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1、Themostimportantinvention----LightIntroductionTheFirstElectricLightMadein1809byHunphryDavy,thisiscalledtheelectricarc.LateTheAmericanCharlesFranciesBrushmanufacturedsomecarbonarcs.TheInventorThomasEdisonexperimentedwiththousandsofdifferentmaterials,event
2、uallyproducedabulbthatcouldglowforover1500hours.漢弗萊·戴維爵士（法拉第的老師）[ɑ?k]電弧manufactured[,m?nj?'f?kt??]制造，加工（manufacture的過去式）carbonarcs[電]碳弧bulb[b?lb]電燈泡Therearethreekindsoflight.1.Incandescentlamp(白熾燈)：a.Incandescentlamp（白熾燈）b.Tungstenhalogenlamp（鹵鎢燈）c.Halog
3、enlamp（鹵素燈）......2.Highintensitydischargelamp-HID（氣體放電燈）a.Fluorescentlamp（熒光燈）b.Sodiumlamp（鈉燈）c.Metalhalidelamp（金屬鹵化物燈）......3.Others.a.ElectrodelessLamp（高頻無極燈）b.LightEmittingDiode（發(fā)光二極管）......Intheearly19thcentury，aBritishchemistmadethefirstarclampinthe
4、worldbyusing2000cells(電池）and2carbonrods.Butthiskindoflightistoostrong，itcannotbeusedinthehousebutonlyinthestreet.In1879ByThomasEdison--anAmericaninventorThetemperatureofthefilament:3000℃Averagelifespan:1000hIt'salampwhichranksfirstintheproductionofthewor
5、ld.Butmanycountriesaretryingtostopusingit,becauseofitsheavypollution.Incandescentlamp（白熾燈）filament['f?l?m?nt]燈絲lifespan壽命ComparetoIncandescentlamp,thiskindoflamphaslongerlifespan(4000h)andhigherlightefficiency.ItItisoftenusedinthemeetingroom,theexhibitio
6、nhallandthestage.TungstenHalogenLamp（鹵鎢燈）lightefficiency光效率FluorescentLamp（熒光燈，俗稱日光燈）Longlifespan:2500h~3500hHighlightefficiencyGoodcolorrenderingThetemperatureofthefilament:≤1000℃colorrendering顯色性SodiumLamp(鈉燈)Thehighestlightefficiency.FogpermeabilityLi
7、fespan:20000hBeusedinroads,airports,terminals,highways,etc.Fogpermeability透霧性ElectrodelessLamp（高頻無極燈）Verylonglifespan:40000h~80000hEnergysavingBrighterSo,itisoftenusedinsomeplaceswhichhavehigherrequirementsforsafety.Suchastunnels,subwaystationsandfactori
8、es.tunnels隧道LightEmittingDiode（發(fā)光二極管）Samefeaturesaselectrodelesslamp,butmoreenergysaving.Itissecurewhenitworkunderthelowthermalvoltage.Andit'ssurfacetemperaturelessthan60℃.lowthermalvoltage低熱電壓Whatwillhappenifourworldhaven
