科技英語(yǔ)一單元

1、一單元fast,cleanandenergyefficient,thesteam-poweredcarwasatonetimethemotoristsvehicleofchoice.sowhydiditrunoutofpuff?快速、清潔、節(jié)能，蒸汽動(dòng)力汽車曾是汽車駕駛者的首選。那么為什么它的氣都用光了呢？mentionsteamenginesandmostpeoplewillthinkofsteamtrains,notsteamcars.butthishasnotalwaysbeenthecase.attheturnofthe20thcenturymorethanhalfthecarsint

2、heusawerepoweredbysteam.mainlyproducedbytheamericancompaniesstanleyandwhite,steamengineshadaseriesofadvantagesoverthenewerinternalcombustionengine.一提到蒸汽機(jī)，大多數(shù)人就會(huì)想到蒸汽火車，而不是蒸汽火車。但情況并非總是如此。在20世紀(jì)之交，美國(guó)一半以上的汽車是由蒸汽驅(qū)動(dòng)的。主要由美國(guó)斯坦利和懷特公司生產(chǎn)，蒸汽機(jī)比新型內(nèi)燃機(jī)有一系列的優(yōu)勢(shì)。theyweresimplermechanically,producingcontinuouspowerfroms

3、teampressuresotheyhadnoneedforthetransmission,clutchorgearsrequiredtoharnessandconvertthestrokesofacombustionengine.它們更簡(jiǎn)單，從蒸汽壓力產(chǎn)生連續(xù)的動(dòng)力，所以它們不需要傳動(dòng)裝置、離合器或齒輪來(lái)利用和轉(zhuǎn)換內(nèi)燃機(jī)的沖程。withfewmovingparts,theyranquietlyandcouldbefueledwithanythingthatburned.theyproduced100%oftheirpowerfromrestsowerealsoeasiertodrive,an

4、dsaferforpedestrians.theirpowercouldbeswitchedintoreverseatanypointtoreducespeedmorequicklythantheineffectivebrakesofthetime.由于幾乎沒(méi)有可移動(dòng)的部件，它們可以悄悄地跑起來(lái)，用燃燒的任何東西來(lái)補(bǔ)充能量。他們從休息中產(chǎn)生了100的能量，因此也更容易駕駛，對(duì)行人也更安全。它們的動(dòng)力可以在任何時(shí)候轉(zhuǎn)變?yōu)榈管?，以比?dāng)時(shí)無(wú)效的剎車更快地降低速度。butsteamcarsalsohaddisadvantages.theyweremorecumbersomethantheirsmall

5、errivals,oftenweighingbetweentwoandthreetonnes.substantialboilersandwatertankswereneededwithearlysteamcarslosinguptoagallon(4.5litres)ofwatereverymile.stanleypartiallyremediedthiswiththeintroductionofcondensersin1915,whichturnedmuchofthesteambacktoliquidwaterbeforeitcouldescape.buteventhentheywerest

6、illonlyachievingeightmilespergallonofwater.但蒸汽汽車也有缺點(diǎn)。它們比規(guī)模較小的競(jìng)爭(zhēng)對(duì)手要笨重，通常重量在兩到三噸之間。大量的鍋爐和水箱是必要的，早期的蒸汽汽車每英里會(huì)損失1加侖（4.5升）的水。斯坦利在1915年引進(jìn)冷凝器，部分地彌補(bǔ)了這一點(diǎn)。冷凝器在蒸汽逃逸前就把大部分蒸汽重新變成了液態(tài)水。但即使如此，每加侖水也只能行駛8英里。anotherdrawbackwashowlongittooktobuildupsteampressurebeforeajourneycouldbegin.astanleysteamerownersmanualpublish

