学生版lecture1.docx
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学生版lecture1.docx
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学生版lecture1
Partone:
科技英语文体特征
StylisticFeaturesofEST(EnglishforScienceandTechnology)
AerodynamicsinCarDesign
Automobiledesignersareworkingonwaystobuildautomobilesthatgetgoodgasmileage.Onewaytodothisistomakecarsmorestreamlinedbyreducingdragorwindresistance.Scientistsdefinedragasaforcethatretards,orslows,anobjectthatismovingthroughtheair.Allmovingobjectsaresubjecttodrag.Studiesestimatethatat88kilometersanhour,one-halfofthecar’sfuelandmorethan60percentofthecar’shorsepowerareusedtoovercomedrag.Soifcardesignerscanreducedragtheycanimproveonthecar’sgasmileage,orfuelefficiency.
Tofindoutmoreaboutdrag,cardesignersuseengineerswhoarespecialistsinaerodynamics.Aerodynamicsisasciencethatinvolvesthestudyofmovingairandtheforcesthatactonobjectsmovingthroughtheair.
Theaerodynamicsspecialistsmeasureairresistanceinunitsindicatingcoefficientofdrag,orCD.Thecoefficientofdragistheratiooftheamountofwindresistanceanobjectencounterstothatofaflatplateofthesameweightheldvertically.AsanexampleofCD,a1.2-by2.4-meterpieceofplywoodheldverticallywouldhaveaCDofabout1.1.OthershapeswouldhavealowerCD.AwatermelonofthesameweightastheplywoodwouldhavealowerCD.AfallingparachutewouldhaveaCDofabout1.3.Incomparison,thetypicalautomobilewouldhaveaCDofabout0.45.
WindTunnels:
TheBasicTool
EngineersusewindtunnelstostudytheCDofautomobiles.Windtunnelsarethebasictoolofaerodynamicresearch.Theyareusedtotestdesignmodels,orsmallerrepresentations,ofbridges,buildings,spacecraft,andmostrecently,automobiles.Awindtunnelcanhaveawidthof12to24metersandbeaslongas275meters.Thetunnelhasaspecialsectionwhereatestmodelisplaced.Theobjecttestedcanbeafull-sizecaroraclaymodeloftherealthing.Ahugefanblowsairintothetestsectionatabout80kilometersanhour.Duringthistimetheaerodynamicspecialistcheckstheareasofthecarwheretheremaybeturbulence,orirregularairmovement.Somespecialistsusepowerfullightstocheckturbulence.Otherengineersusesmoke,smallpieceofpaper,orothervisiblesubstancesinthesameway.
Thewindtunnelstudieshavelocatedseveraltroublespotswheredragoccursaroundthecar.Oneofthemajorproblemsistheundersideofthecar,wheretherearemanyexposedparts.Thisareaaccountsforabout20percentofthedrag.therearsectionofthecaralsopresentsaproblem.Alltheairthatrushesfromthefrontofthecarcollectsinthebackandcreatesavacuum,whilepillsthecarbackwards.
Anothertroublespotistheareaaroundthewindowframes.Evenlicenseplate,windshields,andsidemirrorsareareasofdrag.
Designimprovements
Thewindtunnelstudieshavehelpedmakemanyaerodynamicimprovementsinautomobiles.Todaymanycarshavehoodsthatslopetoactaswedgesagainstthewind.Windshieldsarealsobetterdesignedtocutdownonwindresistance.Specialdamsareinstalledunderthefrontsectionofthecartoreducetheflow,ormovementofairunderthecar.Otherimprovementsincluderetractableheadlampsandsmallerradiatorgrills.Somedesignershavestoppedusingradiatorgrillesaltogether.Otherswanttoeliminatemudflaps,raingutters,andevensidetrimtoreduceairturbulence.
AerodynamicswillplayamajorroleinthedesignoffutureautomobilesbecauseoftheimportanceofimprovinggasMileage.Andthatmeanstheconsumermightseetheautomobilechangedrasticallyinsizeandshapefromwhatitlooksliketoday.
Exercise
I.Accordingtothetext,answerthefollowingquestions.
