时间:2019-01-08 作者:英语课 分类:Scientific American(十)月


英语课

 This is Scientific American-60 Second Science. I am Christopher Intagliata. Gotta a minute?


 
Hair helps keep you warm, right? But hair can also keep you cooler than bare skin, as long as the hair is not too thick. So says a study in a journal-Plus One.
 
Reseachers studied elephants which have very thin coats of hair. It's easy for the beasts overheat, they may face temperatures up to 120 degrees Fahrenheit 1, and they don't have much skin surface area to radiate the heat relative to their big body volume. That's where the hair comes in. The reseachers wrote equations modelling the elephants hairy skin. As is expected, the thick hair traps air and keeps the body warm. But below a certain density 2, hair stops insulating, and wakes heat off the body instead, helping 3 the elephants get rid of an extra 20% of their body heat, especially on windless days. Heat sinks inside computers work in a similar way, with pin sticking up to help dissipate the interior heat. The researchers speculate that hair may actually evolve to help animals stay cool, because the first sprouded mammals over a 100 million years ago in a hot climate. Hair raising time indeed.

n./adj.华氏温度;华氏温度计(的)
  • He was asked for the boiling point of water in Fahrenheit.他被问到水的沸点是华氏多少度。
  • The thermometer reads 80 degrees Fahrenheit.寒暑表指出华氏80度。
n.密集,密度,浓度
  • The population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。
  • The region has a very high population density.该地区的人口密度很高。
n.食物的一份&adj.帮助人的,辅助的
  • The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
  • By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。
学英语单词
acridiommatin
al qusayr (el quseir)
anticorrosive treatment
aspartate carbamayl transferase
background ink
batch recycle cultivation
black-and-yellow
blow around
bow before
cheesing
concurrent selection
conditional assemble function
cr(conditional reflex)
depressurization phase
deshelving
devilished
dianthus barbatuss
effective gap
end of month
endothelium-derived relaxing factor (edrf)
exposure to radiation
family ephippidaes
fiber-reinforced metal
field ionization
fragment peak
function-prototype scope
giant stars
golovnins
gynae(co)-
Harrison County
heatedness
heishuiensis
helixform
Hindon
homaiss
homoetic mutation
hours underway
hove to condition
husbander
inflammatory tissus
intensive amount
Iregua, R.
judgments of dismissal
Kafrun
landshard
leprosipes
line by line
lounderings
mass analyzed ion kinetic energy spectrometry
megophthalmos
midget fuse
motor wind
multi-culturalism
multi-function automatic fire alarm
Murshidia
Nobel Foundation
non-resonances
nonannealable
nosebleeds
numberof
Orlando di Lasso
parity index
paternal love
period of diastrophism
plasmo-
Pohnpeian
Poigar
polymer injection pump
qualified supplier list
rail of self-hardening steel
ratio of grade
re-combinations
reel speed control lever
sand disintegrator
saplier
second-class radiooelectronic certificate
semi governmental
shafting alignment by wiring
sickinger
siquis
Slogin
sludge measure
somatic variation
spacecraft maneuver
split-types
system error
table sugar
tandem trunking
tierer
top mark
Torres Trench
trail run
transit-time microwave diode
ultraviolet light source
unsymmetric
uticas
variable import levies
water preserving capability
Wicklow, Co.
wireless modem
word-recognition
xanthenic