专业英语(环境工程)教案

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1、专业英语（环境工程）教案Unit1ThePopulationExplosion要求：1、了解人口爆炸是当今世界面临的一个重要问题，以及导致人口爆炸的原因。2、了解人口爆炸所带来的问题以及应对方法。I．Somewordsandexpressions1.populationexplosion人口爆炸2.birthratesanddeathrate出生率合死亡率3.food,clothingandshelter衣食住行4．familyplanning计划生育5．Morethantwo-thirdsofthepeopleintheworldliveinth

2、ecountriesthathaveprogramsforfamilyplanning.世界三分之二以上人口的国家都实行计划生育政策。II.Questions1．Pointoutthereasonsthatcausepopulationexplosion.a.Thenumberofbirthsisgreaterthanbefore.b.Peoplecanlivelonger.2.Todayourpopulationissixbillion.Howmanyyearswillittaketoreacheightbillioniftheworldpopu

3、lationincreasedatarateofeightymillion?A.2.5yearB.25yC.250yTheanswerisB.Why?3.Howmanymeasurescanbetakentosolvetheproblemsthatarecausedbylargepopulationgatheringinbigcities?a.Lowerbirthrate_______familyplanb.Improvefoodsupplyc.Limitthesizeofcitiesandencouragepeopletoliveinsmallt

4、ownsandinthecountryside.Unit2EffectsofNoise教学要求：1、了解噪声的特点及来源。2、了解噪声的危害和控制技术。教学内容：1、puretone纯音（频率单一）2、sound-pressurelevel声压级，声压的分贝标度叫做声压级（LP）LP＝20lg(P/P0),P－待测声压P0－基准声压，人耳能察觉的最低声压3、octavebands1倍频程log2(f2/f1)=1。f2、f1－噪声监测终所用滤波器（等比带宽滤波器）的上下截止频率。1倍频程简称倍频程，在音乐上称为一个八度。4、Whatissound?

5、Thatwhichweheariscalledsound.5、Thecharacteristicsofsoundare:speed,pitch(determinedbyfrequency),energy,wavelengthandsoundpower.6、Noise:undesirablesoundThedefinitionofnoiseisvariable.7、Theinstrumentthatmeasuressoundisdecibelmeter,andascaleofsuchiscalledadecibel(dB).(1)ZerodBrepr

6、esentsthesoftestsoundthatisaudibletothehumanear.(2)dB=10×lg(I/I0),I0isthefaintestaudiblesoundandIistherealsoundwemeasured.8、Intensity:声强（I），每秒钟通过与声波传播方向垂直的面积上的平均声能。9、Soundpressure:声压（P），声源震动时，它所辐射出的能量会引起空气介质的压力变化。10、Noisecontrolcanbedoneinreducingnoisesource,interruptingthepat

7、hoftransmission,orprotectingthereceiver.(1)Sourcereducing:a.Modifytechnologicalapproachessoastoaccomplishgivenobjectivesmorequietly.b.Usingthemachinesthatworkquietly.(2)Transmissionpathinterruptinga.Choosingmaterialsthatvibrateveryinefficientlytoconvertthesoundenergyintoheat.(

8、thatis,usingacousticalmaterials)b.Usingmufflersc.deflectingth