试题与答案

使用不溶性硫磺的胶料,在加工过程中应注意哪些问题?

题型:问答题 简答题

题目:

使用不溶性硫磺的胶料,在加工过程中应注意哪些问题?

答案:

参考答案:

不溶性硫磺是不稳定的,它能转化为一般的可溶性硫磺。在室温下转化较慢,但随温度升高而加快,至110℃以上时,便能在10-20分钟以内转化为普通硫磺。因此这种硫磺应在尽可能低的温度下贮存。在配料加工过程中,也要小心保持较低的温度(在100℃以下)以防止其转化为普通硫磺。不溶性硫磺由于它在橡胶中的不溶性,往往难于均匀分散,在工艺上也应充分注意。不溶性硫磺只用以代替一般的可溶性硫磺,不改变硫化过程和硫化胶的性能。因此,如果工艺过程中温度过高,或者较高温度下长时间存放,那么使用它就没有意义。

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题型:阅读理解

Mr. Brown was an old man. He lived in a small village with high mountains all around it.. He had never been to a city before.

Last summer his son came back, and took him to the city. He stayed there for about two months. When he came back, his wife asked him,” Do you like living in the city? Did you have a good time?”

“No, I don’t like living in the city because the buildings are too tall. And the noise is too loud. The bed is too soft. And they never have meals outside the house,” answered Mr. brown.” I’m very angry because the people in the city aren’t kind to the animals.”

“How do you know this?” asked his wife.

“One Sunday morning Jack, our son took me to a place. There are a lot of animals in that place---tigers, elephants, lions and monkeys. But they are in the cages. The place is the prison(监狱) of the animals.” answered Mr. Brown.

小题1:Mr. and Mrs. Brown were______________.

A.doctors

B.teachers

C.zookeepers

D.villagers小题2:The animals in Mr. Brown’s village________.

A.are free

B.are in the cages

C.are sent to the city

D.are in prison小题3:Mr. Brown did not know the place with a lot of animals was a ________.

A.park

B.garden

C.village

D.zoo

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