首页
登录
职称英语
Scientists have taken a giant leap toward making possible the dream of buildi
Scientists have taken a giant leap toward making possible the dream of buildi
游客
2023-12-22
62
管理
问题
Scientists have taken a giant leap toward making possible the dream of building a powerful telescope on the moon that could withstand even the harshest of lunar conditions.
Writing in Thursday’s edition of the journal Nature, they said they coated a special type of liquid surface with a layer of silver to make a highly reflective mirror like one that could be used in any future, moon-based telescope.
"It’s the breakthrough that we need," lead researcher Ermanno Borra of Universite Laval in Quebec, Canada, said in a telephone interview. "If you want to have a liquid mirror telescope on the moon, you need the right liquid. If you don’t have the right liquid, forget it. It’s as simple as that." Borra envisions a telescope with a liquid mirror measuring 66 feet to 328 feet wide.
Such a telescope, which has drawn NASA’s interest, could provide astronomers on Earth unprecedented views into distant reaches of the universe, studying objects far more faint even than NASA’s planned James Webb Space Telescope, due for a 2013 launch. Astronomers hope such an instrument could allow them to study the early phases of the universe after the Big Bang.
Advocates say a large telescope on the moon would be more cheaply and easily built using a liquid mirror rather than a conventional glass one. The researchers think any liquid-mirror telescope on the moon would not come before 2020 at the earliest.
The scientists made use of a liquid made of "ionic salts" that remains fluid at super-low temperatures. They deposited a thin layer of chromium particles on the liquid, then added a layer of silver particles to complete the mirror.
Liquid mirror telescopes differ from conventional ones in that their primary mirrors, which gather and focus light, are made of reflective liquid instead of polished glass. The liquid can be poured into a spinning container, spreading out to make a thin, smooth, parabolic shape that can be used as a telescope mirror, the researchers said.
The silver layer that is created is completely smooth, highly reflective, can stay stable for months, and the ionic liquid that it covers does not evaporate, the researchers said. [br] The word "envisions"(Para. 3)is closest in meaning to______.
选项
A、completes
B、prefers
C、conceives
D、views
答案
C
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3296178.html
相关试题推荐
Theprotestersopposebuildingahigh-riseintheirneighborhood,statingthati
Everystreetinthatneighborhoodhasadifferent______ofbuildingboastingaco
Manyfarmershavetakenadvantageofrainwhenitisgoingtocome,bymakingha
"You’llsortitout,"heassuredhercallouslyastheyenteredthebuilding,and
Healthsystemsstrengthening—which,inglobalhealthspeak,meansbuildingand
Itwouldbewrongto______someoneforerroneousremarksbecauseitisimpossible
Asweknow,beforescientistscomeupwithaneffectivetreatment,cancerissti
Constructionofthegiganticofficebuildinginthiscitywasforyearsintermit
Constructionofthegiganticofficebuildinginthiscitywasforyearsintermit
Scientistsaremakinghugestridesinbattlingoneofthetopthreekillerdisea
随机试题
WhatWorkEnvironmentsDo?Workenvironmentsarethanasv
[originaltext]M:Whatdoyouthinkofthegovernment’snewtaxcutproposal?W:T
SHOPPINGforsaladinsupermarketsistooeasy.Abagofready-washedvegeta
Agoodtitleforthisselectionis______.[br]Theauthorreallytriestomake
建城2500多年来,南京一直是中国多元文化交融的中心城市之一。中国历史上先后有六个朝代定都南京。让这座城市成为悠久的中国历史精彩的浓缩(concent
(2018年)转让新建房计算土地增值税时,可以作为与转让房地产有关的税金扣除的是
行政处罚的适用应遵循的原则有( )。A.行政处罚的设定和实施公正、公开 B.
A.两重性 B.质量的重要性 C.专属性 D.时效性 E.多样性符合法定
数字万用表清洁时只能使用()A.湿布 B.化学溶剂 C.大量洗涤剂
胆固醇体内代谢的主要去路是在肝中转化为A.乙酰CoA B.NADPH C.维
最新回复
(
0
)