes的二栈是到对方的没放的平行时,我们概括在branes的二平行的栈之间的远程的相互作用的计算到各种各样的案例。我们分类相互作用的性质(排斥或吸引人)为每个专辑,大小写和这个分类能被用来认为在象brane界限状态那样的二个复杂brane系统之间的远程的相互作用的性质正当。我们将在这份报纸提供明确的例子表明这。

  • 标签: 相互作用 长距离 分类 堆栈 吸引力 排斥力
  • 简介:P2Psystemsarecategorizedintotree-basedandmesh-basedsystemsaccordingtotheirtopologies.Mesh-basedsystemsareconsideredmoresuitableforlarge-scaleInternetapplications,butrequireoptimizationonlatencyissue.Thispaperproposesacontentsubscribingmechanism(CSM)toeliminateunnecessarytimedelaysduringdatarelaying.Anodecansendcontentdatatoitsneighborsassoonasitreceivesthedatasegment.Noadditionaltimeistakenduringtheinteractivestagespriortodatasegmenttransmissionofstreamingcontent.CSMconsistsofthreesteps.First,everynoderecordsitshistoricalsegmentslatency,andadoptsgammadistribution,whichpossessespowerfulexpressionability,toexpresslatencystatistics.Second,anodepredictssubscribingsuccessratioofeveryneighborbycomparingthegammadistributionparametersofthenodeanditsneighborsbeforeselectinganeighbornodetosubscribeadatasegment.Theabovestepswouldnotincreaselatencyastheyareexecutedbeforethedatasegmentsarereadyattheneighbornodes.Finally,thenode,whichwassubscribedto,sendsthesubscribeddatasegmenttothesubscriberimmediatelywhenithasthedatasegment.ExperimentsshowthatCSMsignificantlyreducesthecontentdatatransmissionlatency.

  • 标签: 国际互联网 分布特点 流动特点 P2P技术
  • 简介:ThespectrumoftheΣ(1193)excitedstates,Σ,withisospinI=1andstrangenessS=??1isoneofthemostimportantissuesinhadronicphysics.TheΣresonancesaremostlyproducedandstudiedinK-inducedreactions.ManyΣresonancesarenowcatalogedbytheParticleDataGroup[1].However,ourknowledgeoftheseresonancesisstillverypoor.Intheenergyregionbelow2GeV,onlyafewofthemarewellestablished,suchastheΣ(1385)ofspin-parityJP=3=2+,Σ(1670)ofJp=3=2??andΣ(1775)ofJp=5=2??.Theothersarenotwellestablishedandsomeofthemareevenoflargeuncertaintiesontheirexistence.Thus,thestudyoftheΣresonancewiththeavailableexperimentaldataisnecessary.

  • 标签: EXPERIMENTAL Π now OUR is
  • 简介:热泵周期广泛地为他们的高效率被用于干衣机。然而,自从一个标准热泵周期不能在低温度操作,电的加热器经常是的lowefficiency在早为冻结的食物或冬季弄干舞台期间使用了。这研究介绍了代替电的加热器在低温度改进干衣机性能的串联热泵。实验被执行在与周围的温度,低阶段的周期团流动率,和高阶段的周期团流动的关系在串联热泵干衣机的性能检验变化率。结果与串联热泵周期的介绍在低温度的干衣机性能显示出重要改进。

  • 标签: 低温干燥机 热泵循环 热泵干燥装置 R134A R404A 电加热器
  • 简介:ThinheavilyMg-dopedInGaNandGaNcompoundcontactlayerisusedtoformNi/AuOhmiccontacttop-GaN.ThegrowthconditionsofthecompoundcontactlayeranditseffectontheperformanceofNi/AuOhmiccontacttop-GaNareinvestigated.Itisconfirmedthatthespecificcontactresistivitycanbelowerednearlytwoordersbyoptimizingthegrowthconditionsofcompoundcontactlayer.WhentheflowrateratiobetweenMgandGagassourcesofp++-InGaNlayeris10.6%andthethicknessofp++-InGaNlayeris3nm,thelowestspecificcontactresistivityof3.98×10-5?·cm2isachieved.Inaddition,theexperimentalresultsindicatethatthespecificcontactresistivitycanbefurtherloweredto1.07×10-7?·cm2byoptimizingthealloyingannealingtemperatureto520℃.

  • 标签: P-GAN 接触电阻率 Mg掺杂 接触层 复合 带宽
  • 简介:Thispaperdealswiththeintegrabilityofafinite-dimensionalHamiltoniansystemlinkedwiththegeneralizedcoupledKdVhierarchy.ForthispurposetheassociatedLaxrepresentationispresentedafteranelementarycalculation.ItisshownthattheLaxrepresentationenjoysadynamicalr-matrixformulainsteadofaclassicaloneinthePoissonbracketonR2N.Consequentlytheresultingsystemisprovedtobecompletelyintegrableinviewofitsr-matrixstructure.