7、edin1918suggestedthatthiswouldtakebetween10and15minutes,butincoldweatheritwaslikelytotakemuchlonger.另一個(gè)缺點(diǎn)是，在旅行開(kāi)始之前，需要多長(zhǎng)時(shí)間才能產(chǎn)生蒸汽壓力。1918年出版的斯坦利輪船所有者手冊(cè)指出，這將需要10到15分鐘，但在寒冷的天氣下，這可能需要更長(zhǎng)的時(shí)間。startinghadalsobeenanissueforcarspoweredbythenewcombustionengines.earlymodelsrequiredhand-operatedcrankstostartwhichc

8、ouldbreakarmsandwristswhenthecarbackfired.buttheinventionoftheelectricstartergavetheinternalcombustionengineanadvantageandledlargemanufacturingcompaniestoinvest.對(duì)于新的內(nèi)燃機(jī)驅(qū)動(dòng)的汽車來(lái)說(shuō)，起動(dòng)也是個(gè)問(wèn)題。早期的車型需要手動(dòng)曲柄來(lái)啟動(dòng)，當(dāng)汽車發(fā)生逆火時(shí)，曲柄可能會(huì)折斷胳膊和手腕。但電起動(dòng)器的發(fā)明給了內(nèi)燃機(jī)一個(gè)優(yōu)勢(shì)，并導(dǎo)致大型制造企業(yè)進(jìn)行投資。by1910,carswithinternalcombustionengineswerebei

9、ngchurnedoutinhugenumbersatpricessolowthatthesmallersteamcarmanufactureshadnochanceofmatchingthem.soon,thefordmodelttookthestanleyscrownasthemostpopularcaronamericanroads.到了1910年，內(nèi)燃機(jī)汽車以極低的價(jià)格大量生產(chǎn)出來(lái)，小蒸汽汽車制造商根本沒(méi)有機(jī)會(huì)與之匹配。很快，福特t型車就成為了美國(guó)公路上最受歡迎的車。steamcarmakersadaptedtotheirmarginalization,marketingtheirca

10、rsasluxuryproducts.stanleytookoutnewspaperadvertsemphasizingthe“soft,motion,”tohelpreaders“(recognize)smooth,glidingthefundamentalsuperiorityofsteam,”astheyputit.蒸汽汽車制造商適應(yīng)了他們的邊緣化，把他們的汽車當(dāng)作奢侈品來(lái)銷售。斯坦利拿出報(bào)紙廣告，強(qiáng)調(diào)“柔軟，流暢，滑行的動(dòng)作”，以幫助讀者“（承認(rèn)）steam的根本優(yōu)勢(shì)，”正如他們所說(shuō)。butby1918thestanleysteamerwasalmostsixtimestheprice

11、ofamodelt.thestanleycompanydeclinedandeventuallystoppedtradingin1924,bywhichpointsteamcarswereconsideredarareandantiquatednovelty.但到了1918年，斯坦利蒸汽機(jī)車的價(jià)格幾乎是t型車的六倍。斯坦利公司(stanleycompany)在1924年下跌，并最終停止了交易。到那時(shí)候，蒸汽汽車被認(rèn)為是一種罕見(jiàn)的過(guò)時(shí)的新奇玩意兒。sincethen,steamcarshaveallbutdisappearedfromroads.however,manyhavebeenprese

12、rvedbyenthusiastslikealungriffiths,secretaryofthesteamcarclubofgreatbritain,whoownsa1916stanleysteamer.從那以后，蒸汽汽車幾乎從道路上消失了。然而，很多都被像英國(guó)蒸汽汽車俱樂(lè)部的秘書(shū)阿倫格里菲斯這樣的狂熱者所保存，他擁有一艘1916年的斯坦利輪船?！?ihear)thewindwhistlinginthehoodfittingsandnoothersoundapartfromafaintthump,thumpfromthefeedwaterpumps,likethebeatofthemachi

