closed root

Because the closed-loop system has the time delay unit in its characteristic equation, it is difficult to analyze the stability with the latent root. The paper uses the bode plot frequency-domain design method of the classical control theory.

由于闭环系统的特征方程分母中含有时滞项，从特征根角度分析系统的稳定性具有一定的难度，因此本文采用的是经典控制理论中的波特（Bode）图频域分析法。

We must deal with the root cause of the problem which lies in the formal and informal systems that educate young people in a closed-minded approach to religion and culture.

我们必须从根源入手解决问题，而问题的根源就在于那些培养年轻人形成保守的宗教和文化观念的正规与非正规体制。

Objective To summarize the clinical effect of closed empty canal in root cavity therapy.

目的总结根管治疗中空管封闭疗法的临床效果.