首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Scientists have taken a giant leap toward making possible the dream of building a powerful telescope on the moon that could with
Scientists have taken a giant leap toward making possible the dream of building a powerful telescope on the moon that could with
admin
2018-06-06
61
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.
When would the liquid-mirror telescope on the moon come out at the earliest?
选项
A、After 2020.
B、Before 2020.
C、After 2013.
D、Before 2013.
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/BnSO777K
本试题收录于:
NAETI中级口译笔试题库外语翻译证书(NAETI)分类
0
NAETI中级口译笔试
外语翻译证书(NAETI)
相关试题推荐
Thereisamythouttherethattoomanypeoplebelieve:thatwhenwereachacertainage,wecannolongerbehappy,independent
Thereisamythouttherethattoomanypeoplebelieve:thatwhenwereachacertainage,wecannolongerbehappy,independent
Thereisamythouttherethattoomanypeoplebelieve:thatwhenwereachacertainage,wecannolongerbehappy,independent
Conversely,aEuropeweakenanddividebytheworld’smostpowerfulcountrywouldexacerbateproblemsfarbeyondtheEU’sborder
Thewriterreceiveda________amountofpraiseforhisnewlypublishednovel.
Theprofessor’snewbookisagreatsellerandhasreceived________fromtheacademiccircles.
女士们、先生们:我非常高兴能利用英中贸协年会的机会向英国工商界朋友们致以诚挚的问候。多年来,英中贸协一直关心和支持中英关系发展,是堪称两国友好交流的桥梁和互利合作的纽带。在此,我谨对英中贸协及诸位长期为促进中英经贸合作所做的不懈努力和杰出贡献表示
台湾当局和少数国家宣称台湾因为未能加入WHO影响了防治SARS,这完全违背事实海峡两岸中国人民根连根、心连心。台湾发生SARS疫情后,中国中央政府十分关心,迅速采取了一系列加强两岸交流与合作的措施。//除通过医学专业机构向台湾同行传送有关SARS疫情、防
奥运会主中心区将设在奥林匹克公园内。北京奥林匹克公园位于北京城市中轴线的北端,占地1215公顷,其中有760公顷的森林公园,与北京市著名的中关村大学区、历史风景名胜区和大型住宅区相邻。奥运村、记者村、主新闻中心、国际广播电视中心及14座比赛场馆,中国体育博
A、One.B、Two.C、Three.D、Four.C注意分类提示的句子结构,如本题文.中使用了Therearemanykindsofnervecells提示听者注意神经细胞的分类;thischapterdealsmainly
随机试题
早期学者把心理契约界定为双方相互的期望的概念太过宽泛(含有某些不现实的内容);现在许多学者认为:心理契约不仅有期望的性质,还包括那些对责任和义务做出承诺的内容。期望不能实现,会产生失望感;契约未兑现会产生更强烈的消极情感反应与后续行为。因此,一般认为心理契
患者,男性,88岁,戴用全口义齿2周后复诊,自述义齿易松动。受限应做的检查是
落实施工成本管理的组织机构和人员,属于施工成本管理措施中的()。
按规定,记账时不能用下列书写工具书写( )。
考核交通、教育等支出时,应采用的方法是()。
甲公司将一套设备租赁给乙公司使用,租赁期间,经询问确认乙公司无购买意向后,甲公司将该设备卖给丙公司。根据《公司法》的规定,下列关于买卖合同与租赁合同效力的表述中,正确的是()。
甲是乙公司依法设立的分公司。下列表述中,符合公司法律制度规定的是()。(2010年单选题)
下列控制活动中,属于经营业绩评价方面的有()。
有关建构主义和认知主义的区别,表述正确的一项是()
Weweresurprisedatthe(achieve)______theyoungmanhadmadeinthelastthreeyears.
最新回复
(
0
)