1)Whatkindofautomobilesareautomobiledesignersworkingonwaystobuild?
2)Whatisthedefinitionofdrag?
3)Whatcancardesignersimproveoniftheycanreducedrag?
4)Whatisaerodynamics?
5)Howdotheaerodynamicspecialistsmeasureairresistance?
II.Readthefollowingstatementscarefullyanddecidewhethertheyaretrueorfalseaccordingtothetext.
1)Onewaytobuildautomobilesthatgetgoodgasmileageistomakecarsmorestreamlinedbyincreasingdragorwindresistance.
2)Allobjectsaresubjectedtodrag.
3)AfallingparachutewouldhaveaCDofabout1.5.
4)Engineersusewindtunnelstostudythecoefficientofdragofautomobiles.
5)Otherengineersusesmoke,smallpiecesofpaper,orothervisiblesubstancestocheckturbulence.
6)Theundersideofthecarwheretherearemanyexposedpartstakesupabout20percentofthedrag.
7)Thereisnodragonlicenseplates.
8)Todayalotofcarshavehoodswhichslopetoserveasprotectionsagainstthewind.
9)Specialdamsarefixedundertherearsectionofthecartocutdowntheflow,ormovementofairunderthecar.
10)Inordertocutdowntheairturbulence,somedesignerswanttoremovemudflaps,rainguttersandsidetrim.
.PutthefollowingparagraphintoChinese.
Thewindtunnelstudieshavehelpedmakemanyaerodynamicimprovementsinautomobiles.Todaymanycarshavehoodsthatslopetoactaswedgesagainstthewind.Windshieldsarealsobetterdesignedtocutdownonwindresistance.Specialdamsareinstalledunderthefrontsectionofthecartoreducetheflow,ormovementofairunderthecar.Otherimprovementsincluderetractable可回收的headlampsandsmallerradiatorgrills.Somedesignershavestoppedusingradiatorgrillesaltogether.Otherswanttoeliminatemudflaps,raingutters,andevensidetrimtoreduceairturbulence.
StylisticFeatures1:
lexicalfeatures
科技英语文体特征1:
词汇特征
科技英语(EnglishforScienceandTechnology简称EST)是英语的一种语体,有关自然科学和社会科学的学术著作、论文、研究报告、专利产品的说明等均属于此类。
科技英语注重科学性、逻辑性、正确性与严密性,在词汇、语法、修辞方面都具有自己的特色。
比较下面两个句子:
1)Thefactoryturnsout100,000carseveryyear.
2)Theannualoutputofthefactoryis100,000cars.
再看一组例子:
1)Whatapieceofworkisaman!
Hownobleinreason!
Howinfiniteinfaculties(天赋)!
informandmoving,howexpressandadmirable!
inaction,howlikeanangel!
inapprehension,howlikeaGod!
Thebeautyoftheword!
Theparagon(典范)ofanimals.
2)Manismetazoan(后生动物,多细胞动物),triploblastic(三胚层的),vertebrate(脊椎动物)pentadactyl(adj.有五指的),mammalian(哺乳动物),eutherian(真哺乳亚纲的(动物),primate(灵长目动物)....Themainoutlineofeachofhisprincipalsystemoforgansmaybetracedback,likethoseofothermammals,tothefishes.
Practice:
分析下面一篇短文的文体特征。
DespitethetestsdescribedinChapters1land12,materialsmaystillfailinservice,sometimeswithdisastrousresults(e.g.whenthefailureoccursinaircraft.bridges,ships,etc.).Totrytoavoidsuchdisastrousoccurring,thedesigneravoidsusingmaterialscontinuouslyattheirmaximumallowablestress.Thisisdonebyemployingafactorofsafety.
Unfortunately,increasingthestrengthofacomponentintheinterestsofsafetynotonlyincreasestheinitialmaterialcosts,butalsotheoperatingcosts.Forexample,thestrongerandheavierthestructuremembersofanaircraft,thefewerpassengersitcancarryandthemorefuelitconsumers.Thereforeabalancehastobemaintainedbetweensafety,initialcostandoperatingcosts.Thedesignerisconstantlystrivingtoimprovetheformerwhilstreducingthelatter.
