学科分类
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3 个结果
  • 简介:buttheYANXIANGERPpersistsfinallyandobtainssuccess.ThenewERPsystemhelpstheYANXIANGLtdalot.Theoutputvalueturnsdouble,theYANXIANGLtd.ManagementteamdecideuseERPsystemtomanagetheenterpriseinformationandplantheenterpriseresource.Althoughmetlotsofhindranceinimplementationprocess,makestheseinformationobtainthebiggesteffect.ERPandtheenterpriseisonewholegroup.Eachonecannotlack.4.ThemanagementimprovementwillcontinueAlongwiththeERPsystemandtheenterpriserationalization

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  • 简介:Low-frequencychorusemissionshaverecentlyattractedmuchattentionduetothesuggestionthattheymayplayimportantrolesinthedynamicsoftheVanAllenBelts.However,themechanism(s)generatingtheselow-frequencychorusemissionshavenotbeenwellunderstood.Inthisletter,wereportaninterestingcaseinwhichbackgroundplasmadensityloweredthelowercutofffrequencyofchorusemissionsfromabove0.1fce(typicalordinarychorus)to0.02fce(extremelylow-frequencychorus).Thoseextremelylow-frequencychoruswaveswereobservedinaratherdenseplasma,wherethenumberdensityNewasfoundtobeseveraltimeslargerthanhasbeenassociatedwithobservationsofordinarychoruswaves.Forsuprathermalelectronswhosefreeenergyissuppliedbyanisotropictemperatures,lineargrowthrates(calculatedusingin-situplasmaparametersmeasuredbytheVanAllenProbes)showthatwhistlermodeinstabilitycanoccuratfrequenciesbelow0.1fcewhenthebackgroundplasmadensityNeincreases.EspeciallywhenNereaches90cm^-3ormore,thelowestunstablefrequencycanextendto0.02fceorevenless,whichisconsistentwithsatelliteobservations.Therefore,ourresultsdemonstratethatadensebackgroundplasmacouldplayanessentialroleintheexcitationofextremelylowfrequencychoruswavesbycontrollingthewavegrowthrates.

  • 标签: LOW-FREQUENCY CHORUS EMISSIONS anisotropic temperature instability
  • 简介:PrecipitationobservationscollectedatweatherstationsineasternChina,theNCEP/NCARreanalysisdata,thetropicalcyclone(TC)BestTrackDataset,andasensitivitynumericalexperimentwereusedinthepresentstudytoinvestigatetheroleintheEastAsiansummermonsoon(EASM)systemplayedbyfrequentTCactivitiesoverthewesternNorthPacific(WNP).Resultsindicatedthat,inactiveTCyears,theEASMisstrongerandthesoutherlywindsinthelowertroposphereadvancefarthernorthandreachhigherlatitudes.Meanwhile,themonsoonrainbeltremainsinthelowerandmiddlereachesoftheYangtzeRivervalleyforarelativelyshortperiod,leadingtolessprecipitationthere.BoththewesternPacificsubtropicalhighandtheSouthAsianhighweakenwiththenorthwardshiftoftheridgelinesforbothhigh-pressuresystemsaswellastheEastAsiansubtropicalupper-leveljet.Therefore,theimpactsoffrequentTCactivitiesovertheWNPoneachindividualcomponentoftheEASMareinphasewiththoseofthestrongerEASMitself,amplifyingfeaturesofthealreadystrengthenedEASM.

  • 标签: East Asian summer MONSOON TROPICAL CYCLONE