问题 问答题 论述题

论述海底MCSEM接送机的原理及设计需求?

答案

参考答案:

海底可控源电磁法接收机可下沉到海底,数据采集完成后通过声学释放单元回收。海底可控源电磁法数据记录器原理框图,接收机采集正交的电场和磁场分量。接收机信号调理部分采用斩波放大器消除1/f噪声,高通滤波器压制极低频大地电磁信号及电极极差。海底电磁接收系统一般有4~6个道,接收电磁场4~6个分鼍,即E、E,H、H,E及H。目前用得较多的为四分量采集站(E、E、H、H)。采集站由电场传感器、磁场传感器、数据记录系统、定位系统、声控系统、浮球及水泥重块等构成。每个采集站由船上自由下沉到海底。通过声波超短基线通讯装置可以精确确定接收器位置。采集结束后通过船上发送声波控制信号,带有采集系统的浮球与水泥重块分离浮出海面,实现采集资料的回收。一般单个采集站的布设需1~2h左右。视海况条件而定。

阅读理解

阅读理解。

     The English, as a race, are very different in many ways from all other nationalities, including their closest

neighbors, the French, the Belgians and the Dutch. It is claimed that living on an island separated from the rest

of Europe has much to do with it. Whatever the reasons are, it may be fairly stated that the Englishman has

developed many attitudes and habits which distinguish him from other nationalities.

     Broadly speaking, the Englishman is a quiet, shy, reserved person who is fully relaxed only among people

he knows well. In the presence of strangers or foreigners he often seems restrained, even embarrassed. You

have only to witness a city train any morning or evening to see the truth of this. Serious-looking businessmen

and women sit reading their newspapers or having a light sleep in a corner, and no one speaks. In fact, to do

so would seem most unusual. An Englishman, pretending to be giving advice to overseas visitors, once

suggested, "On entering a railway carriage, shake hands with all the passengers." Needless to say, he was not

being serious. There is an unwritten but clearly understood code of behavior which, if broken, makes the

person immediately suspected.

     In many parts of the world it is quite normal to show openly extremes of enthusiasm, emotion, excitement,

etc., often accompanied by appropriate gesture. The Englishman is somewhat different. Of course, an

Englishman feels no less deeply than anyone of a different nationality, but he tends to display his feelings far

less. This is reflected in his use of language. Imagine a man commenting on the great beauty of a young girl.

A more emotional man might de- scribe her state "Oh, she is a goddess", whereas an Englishman might just

say "Oh, she's all right." An Englishman who has seen a highly successful and enjoyable film recommends it

to a friend by commenting, "It's not bad you know", or on seeing some very unusual scenery he might convey

(表达) his pleasure by saying," Nice, yes, very nice." The overseas visitor must not be disappointed by this

apparent lack of interest and involvement. Instead, he must realize that "all right," "not bad," and "nice," very

often have the sense of "first-class," "excellent," "beautiful". This unique style of language use is particularly

common in England, and is known as restrained statement.

1. According to the passage, the English are different from other nationalities in _____.

A. habits

B. attitudes

C. character

D. all of the above

2. The underlined word "restrained" in the second paragraph probably means "_____".

A. calm and controlled

B. polite and friendly

C. nervous and quiet

D. silent and kind

3. In Britain, if you don't want other people to think you are strange, you'd better _____.

A. talk with others as much as possible

B. behave just like the English do

C. say nothing about yourself

D. shake hands with everyone you meet

4. If an Englishman says "all right", it may mean "_____".

A. not bad

B. correct

C. quite right

D. wonderful

5. From the passage, we can infer that an Englishman _____.

A. doesn't like to show his feelings so much

B. has less emotion than people of other nationalities

C. finds it easy to express his emotion

D. likes to have a joke with strangers

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