搜题
网友您好,请在下方输入框内输入要搜索的题目:
搜题
题目内容 (请给出正确答案)
提问人:网友wf8900422 发布时间:2022-01-07
[主观题]

The word laser was coined as an acronym for Light Amplification by the Stimulated Emission

of Radiation. Ordinary light, from the Sun or a light bulb, is emitted spontaneously, when atoms or molecules get rid of excess energy by them-selves, without any outside intervention. Stimulated emission is different because it occurs when an atom or molecule holding onto excess energy has been stimulated to emit it as light.

Albert Einstein was the first to suggest the existence of stimulated emission in a paper published in 1917. However, for many years physicists thought that atoms and molecules always were much more likely to emit light spontaneously and that stimulated emission thus always would be much weaker. It was not until after the Second World War that physicists began trying to make stimulated emission dominate. They sought ways by which one atom or molecule could stimulate many others to emit light, amplifying it to much higher powers.

The first to succeed was Charles H. Townes, then at Columbia University in New York. Instead of working with light, however, he worked with microwaves, which have a much longer wavelength, and built a device he called a "maser," for Microwave Amplification by the Stimulated Emission of Radiation. Although he thought of the key idea in 1951, the first maser was not completed until a couple of years later. Before long, many other physicists were building masers and trying to discover how to produce stimulated mission at even shorter wavelengths.

The key concepts emerged about 1957. Townes and Arthur Schawlow, then at Bell Telephone Laboratories, wrote a long paper outlining the conditions needed to amplify stimulated emission of visible light waves. At about the same time, similar ideas crystallized in the mind of Gordon Gould, then a 37-year-old graduate student at Columbia, who wrote them down in a series of notebooks. Townes and Schawlow published their ideas in a scientific journal, Physical Review Letters, but Gould filed a patent application. Three decades later, people still argue about who deserves the credit for the concept of the laser.

Which of the following statements best describes a laser?

A.A device for stimulating atoms and molecules to emit light.

B.An atom in a high-energy state.

C.A technique for destroying atoms or molecules.

D.An instrument for measuring light waves.

简答题官方参考答案 (由简答题聘请的专业题库老师提供的解答)
查看官方参考答案
更多“The word laser was coined as an acronym for Light Amplification by the Stimulated Emission”相关的问题
第1题
The ductility of a material can be specified by the specimen's or the in area.
点击查看答案
第2题
The Neishi Department dealt with the verification of orders and policies.
点击查看答案
第3题
Traditional pedagogy tends to focus on one or two language skills and ignore the others .But in real language use we use all skills, including receptive skills and productive skills.
点击查看答案
第4题
Who is the father of Zeus?

A、Uranus

B、Hades

C、Poseidon

D、Cronus

点击查看答案
第5题
American writers after World War I self-consciously acknowledged that they were (a)”_______,” devoid of faith and alienated from the Western civilization.

A、Sons of Liberty

B、Beat Generation

C、Lost Generation

D、Angry Young Men

点击查看答案
第6题
The Ancient Olympic Games古代奥林匹克运动会

According to historical records,the first (1) Olympic Games can be traced back to 776 BC.They (2) dedicated to the Olympian gods and were staged on the (3) plains of Olympia.They continued for nearly 12 centuries, (4) Emperor Theodosius decreed in 393 A.D.that aU such"pagan cults" (5) banned.

The oldest myth which concerns the beginning of the (6) Games is that of Idaios Daktylos Herakles.According to other (7) ,Zeus,the father of humanity,fought and defeated Cronus in a (8) for the throne of the gods.Finally,the well-known (9) Herakles is mentioned who staged games in Olympia in honour (10) Zeus,because the latter had helped him conquer Elis when (11) went to war against Augeas.

Through the 12 centuries of (12) Olympic Games,many wonderful athletes competed in the stadium and (13) hippodrome of ancient Olympia's sacred area,moving the crowds with (14) great achievements.Although mortal,their Olympic victories immortalised them.Of (15) best athletes who left their mark on the sacred vallev (16) Olympia,some surpassed all limits and became legends by winning (17) successive Olympic Games and remaining at the forefront of their (18) for more than a decade.

The ancient Olympic Games were (19) a one.day event until 684 BC.when they were extended (20) three days.In the 5th century B.C.,the Games were extended again to cover five days.

(1)

点击查看答案
第7题
Donald Trump faced a new conservative challenger — a former CIA counter-terrorism officer who launched an independent presidential bid him.
点击查看答案
第8题
Management in Cyberspace

Virtual reality is often used to mimic hazardous environments—cockpits of combat aircraft, burning oil rigs, the treasure-strewn caves of irritable dragons and so on. Until now, though, it has rarely been deployed to simulate that most hazardous environment of all—the office. But if Sandra Testani of the Franklin Institute in Philadelphia has her way, it will soon be possible to hone the black arts of office politics and corporate survival on a computer before you employ them against your colleagues in the real world. Or, from the boss' s point of view, you will be able to practise your skills at "co-operating" in virtual "team-building" exercises.

