时间:2018-12-24 作者:英语课 分类:Scientific American(四)月


英语课

As it ages, white paper turns distinctive 1 of yellow, but why? To find out, scientists artificially aged 2 modern paper to rebuild the changes on the molecular 3 level, the researchers in the Journal physical review of letters, for 48 days, 3 unpleached paper samples aged rapidly on reactors 4 that's simulated in different environmental conditions, the researchers then compared the artificially aged samples to the real deal, 3 pieces of paper crafted in 15 century Europe, this technique allowed them to gauge 5 the types and the months of changes going on, about 90% of the weight of old paper is cellulose, the sturdy material that makes plants so walls, but over time cellulose fibers 6 oxidase, the process modifies parts of burriest molecules 7 and turns them into what we call chromophores which absorb light, white paper is white because it reflect all colors of lights, aging paper filled with chromophores reflects wavelength 8 that makes it look yellow, the non-destructive technique used in the study couldn't inform research to preserve and even widen in ancient * art and give paper conservation a brighter outlook. 



1 distinctive
adj.特别的,有特色的,与众不同的
  • She has a very distinctive way of walking.她走路的样子与别人很不相同。
  • This bird has several distinctive features.这个鸟具有几种突出的特征。
2 aged
adj.年老的,陈年的
  • He had put on weight and aged a little.他胖了,也老点了。
  • He is aged,but his memory is still good.他已年老,然而记忆力还好。
3 molecular
adj.分子的;克分子的
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时,分子的碰撞就停止了。
4 reactors
起反应的人( reactor的名词复数 ); 反应装置; 原子炉; 核反应堆
  • The TMI nuclear facility has two reactors. 三哩岛核设施有两个反应堆。 来自英汉非文学 - 环境法 - 环境法
  • The earliest production reactors necessarily used normal uranium as fuel. 最早为生产用的反应堆,必须使用普通铀作为燃料。
5 gauge
v.精确计量;估计;n.标准度量;计量器
  • Can you gauge what her reaction is likely to be?你能揣测她的反应可能是什么吗?
  • It's difficult to gauge one's character.要判断一个人的品格是很困难的。
6 fibers
光纤( fiber的名词复数 ); (织物的)质地; 纤维,纤维物质
  • Thesolution of collagen-PVA was wet spined with the sodium sulfate as coagulant and collagen-PVA composite fibers were prepared. 在此基础上,以硫酸钠为凝固剂,对胶原-PVA共混溶液进行湿法纺丝,制备了胶原-PVA复合纤维。
  • Sympathetic fibers are distributed to all regions of the heart. 交感神经纤维分布于心脏的所有部分。
7 molecules
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。
8 wavelength
n.波长
  • The authorities were unable to jam this wavelength.当局无法干扰这一波长。
  • Radio One has broadcast on this wavelength for years.广播1台已经用这个波长广播多年了。
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学英语单词
- head
Aroania
attrition loss of catalyst
beam-lead bonder
benefit trust
bewing
bhatts
blast-furnace tar
bleach solution
borrowing powers
central layer
chlorine treatment
chloro-fluorocarbon
cladosporin
clip on
clonaid
coctoantigen
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common interosseous artery
condensation of nonsugar precipitates
conter of gravity
coppins
craniocerebral operations
cska
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discrete circular uniform distribution
dixies
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earthquaky
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Elachanthemum
ensign staff
ethocel
ethyl liquor
expected effect
facekini
female end of pipe
field (testing)system
flop gate
fourling
hair cycle
half-rip saw
Hemicolon
housekeeping routine
hypersyn motor
intermontane basin
intervascular tissue
Isaiah, Ascension of
Janus-headed
jenswold
Jodobromite
lake fly
larimichthys polyactis
linguicide
lymphocyte-defined(LD)a's
machina
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malt vinegar
maskey
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Muanza
multiple jib machine
multiplier gain
mybotoes
nerks
nonexcitation state
offset shooting
photoengraving method
pnpndiode
postal packet
power factor clause
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print zone
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Prochowice
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rear axle nut washer
recharted
rotary oscillation
ruling engine diffraction grating
running direction
RVOTP
secondary metabolism
Sel'd
severe calcification of valve
single-motion turbine
sisel
sliding blade compressor
static coherence check
steel man
stretto by diminution
striate area
tap drill
tarsal glands (or meibomina glands)
top slice
transmitting zone
unsensitivity
Uyere
varieties of
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Whittle, Sir Frank
workingman