查询词典 imaginary point

The transcendental characteristic equation is converted into a polynomial equation at the imaginary axis without any substitutions.

针对具有单输入反馈控制的单时滞电力系统，提出了一种求解时滞稳定裕度的简便方法。

Because it can pull the loci, or parts thereof, away from the imaginary axis,deeper into the left-half plane.

对根轨迹或部分根轨迹有拉的作用，使根轨迹远离虚轴，向更左的左半平面移动。

The vertical axis is therefore called the imaginary axis.

因而纵轴称为虚轴。

A zero can improve relative stability because it can pull the loci, or parts thereof, away from the imaginary axis, deeper into the left-half plane.

零点可以提高系统的相关稳定性，因为零点对根轨迹或部分根轨迹有拉的作用，使根轨迹远离虚轴，向更左的左半平面移动。

The symmetric values about the imaginary axis of zero-poles which the unstable process lies in the open and closed right-half plane are defined as their mirror-injection.

非稳定过程在开右半平面的零极点关于虚轴的对称值称为该零极点的镜像映射。

Secondly, a conjecture about the stability for these systems is proposed based on the sufficient and necessary condition of the isolated transfer function being positive real. When the zeros and poles of the transfer functions lie in the imaginary axis, a known conclusion is derived from the conjecture; while the zeros and poles are on the real axis, a new result is obtained and is proved in this note. Finally, according to the conjecture, an example with poles existing on the complex plane is presented, which is not only interesting but also challenging.

然后， 基于所有孤立部分传递函数都正实的充分必要条件给出了上述系统为稳定的一个猜想，当传递函数的零极点都位于虚轴上时，由这一猜想得到了一个已知的结论；当传递函数的零极点都位于实轴上时，由这一猜想得到了一个新的结论，本文证明该结论是正确的；最后，根据这一猜想，给出了传递函数极点位于复平面的一个例子，它涉及到一类系数矩阵为时变正定矩阵的振动方程的稳定性问题，值得去深入研究。

Based on two algebra Riccati equation method especially the structure of the system Hamilton matrix and system observability theory, the role of invariant zeros in constructing system reduced order controllers was given. That is, by the suitable selection of free parameters of the system H(subscript ∞) controller, some points which were symmetry with the unstable invariant zeros about the imaginary axis became the stable poles of the system controller which were not observable and could be reduced from the system, thus could get further reduced order controller.

基于2代数黎卡提方程方法，特别是系统Hamilton矩阵的结构特点和系统可观测性理论，论述了不变零点在构造系统降阶控制器中所起的作用，即通过选择控制器的自由参量，使某些不稳定的不变零点关于虚轴对称的点构成系统控制器不可观的稳定极点，从而实现了控制器进一步降阶。

The transcendental characteristic equation is converted into a polynomial equation at the imaginary axis without any substitutions. This method needs less computation than the CTCR method.

该方法将含有指数项的特征方程在虚轴上转化为多项式方程进行研究，无需任何中间变量代换，处理方法简单，计算量小。

Specially, in Hilbert spaces, some necessaryand sufficient conditions are given in terms of the uniformly square integrability anduniform boundness of the resolvent on the imaginary axis respectively. Furthermore,we consider this robustness fordifferential equations with unbounded operatorin the delay term.

我们进一步研究了时滞项含无界算子的抽象微分方程的小时滞鲁棒稳定性，获得了一些充分必要条件，并应用所得结论讨论了具解析半群生成元的时滞系统。

According to analysis of roots locus,fast excitation tends to decrease damping of power systems which is controlled by AVR than slow excitation.But eigenvalues of power system are far from imaginary axis and strong damping is obtained when fast excitation system is added.

在高放大倍数的AVR控制下，快速励磁较慢速励磁更容易恶化系统阻尼；但是在同时附加励磁控制的情况下，快速励磁可使系统的机电模式根轨迹远离虚轴，机电模式阻尼较大；而慢速励磁下，系统机电模式根轨迹接近虚轴，机电模式阻尼较小，快速励磁优于慢速励磁。

Aquatic or marsh-growing fern allies; known to have existed since the Cenozoic; sometimes included in Lycopodiales.

生活于水中或湿地的蕨类；从新生代生存至今；有时归于石松目之中。

The engine was uprated from a 90hp Franklin to a 125hp Lycoming.

改良过的引擎是从90hp到125hp莱康明富兰克林。