Dr. Testani' s virtual world is called CIMBLE. The acronym stands for CADETT which in turn stands for Consortium for Advanced Education and Training Technologies Interactive Multi-user Business Learning Environment. The idea behind CIMBLE is to let people who are unable or unwilling to meet face to face practise collaborating with each other over a computer network.

To do this, CIMBLE' s software creates a virtual world for up to six participants. Each acts via an electronic representative known as an avatar. A participant sees the world (including the other players' avatars, which appear on screen as cartoon-like images of men and women) from his own avatar' s point of view. Any other characters that the avatars might interact with are played by a moderator, who also acts as Big Brother, overseeing and monitoring the activities of the group and steering things in a suitable direction.

The CIMBLE software allows the avatars to walk around and manipulate objects in the virtual world (opening doors, for example) at the click of a mouse. It also lets avatars (and hence the participants) talk to one another. Most conversations are assumed to be in the open, and can be heard by everybody. But true office Machiavellis will be pleased to learn that private chats are also possible, since the software can work out who is within earshot of whom, and will transmit sound only to those who should be able to hear it.

So far, Dr. Testani and her colleagues have devised two exercises in their new electronic world. One simply brings the participants together around a virtual conference table and lets them chew over an agenda provided by the moderator. The second, however, is more sophisticated. The participants are deemed to be working for a civil-engineering firm, and are sent off to the proposed site of a new bridge to settle a dispute with local residents and officials. After a long car ride and a night in a hotel (all depicted in loving detail by CIMBLE' s software) , they meet the irate local and try to mollify them. A successful outcome, allowing the bridge to go ahead, is greeted by an onscreen display of virtual fireworks. Summary:

Dr. Testani of Franklin Institute designed a software called CIMBLE which【71】CADETT Interactive Multi-user Business Learning Environment. This virtual world is used to mimic the office and has made it possible for【72】people to practise collaborating with others over a computer network.【73】is represented by an avatar, and their activities are monitored by a moderator. With this software, participants can talk to each other—as well as have【74】in the virtual world because the software will transmit sound only to people who should be able to hear it. Two exercises have been devised up till now. One allows the participants to think over an agenda, while the other requires them to【75】over the construction of a new bridge.

(31)

点击查看答案
第9题
5) Why does the author think India is definitely worth a visit except ?

A、A. For exotic achievements.

B、B. For its glorious ancient civilization.

C、C. For foreign animals.

D、D. For a different way of life.

点击查看答案
第10题
宙斯为希腊神话第三代谱系中最高的神,主宰一切天象,尤其是闪电。
点击查看答案
重要提示: 请勿将账号共享给其他人使用,违者账号将被封禁!
查看《购买须知》>>>
重置密码
账号:
旧密码:
新密码:
确认密码:
确认修改
购买搜题卡查看答案
购买前请仔细阅读《购买须知》
请选择支付方式
微信支付
支付宝支付
点击支付即表示你同意并接受《服务协议》《购买须知》
立即支付
搜题卡使用说明

1. 搜题次数扣减规则:

功能 扣减规则
基础费
(查看答案)
加收费
(AI功能)
文字搜题、查看答案 1/每题 0/每次
语音搜题、查看答案 1/每题 2/每次
单题拍照识别、查看答案 1/每题 2/每次
整页拍照识别、查看答案 1/每题 5/每次

备注:网站、APP、小程序均支持文字搜题、查看答案;语音搜题、单题拍照识别、整页拍照识别仅APP、小程序支持。

2. 使用语音搜索、拍照搜索等AI功能需安装APP(或打开微信小程序)。

3. 搜题卡过期将作废,不支持退款,请在有效期内使用完毕。

请使用微信扫码支付(元)

订单号:

遇到问题请联系在线客服

请不要关闭本页面,支付完成后请点击【支付完成】按钮
遇到问题请联系在线客服
恭喜您,购买搜题卡成功 系统为您生成的账号密码如下:
重要提示:请勿将账号共享给其他人使用,违者账号将被封禁。
发送账号到微信 保存账号查看答案
怕账号密码记不住?建议关注微信公众号绑定微信,开通微信扫码登录功能
警告:系统检测到您的账号存在安全风险

为了保护您的账号安全,请在“简答题”公众号进行验证,点击“官网服务”-“账号验证”后输入验证码“”完成验证,验证成功后方可继续查看答案!

- 微信扫码关注简答题 -
警告:系统检测到您的账号存在安全风险
抱歉,您的账号因涉嫌违反简答题购买须知被冻结。您可在“简答题”微信公众号中的“官网服务”-“账号解封申请”申请解封,或联系客服
- 微信扫码关注简答题 -
请用微信扫码测试
欢迎分享答案

为鼓励登录用户提交答案,简答题每个月将会抽取一批参与作答的用户给予奖励,具体奖励活动请关注官方微信公众号:简答题

简答题官方微信公众号

简答题
下载APP
关注公众号
TOP