汽车专业毕业设计 翻译 中英文全automobile emissions.docx

汽车专业毕业设计 翻译 中英文全automobile emissions.docx

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汽车专业毕业设计翻译中英文全automobileemissions

Lesson6-AutomobileEmissions

TrafficJam

BackgroundInformation

Emissionsfromanindividualcararegenerallylow,relativetothesmokestackimagemanypeopleassociatewithairpollutionbutinnumerouscitiesacrossthecountry,thepersonalautomobileisthesinglegreatestpolluterwithemissionsfrommillionsofvehiclesontheroad.Drivingaprivatecarisprobablyatypicalcitizen’smost“polluting”dailyactivity.

TheCleanAirActof1970gaveEPAbroadauthoritytoregulatemotorvehiclepollution,andtheagency’semissioncontrolpolicieshavebecomeprogressivelymorestringentsincetheearly1970’s.

EPAstandardsdictatehowmuchpollutionautosmayemitbutautomakersdecidehowtoachievethepollutionlimits.Theemissionreductionsofthe1970’scameaboutbecausefundamentalimprovementsinenginedesignplustheadditionofcharcoalcanisterstocollecthydrocarbonvaporsandexhaustgasrecirculationvalvestoreducenitrogenoxides.

Theadventof“firstgeneration”catalyticconvertersin1975significantlyreducedhydrocarbonandcarbonmonoxideemissions.Theuseofconvertersprovidedahugeindirectbenefitaswell.Theconvertersleadtothewidespreadintroductionofunleadedgasolinebecauseleadinactivatesthecatalyst.Thisresultedindramaticreductionsinambientleadlevelsandalleviatedmanyseriousenvironmentalandhumanhealthconcernsassociatedwithleadpollution.

Thenextmajormilestoneinvehicleemissioncontroltechnologycamein1980-81.Inresponsetotighterstandards,manufacturersequippednewcarswithevenmoresophisticatedemissioncontrolsystems.Thesesystemsgenerallyincludea“three-way”catalyst,anon-boardcomputer,andanoxygensensor.Thisequipmenthelpsoptimizetheefficiencyofthecatalyticconverter.

Provisionsofthe1990CleanAirActarefurtherreducingvehicleemissions.Mobilesourceprovisionsincludeeventightertailpipestandards,increaseddurability,improvedcontrolofevaporativeemissions,andcomputerizeddiagnosticsystemsthatidentifymalfunctioningemissioncontrols.

Eventhougheffortsbygovernmentandindustryhavegreatlyreducedtypicalvehicleemissions,thenumberofmilesAmericansdrivehasmorethandoubledsince1970.Theincreaseintravelhasoffsetmuchoftheemissioncontrolprogress.Thenetresultisamodestreductionineachautomotivepollutantexceptleadforwhichaggregateemissionshavedroppedbymorethan95percent.

Withozonecontinuingtopresentapersistenturbanairpollutionproblem,futurevehicleemissioncontrolprogramswillemphasizehydrocarbonandnitrogenoxidereductions.Carbonmonoxidecontrolwillremaincriticalinmanycitiesandlimitsonvehicle-generatedcarbondioxidemaybecomeimportantinthefuture.

Objectives

Aftercompletingthelesson,thestudentswillbeableto:

1.Describehowautomobileemissionspollutetheair.

2.Makeinferencesandpredictionsabouttrafficandairpollution.

3.Organizethedataintochartsandtablesforinterpretation.

4.Chooseareasonablesolutionfromvariousalternatives.

5.Interpretdataanddrawconclusionspertainingtotraffic.

6.Namethebenefitsofusinghighoccupancyvehicles.

Materials

1.OneTrafficSimulationDataTable1perstudent

2.OneTrafficSimulationDataTable2-5perstudent

3.16oz.plasticsodabottles（oneperteamof2-4students）

4.Largelimabeans,kidneybeans,blackbeans,lentils,andsplitpeasorotherbeansorobjectsofcomparablesize（enoughtomorethanfillallthesodabottles）

4.Plasticcups（fiveperteamof2-4students）

5.Onecalculatorperstudent（optional）

Preparation

1.Youwillneedtomakeone“trafficsimulator”perevery2-4studentteam.Atrafficsimulatorisasodabottlefilledwiththreekindsofbeansofdifferentsizes.Tomakethesimulators,placeonelargelimabeanineachbottle.Thisbeanrepresentsaformofmasstransit（bus）carrying55people.Next,placetwoblackbeansineachbottle.Theblackbeansrepresentacarpoolwiththreepeopleinthevehicle.Thenfilltherestofthebottlewithsmallkidneybeansuntilitistightlypacked.Thekidneybeansrepresentvehicles（cars,trucks,SUVs）carryingoneperson.Finally,putthetoponthebottleandclosetightly.

2.Togowitheachtrafficsimulatoryoumade,youwillalsoneedtopreparetwosmallcupsofsmallbeans（onewithlentilsrepresentingbicycles;theotherwithsplitpeasrepresentingpedestrians）.Laterinthelesson,thestudentswillbeaskedtoexchangethesesmallerbeanswithsomeofthelargerbeansinthesimulators.

3.Ontheboard,maketheTrafficSimulatorKeychart.

Procedure

1.Askthestudentsiftheyhaveeverbeeninatrafficjamanddiscussbriefly.

