专业英语第48篇翻译.docVIP

Lesson?48 Communications?Satellites 1.?In?a?world?that?is?becoming?more?and?more?interdependent, there?is?an?ever-increasing?need?to?link?communications?systems?on various?continents?and?to?provide?live?international?television coverage,?This?need?is?now?being?met?by?the?communications satellites. 1.在一个变得更加相互依存的世界中 有不断增加的需要上的链接通信系统 世界各大洲，并提供国际电视直播 覆盖范围，这种需要是如今遭到 communicatians 卫星。2.?Communications?satellites?make?use?of?technology?that?has been?available?for?some?time;the?microwave?radio?relay.Microwaves,?which?have?a?higher?frequency?than?ordinary?radio waves,?are?used?routinely?in?sending?thousands?of?telephone?calls and?television?programs?across?long?distances.?They?give?high- quality?performance,?and?they?can?carry?many?messages?at?the same?time. 2.通信卫星使有的技术的使用 已经一段时间 ； 可用微波无线电中继。微波炉、 有较高的频率比普通的无线电波，用于定期发送成千上万的电话 和跨远距离的电视节目。他们给高- 质量性能，和他们可以携带在许多消息 同一时间。 3?.But?there?has?always?been?one?problem?in?using?radio?relay in?overseas?communications.?Although?hjgh-frequency?waves?can travel?almost?unlimited?distances,?they?travel?only?in?straight?lines. Since?the?curvature?of?the?earth?limits?a?microwaves?line-of-sight path?to?about?30?miles,?good?reception?requires?a?series?of?relay towers?spaced?every?30?miles?or?so.?Obviously ?it?isnt?possible?to build?these?towers?across?the?ocean.?But?by?sending?signals?high up?into?the?sky?and?then?bouncing?them?back?again?to?a?far-off spot,?we?can?send?microwave?messages?long?distances 3。但在使用无线电中继一直存在的一个问题 在海外的 communicatians。尽管高频率波可以 旅行几乎无限的距离，他们只有在直线旅行。 以来的一个微波地球极限曲率的视线 约 30 英里的路径，良好的接待需要一系列的继电器 塔间距每 30 英里左右。很明显它不是可能的 穿越海洋建立这些塔。但通过发送信号高 起来到天空，然后弹跳一回再遥远 现货，我们可以发送微波消息很长的距离4.?As?long?ago?as?1945,Arthur?C.?Clarke,an?English?science- fiction?writer,?proposed?that?manned? ‘stationary’?satellites?be used?to?relay?and?broadcast?electromagnetic?communication signals.?In?1945,?of?course,?the?idea?of?getting?a?satellite?out?into space?seemed?fantastic.?But?within?ten?years,satellites?were?close to?reality.With the?first?launching?of?a?sat