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You might think frogs catch insects ‘cause their tongues are sticky. "But why is the tongue sticky, and how does it actually adhere to these insects at these very high accelerations?"
Those are the questions Alexis Noel, a PhD candidate in mechanical engineering at Georgia Tech, wanted to answer. So she and her team got frog tongues from a dissection lab, and tested their consistency. Ten times softer than human tongues. A texture more like brain tissue. "Their tongue is very much like a sponge. It's infused with this thick, viscous saliva."
That saliva was their next study subject. "And in order to test the saliva we had to get about a fifth of a teaspoon of fluid. Which is a lot of saliva, in a frog's case." They put the saliva in a rheometer, a tool that can measure viscosity. And they found that frog saliva is what's called a 'shear-thinning fluid'—its viscosity changes, depending on conditions.
You might be more familiar with a different shear-thinning fluid. "Ketchup. When you smack the bottom of the ketchup bottle you're actually invoking shear forces within the ketchup itself. And ketchup, because it's shear thinning, its viscosity actually drops and allows it to slide out of the bottle easily."
So back to our frogs: the tongue shoots out, hits the bug and deforms around it. That impact is like a smack on a ketchup bottle—it changes the saliva from thick and sticky to more watery, free to flow all over the bug. Then the tongue bounces back, like a bungee cord, and the saliva thickens up again. What's next is beyond weird.
"Frogs actually take their bulbous eyeballs and bring them down into their mouth cavity and use their eyeballs to shove the insect down the throat." That force turns the saliva watery again, "and the insect slides down the gullet." The study is in the Journal of the Royal Society Interface.
【视频讲解】
You might think frogs catch insects ‘cause their tongues are sticky. "But why is the tongue sticky, and how does it actually adhere to these insects at these very high accelerations?"
你可能认为，青蛙因为要抓昆虫，所以它们的舌头都是粘性。但，为什么舌头是黏黏的？舌头是如何能极其快速地抓住昆虫呢？
adhere to = stick to 粘附
Adhere
1. 遵守
例：All members of the association adhere to a strict code of practice.
所有该协会的成员都遵守严格的业务守则。
2. 紧贴，粘住
例：Small particles adhere to the seed.
微小的粒子紧贴着种子。
Those are the questions Alexis Noel, a PhD candidate in mechanical engineering at Georgia Tech, wanted to answer. So she and her team got frog tongues from a dissection lab, and tested their consistency.
乔治亚理工大学生物工程学博士Alexis Noel想回答这些问题！所以，她和她的团队从解剖实验室取得青蛙的舌头，然后检查粘度。
Dissect
1. 解剖
2. 剖析
People want to dissect his work and question his motives.
人们想剖析他的作品，质疑他的动机。
Consistency
1. 黏稠度
2. 连贯性; 一致性
例：She scores goals with remarkable consistency.
她以非凡的连贯性进球得分。
Ten times softer than human tongues. A texture more like brain tissue. "Their tongue is very much like a sponge. It's infused with this thick, viscous saliva."
青蛙的舌头比人类的柔软十倍，纹理更像人类大脑。“它们的舌头像海绵，它吸收浓厚，粘性的唾液”
Sponge 海绵
Infuse 注入 (某种特性)
例：Many of the girls seemed to be infused with excitement on seeing the snow.
许多女孩子似乎一看到雪心里就充满了兴奋。
Viscous 黏稠的
dark, viscous blood.
...深色且黏稠的血液。
Saliva 唾液
That saliva was their next study subject. "And in order to test the saliva we had to get about a fifth of a teaspoon of fluid. Which is a lot of saliva, in a frog's case."
唾液是那些研究课题，为了得到唾液，他们取样了五分之一的茶匙. 对青蛙而言，已经足够了
Subject
1. 课题，主题
2. 受…影响的 （subject to ）
例：Prices may be subject to alteration.
