1.Whales,seals and walruses stay warm in cold water because they have a thick layer of blubber.We humans rely on something like blubber-neoprene rubber wet suits-to spend time in cold water.But the thick versions for really icy water are heavy and clumsy.So rather than taking after big marine mammals,what if we could learn from the littler ones,like beavers and otters?
"These animals are quite small and they can't carry around a thick layer of blubber.So instead they have fur that is evolved to trap air,and this air provides a layer of insulation for them in water."
Alice Nasto is a graduate student in mechanical engineering at MIT.Scientists have known about this air-trapping insulation mechanism for a long time,but they had not teased out the details of how it works.So Nasto and her colleagues took on the challenge.
"We're creating these furry samples from these rubbery materials by laser cutting molds and casting these hairy surfaces.And through our approach we can precisely control the spacing of the hairs and the length of the hairs."
The researchers then created a system to gather data when their pelts (毛皮) entered and moved through a liquid-in this case not water,but silicone oil,which makes it easier to see air bubbles.The key is to keep the pelt's air layer intact (完好的).
"So when they're crossing the air water interface,initially their hairy texture is full of air.And then you go into water.How much of the air comes down with you as you're moving in through the interface.So that's what this model will tell you."
They found that the denser the hairs,the more the air gets trapped,which should keep the animal-or potentially the human in a future furry wet suit-warm.The research is in the journal Physical Review Fluids.
"What we would like to work on moving forward is understanding,after you dive into the water,how do you maintain this air layer trapped in your fur.And there's lots of interesting properties of the fur in nature that we haven't yet looked at in our model that could help explain how this mechanism might work."
So for now,cold-water divers and surfers will still emulate seals or sea lions.But the day may come when they'll more closely resemble otters or beavers.
62.What can make littler mammals keep warm in cold water?C
A.An air-trapping insulation mechanism.
B.A thick layer of blubber.
C.A fur that is evolved to trap air.
D.A neoprene rubber wet suit.
63.Nasto and her colleagues have revealedA.
A.the denser the hairs,the more the air can be carried with.
B.the way this air-trapping insulation mechanism works.
C.how the air layer trapped in the fur is maintained in water.
D.the existence of the air-trapping insulation mechanism.
64.The passage is most probably taken fromD.
A.a(chǎn) newspaper
B.a(chǎn) travel book
C.a(chǎn) medical report
D.a(chǎn) science magazine
65.What is the best title for the passage?A
A.A Fantastic Layer of Fur
B.An Important Research
C.A Wonderful Mechanism
D.A Graduate's Challenge.
分析 主要講述了小型動物在冬天的時候依靠他們薄薄的皮毛,進化成空氣滯留的隔熱機理的事,說明皮毛層也是很神奇的.
解答 62.C 細(xì)節(jié)題.根據(jù)文章內(nèi)容,So instead they have fur that is evolved to trap air,and this air provides a layer of insulation for them in water…Scientists have known about this air-trapping insulation mechanism for a long time,but they had not teased out the details of how it works.沒有又厚又濃的皮毛保暖,像海貍這樣的小動物會有進化成隔絕空氣,尤其冷空氣的皮,而這種空氣滯留的隔熱機理也正是科學(xué)家們所研究的對象,結(jié)合選項,故選C
63.A 細(xì)節(jié)題.根據(jù)文章內(nèi)容,They found that the denser the hairs,the more the air gets trapped,…由此可知,Nasto和他的同事們發(fā)現(xiàn)毛發(fā)越濃密,更多的空氣會進入,結(jié)合選項,故選A
64.D 文章來源題.本文主要研究的是小型動物是如何在冬日保暖,還涉及到科學(xué)家對他們的研究等,應(yīng)該出現(xiàn)在科學(xué)雜志上.結(jié)合選項,故選D
65.A 主旨題.根據(jù)文章內(nèi)容.主要講述了小型動物在冬天的時候依靠他們薄薄的皮毛,進化成空氣滯留的隔熱機理的事,說明皮毛層也是很神奇的.結(jié)合選項,故選A
點評 本文是一個科教類閱讀,題目涉及多道細(xì)節(jié)理解題,做題時結(jié)合原文和題目有針對性的找出相關(guān)語句進行仔細(xì)分析,結(jié)合選項選出正確答案.推理判斷題也是要在抓住關(guān)鍵句子的基礎(chǔ)上合理的分析才能得出正確答案,切忌胡亂猜測,一定要做到有理有據(jù).