13、nesheart.”“風(fēng)在引擎蓋里呼呼地吹著，除了從給水泵里發(fā)出的微弱的砰砰聲，沒(méi)有別的聲音，就像機(jī)器的心臟在跳動(dòng)“ithasbeensaidofsteamcars,andofsteamenginesgenerally,thattheyseemalivecomparedtootherpiecesofmachinery,andicanonlyagreewiththat.”“有人說(shuō)蒸汽車，以及一般的蒸汽機(jī)，和其他機(jī)器相比，它們似乎是活的，我只能同意這一點(diǎn)?！眀utaresteamcarsconsignedtothepast,anowobsoletesteppingstoneinautomotive

14、history?perhapsnot.但是，蒸汽汽車已經(jīng)成為汽車歷史上過(guò)時(shí)的墊腳石了嗎？也許不。internalcombustionengineshavetheirowninherentdrawbacks.theydependonfossilfuels,afiniteresourcelikelytobecomeevermoreexpensive.andtheyproducepollutantsincludingcarbonmonoxideandnitrogenoxides.內(nèi)燃機(jī)有其固有的缺點(diǎn)。它們依賴于化石燃料，這是一種有限的資源，可能會(huì)變得越來(lái)越昂貴。它們產(chǎn)生的污染物包括一氧化碳和氮氧化物

15、。steamcontinuouspowercarscouldusearangeoffuelsandtheiravailableevenwhentheyareatrestlendsitselftomoderntraffic,withonlylighttouchesofthethrottleandbrakeneededtostopandstart.蒸汽汽車可以使用一系列的燃料，而且它們的連續(xù)動(dòng)力即使它們處于靜止?fàn)顟B(tài)也能使其適合現(xiàn)代交通，只需輕微的油門和剎車就可以停止和啟動(dòng)。moderntechnologycouldreducemanyofthehistoricproblemsofsteamcars

16、.lightweightmaterialsandheatresistantcoatingscoulddrasticallyreducetheweightoftheboilerandcondenser,andwaterretentioncouldbemaximised.starttimeswithmodernboilerscouldbereducedfromminutestoseconds.現(xiàn)代技術(shù)可以減少蒸汽汽車的許多歷史問(wèn)題。輕質(zhì)材料和耐熱涂層可以大幅度降低鍋爐和冷凝器的重量，最大限度地保持水的能力。現(xiàn)代鍋爐的啟動(dòng)時(shí)間可以從分鐘減少到秒。somecarcompanieshaveresearc

17、hedanddevelopedsteamtechnologyovertheyears,mostnotablyinthe1990swiththevolkswagenspin-offenginionag.thiswasasteamenginewithefficiencycomparabletomoderninternalcombustionengineswithloweremissions.sincethen,cyclonetechnologieshasdevelopedanewsteamenginewhichitclaimsisalmosttwiceasefficientasaninternal

18、combustionengine.一些汽車公司多年來(lái)一直在研究和開(kāi)發(fā)蒸汽技術(shù)，最引人注目的是在20世紀(jì)90年代，大眾汽車公司剝離了英力集團(tuán)。這是一個(gè)蒸汽機(jī)與效率相當(dāng)于現(xiàn)代內(nèi)燃機(jī)較低的排放量。自那時(shí)以來(lái)，旋風(fēng)技術(shù)公司開(kāi)發(fā)了一種新的蒸汽機(jī)，它聲稱這種發(fā)動(dòng)機(jī)的效率幾乎是內(nèi)燃機(jī)的兩倍。asyetneitheroftheseengineshasbeenputintoaproductioncar,soisthereanychancethesteamcarcouldmakeareturnontoourroadsasamodern,consumervehicle?到目前為止，這些引擎都沒(méi)有投入生產(chǎn)，那么蒸汽車是否有可能作為一種現(xiàn)代的消費(fèi)型汽車回到我們的道路上呢？asinternalcombustionenginesdeficienciesbecomemoreapparentamarketmayemerge.“ifacommitteewasfacedwithacleansheetandthechoiceofasteamoradieselfuture,theymightdecidethatsteamwasabetterwayforward,”saidrogerkemp,professorofengineeringatlancasterunive