问题 问答题 简答题

什么是三点检查?X至IG接车进路正常解锁时,3DG和5DG区段是如何实现三点检查的?

答案

参考答案:

(1)三点检查:就是用相邻的三个轨道电路区段作为解锁的条件。

一个区段的解锁不仅要检查车占用过并且已出清本区段,还要检查占用过并出清前一区段,而且已进入后一区段。

例如;

A、当车占用且出清前一区段且占用本区段时,1LJ↑--作第一点出清和第二点占用记录;

B、当车出清本区段并占用下一区段时,2LJ↑--作第二点出清和第三点被占用记录;这样,1LJ↑、2LJ↑完成了被解锁区段的三点检查。

(2)X至IG接车进路正常解锁时,当列车压入5DG区段,5/1LJ↑电路中列车占用前一区段IAG,用IAGJ落下为第一点检查;本区段5DG被占用,5DGJ↓,5FDGJ↑为第二点检查;当列车驶入3DG区段,3DGJ↓,3FDGJ↑,车出清5DG区段时,5DGJ↑使5/2LJ↑,在其励磁电路中检查了5DG区段的出清和下一区段3DG的占用,即5/1LJ↑、5/2LJ↑做到了三点检查;

5/1LJ↑、5/2LJ↑和5CJ的慢吸特性给3DG区段送电,使3/1LJ↑,说明车出清5DG,占用3DG,对于3DG来说,实现了第一点出清,和第二区段占用的检查,当列车进入下一区段,出清3DG区段时,3DGJ↑,同时3/2LJ↑,证明了3DG区段也实现了三点检查。

单项选择题 A1/A2型题
阅读理解

阅读理解。

     A newspaper, published usually on a daily or weekly basis, has the main function of reporting news. Many

newspapers also furnish their readers with other pieces of useful information, such as weather reports, TV

program broadcast, and other kinds of information. They provide commentary on politics, economics, arts

and culture. In nearly all cases and in different degrees, newspapers depend on commercial advertising for

their income.

     A survey said that nearly six out of ten adults in the United States and Canada read a newspaper every day,

and seven out of ten read a paper each weekend. By the time they see a newspaper, most people have already

heard about breaking news stories on TV or on the radio. Readers depend on newspapers to provide detailed

information and analysis (分析) which TV and radio almost don't offer. Newspapers not only tell readers that

an event has happened but also help readers understand what led to the event and how it will affect the world.

     The members of a large newspaper work under the nonstop pressure of deadlines to bring news to readers

as quickly as their minds, bodies and the technology they use permit. Reporters, photographers, artists, and

editors find the materials and form articles and graphics (图片) -sometimes in just a few hours. Page designers

combine articles, photos, advertisements, and eye-catching headlines into page layouts (版面), then quickly

print the paper out. Printing system may work through the night to print out more than 60,000 copies per hour.

1. What does the second paragraph mainly tell us?[ ]

A. How many people read newspapers.

B. Why many people read newspapers.

C. How a newspaper comes into being.

D. How newspapers affect us.

2. The underlined word in Paragraph 1 means "_____". [ ]

A. offer

B. review

C. found

D. produce

3. What can we learn from the passage? [ ]

A. All the income of a newspaper comes from ads.

B. Canadians depend on newspapers more than Americans.

C. The staff of a newspaper must meet deadlines from time to time.

D. Only by reading the newspaper can readers get the latest news.

4. According to the passage, what affects the pace of a newspaper's publication? [ ]

A. The editors.

B. The printers.

C. Its human resources and technology.

D. The reporters.