时间:2019-01-20 作者:英语课 分类:2017年Scientific American(三)月


英语课

 


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 1?"


也许你认为青蛙能捕食昆虫是由于舌头很粘的缘故。但是为什么它们的舌头是粘的,同时舌头是如何在昆虫快速移动的时候黏住它们的呢?


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 2 lab, and tested their consistency 3. Ten times softer than human tongues. A texture 4 more like brain tissue. "Their tongue is very much like a sponge. It's infused with this thick, viscous 5 saliva 6."


亚历克西斯·诺埃尔,是佐治亚理工大学的机械工程专业博士研究生。他想要回答上述问题。所以和研究团队从解剖实验室获取了一些青蛙的舌头,并且检测了这些舌头的的粘度。青蛙舌头的柔软性是人类舌头的十倍之多。纹理更像大脑组织。“青蛙的舌头就像一块海绵。充满了粘稠的唾液。”


That saliva was their next study subject. "And in order to test the saliva we had to get about a fifth of a teaspoon 7 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 8. And they found that frog saliva is what's called a 'shear 9-thinning fluid'—its viscosity changes, depending on conditions.


青蛙的唾液是他们下一个研究的课题。“并且为了检测这些唾液,我们收集了五分之一茶匙的青蛙唾液。对一只青蛙而言,这些唾液的量很大了。之后,他们将这些唾液放入了一个流变计,这是一种可以检测粘稠度的工具。结果研究人员发现,青蛙的唾液是一种“剪切稀化的液体”——也就是说其粘度取决于外部环境。


You might be more familiar with a different shear-thinning fluid. "Ketchup 10. When you smack 11 the bottom of the ketchup bottle you're actually invoking 12 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."


也许你对另一种剪切稀化的液体更为熟悉。番茄酱。当你拍打番茄酱瓶底部时,实际上是在激发番茄酱内的剪切力。由于番茄酱剪切力很弱,它的粘度就会降低,然后就很容易从瓶子上滑下来。


So back to our frogs: the tongue shoots out, hits the bug 13 and deforms 14 around it. That impact is like a smack on a ketchup bottle—it changes the saliva from thick and sticky to more watery 15, 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 16.


现在回到我们的青蛙的问题上:舌头突然伸出来,碰到虫子,绕着虫子变形。这种影响就像是你轻拍番茄酱瓶底——它使唾液从高粘稠度转变为像水一样稀,轻易自由的流过虫子的全身。然后舌头像一个弹簧绳一样被拉回,然后唾液再次变得粘。接下来也就不奇怪了。


"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 17.


青蛙将眼球压入口腔,将昆虫从舌头上压入腹中。”这种眼球产生的挤压力让舌头上的唾液再次液化,使昆虫与舌头分离,然后昆虫就顺流滑入食管。该研究已经发表在《皇家学会界面》杂志上。


With the case closed on this one, Noel's next inquiries 18 are on grippy fingertips. The dust-collecting properties of earwax. And—wait for it—cat tongues. "Yeah, I get paid to watch cat videos all day."