2.Havethestudentsdrawaquicksketchofatrafficjam.Givethemaboutfiveminutestodrawandthenaskthemwhattheythinkcausestrafficjams.

3.Havethestudentsdrawsomethingtorepresentairqualityintheirpictures.Remindthemofthe“KnockingOverPollutants”lessonandhowtheclasshadmadeinvisiblethingsvisible.Givethemtimetocompletethisandthendiscuss.Guidestudentstoidentifyground-levelozone,nitrogenoxides,andcarbonmonoxideasthemostcommonpollutantsthatcomeheavilyfromcars,trucks,andothermotorvehicles.

4.Writetheword“emissions”ontheboardandexplainthattheexhaustthatcomesfromcartailpipesiscalled“emissions.”Emissionsalsocomefromunderthehoodofthecarwhentheenginegetshot.Askthestudentstoexplainwhyatrafficjamwouldcauseevenmorepollutionthanalargenumberofcarsmovingfreely.Guidestudentstounderstandthatcarsidlingintrafficoratthedrive-throughwindowsusefuelinefficientlybecausetheyarenotmovingforwardtowardtheirdestination.

5.Writetheword“congestion”ontheboardandaskthestudentstodefineitandexplainhow“congestion”isappliedtotraffic.Tellthestudentsthattherearepeoplecalledtransportationplannerswhosejobitistofigureouthowtogetridofthecongestionincities.Thesepeopleoftenusemodelsintheirworktogetapictureofwhattrafficmightbelikeinacity.Trafficplannershavetothinkalotabouthowtoreduceairpollution.

6.Showstudentsapre-maketrafficsimulatorandtellthemthatinthislessontheywillbetransportationplannersusingamodelcalleda“trafficsimulator.”

7.Dividethestudentsintoteamsof2-4（dependingonthenumberoftrafficsimulatorsavailable）.Giveeachteamasimulatorandexplainthatthesimulatorrepresentsatrafficjam.ExplainwhateachtypeofbeanrepresentsusingtheTrafficSimulatorKeychart.

8.Havethestudentsshaketheirsimulators.Askthemwhathappens.Theyshouldrespondthatthebeansbarelymove.Askthestudentswhythismodelislikeahighwayorstreet.Pointoutthatitisaconfinedspaceandcanonlyholdafiniteamount.Whenyouhavetoomanycarsonthehighway,thevehiclesslowdownandcan’tmoveverymuch.Whenthereisallthatcongestion,airpollutionincreases.

9.Explainthatthismodelrepresentsa“rushhour”situationinwhichpeoplearetryingtogettoworkinthemorning.Discussthesizeofeach“vehicle”andthenumberofpeopleitcanmove.Giveeachstudentacopyofthe“TrafficSimulationDataTable1”handout.Havethestudentsopenthetrafficsimulatorsandcountthenumberofbeans/vehicleofeachtypecurrentlyinthesimulator.HavethemrecordthisdatainDataTable1.

10.Guidethestudentstodeterminethemathematicaloperationfordiscoveringhowmanytotalpeoplearecarriedbyeachtypeofvehicle（multiplication）anddemonstratewithanexample（e.g.5busesx55peopleperbus=275peoplecarriedbybuses）.AskthestudentstocalculatethetotalnumberofpeoplecarriedbyeachtypeofvehicleandenterthisdatainDataTable1.InstructthestudentstoalsocalculatethetotalnumberofvehiclesinthisscenarioaswellasthetotalnumberofpeoplebeingmovedandwritethenumbersintheTotalcolumnofTable1.Tellthestudentstoleavethe“PollutionValue”rowblankfornow.

11.Tellthestudentsthat,asgoodtransportationplanners,wewantthebeans/vehiclestomoveaboutfreelysothatthepeoplecangetwheretheyaregoinginatimelyfashionandnotcreateexcessairpollution.

12.Askthestudentsifthereareanyotheroptionsforgettingtoworkotherthantheonesalreadynamed.（Ifthestudentssuggesttrains,planes,orboats,indicatethatwearefocusingonroadsincities.）Focusonbicyclesandwalkingastwowayspeoplecangettoworkandwritetheminonthetrafficsimulatorkeyintheblankspacesnexttolentilandsplitpea.Indicatethattheycarryonepersonandwritethatinthe“numberofpeople”column.

13.Handouttwoadditionalcupsofsmallbeans;onewithlentilsrepresentingbicyclesandtheotherwithsplitpeasrepresentingwalkersor“pedestrians”.Discusswhythesebeansaresmall（abicycletakesupapproximately1/12ofthespaceacardoes）.Indicate,however,thatittakeslongertogofardistancesbybicycleandevenlongertogobyfoot.Inaddition,tellstudentsthatsomeemployeesareallowedtoteleworkwhichmeansthattheycanworkfromhomeratherthanattheoffice.Inthisactivity,nomorethanfivepeoplewhoarerepresentedinthesimulatorsatthebeginningwillbeallowedtoteleworksothestudentsmaytakeoutuptofivebeans.

14.Nowchallengethestudentstoworkinagroupusingthesimulatortofindbeancombinationsthatallowthebean“traffic”tomovefreelybuttomovethemaximumnumberofpeopleaspossible.Giveeachteamthreeadditionalplasticcupsfortheirextrabeans.Makeextrabeansofeachtypeavailabletothestudents.HandoutcopiesoftheTraf