时间:2019-01-30 作者:英语课 分类:健康与环境


英语课

ENVIRONMENT REPORT - September 6, 2002: Geckos and Their Sticky Feet


By Cynthia Kirk



This is the VOA Special English ENVIRONMENT REPORT.


Geckos are small lizards 1 that live in warm climates. These lizards can stick to any surface.
For example, geckos can climb up walls and across the top of a room. Scientists have studied
the little lizards for hundreds of years to learn the secret of how they stick to things. Now,
they say they have finally solved the mystery. They hope the finding will help them develop
powerful materials that hold things together.


A team of American biologists and engineers carried out the study. Their findings were
published in the Proceedings 2 of the National Academy of Sciences.


Geckos have millions of very small hairs on their toes. The end
of each hair splits into as many as one-thousand smaller hairs. So the gecko’s foot
has hundreds of millions of tiny hairs that touch a surface.


Scientists have debated the purpose of these hairs. Some thought the hairs dug into a
surface. Others thought geckos released a natural sticky substance onto their hairy
toes to hold onto a surface, like a leaf, and prevent enemies from pulling them loose.


Over the years, scientists have put geckos into water to see if they would stick. They


do. They have dropped them into strong devices, but their sticking ability was not
weakened. Scientists also have used radiation to neutralize 3 static electricity. They thought electrostatic force
helped the animals hold on to a surface.


Scientists say the gecko’s sticking power comes from something called the van der Waals force. The term was
named after the Dutch scientist who first described it more than one-hundred years ago. The force is the attraction
between molecules 4 at the ends of the gecko’s toe hairs and the surface of an object. When molecules are so
close together, the unbalanced electrical charges around the molecules can attract one another. This provides the
attraction between the foot of the gecko and a wall or other object.


The scientists showed that a single gecko toe hair has enough holding power to lift an insect. They say a small
group of hairs the size of a coin could possibly lift a small child.


Scientists say they have created the first sticky substance based on the geckos’ hairs. They hope to use the
powerful substance to develop new products. The scientists recently joined with a company to develop robots that
can climb walls.


This VOA Special English ENVIRONMENT REPORT was written by Cynthia Kirk.



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n.蜥蜴( lizard的名词复数 )
  • Nothing lives in Pompeii except crickets and beetles and lizards. 在庞培城里除了蟋蟀、甲壳虫和蜥蜴外,没有别的生物。 来自辞典例句
  • Can lizards reproduce their tails? 蜥蜴的尾巴断了以后能再生吗? 来自辞典例句
n.进程,过程,议程;诉讼(程序);公报
  • He was released on bail pending committal proceedings. 他交保获释正在候审。
  • to initiate legal proceedings against sb 对某人提起诉讼
v.使失效、抵消,使中和
  • Nothing could neutralize its good effects.没有什么能抵消它所产生的好影响。
  • Acids neutralize alkalis and vice versa.酸能使碱中和碱,亦能使酸中和。
分子( molecule的名词复数 )
  • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
  • Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里,大分子裂变为小分子。
标签: Geckos Sticky Feet
学英语单词
5'-iodouridine
abnormal shrinkage
adrianne
Aigrettes, Pointe des
amphimutation
Aspie
at one's ease
beet combine
bell-pulls
Blaye-les-Mines
bruit
camp-beds
cardinal variable
circumpolar distribution
coal heaver
cold-off shank
covert entry
Crayette
crescent-type arch bridge
cross head pin
curved line
cystectomies
do sb harm
dosse
epinikion
external data record
false drumlin
false widows
feasible schedule
feeder sleeve
film makings
finger joint
foamable composition
fodder grinder
forgeard
Freedomite
g protein-coupled receptor
garcon (france)
generalized Kelvin body
gracila albomarginata
Gross Grönau
hard point defence system
hemiparaplesia
high-thermal conductivity
his' band
homeovestism
hydrostatic lubri cation
ichthyopterin
inactive storage
kanavis
kokum
latsts
Le Kef, Gouvernorat
megachips per second
metainstruction
metastrongylus salmi
mixed-cooling compressor
moderately structured problem
Monosan
motor analyser
multiple bus control processor
myasthenic facies
non-magnetic ring
oil-immersed switching device
old-fashioned
onomatopoesis
oxamoyl
parrot's-feather
pearlite malleable cast iron
Penllyn
pilot scale test
populneas
Proganosauria
pulmoniferous
raise a big fanfare
ravestre
re-wash
red lamp
regulator
replacement of track materials
Riemann function
rumpelkammer
share placement
simarouba glaucas
splitless sampling
stages of moral development
stringent specification
system pattern
theologics
time per loading
transantarctic
Tuner card
two-way track
uded
unconditional jump
vacatable
wanderest
warm water tongue
waste packaging
water-proof packing
wiren
Yeysk