Allowableworkingstressistakenasaproportionoftheyieldorproofstress;thatis,thecomponentisonlystressedwithinitselasticrangewheninservice.Forexample,considerthescrewedfasteningshowninFig.1.l.Whenthenutistightenednormallytheboltisstretchedslightlyand,providingitisstressedwithinitselasticrange,itwillbehavelikeaverypowerfulspringandwillpullthejointfacestogetherveryfirmly.
Thestressintheboltismadeupoftwoelements.Firstly,thestressimpartedbytheinitialtighteningofthebolt;secondly,thestressimpartedbytheloadonthefasteninginservice.Thesumofthesestressmustnotbeallowedtoapproach,letaloneexceed,theyieldstressforthematerialofitwillceasetoactinanelasticmanner.Thereforethedesignerproportionsthefastening(anothercomponents)soasthatthereisafactorofsafety.Usuallythedesignerassumesanallowableworkingstressofonlyhalftheyieldstressforthematerial.
科技英语文体的词汇的组成:
A.专业术语:
这类词语是指在不同专业中使用的专业技术词汇。
它们严谨、规范、词义单一、使用范围狭窄,而且多是国际上通用的。
这类词语中有很多是从希腊或者拉丁语中吸收而来。
如:
biorhythm生物节奏turbo-propengine涡轮浆发动机hypercharge超荷量lathe车床planer刨床emery金刚砂
再如:
therm热,thesis论文(希腊语)parameter参数,radius半经(拉丁语)
这些来源于希腊语和拉丁语的词的复数形式有些仍按原来的形式,如thesis的复数形式theses,stratus的复数形式是strati。
但是不少词由于在英语里用的时间较长,除保留了原来的复数形式外,又采用了英语的复数形式。
如:
formula公式(拉丁语)的复数形式可以是formulae,也可以是formulas,stratum层(拉丁语)可以是strata,也可以是stratums。
特别有意思的是datum数据(拉丁语)它的复数形式是data,但是由于这个词经常用复数,所以有些外国人甚至误把它当成单数,又造出了一个所谓的复数形式datas。
B.半专业术语
这类词语来自英语中的普通词,它除了本身的基本词义外,在不同的专业中又有不同的词义。
这类词词义繁多,用法灵活,搭配形式多样,使用范围极广,量也极大,在科技英语中出现频率较高,较难掌握。
如:
Workisthetransferofenergyexpressedastheproductofaforceandthedistancethroughwhichitspointofapplicationmovesinthedirectionoftheforce.
这句话中哪些词是半专业术语?
C.新造词。
构造新词有以下几种方法:
a、转化:
通过词类转化构成新词。
英语中名词、形容词、副词、介词可以转化成动词,动词、形容词、副词、介词可以转化成名词。
但最活跃的是动词转化名词和名词转化成动词。
如:
island小岛转化成动词为:
隔离;动词:
coordinate协调转化成名词为:
坐标。
b、合成:
由两面个独立的词合成为一个词。
如:
Air+craft=aircraft飞机
Metal+work=metalwork金属制品
Power+plant=powerplant发电站
有的合成词之间要有连字符“-”。
如:
cast-ironconveyer-beltmachine-made
英语中有很多专业术语由两个或更多的词组成,叫复合术语。
Liquidcrystal液晶
Computerlanguage计算机语言
Civilengineering土木工程
c、派生词:
由词根加上前缀或和后缀构成。
加前缀只变词义不变词性。
如
Decontrol取消控制
Ultrasonic超声,ultrared红外线的,ultramodern超现代化的.
Subsystem分系统
有些加前缀的派生词有前缀和词根之间有连字符。
Hydro-electric水力发电
Non-metal非金属
Extra-terrestrial地球外的
英语的前缀是有固定意义的,记住其中的一些常用前缀对于记忆生词和猜测词义很有帮助。
这里只举一些表示否定的词缀来说明:
Anti-表反对antibody抗体
Counter-表反对,相反counterbalance反平衡
Contra-表反对,相反contradiction矛盾
De-表减少,降低,否定decrease,devalue贬值,decompo
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