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  • 简介:OneofthethreethingsIcannotresist~1lovingistherhythmofsongs.NowIhavetorephrase~2it.WhatIcannotresististherhythmicsongsplayedinrunningvehicles.Thiswinterbreak,IwenttoCaliforniatovisitsomeofmyfriends.Trying

  • 标签: 课外阅读 初中英语 阅读训练 优秀文章
  • 简介:Rhythmofbrainactivitiesrepresentsoscillationsofpostsynapticpotentialsinneocortex,thereforeitcanserveasanindicatorofthebrainactivitystate.Inordertochecktheconnectivityofbrainrhythm,thispaperdevelopsanewmethodofconstructingfunctionalnetworkbasedonphasesynchronization.Electroencephalogram(EEG)datawerecollectedwhilesubjectslookingatagreencrossintwostates,performinganattentiontaskandrelaxingwitheyes-open.TheEEGfromthesetwostateswasfilteredbythreeband-passfilterstoobtainsignalsoftheta(4-7Hz),alpha(8-13Hz)andbeta(14-30Hz)bands.Meanresultantlengthwasusedtoestimatestrengthofphasesynchronizationinthreebandstoconstructnetworksofbothstates,andmeandegreeKandclustercoefficientCofnetworkswerecalculatedasafunctionofthreshold.Theresultshowshigherclustercoefficientintheattentionstatethanintheeyes-openstateinallthreebands,suggestingthatclustercoefficientreflectsbrainstate.Inaddition,anobviousfronto-parietalnetworkisfoundintheattentionstate,whichisawell-knownattentionnetwork.Theseresultsindicatethatattentionmodulatesthefronto-parietalconnectivityindifferentmodesascomparedwiththeeyes-openstate.Takentogetherthismethodisanobjectiveandimportanttooltostudythepropertiesofneuralnetworksofbrainrhythm.

  • 标签: 大脑活动 功能网络 同步功能 节奏 基础 相分析
  • 简介:Thispaperaimstoconfirmtheoptimalpruningintensitytopromotepaulowniagrowth.Annualdynamicof8growthindicatorsforpruningofthree-year-oldPaulowniatopromotetnmkextensionweresimulatedunder7treatments.TheresultsshowedthatannualgrowthprocesscouldbemodeledreliablybyRichards'function.Eightgrowthparametersweredevelopedincludingfast-growingpoint(t0),initialpointoffast-growingperiod(tl),finalpointoffast-growingperiod(t2),fast-growingperiod(t),growthperiod(Dg),maximumdayincrement(AGRmax),maximumannualincrement(A).Effectsofpruningtopromotetrunkextensionongrowthparameterswereanalyzed.Paulowniaremaining3-6lowerbranchesafterpruninghadrelativelylongerfast-growingperiod(t),growthperiod(Dg),higheraveragedayincrement(Am),maximumdayincrement(AGRmax)andmaximumannualincrement(A).Therefore,lowerdiametergrowthoforiginaltrunkdidnotdecreasesignificantly,andupperdiametergrowthincreasedtosomeextent,Heightanddiametergrowthofgraftingtrunk,andformratioofgraftingtrunkwererelativelyhigher.Totalstockvolumeincrementwasimprovedsignificantlyundertheconditionthatstockvolumeincrementoforiginaltrunkdidnotdecrease.

  • 标签: 泡桐 生长规律 修枝 主干生长
  • 简介:Nitratereductaseactivity(NRA)indifferentplantorgansandleavesindifferentpositionsofCamptothecaacuminataseedlingswasdeterminedbyanInvivoassay,thediurnalvariationrhythmofNRAinleavesofdifferentpositionswasobserved,andthecorrelationsbetweenleafNRA,leafareaandlaminamassperunitarea(LMA)werealsoexamined.TheresultsshowedthatNRAintheleafwassignificantlyhighest,comparedwiththatinotherorganssuchasroots,stemsandleaves.Inthisexperiment,the10leaveswereselectedfromtheapextothebaseoftheseedlingsinorder.ThedifferentNRAoccurredobviouslyinleavesofdifferentpositionsofC.acuminataseedlingsfromtheapextothebase,andNRAwashigherinthe4th-6thleaves.ThediurnalchangerhythmofleafNRAshowedaonepeakcurve,andmaximumNRAvalueappearedataboutmidday(at12:30orso).NoobviouscorrelationsbetweenNRAandleafareaorlaminamassperunitareawereobserved.ThisstudyofferedscientificfoundationforthefurtherresearchonnitrogenmetabolismofC.acuminata.

  • 标签: 喜树 幼苗 硝酸还原酶 酶活性 叶片