科學(xué)60秒:大象：動(dòng)物界的SUV
來源：滬江聽寫酷
2011-04-01 15:32
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Elephants. They’re the SUVs of the animal kingdom. They’re big and rugged, and can carry lots of cargo. And now a study in the Proceedings of the National Academy of Sciences suggests they ___1___ the quadruped version of all-wheel drive.
When it comes to locomotion, elephants are not exactly ___2___ of foot. And they seem to hold their legs straighter than other animals do, at least when they walk. So scientists set out to examine more closely how elephant limbs mechanically ___3___.
Six Asian elephants walked or ran over a sidewalk equipped with pressure sensors, as the scientists used high-speed video cameras to monitor their gait. And they found that elephant legs actually do bend enough to provide significant leverage when on the move. More surprising is that pachyderms’ front and rear legs are ___4___ when it comes to acceleration and braking. All other four-legged animals, like dogs or cats or horses, divvy up those duties. With their rear legs powering the push forward, and their front legs acting as brakes.
That arrangement lets elephants ___5___. Sadly, it does nothing for their fuel economy. Of course, they do have the roomiest trunk.
Elephants. They’re the SUVs of the animal kingdom. They’re big and rugged, and can carry lots of cargo. And now a study in the Proceedings of the National Academy of Sciences suggests they ___1___ the quadruped version of all-wheel drive.
When it comes to locomotion, elephants are not exactly ___2___ of foot. And they seem to hold their legs straighter than other animals do, at least when they walk. So scientists set out to examine more closely how elephant limbs mechanically ___3___.
Six Asian elephants walked or ran over a sidewalk equipped with pressure sensors, as the scientists used high-speed video cameras to monitor their gait. And they found that elephant legs actually do bend enough to provide significant leverage when on the move. More surprising is that pachyderms’ front and rear legs are ___4___ when it comes to acceleration and braking. All other four-legged animals, like dogs or cats or horses, divvy up those duties. With their rear legs powering the push forward, and their front legs acting as brakes.
That arrangement lets elephants ___5___. Sadly, it does nothing for their fuel economy. Of course, they do have the roomiest trunk.
come equipped with
fleet
move all that mass around
on equal footing
trade speed for stability
高大健碩、負(fù)重量大的大象可謂動(dòng)物王國(guó)中的SUV?！睹绹?guó)國(guó)家科學(xué)學(xué)院院刊》上的一項(xiàng)研究稱它們配備有“四足驅(qū)動(dòng)”。
說到行動(dòng)的話，大象走起路來腿伸得要比其他動(dòng)物直，并不敏捷。因此，科學(xué)家們開始進(jìn)一步研究大象是如何負(fù)重行走的。
科學(xué)家們?cè)诹^亞洲象身上安裝了壓力傳感器，并通過高速紅外線攝影機(jī)監(jiān)視它們通過一條人行道時(shí)候的步態(tài)。結(jié)果顯示，實(shí)際上大象在行走時(shí)，腿部彎曲程度并不小，更令人吃驚的是，無(wú)論是加速還是剎車，大象的前腿和后退竟然扮演同樣的角色！而貓啊、狗啊、馬啊，其他任何一種四足動(dòng)物都有明確的分工：后腿用來蹬地加速，前腿用來剎車減速。
這樣一來，大象行動(dòng)雖緩但步伐穩(wěn)健，只可惜，這一點(diǎn)都沒幫大象省力。不過話說回來，大象背脊寬廣，載重量之大那是不容置疑的~
