时间:2019-01-08 作者:英语课 分类:Scientific American(八)月


英语课

 This is Scientific American’s 60-Second Science. I’m Sophie Bushwick. Got a Minute?


 
What's the best way to find out if an unknown mixture contains a specific substance, like an environmental contaminant? You could use an expensive, bulky gas chromatograph—but Harvard researchers have developed an instrument you can carry in your pocket. They describe the device, called an inverse 1 opal, in the Journal of the American Chemical Society. 
 
An inverse opal is a chip of layered glass that includes numerous tiny channels. This mini-labyrinth gets treated with chemicals to modify its inner surfaces. The resulting porous 2 chip then sucks up only liquids that have specific surface tensions. When such a liquid enters the network, it changes the chip's color over a set area. An inverse opal designed to determine if ethanol is laced with methanol could thus reveal the letter M if the poison is present.
 
With this so-called Watermark Ink writing, the chips could also serve as secret code devices. For example, swabbing a chip with water might make a decoy word like “hello” visible. While exposure to, say, benzene, could expose a secret message, such as “ditch your gas chromatograph.
 
Thanks for the minute. For Scientific American’s 60-Second Science. I’m Sophie Bushwick.

adj.相反的,倒转的,反转的;n.相反之物;v.倒转
  • Evil is the inverse of good.恶是善的反面。
  • When the direct approach failed he tried the inverse.当直接方法失败时,他尝试相反的做法。
adj.可渗透的,多孔的
  • He added sand to the soil to make it more porous.他往土里掺沙子以提高渗水性能。
  • The shell has to be slightly porous to enable oxygen to pass in.外壳不得不有些细小的孔以便能使氧气通过。
标签: sss 托福素材
学英语单词
aither
anisate
anoysance
biomonitors
biplumbic
bisarylated
blockade and embarge
brake moment
Burdiehouse limestone
calling trace
coacervation dyeing
come into existence
commercial access provider
compacted sub-soil base
course change index
crippling load
culmina
cytobiologist
decampments
decides upon
detokenization
deuteranoid
direct-contact heat exchanger
disinthrall
distichophyllum maibarae
diversifier
double strength glass
dursun
Dysecdysis
ellipse of concentration
empty nests
fays
fibrillated strand
flatcap
friendship benches
frigatebird
fur beetles
glenarden
goat-milk
granulation tumor
gun-cooling lines
Haller's rete
heliangine
high voltage source filter
horizontal tailplane
hydra (ydra )
hypercolour
Hövsgöl Aymag
in progression
indirect humidifier
keep their head above water
kid brother
lamb reverse
long draft spinning
midday prayer
middling particle
monometallic standard system
moulded steel
nulli-tetrasomics
oded
ovulariopsis ampelopsidis-heterophyllae
Panpipes
passenger ship subdivision
pemmicanized
photon drag photodetector
planktologist
platelet agglutination
record breaker
relative transmission level
rhytidocarpous
right hand plough
section dividing
self-reformings
sermocinators
ship auger
Small Holding Act
software network design
spinmeisters
stirred yoghurt with fruits
straight pedicellaria
straightly travelling s/r machine
supersampled
Synandon
synthetic inorganic pigment
the competition
thou mayest
three-way bulb
ultima ratio regum
universal potentiometer
vaporizing burner
vena ulnariss
video equipment
waiting period
wallaby bush
warangalone
warrenage
well-browed
wind resistance loss
worst-affected
wriht
Zehlendorf