这个课题就此结束,诺埃尔博士下面的研究内容是粗糙指尖。耳垢的集尘特性。还有,等等,猫舌头。是的,有人给我钱,让我整天看猫咪的视频。



n.加速( acceleration的名词复数 );加速度;(车辆)加速能力;(优秀学生的)跳级
  • The two particles will undergo accelerations as a result of their interaction. 这两个粒子由于相互作用将获得加速度。 来自辞典例句
  • Since the cord connecting the two blocks is inextensible, the accelerations are the same. 由于连接两物块的绳子无伸缩性,因此它们的加速度相同。 来自辞典例句
n.分析;解剖
  • A dissection of your argument shows several inconsistencies.对你论点作仔细分析后发现一些前后矛盾之处。
  • Researchers need a growing supply of corpses for dissection.研究人员需要更多的供解剖用的尸体。
n.一贯性,前后一致,稳定性;(液体的)浓度
  • Your behaviour lacks consistency.你的行为缺乏一贯性。
  • We appreciate the consistency and stability in China and in Chinese politics.我们赞赏中国及其政策的连续性和稳定性。
n.(织物)质地;(材料)构造;结构;肌理
  • We could feel the smooth texture of silk.我们能感觉出丝绸的光滑质地。
  • Her skin has a fine texture.她的皮肤细腻。
adj.粘滞的,粘性的
  • Gases are much less viscous than liquids.气体的粘滞性大大小于液体。
  • The mud is too viscous.You must have all the agitators run.泥浆太稠,你们得让所有的搅拌机都开着。
n.唾液,口水
  • He wiped a dribble of saliva from his chin.他擦掉了下巴上的几滴口水。
  • Saliva dribbled from the baby's mouth.唾液从婴儿的嘴里流了出来。
n.茶匙
  • Add one teaspoon of sugar.加一小茶匙糖。
  • I need a teaspoon to stir my tea.我需要一把茶匙搅一搅茶。
n.粘度,粘性
  • The viscosity shows a rather pronounced variation with temperature.温度对粘度的影响十分明显。
  • The reciprocal of viscosity is known as fluidity.粘度的反意就是流动性。
n.修剪,剪下的东西,羊的一岁;vt.剪掉,割,剥夺;vi.修剪,切割,剥夺,穿越
  • Every spring they shear off the sheep's wool and sell it.每年春天他们都要剪下羊毛去卖。
  • In the Hebrides they shear their sheep later than anywhere else.在赫伯里兹,剪羊毛的时间比其他任何地方都要晚。
n.蕃茄酱,蕃茄沙司
  • There's a spot of ketchup on the tablecloth.桌布上有一点番茄酱的渍斑。
  • Could I have some ketchup and napkins,please?请给我一些番茄酱和纸手巾?
vt.拍,打,掴;咂嘴;vi.含有…意味;n.拍
  • She gave him a smack on the face.她打了他一个嘴巴。
  • I gave the fly a smack with the magazine.我用杂志拍了一下苍蝇。
v.援引( invoke的现在分词 );行使(权利等);祈求救助;恳求
  • You can customise the behavior of the Asynchronous Server and hence re-brand it by defining your own command set for invoking services. 通过定义自己调用服务的命令集,您可以定制自定义异步服务器的行为,通过为调用服务定义自己的命令集从而对它重新标记。 来自《简明英汉词典》
  • You can customize the behavior of the Asynchronous Server and hence re-brand it by defining your own command set for invoking services. 通过定义自己调用服务的命令集,您可以定制自定义异步服务器的行为,通过为调用服务定义自己的命令集从而对它重新标记。 来自辞典例句
n.虫子;故障;窃听器;vt.纠缠;装窃听器
  • There is a bug in the system.系统出了故障。
  • The bird caught a bug on the fly.那鸟在飞行中捉住了一只昆虫。
使变形,使残废,丑化( deform的第三人称单数 )
  • Bad rheumatoid arthritis deforms limbs. 严重的类风湿性关节炎会造成四肢变形。
  • The specimen deforms under a tensile stress applied parallel to the fibres. 试样在平行于纤维的张应力作用下发生变形。
adj.有水的,水汪汪的;湿的,湿润的
  • In his watery eyes there is an expression of distrust.他那含泪的眼睛流露出惊惶失措的神情。
  • Her eyes became watery because of the smoke.因为烟熏,她的双眼变得泪汪汪的。
adj.古怪的,离奇的;怪诞的,神秘而可怕的
  • From his weird behaviour,he seems a bit of an oddity.从他不寻常的行为看来,他好像有点怪。
  • His weird clothes really gas me.他的怪衣裳简直笑死人。
n.接合部位,分界面;v.(使)互相联系
  • My computer has a network interface,which allows me to get to other computers.我的计算机有网络接口可以与其它计算机连在一起。
  • This program has perspicuous interface and extensive application. 该程序界面明了,适用范围广。
n.调查( inquiry的名词复数 );疑问;探究;打听
  • He was released on bail pending further inquiries. 他获得保释,等候进一步调查。
  • I have failed to reach them by postal inquiries. 我未能通过邮政查询与他们取得联系。 来自《现代汉英综合大词典》
学英语单词
a. perinealis
accrued charge
acoustic magnetic mine
adlecting
administration of internal affairs
Aflogualnum
ai chi
alternative procedure
ampholite
art and part
artificial caving
assidue
base of petroleum
black cottonwood
blue-green bacterium
bursting speed
cascading down
centricdiatom
cloud-bases
complementary scale
consistorial
conventional-arms
counter-cast
Crista sacralis intermedia
Cynwyl Elfed
Daphne holosericea
departmental arrangement and distribution in commodity stock
Direct Copper Blue 2R
disinflations
drip channel
event oriented simulation
eye-serve
factorization method
facular
Fentathienil
flower
geomagnetic periodic variation
go yachting.
group demodulator filter
harpending
hepatitis sequestrans
information management program
initial overburden pressure
insulation varnish
intrapore
inverse beta process
journal box lid hinge
lanatest
light pressure separator
Lothair
megalodiscs
merry-go-round
monoethanolamine(surfactant)
moving current-weighted Passche indexes
neutralizing water tank
new staff
Nihon-maru
non-specified-time relay
nuclear quadrupole spectrum
oil pressure switch
one-cancels-the-other order
orbit maneuver engine
output transfer function
Pare's suture
plain shank
plant hole
poikilosmotic character
preregeneration
progressive wave
pushback
put somebody up to
RCITR
reducing capacity
reductive alkylation
regional index call warrant
RFRNA
Rhodiola wallichiana
Richardson's ground squirrel
rosette phyllotaxy
semi-tractor
sexlessnesses
sgd.
shell tuck
sickling diathesis
simple deterministic language
spaces out
spantik
spread back
sugarcane top
system of gravitational unit
tea-tree
telephone bills
tiled mode
use test
vendibler
vertical decomposition
voltage and frequency response
wear plate
Y ligament
Yang Shiying
zori