问题 问答题 简答题

电能计量—远程集中抄表系统(如大学校园电能计量系统)的框架结构和各部分的组成示意图如下,请说出各部分的主要功能。

答案

参考答案:(1)单表为智能电表:智能电表具有有功电量计量和历史电量存储,通讯功能,防窃电功能,计量准确度高,能接收停、送电操作等功能。

(2)集中器:根据已设置好的不同的抄表方案对各电表实现双向数据传送。集中器具有内部硬时钟可与系统进行广播校时,并实施定时抄表命令,存储抄表数据,接受上位机下达的指令(单抄、定时抄表、实时抄表、校时、路径设置、复位集中器等)。集中器可通过各种网络媒介与主站完成数据交换。集中器的作用是将各区载波电能表连成本地网络,并能自动抄录采集终端及载波电表的数据,进行集中并存储。集中器根据上位机的下传指令进行数据收集,然后通过GSM/GPRS、光纤或电话线与数据电脑之间建立准确可靠的数据传输纽带,最后将数据传输给结算中心的计算机。

(3)终端计算机:实际上是一部普通的计算机,其主要功能为:

①接受通讯集中器上传的数据,进行相关处理;

②通过相关软件把每月各用户用电量、电费、线损、用电峰值时间等数据计算出来,如果条件允许可以把热水、冷水一起通过计算机进行结算;

③还能通过结算中心电脑与网络中心电脑互联,把用电量数据上传网络,每个用户可以通过用户帐户密码登陆校园网,进行实时的用电量、本月应缴电费等查询。同时学校也能通过网络进行催缴电费、水费的通知,达到通知迅速、节省电费表纸张等节能目的,也方便各用户得知费用,做到收费透明化。

阅读理解

Some students get so nervous before a test, they do poorly even if they know the material. Sian Beilock has studied these highly anxious test-takers.

Sian Beilock: “They start worrying about the consequences. They might even start worrying about whether this exam is going to prevent them from getting into the college they want. And when we worry, it actually uses up attention and memory resources.I talk about it as your cognitive horsepower that you could otherwise be using to focus on the exam.”

Professor Beilock and another researcher, Gerardo Ramirez, have developed a possible solution. Just before an exam, highly anxious test-takers spend ten minutes writing about their worries about the test.

Sian Beilock: “what we think happens is when students put it down on paper , they think about the worst that could happen and they reappraise the situation. They might realize it’s not as had as they might think it was before and, in essence(本质上), it prevents these thoughts from popping up when they’re actually taking a test.”

The researchers tested the idea on a group of twenty anxious college students. They gave them two short math tests. After the first one, they asked the students to either sit quietly or write about their feelings about the upcoming second test.

The researchers added to the pressure. They told the students that those who did well on the second test would get money. They also told them that their performance would affect other students as part of a team effort.

Professor Beilock says those who sat quietly scored an average of twelve percent worse on the second test. But the students who had written about their fears improved their performance by an average of five percent.

Next, the researchers used younger students in a biology class. They told them before final exams either to write about their feelings or to think about things unrelated to the test.

Prefessor Beilock says highly anxious students who did the writing got an average grade of B+, compared to a B- for those who did not.

Sian Beilock: “What we showed is that for students who are highly test-anxious, who’d done our writing intervention, all of a sudden there was no relationship between test anxiety and performance. Those students most likely to worry were performing just as well as their classmates who don’t normally get nervous in these testing situations.”

But what if students do not have a chance to write about their fears immediately before an exam or presentation? Professor Beilock says students can try it themselves at home or in the library and still improve their performance. 

小题1:What may happen if students have the problem of test anxiety?

A.Test anxiety can improve students’ performance to some degree.

B.Students’ attention and memory resources run out when worried.

C.Students may not be admitted into their favorite college if worried

D.Test anxiety is sure to cause students to fail the test.小题2:Which of the following if TRUE?

A.In the first math test, students who sat quietly performed better.

B.In the second math test, students who wrote about their feelings did worse.

C.Some college students are highly anxious test-takers while others are not in the tests.

D.The result in the math test agrees with that in the biology test.小题3:What does the underlined phrase “popping up” mean?

A.Giving out

B.Fading away

C.Becoming clearly

D.Appearing suddenly小题4:what is most probably Sian Beilock?

A.A psychology professor.

B.A philosophy researcher.

C.A politics professor

D.A tutor小题5:What is the main idea of the passage?

A.It is a common practice for students being worried before a test.

B.Being worried before tests does harm to students’ performance.

C.Anxious students overcome test anxiety by writing down fears.

D.It is important for students to overcome test anxiety.

单项选择题