【判断题】对于开环稳定系统,闭环系统稳定的充分必要条件为系统的开环频率特性曲线不包围(-1,j0)点。
【单选题】(2006.10) An ______idea suddenly came upon him when he was taking a walk with his wife.
【判断题】奈奎斯特曲线包围(-1,j0)点,则系统不稳定。
【单选题】主蒸汽额定压力为13.7Mpa的汽轮机属于( )汽轮机。
【单选题】He was taking a _____ by overtaking on a bend.
【单选题】主蒸汽额定压力为13.7Mpa的汽轮机属于( )汽轮机。
【单选题】缺铁性贫血采用铁剂治疗,观察疗效最早的指标是