问题 问答题 简答题

什么是木材干燥窑?木材干燥窑应满足的技术要求是什么?

答案

参考答案:

木材干燥窑是指装配有加热设备、调湿设备和通风设备,并能控制干燥介质温、湿度和气流循环方向及速度的密闭建筑物或金属容器。木材干燥窑应满足的技术要求有:

(1)气流循环效果好,一般气流循环速度为1~3m/s,且分布均匀;

(2)有足够的加热能力和调湿能力,以满足工艺要求;

(3)温、湿度检测安全、可靠;

(4)设备耐腐、保温。

填空题
单项选择题

Nuclear power’s danger to health, safety, and even life itself can be summed up in one word: radiation.

Nuclear radiation has a certain mystery about it, partly because it cannot be detected by human senses. It can’t be seen or heard, or touched or tasted, even though it may be all around us. There are other things like that. For example, radio waves are all around us but we can’t detect them, sense them, without a radio receiver. Similarly, we can’t sense radio activity without a radiation detector. But unlike common radio waves, nuclear radiation is not harmless to human beings and other living things.

At very high levels, radiation can kill an animal or human being outright by killing masses of cells in vital organs. But even the lowest levels can do serious damage. There is no level of radiation that is completely safe. If the radiation does not hit anything important, the damage may not be significant. This is the case when only a few cells are hit. And if they are killed outright, your body will replace the dead cells with healthy ones. But if the few cells are only damaged, and if they reproduce themselves, you may be in trouble. They reproduce themselves in a deformed way. They can grow into cancer. Sometimes this does not show up for many years.

This is another reason for some of the mystery about nuclear radiation. Serious damage can be done without the victim being aware at the time that damage has occurred. A person can he irradiated and feel fine, then die of cancer five, ten, or twenty years later as a result. Or a child can be born weak or liable to serious illness as a result of radiation absorbed by its grandparents.

Radiation can hurt us. We must know the truth.

Which of the following can be best inferred from the passage()

A. The importance of protection from radiation cannot be over-emphasized.

B. The mystery about radiation remains unsolved.

C. Cancer is mainly caused by radiation.

D. Radiation can hurt those who are not aware of its danger.