问题 问答题

叙述系统时间响应的概念和组成。

答案

参考答案:时间响应是系统在外作用激励下,其输出随时间变化的函数关系,通过对时间响应的分析可揭示系统本身的动态特性。时间响应由两部分组成:(1)瞬态响应系统受到外作用激励后,从初始状态到最终状态的响应过程。它反映了系统的响应快速性和稳定性。(2)稳态响应系统受到外作用激励后,当时间趋于无穷大时,系统的输出状态。它反映了系统的准确性。

单项选择题
阅读理解

“The first and best of victories for a man is to conquer himself; to be conquered by himself is, of all things, the most shameful,” says Plato. Self-control is at the root of all the advantages. Let a man give in to his impulses (冲动) and feelings, and from that moment he gives up his moral freedom.

A single angry word has lost many friends. When Socrates found in himself any temper or anger, he would check it by speaking low in order to control himself. If you are conscious of being angry, keep your mouth shut so that you can hold back rising anger. Many a person has dropped dead in great anger. Fits of anger bring fits of disease. “Whoever the gods would destroy, they first make them mad.” “Keep cool,” says Webster, “anger is not argument.” “Be calm in arguing,” says George Herbert, “for fierceness makes error a fault.”

To be angry with a weak man is to prove that you are not strong yourself. “Anger,” says Pythagoras, “begins with foolishness and ends with regret.” You must measure the strength of a man by the power of the feelings he conquers, not by the power of those which conquer him.

Self-control is man’s last and greatest victory.

If a man lacks self-control he seems to lack everything. Without it he can have no patience, no power to govern himself; he can have no self-confidence, for he will always be controlled by his strongest feeling. If he lacks self-control, the very backbone and nerve of character are lacking too.

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

A.Self- control is important for a man

B.We should learn to be strong.

C.A man who keeps cool won’t lose any game.

D.The great heroes in history knew how to control themselves.小题2:What does the underlined sentence in Paragraph 2 mean?

A.If you are mad, the gods will fail you.

B.If you lose your temper first, gods will fail you first.

C.If you can’t control yourself, you will be crazy.

D.If the gods want to fail you, they will make you mad first.小题3:Which of the following is NOT true, according to passage?

A.The first and best of victories for a man is to conquer himself.

B.You will make a small mistake serious if you don’t keep cool.

C.You must measure a man’s strength by the power of the feelings which conquer him.

D.Anger begins with foolishness and ends with regret.小题4:Which of the following can’t help you avoid anger, according to the passage?

A.Being calm in arguing

B.Checking your temper or anger by speaking low.

C.Keeping your mouth shut

D.Trying to make the other angry first.小题5:If a man lacks self-control,______________________________

A.He will always be controlled by all the people all the time.

B.He will began with foolish everything every day and lack the strength.

C.Moral strength and nerve of character will lack as well.

D.He will have power of gover himself.