问题 单项选择题

关于射频线圈的说法,错误的是()

A.射频线圈的形状都是马鞍形

B.表面线圈用于接收信号

C.相控阵线圈具有较好的信噪比

D.发射线圈用于射频激发

E.发射线圈和接收线圈不能同时工作

答案

参考答案:A

解析:射频线圈是接收电磁信号用的,他有两种作用:一种是为芯片提供能量,另一种是通信信号的发射、接收。可适当的改变形状,但是必须保证线圈内面积的最大,这样才能保证最可靠的使用环境。假如对折则不能继续正常使用。

单项选择题
阅读理解

阅读下面短文,从各题A、B、C、D四个选项中,选出最佳答案。

People who smoke could lose around one third of their daily memory, researchers say.

A study by a team at Northumbria University showed that smokers lost more of their memory when compared to non-smokers.

And the research also found that those who kicked the habit saw their ability to recollect information restored to almost the same level as non-smokers.

The study involved more than seventy 18-to-25-year-olds and included a tour of the university’s campus. Those who took part were asked to recall small details, such as a list of songs played at a campus concert and tasks completed at various points-known as real world memory test. Smokers performed badly, remembering just 59 percent of tasks. But those who had given up smoking remembered 74 percent and those who had never smoked recalled 81 percent of tasks.

Dr. Tom Heffernan, who leads Northumbria University’s Collaboration for Drug and Alcohol Research Group, said the findings would be useful in anti-smoking campaigns. He said, “Given that there are up to 10 million smokers in the UK and as many as 45 million in the United States, it's important to understand the effects smoking has on everyday cognitive(认知的)function-of which prospective memory is an excellent example. ”

“This is the first time that a study has set out to examine whether giving up smoking has an impact on memory. We already know that giving up smoking has huge health benefits for the body, but this study also shows how stopping smoking can have knock-on benefits for cognitive functions too. ’’

The research will now investigate the effects of passive smoking on memory, while Dr. Heffernan and Dr. Terence O’Neil will look into the effects of third-hand smoking-toxins left on curtains and furniture.

小题1:What’s the main idea of the passage?

A.Smoking does harm to health.

B.Smokers take a tour to the University’s campus.

C.Smoking can affect one’s memory.

D.Smokers are compared to non-smokers.小题2:How did those who took part in the study perform when asked to recall small details?

A.Smokers did the worst among the participants.

B.Non-smokers could recall about half of them.

C.Smokers could recall nothing at all.

D.Those who gave up smoking did best.小题3:According to Dr. Tom Heffernan, the findings_______.

A.would be really a surprise to the public

B.would contribute to fighting against smoking

C.would be used in real world memory test

D.would be nothing new to the researchers小题4:What does the underlined word “impact’’ most probably mean?

A.order

B.impression

C.expression

D.effect小题5:What will Dr. Heffernan and Dr Terence O’Neil do?

A.Investigate the effects of third-hand smoking.

B.Do research on how smoking affects passive smokers.

C.Find ways to persuade people to quit smoking.

D.Study whether giving up smoking affects memory.