简介：中国和加拿大的教育体制有何不同？这一问题在读者来信中经常被提及。Brad比较了两国的学制安排和教学特点，谈了自己的看法。

简介：ThepaperpresentsthebasicmodelforthetransmissiondynamicsofWestNilevirus(WNV).Themodel,whichconsistsofsevenmutually-exclusivecompartmentsrepresentingthebirdsandvectordynamics,hasalocally-asymptoticallystablediseasefreeequilibriumwhenevertheassociatedreproductionnumber(R0)islessthanunity.Asrevealin[3,20],theanalysesofthemodelshowtheexistenceofthephenomenonofbackwardbifurcation(wherethestabledisease-freeequilibriumofthemodelco-existswithastableendemicequilibriumwhenthereproductionnumberofthediseaseislessthanunity).Itisshown,thatthebackwardbifurcationphenomenoncanberemovedbysubstitutingtheassociatedstandardincidencefunctionwithamassactionincidence.Analysisofthereproductionnumberofthemodelshowsthat,thediseasewillpersist,wheneverR0>1,andincreaseinthelengthofincubationperiodcanhelpreduceWNVburdeninthecommunityifacertainthresholdquantities,denotedby△band△varenegative.Ontheotherhand,increasingthelengthoftheincubationperiodincreasesdiseaseburdenif△b>0and△v>0.Furthermore,itisshownthataddingtimedelaytothecorrespondingautonomousmodelwithstandardincidence(consideredin[2])doesnotalterthequalitativedynamicsoftheautonomoussystem(withrespecttotheeliminationorpersistenceofthedisease).

简介：Inthelastseveralyearssince2004animportantnewfindinghasbeenunveiledbycombinedeffortsduetoJapanese(SatoruTanaka),French(RenaudDeguen,TAlbousierreandMarcMonnereau),AmericanandChinesegeophysicists(XiaodongSongandVernonFCormier)whoemployedfromunambiguousdetailedseismologicalevidenceandexplainedbycleartheoreticalandsoundlaboratoryargumentsdrawnfromfluiddynamicsthatthereexistsastrong

简介：FromthecasestudyofEveningBellRingingatNanpingHill,oneoftheWestLakeCulturalLandscapesinHangzhou,China,weinvestigatedthesoundscapeofascenicareawithaprofoundculturalbackground.First,weconductedthesoundscapephysicalindexoftheareainbothwinterandspringseasonstoanalyzeitsobjectivegraphicalexpression.Second,wefocusedonpeople’sreactionstothesoundscapeinordertoobtainasubjectiveevaluationofeachcomponentinthesoundscapeandintegratedenvironment.Then,therelationshipbetweentheobjectivedataandthesubjectiveevaluationwasanalyzed.Finally,theimpactsofthenaturalenvironment,history,andculturalfactorsontheevaluationoftheJingciTemplesoundscapewerestudied.Itwasfoundthatnaturalsounds,culturalsounds,andhistoricsoundswerewidelyacclaimedinpeople’ssubjectivefeelings,whichindicatedthecloserelationshipsamonghistoricalandculturalbackground,soundscape,andnaturalenvironment.Thus,theconclusionwasmadethatsoundscapeshouldbeconsistentwiththelocalnaturalenvironmentandthehistoricalandculturalbackground.