价格可能会受变更影响。
Teaspoon 茶匙
They put the saliva in a rheometer, a tool that can measure viscosity. And they found that frog saliva is what's called a 'shear-thinning fluid'—its viscosity changes, depending on conditions. ,
他们将唾液放在测试粘度的电流计中；他们发现，青蛙的粘液是“剪切稀化液”，也就说粘度会随着环境而改变
Rheometer 电流计，血流速度计
Shear
1. 剪毛
例：Competitors have six minutes to shear four sheep.
参赛者们有6分钟的时间来给4只羊剪毛。
2. 大剪刀
例：Trim the shrubs with shears.
用大剪刀修剪这些灌木。
Thin
1. 稀释
2. 消磨掉
例：War has achieved little, and public patience is wearing thin.
战争收获甚微，公众的耐心日渐消磨。
You might be more familiar with a different shear-thinning fluid. "Ketchup. When you smack the bottom of the ketchup bottle you're actually invoking shear forces within the ketchup itself.
你可能熟悉其他不同的剪切稀化液“比如番茄酱。当你拍打番茄酱底部的时候，实际上就在唤起番茄酱内部剪力”
Ketchup 番茄酱
Smack
1. 击打
例：She smacked me on the side of the head.
她打到了我一边脑袋上。
2. 带有…迹象; 含有…意味
例：The engineers' union was unhappy with the motion, saying it smacked of racism.
工程师联合会不满意这个提议，说它有种族主义的味道。
3. 恰好
例：In part that's because industry is smack in the middle of the city.
部分是因为工业恰恰就在该市的中心地带。
And ketchup, because it's shear thinning, its viscosity actually drops and allows it to slide out of the bottle easily."
由于剪力稀释，所以番茄酱的的粘度实际下降，然后让番茄酱轻松流出来
Drop
1. 下降
2. 放弃
例：This was one of the factors that led to President Suharto's dropping of his previous objections.
这是导致苏哈托总统放弃他先前反对意见的因素之一。
3. 滴; (如酒) 少量
例：...a drop of blue ink.
…一滴蓝墨水。
So back to our frogs: the tongue shoots out, hits the bug and deforms around it. That impact is like a smack on a ketchup bottle—it changes the saliva from thick and sticky to more watery, free to flow all over the bug.
回到青蛙上来：舌头射出去，击中虫子，然后使它变形。这种影响力，就像在番茄酱瓶子底部拍打——它改变了从唾液最粘变到不太粘，然后自由将虫子包裹住
Bug
1. 小虫
2. 故障
例：There is a bug in the software.
软件出了故障
Watery
1. 微弱的; 淡薄的
A watery light began to show through the branches.
一缕微弱的光线从树枝间透射过来。
2. 含水的; 似水的; 由水组成的
例：There was a watery discharge from her ear.
她的耳朵里有水状物流出。
Then the tongue bounces back, like a bungee cord, and the saliva thickens up again. What's next is beyond weird.
然后，舌头像皮筋一样弹回去，唾液再次变厚。接下来更加不可思议
Bounce
使…弹起; 弹起
例：My father would burst into the kitchen bouncing a tennis ball.
我父亲会拍打着网球闯进厨房。
bungee cord
弹力绳
Cord 线路，绳子
...electrical cord.
…电源接线。
"Frogs actually take their bulbous eyeballs and bring them down into their mouth cavity and use their eyeballs to shove the insect down the throat."
青蛙实际上要用他们的球状眼睛，然后将他们送入嘴里。然后用眼球将昆虫进入到喉咙里面
bulbous
圆滚滚的
例：his bulbous purple nose.
...他的紫红色酒糟鼻。
Shove
猛推
例：He shoved her out of the way.
他把她推开。
That force turns the saliva watery again, "and the insect slides down the gullet." The study is in the Journal of the Royal Society Interface.
这种力量会使得唾液稀释些，然后昆虫会从滑过食道。这项研究发表皇家社会联系期刊上
Turn
变得 (接形容词)
例：If the bailiff thinks that things could turn nasty he will enlist the help of the police.
如果司法官认为情况可能会变糟，他会寻求警方帮助。
gullet
食道
Interface
相互联系; 连接
例：...the way we interface with the environment.
…我们与环境相互联系的方式。
n. 耐心，忍耐，毅力
n. 单人玩的牌
