辐射与儿童恶性肿瘤之间的联系◊ a radiation 〖eafc/rom a nuclear power station    〇 radiation sick-

ness 放•病◊ the radiations emitted by radium 镭释放出 的放—$ 2 [U] heat, energy, etc. that is sent out in the form of rays 辐射g热（或能量等）：uitmvioiet radi­ation 紫夕卜线辐射 ◊ eZectromagneric radiation 介om power Zines 电线的电磁辐射 3 (also .radi'ation therapy)丨U] the treatment of cancer and other diseases using radiation 放射疗法一compare chemotherapy, radiotherapy ra-di-ator /'reidieit8(r)/ noun 1 a hollow metal device for heating rooms. Radiators are usually connected by pipes through which hot water is sent.散热器；暖 气片：a central heating system with a radiator in each room每个房间都配有一个散热器的中央供暖系统2 a device for cooling the engine of a vehicle or an aircraft (f辆或飞机发动机的）冷却器，水箱 rad-ical /'raedikl/ adj., noun

■                  [usually before noun] 1 concerning the most basic and .important parts of sth; thorough and complete 根 本的；彻底的；完全的 far-reaching• the need /or radical changes in education对教育进行彻底变革的 需要◊ demands/or radica丨 re/orm o/t/ie iaw 彻底改变法 _的要求◊ racficaZ dij〇ferences between the sexes 两性间 沾根本—异 2 new, different and likely to have a great effect全‘的；不同凡响的：radicai ideas不同凡响的观 点◊ a radfcaZ solution to the proWem 解决问题的全新的 女法◊ radical proposals 有创见的建议 3 in favour of thorough and complete political, or social change 激进 的；极端的：the racficaZ wing 〇/ t/ie party党内的激缶派 ◊ radicaZ pohricians/students/writers 激金的政治家/ 学 生 / 作家 4 (o/d-fash/oned, NAmE, skmg) very good 很好； 非常好► rad.ic.al.ly /-kli/ flt/v.: The new methods are mdicaHy dijjerent亓om the oid.新的方法迥然不同于旧的 方法。◊ Attitudes have changed mdfcaHy.态度发生了根 本的变化。

■                  nown 1 a person with radical opinions 激进分子：polit- icaZ radicak 政治激进分子 2 (d?e/??/5fAy 化）a group of atoms that behave as a single unit in a number of compounds 游离基；自.由基一see also free radical

radical 'chic /iow/7 [U] fashionable left-wing views; the people, behaviour and way of life connected with these views时髦的左派观点；时髦左派（或行为、生活 方式)♦

rad-ic-al-ism /'raedikalizam/ noun [U] belief in radical ideas and principles 激进主乂 racMc-al-ize (BrE also -ise) /'raediklaiz/ verb [VN] to make people more willing to consider new and different policies, ideas, etc.; to make people more radical in their political opinions 使人趋手标新立异地 考虑（政策或观点等）；無激进：events have radicaZized opinion on educarionaZ matters.最近发生.的 事人们I对教育的看法有了全新的改变。 rad-icchio /rae'diikiau; NAmE -kiou/ noun [U] a type of chicory (= a leaf vegetable) with dark red leaves 紫叶 菊苣

radii pi. of radius

radio /'reidiau; NAmE-ou/ noun, verb • noun 1 (often the radio) [u, sing.] the activity of broad­casting programmes for people to listen to; the programmes that are broadcast 无线电广播；无_ 电广 播节目：The mtervfevv was broadcast on radio and teZe- vision.广播和电视都报道了这次会见。◊ The was written speciaHy /or radio•这出戏是专为无线电广fi而写 的。◊ Histen to the radio on the way fo worfc.我在上 班的路上听广播。◊ Did you hear the interview vvft/i Wm cm the radio?你有没有在广播里听到采访他的情况？ ◊ Zocal/narional radio地方/国家无线屯广播◊ a radio programme/station 广播节.目 /电_台 2 [C] a piece of equipment used for listening to programmes that are broadcast to the public 收音机：to turn the radio on/ 〇J9T打开/关上收音机◊ a car radio汽车收音机◊ a radi‘0 cassette piayer 盒式收音放音机 一 see also clock radio 3 [U] the process of sending and receiving messages through the air using electromagnetic waves 无线 电传送；无线电通信：He was unabie to contact byradio.他未能通过无线电和布莱克取得联系。Ofo keep in radio contact 保持无线电联系◊ radio signals/ waves"无线电信号 / 电玻 4 [C] a piece of equipment，for

