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107 个结果
  • 简介:SAMisanetwork-distributeddatamanagementsystemdevelopedatFermilabforusewithRunIIdata,ItisbeingEmployedbytheD0Experimenttostore,manage,deliver,andtrackprocessingofalldata.Wedescribethedesignandfeaturesofthesystemincludingresourcemanagementanddatatransfermechanisms,WeshowtheoperationalexperienceD0hasaccumulatedtodateincludingdataacquisitionprocessing,andalllevelsofaccessanddelivery.Wepresentvariousconfigurationsofthesystemanddescribetheiruseinthecollaboration.

  • 标签: SAM 数据处理系统 D0实验
  • 简介:The2Dplanegasflowunderheating(withnonentityboundarycondition)hasbeendiscussedbytheanalyticalapproachinthispaper.Theapproximateanalyticalsolutionshavebeenobtainedfortheflowpassingvariouskindsofheatsources.Solutionsdemonstratethethermaldisplacementphenomenaarestronglydependontheheatingintensity.

  • 标签: 热流体流 热位移 解析解
  • 简介:Cavitationisoneofthetroublesomeproblemsinrocketturbopumps,andsincemostofhigh-efficiencyrocketpropellantsarecryogenicfluids,socalled'thermodynamiceffect'becomesmoreevidentthaninwater.Inthepresentstudy.numericalandexperimentalstudyofliquidnitrogencavitationin2DLavalnozzlewascarriedout,sothattheinfluenceofthermodynamiceffectwasexamined.Itwasrevealedthattemperatureandcavitationhavestronginter-relationshipwitheachotherinthermo-sensitivecryogenicfluids.

  • 标签: 计算流体力学 CFD 喷流 两相流 空化 低温
  • 简介:WereportonthefirstoperationsofthereconstructionfarmsfortheD0experiment.Datawerereadfromataperobotto50PC'srunningLinux,processed,spooledtoacentraldiskbufferformergingandthenwrittenbacktothetaperobot.Thefarmsarebeingusedsuccessfullytoreconstructthedataasitcomesin.Transferrateswelloverthe12.5MB/secneededforfulldatarateshavebeenachieved.

  • 标签: D0实验 探测器 软件开发
  • 简介:Oneofthekeycomponentsofanygridarchitectureismanagingcomputeandstorageresourcesandoptimizingtheirutilization.SAMhasimplementedfeaturesthatallowittoexercisea"fairshare"and"prioritized"policyamongmanygroupsofusers.Thegoalsareasfollows:1)implementthexperimentspoliciesforresourceusagebyresearchgroupandbydataaccessmode,and2)optimizetheresourceusagetomaximizetheoverallthroughputdefinedintermsofrealdataprocessingactivity,AtthelowestlevelofSAMarchitecture,calledthestation,theSAMsystemintegratesthedatadeliveryandcachemanagementwiththejobcontrolandschedulingofthebatchsystem.Atthesite-level,forexampleatFermilab,requestsfordatafromon-sitestationsaremanagedtooptimizeMassStorageSystemresourcesandnetworkthroughput,Managementofresourcesatavariousgeographiclevelsarediscussed.

  • 标签: 广域网 数据管理 数据存储 D0数据网格
  • 简介:AKondomodelinasquaretight-bondinglatticeofconductionelectronsisconsidered.TheKondointeractiontakesad-wave.Usingmean-fieldtheoryandnumericalsimulations,itisfoundthatthereisapseudo-gapfortheimpuritydensityofstatesattheFermilevel.Numericalresultsalsoshowthattheexponentsofthelowtemperaturethermodynamicquantitiesarenon-universalbutdependentontheinteraction.

  • 标签: 凝聚态物理 kondo问题 数字重整化群法
  • 简介:Thevariationalprinciplesfor1-Dunsteadycompressibleflowinadeformingtubederivedinapreviouspaper^[1]areimprovedessentiallybyreconstructingtheinitial/final-integraltermsaccordingtoanewmethodsuggestedinarecentpaper[2],Asaresult,theinherentshortcomingofvariationalprinciplesofbeingunabletoadmitphysicallyrationalinitial/final-valueconditionsininitial/boundary-valueproblemsissuccessfullyeliminated.Thus,anewtheoreticalbasisforthetime-spacefinite-elementanalysisisprovided.

  • 标签: 一维不定常可压缩流体 变化规律 时间边界条件 流体力学 气体动力学
  • 简介:氢存储的关键是与轻集体、大表面和富有的吸附地点设计新材料。在综合基于最近的试验性的成功tripyrrylmethane,我们探索了Ti-tripyrrylmethane基于的2D为氢存储使用的多孔的结构密度功能的理论。我们发现了结构是稳定的,并且暴露的Ti地点能与平均绑定绑三个氢分子0.175eV/H的精力在房间温度并且在周围的压力为氢的存储和版本躺在精力窗户的2,。

  • 标签: 多孔结构 储氢 二维 密度泛函理论 平均结合能 释放能量
  • 简介:氢同位素研究中,D/H比值是掌握氢同位素丰度变化规律的关键参数,但是低于天然氘丰度(1.4×10^-4)的气体没有成熟的测量技术可以应用,为此,开展了低于天然D丰度氢样品(以下简称贫氘氢)的色谱测量技术研究。

  • 标签: 同位素丰度 氢同位素 测量技术 天然 色谱 样品
  • 简介:Thecomplexbandstructuresofa1Danisotropicgraphenephotoniccrystalareinvestigated,andthedispersionrelationsareconfirmedusingthetransfermatrixmethodandsimulationofcommercialsoftware.Itisfoundthattheresultofusingeffectivemediumtheorycanfitthederiveddispersioncurvesinthelowwavevector.Transmission,absorption,andreflectionatobliqueincidentanglesarestudiedforthestructure,respectively.Omni-gapsexistforanglesashighas80°fortwopolarizations.Physicalmechanismsofthetunabledispersionandtransmissionareexplainedbythepermittivityofgrapheneandtheeffectivepermittivityofthemultilayerstructure.

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