【简答题】(中国科学院一中国科学技术大学2004年硕士研究生入学考试试题)设单位负反馈系统的开环传递函数为: (1)已知系统的一个闭环极点为-0.9,试求出其余的闭环极点。 (2)该系统是否可以用低阶系统来近似?若能,则求出它的闭环传递函数;若否,则给出理由。
【简答题】已知单位反馈系统的开环传递函数为 ,若要绘制根轨迹,则其幅角条件为 ;若要绘制开环相频特性,则其相角 为 。
【简答题】若某单位负反馈控制系统的开环传递函数是 G(s)=100/[s 2 (0.1s+1)] ,则该系统为 型系统,其静态位置误差系数 K p = 。
【单选题】The child hid himself behind his mother's skirt, ______ he was afraid of the dog.
【单选题】The child was ____ afraid that he didn't leave his room.
【单选题】血液增菌培养结果呈均匀混浊生长并有胶胨状凝块者,可能为
【单选题】She is afraid the child was ______.
【简答题】She is afraid the child was _______(normal).