问题 问答题

阅读下面材料,并回答热管的导热原理是什么。

热管是20世纪80年代研制出来的一种导热本领非常大的装置,如图所示,它比铜的导热本领大上千倍。管内壁衬了一层多孔的材料,叫做吸收芯,吸收芯中充有酒精或其他易汽化的液体,当管的一端受热时,热量会很快传到另一端。

答案

从题目可知,热管充有“易汽化的液体”,那么易汽化就易液化,汽化吸热,液化放热,故液体从加热端吸热,沿管子运动到另一端遇冷放热,使得热量传递过去。

“热管”的一端受热时,这一端吸收芯中的液体因吸热而汽化,蒸汽沿管子由受热一端跑到另一端,另一端由于未受热,温度低,蒸汽就在这一端放热而液化,冷凝的液体被吸收芯吸附,通过毛细作用又回到了受热的一端,如此循环往复,热管里的液体不断地汽化和液化,把热量从一端传到另一端。

阅读理解

阅读理解。

     Tell a story and tell it well, and you may open wide the eyes of a child, open up lines of communication

in a business, or even open people's mind to another culture or race.

     People in many places are digging up the old folk stories and the messages in them. For example, most

American storytellers get their tales from a wide variety of sources, cultures, and times. They regard

storytelling not only as a useful tool in child education, but also as a meaningful activity that helps adults

understand themselves as well as those whose culture may be very different from their own.  

     "Most local stories are based on a larger theme," American storyteller Opalanga Pugh says, "Cinderella

(灰姑娘), or the central idea of a good child protected by her goodness, appears in various forms in almost

every culture of the world."

     Working with students in schools, Pugh helps them understand their own cultures and the general messages

of the stories. She works with prisoner too, helping them knowing who they are by telling stories that her

listeners can write, direct, and act in their own lives. If they don't like the story they are living, they can rewrite

the story. Pugh also works to help open up lines of communication between managers and workers. "For

every advance in business," she says, "there is a greater need for communication." Storytelling can have a great

effect on either side of the manager-worker relationship, she says.

     Pugh spent several years in Nigeria, where she learned how closely storytelling was linked to the everyday

life of the people there. The benefits of storytelling are found everywhere, she says.

     "I learned how people used stories to spread their culture," she says, "What I do is to focus on the value

of the stories that people can translate into their own daily world of affairs. We are all storytellers. We all have

a story to tell. We tell everybody's story."

1. What do we learn about American storyteller from Paragraph 2?

A. They share the same way of storytelling.

B. They prefer to tell the stories from other cultures.

C. They learn their stories from the American natives.

D. They find storytelling useful for both children and adults.

2. The underlined sentence (Paragraph 4) suggests that prisoners can _____.

A. start a new life

B. settle down in another place

C. direct films

D. become good actors

3. Pugh has practised storytelling with _____ groups of people.

A. 2

B. 3

C. 4

D. 5

4. What is the main idea of the text?

A. Storytelling can influence the way people think.

B. Storytelling is vital to the growth of business.

C. Storytelling is the best way to educate children in school.

D. Storytelling helps people understand themselves and others.

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