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今日主題:Fuel-Efficient Engines Have a Sooty Flaw / 節能引擎的缺陷噴射黑碳

洪欣老師推薦:托福聽力最好的課外教材:60-Second Science
康康精選托福會考的主題,堅持每天精聽一定會進步的哦!!

建議方法:
1.
先聽兩三遍 (不看文稿)
2.
再一句一句聽寫 (每句都要聽寫數遍,直到寫出85%以上的字)
3.
最後check文稿,看哪聽不出來,單字沒背過,還是發音不熟。
4.
堅持天天聽,就能每天進步哦。

MP3音檔 (按右鍵可下載聽):喜歡的同學,幫忙推或按讚哦~~
http://k6.kekenet.com/Sound/2016/…/6020160831_05438663RR.mp3

只有音檔怎夠,聽不懂地方,不用怕,康康幫你準備好中英文稿了:

中英文稿:
If you've gone shopping for a car lately, 
如果你最近買了一輛車,


you might have noticed that fuel economy—the number of miles per gallon—is slowly creeping up. 
你可能已經注意到燃油經濟,也就是每加侖行駛的總英里數正在悄然上升。


One reason is a more efficient type of fuel injection, called gas direct injection. 
原因之一在於燃油噴射裝置的效率更高,這被稱為缸內直接噴射技術。


It's a feature of half the new cars sold in the U.S. last year. 
去年美國出售的新車中,有一半車輛都具有這個特徵。


"With that kind of engine design you can also introduce turbocharging— 
這種引擎設計也可以引進渦輪增壓,


that's really what it comes down to: more engine power with a smaller engine." 
這才是真正的原因:更小的引擎,更大的發動機功率。


Naomi Zimmerman, an air-quality scientist at Carnegie Mellon University—who has, by the way, never owned a car. 
娜奧米齊默爾曼是卡內基梅隆大學的空氣品質科學家,她從未買過汽車。


"Probably because I did a whole PhD on engine emissions." 
可能是因為我在博士研究生階段對發動機排放進行了整體研究。


Here's how the two injection methods differ. 
下面說明一下這兩種噴射方式的不同之處。


In the old standard, called "port fuel injection," 
按照舊標準,車輛使用的是進氣道燃油噴射技術,


gas is injected into the air intake, where it mixes with air before hitting the cylinder. 
將氣體注入進氣口,在衝擊汽缸之前與空氣混合。


In direct injection though, as the name implies, the fuel is injected directly into the cylinder. 
而缸內直接噴射,顧名思義,就是直接式燃料噴射,將燃料直接注入汽缸。


It's more fuel efficient, meaning lower CO2 emissions, which will help slow climate change. 
這種方法更省油,二氧化碳排放量更少,這將有助於減緩氣候變化。


But here is a paradox, it also emits more particulate matter, 
但是,與此相矛盾的是,這種方法會噴射出更多的顆粒物,


including black carbon, or soot—a pollutant implicated in global warming. 
包括黑碳或煤灰等與全球變暖有關的污染物。


Zimmerman and her colleagues analyzed studies of direct injection engines 
齊默爾曼和同事對直接噴射式發動機進行了研究分析,


to see how this pollution tradeoff works out for the climate. 
以查明這種污染均衡怎樣解決氣候問題。


"The answer is that it's really complicated and it's not certain." 
答案是,這種方法非法複雜,目前還不能確定。


But on average, she says, boosting fuel economy five to nine percent would probably cancel out the warming effects of black soot, 
不過她表示,總體來說,將燃油經濟性由5%提高到9%,可能會抵消黑炭的暖化效應,


and score a net positive for the climate. 
這對氣候是有益的。


The findings are in the journal Environmental Science and Technology. 
該項研究結果發表在《環境科學與技術》雜誌上。


The fuel economy goal might be different in places with big temperature swings, and where gasoline has more aromatic compounds— 
燃油經濟性目標可能在那些溫度波動較大、汽油中含有更多芳香化合物的地方會有所不同,


which seem to boost black carbon emissions. 
這似乎促進了黑碳排放。


One place that fits the bill: Canada. 
有一個地方剛好符合要求,這個地方就是加拿大。


"There we might need to be closer to the 10 percent, 15 percent mark in terms of improving fuel economy. 
在這裡,就改善燃油經濟性而言,我們可能需要將其提高至10%,甚至是15%


Which is actually a very aggressive increase in fuel economy." 
這確實是燃油經濟性的大幅提高。


She says one solution that might reduce black carbon emissions is gasoline particulate filters. 
她表示,汽油顆粒篩檢程式可能是減少黑碳排放的解決方法。


Which would also screen out particulate matter dangerous to human health. 
該篩檢程式還可以篩選出危害人類健康的顆粒物。


Meaning a win for the planet—and the people who live on it. 
這意味著,這個星球以及生活在這個星球上的人們贏得了勝利。

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