科学60秒:大象：动物界的SUV
来源：沪江听写酷
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
高大健硕、负重量大的大象可谓动物王国中的SUV。《美国国家科学学院院刊》上的一项研究称它们配备有“四足驱动”。
说到行动的话，大象走起路来腿伸得要比其他动物直，并不敏捷。因此，科学家们开始进一步研究大象是如何负重行走的。
科学家们在六头亚洲象身上安装了压力传感器，并通过高速红外线摄影机监视它们通过一条人行道时候的步态。结果显示，实际上大象在行走时，腿部弯曲程度并不小，更令人吃惊的是，无论是加速还是刹车，大象的前腿和后退竟然扮演同样的角色！而猫啊、狗啊、马啊，其他任何一种四足动物都有明确的分工：后腿用来蹬地加速，前腿用来刹车减速。
这样一来，大象行动虽缓但步伐稳健，只可惜，这一点都没帮大象省力。不过话说回来，大象背脊宽广，载重量之大那是不容置疑的~