  • 标签: r矩阵结构 Poisson支架 Liouville积分 Lax表示法
  • 简介:Inthisstudy,weinvestigatetheinfluenceofdopingonthechargetransferanddevicecharacteristicsparametersinthebulkheterojunctionsolarcellsbasedonpoly(3-hexylthiophene)(P3HT)andamethanofuUerenederivative(PCBM).Organicsemiconductorsarealsoknowntobenotpureandtheyhavedefectsandimpurities,someofthemarebeingchargedandactasp-typeorn-typedopants.Calculationsofthesolarcellcharacteristicsparametersversusthep-dopinglevelhavebeendoneatthreedifferentn-dopings(N_d)thatconsistof5×10~(17)cm~(-3),10~(18)cm~(-3),and5×10~(18)cm~(-3).Weperformtheanalysisofthedopingconcentrationthroughthedrift-diffusionmodel,andcalculatethecurrentandvoltagedopingdependency.Wefindthatatthreedifferentn-dopantlevels,optimump-typedopingisaboutN_p=6×10~(18)cm~(-3).Simulationresultshaveshownthatbyincreasingdopinglevel,V_(oc)monotonicallyincreasesbydoping.CellefficiencyreachesitsmaximumatsomewhathigherdopingasFFhasitspeakatN_p=3×10~(18)cm~(-3).Moreover,thispaperdemonstratesthattheoptimumvalueforthep-dopingisaboutN_p=6×10~(18)cm~(-3)andoptimumvalueforn-dopantisN_d=10~(18)cm~(-3),respectively.Thesimulatedresultsconfirmthatdopingconsiderablyaffectstheperformanceoforganicsolarcells.

  • 标签: 有机太阳能电池 掺杂剂 异质结 聚合物 基质材料 模拟
  • 简介:<正>BasedonsymboliccomputationsystemMapleandLyapunovstabilitytheory,anactivecontrolmethodisusedtoprojectivelysynchronizetwodifferentchaoticsystems—Lorenz-Chen-Lüsystem(LCL)andRsslersystem,whichbelongtodifferentdynamicsystems.Inthispaper,weachievegeneralizedprojectivesynchronizationbetweenthetwodifferentchaoticsystemsbydirectingthescalingfactorontothedesiredvaluearbitrarily.Toillustrateourresult,numericalsimulationsareusedtoperformtheprocessofthesynchronizationandsuccessfullyputtheorbitsofdrivesystem(LCL)andorbitsoftheresponsesystem(Rsslersystem)inthesameplotforunderstandingintuitively.

  • 标签: Rssler SYSTEM Lorenz-Chen-Lü SYSTEM generalized PROJECTIVE
  • 简介:现在的学习报导R134a流动在微隧道的热水池沸腾特征的热转移的试验性的评估。热水池由30平行组成矩形与500m宽度和深度的代表性的尺寸微隧道,以及全部长度30mm。实验与热流动被进行直到从373.33~1244.44kg/m22,团速度>s,蒸汽质量从0.06~0.9。加热的热水池的墙温度能在约50点被控制

  • 标签: 流动沸腾传热 矩形微通道 R134A 实验评价 质量范围 传热特性
  • 简介:水泡的行为上的可视化研究为水池在压力0.1MPa在一个水平透明加热器上沸腾R141b被执行了。水泡的行为被在加热器表面下面放的一个高速度的照相机记录。离开直径,水泡的离开时间和在不同的热流动的成核地点密度被获得。可视化结果证明水泡离开直径和离开时间减少,当当热流动增加,成核地点密度增加时。没有液体,在实验招募进microlayer,这也被观察。基于试验性的结果,煮曲线因为R141b被使用动态microlayer模型预言。作为结果,在基于动态microlayer,为沸腾的模型和实验数据R141b弄弯的预兆的结果之间的协议擅长高热流动。关键词R141b-热转移-水泡动力学-水池沸腾CLC数字TK124

  • 标签: 热传递 气泡动力学 可视化学习 高速照相 热通量
  • 简介:Westudytheconsistencyconditionsofthegeneralizedf(R)gravitybyextendingf(R)gravitywithnon-minimalcouplingtothegeneralizedf(R)witharbitrarygeometry-mattercoupling.Specifically,wediscussthetwoparticularmodelsofgeneralizedf(R)bymeansofconsistencyconditions.Itisfoundthatthesecondmodelisnotphysicallyviablesoastoberuledout.Moreover,wefurtherconstrainthefirstmodelusingtheDolgovKawasakistabilitycriterion,andgivethevaluerangesoftheparametersinthefirstmodel.Itisworthstressingthatourresultsincludetheonesinf(R)gravitywithnon-minimalcouplingasthespecialcaseofQ(L_m)=L_m.

  • 标签: 一致性条件 几何体 耦合 广义 二次模型 相容性条件
  • 简介:利用天然气脱硫厂的酸气、氢氧化钠、对二氯苯和助剂磷酸钠,在六甲基苯磷酰三胺溶剂中,常压下缩聚4~6小时,制备了线型结晶性高分子量聚苯硫醚(HMWPPS)。该方法具有的明显优点是:设备简单、容易操作、活性高、溶剂稳定、产品收率高、成本低、适宜于大规模工业生产。

  • 标签: 高分子量聚苯硫醚 重复单元 切变粘度 六甲基磷酰三胺