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
74
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.
What is the main idea expressed in the passage?
选项
A、Ermanno Borra of Universite Laval as a leading role in the research.
B、The feats of Astronomers by using the liquid mirror telescope.
C、The silver layer used in the liquid mirror telescope.
D、The dream of building a liquid mirror telescope on the moon.
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/InSO777K
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
Marymusthavereceivedmymail;otherwiseshewouldhaverepliedbeforenow.
下面你将听到外国媒体就中国艾滋病问题的一段评论。HIV/AIDSisnowrecognizedclearlyasagrowingthreattoChina.AccordingtoofficialChineseesti
下面你将听到一段关于中国教育状况的介绍。中国人历来重视教育,实施“独生子女”政策后尤为如此。中国家庭的平均教育支出约占其收入的15%,而据中国社会调查所的一项研究成果显示,有43%的家庭都设立了专门账户,用来支付孩子的教育费用。近年来,
下面你将听到外商有关中国零售业发展情况的一段讲话。China’seconomy,oncereliantonstatespendinginheavyindustry,hasincreasinglylookedtothe
女士们,先生们,上午好!中国和马来西亚是友好近邻,两国传统友谊源远流长。中国明朝郑和七下西洋,五次到达马六甲,同当地人民友好交往和互利通商,至今传为佳话。中马建交33年来,两国经贸合作持续快速发展。中国海关统计,2006年两国贸易额达371亿
旅游是一项集观光、娱乐、健身为一体的愉快而美好的活动。旅游业随着时代进步而不断进步。从20世纪中期起,现代旅游业在全世界迅速发展。游客人数不断增长,旅游业规模持续扩大,旅游经济地位显著提升,旅游活动愈益成为各国人民交流文化、增进友谊、扩大交往的重
海洋是全球生命支持系统的一个不可缺少的组成部分。海洋不仅是自然资源的宝库,同时也是我们人类居住环境的重要调节器。中国政府高度重视海洋的开发和保护,不断加强海洋综合管理,促进海洋产业的协调发展。中国已经形成了具有区域特征的多学科的海洋科学体系。国家
信息通讯技术进步带来无限机遇,推动商务和生产走向高增值,并改善了香港公民的生活质量。同时,这一进步也在多方面带来了新挑战,例如信息安全、数码环境中知识产权及私稳保护、媒体交汇趋势下的适当监管模式方面。领先的数码经济体系需抓住机遇,接受挑战,才能稳居世界前列
为了成为国际一流的商业银行,今后国有商业银行必须围绕以下两个重点加快综合改革:一是进行产权制度改革,通过建立多元化股权结构,实现所有权与经营权的分离,建立起法人治理结构和现代银行制度。二是推进银行内部机制改革,强化内部管理,建立创新和激励机制,提高核心竞争
感谢校长先生的盛情邀请和贵校的热情接待,能前来参加贵校宏大的百年校庆,是我的荣幸。我谨代表来自各国诸大学所有的客人,也以我个人的名义,向校长先生、全体教员和同学表达我们最为热烈的祝贺,祝愿贵校“苟日新、又日新、日日新!”在11世纪,由于人类文明的
随机试题
乳糖操纵子的基因表达调节属于
妊娠性瘙痒症有如下特征,除外的是
患者,男,68岁。饱餐后出现脐周阵发性腹痛,伴呕吐、腹胀,肛门停止排便排气2天。查体:腹软,脐周有轻度压痛,无反跳痛,肠鸣音亢进,有气过水声。患者2年前曾因化脓性阑尾炎行阑尾切除术,半年来间断性腹部隐痛不适。目前对该患者最重要的处理措施是
马,枣红色,4岁,营养中等。就诊当天早晨突然发病,症见蹇唇似笑,不时前蹄刨地,回头观腹,起卧打滚,间歇性肠音增强,如同雷鸣,有时排出稀软甚至水样粪便,耳鼻四肢不温,口色青白,口津滑利,脉象沉迟。该病可首选针刺
A.金黄色葡萄球菌B.痢疾杆菌C.草绿色链球菌D.Coxsachie(柯萨奇)病毒E.产气杆菌引起急性细菌性心内膜炎
除法律另有规定外,下列财产中,不得用于抵押的有()。
市场机制本身存在缺陷,所以不能单纯依靠市场机制,但下列各项中,()不属于市场机制的缺陷。
有人把学业失败的原因说成努力不够,这种归因属于()
下列选项中,体现物权特征的是()。
•Youwillhearadiscussion.•Foreachquestion23-30markoneletter(A,BorC)forthecorrectanswer.•Afteryouhaveli
最新回复
(
0
)