1631 radio wave

example on ships or planes, for sending and receiving radio signals 无线电收发报机：to /zear a gaZe warning o；l/〇ver the ship’s radio在船上的无线电收发报机中接到 大风警报

■ verb (ra dio ing, ra-dioed, ra dioed) to send a message to sb by radio (用无线电）发送，传送：[V] TTie poZice ojQfker radioed /or he〖jp.警察用无线电呼救。◊ [VN] rhe vvarning was radioed to headquarters.通过无线电向总部 发出了 警报。[also V that, VN that, VN to inf] radio- /'reidieu; NAmE -ou/ combining form (in nouns, adjectives and adverbs构成名词、私容词和副词j

■                  connected with radio waves or broadcasting 无线电 波的；无线电广播的：radio-controHed无线今遥控的

■                  connected with radioactivity 放射的；辐射的： radiotherapy

radioactive /.reidiau'aektiv; NAmE -ou'aek-/ adj. sending out harmful radiation caused when the nuclei (= central parts) of atoms are broken up 放射性 的； '有*射的►radio-activ-ity /ireidiwaek'tivati; AMmf -ouaek-/ noun [U] ： the study 〇/ radioactivity 放射性研究 ◊ a rise fn the Zevd o/radfoactiv办辖射强度的增加 .radio a'stronomy noun [U] the part of astronomy that studies radio waves sent out by objects in space 射,天文学

'radio button noun (computing if) a small circle that you click on in order to make a particular choice. The radio button is then marked with a dot to show that it has been selected.单选按钮

radio-carbon /.reidiau'kaiban; NAmE -ou'kairb-/ noun [U]

:术语）a radioactive form of carbon that is present in the materials of which living things are formed, used in carbon dating放射性碳（碳的放射性 同位素，用以测定物体的年代）：radiocarbon analysis 放射性碳分析

.radiocarbon 'dating not/n [u] (formal) = carbon

DATING

radio.chem.is.try /.reidiau'kemistri; NAmE -ou'k-/ noun [U] the area of chemistry which is concerned with radioactive substances 放 •化学► radio.chem.ical /.reidiau'kemikl; NAmE -ou'k-/ adj.

.radio-con'trolled adj. controlled from a distance by raqio signals无线电操纵的；无线电遥控的 radi-og-raph-er /,reidi'Dgrafa(r); NAmE -'a:g-/ noun a person working in a hospital whose job is to take X-ray photographs or to use X-rays to treat some illnesses, such as cancer *X光摄影师；放射治疗师 radi*og-raphy /.reidi'Dgrafi; NAmE -'a:g-/ noun [u] the process or job of taking X-ray photographs * X 光照相 radio*iso*tope /.reidiau'aisataup; NAmE .reidiou'aisa- toup/ noun (chemistry it) a form of a chemical element which sends out radiation 放射性同位素 radi-olo-gist /.reidi'oladsist; NAmE -'a:la-/ noun a doctor who is trained in radiology放射科医生；X光科的医生 radi-ology /,reidi'Dlad3i; NAmE -'a:la-/ noun [U] the study and use of different types of radiation in medicine, for example to treat diseases 放射学；放射医疗 radio.met.ricAreidi9u’metrik;/V/\m£.-dioo-/flt/_/. relating to a measurement of radioactivity 辖射度命J 量的.► raciio-met.ric.ally /-ikli/ flc/v.: These rocks have been dated radiometrically at two billion years old.

射-探测，这些岩石形成于20亿年前。. ,radio-'telephone noun a telephone that works by sending and receiving radio signals, used especially in cars, boats, etc.无线电话

,radio 'telescope noun a piece of equipment that receives radio waves from space and is used for finding stars and the position of spacecraft, etc•射电望远镜 radio-therapy /.reidiau'Berapi; NAmE -ou'0e-/ noun [u] the treatment of disease by radiation 放射疗法：a course of radiotherapy It @ * — compare chemo­therapy ► radio-thera-pist noun 'radio wave noun a low-energy electromagnetic wave, especially when used for long-distance commu- nication无线电波