简介:为了庆祝Focal发展的重要里程碑,原厂推出了Chorus826W30周年限量纪念版本,Chorus826W延续既有Chorus的造型,但细节更为精进,可说是AMG版本的Chorus。铝镁合金内凹式TNV高音单元安装在铝合金框架上,高频延伸直上28kHz。
简介:Inordertolistentobrainactivityasapieceofmusic,weproposedascale-freebrainwavemusic(SFBM)technology,whichtranslatesthescalpEEGintomusicnotesaccordingtothepowerlawofbothEEGandmusic.Inthispaper,themethodologywasfurtherextendedtochorusmusicoftwochannelsfromthetwohemispheres.Firstly,EEGdatafromtwochannelssymmetricallylocatedontheleftandrighthemispheresaretranslatedintoMIDIsequencesbySFBM,respectively,wheretheEEGparametersmodulatethepitch,durationandvolumeofeachmusicnote.Then,thetwosequencesarefiiteredintoachorusoftheChinesepentatonicscaleortheWesternmajorscale.TheresultedChineseandWesternmusicatdifferentsleepstagesillustratedistinctdifferencesinharmony,andthemusicwithChinesepentatonicscalesoundsmoreharmonious.
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.
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简介:Whistler-modechoruswavesareregardedasanimportantaccelerationmechanismcontributingtotheformationofrelativisticandultra-relativisticelectronsintheJovianradiationbelts.QuantitativedeterminationofthechoruswavedrivenelectronscatteringeffectintheJovianmagnetosphererequiresdetailedinformationofbothambientmagneticfieldandplasmadensityandwavespectralproperty,whichhowevercannotbealwaysreadilyacquiredfromobservationsofexistedmissionstoJupiter.WethereforeperformacomprehensiveanalysisofthesensitivityofchorusinducedelectronscatteringratestoambientmagnetosphericandwaveparametersintheJovianradiationbeltstoelaboratetowhichextentthediffusioncoefficientsdependonanumberofkeyinputparameters.Itisfoundthatquasi-linearelectronscatteringratesbychoruscanbestronglyaffectedbytheambientmagneticfieldintensity,thewavelatitudinalcoverage,andthepeakfrequencyandbandwidthofthewavespectraldistributionintheJovianmagnetosphere,whiletheyonlyrelyslightlyonthebackgroundplasmadensityprofileandthepeakwavenormalangle,especiallywhenthewaveemissionsareconfinedatlowerlatitudes.Giventhechoruswaveamplitude,chorusinducedelectronscatteringratesstronglydependonJovianL-shelltoexhibitatendencyapproximatelyproportionaltoLJ3.OurcomprehensiveanalysisexplicitlydemonstratestheimportanceofreliableinformationofboththeambientmagnetosphericstateandwavedistributionpropertytounderstandingthedynamicelectronevolutionintheJovianradiationbeltsandthereforehasimplicationsforfuturemissionplanningtoexploretheextremeparticleradiationenvironmentofJupiteranditssatellites.
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