查询词典 bifurcation point

The model in this paper takes the form as belowThe main contents and results in this paper are as follows:In section 1, we state our main analytical results on equilibria of the above system. First, several sufficient conditions for coexistence of the steady-state are given by the standard fixed-point index theory in cone. Second, the global structure of the coexistence solutions and their local stability are established by using bifurcation theory. Third, the multiplicity, uniqueness and stability of positive steady-state solutions to this system are derived by means of perturbation theory of eigenvalues, standard regularity theory, Sobolev embedding theorem and fixed-point index theory.

本文主要有两章内容：第一章研究了该模型正平衡解的性质，可分为三部分：第一部分运用极值原理、上下解方法和锥映射不动点指标理论得到正平衡解存在的充分条件；第二部分利用分歧理论给出了平衡态系统正分歧解的结构，并讨论了局部分歧解的稳定性；第三部分利用特征值扰动理论、标准椭圆正则化理论、Sobolev嵌入定理及指标理论讨论了正平衡解的多重性、唯一性及稳定性，并讨论了参数对解的影响。

This thesis is devoted to singular point quantities and integrability conditions of complex polynomial differential systems with resonant singular point, and center-focus determination and bifurcation of limit cycles of planar polynomial differential systems.

在第二章中，对具p∶-q共振奇点的复自治多项式微分系统引入广义奇点量的概念，它是文[103]中奇点量概念的推广，它以在实平面多项式微分系统的中心焦点判断与极限环分支中有着极为重要意义的焦点量和鞍点量作为特例。

The joint effect of active and reactive power on the voltage stability of a typical power system was considered by analysing the two parameter bifurcation problem related to nonlinear oscillation phenomena. Numerically, as the active power P1 increases, the Hopf points get closer and eventually coincide at P1=1.455 43 the cyclic fold curve gets closer and closer to the Hopf curve and finally intersects the Hopf curve at a singular point the period-doubling points also get closer and finally coincide at P1≈0.65. The stability behaviour is pre-determined using the normal form approach near the limit point of the Hopf curve. Hence, in the power system attention should be paid to both the consumption of active power and the decrease in the reactive power to prevent nonlinear oscillations. A controller can be designed to absorb some active power and to avoid the nonlinear oscillations that damage the system components.

针对一个典型的单机无穷大电力系统，通过分析系统的双参数分岔的非线性振荡现象，综合考虑有功和无功功率对电压稳定性的影响数值分析表明，随着有功功率的增加，电力系统的Hopf点越来越靠近，最终合为一点在P1=1.455 43处同时圈折cyclic fold 曲线也越来越靠近Hopf曲线，并在Hopf曲线的稳定与不稳定临界点处与Hopf曲线相交倍周期分岔点也随着越来越靠近，最终在P1≈0.65 合为一点应用正规形理论方法，初步确定了Hopf曲线极限点附近的稳定性态因而，电力系统应注意让负荷利用有功功率，减少无功功率的产生以防止非线性振荡另外，可以设计一个稍微吸收网络的有功功率的控制器，以避免因周期振荡而造成电力系统仪器的损坏或电压崩溃

Unlike the conventional indirect method, it can directly implement the generator field and armature current limits accurately, thereby assuring power flow convergence and voltage collapse point identification during tracing the PV curve when generator limits constraints are considered. The critical limit constraint equation is introduced in the corrective stage of the continuation method as the additional equation to solve the limit induced bifurcation point accurately.

给出新的发电机电流极限约束的直接处理算法，解决了计及发电机电流约束时，潮流难于收敛和不易精确求出电压崩溃点的问题；对不易精确求得的极限诱导分岔点，通过在连续潮流法的校正步骤中将关键的极限约束方程作为附加方程来快速而精确地求解。

The kernel of the problems stressed are the two: the link path of saddle point to saddle point on the topological structure is instable, so it will break easily with the changing of main control coefficient, and nonlinear bifurcation of the vortex structure along the vortex axis line.

强调了不稳定拓扑结构中的鞍—鞍连接轨线随主控参数变化而"撕裂"、以及旋涡沿轴线的非线性分叉是非对称形成与多涡系演化的途径。

On the basis of distributive shapes of point collection on the Poincare section, define three indexes to quantitatively describe the distribution of point collection. Which are distance between two adjacent points, diffused angle and distance between every point and center point of point collection.

以庞卡莱截面上RR间期序列的点集分布形式为基础，提出点集中相邻点间距离、扩散角度和点到点集中心距离三项指标，用以定量地衡量点集的分布形式。

Firstly, according to this character, primacy central point is detected by the exploring extremum method in the windows of 3×3 pixels. Then, basing on this central point, approximate normal line at ±45°、0°and 90°angle are drew.if the minimums of normal line is at central point and the difference between the minimums and the maximum in the normal line is more than the threshold, this point is considered to the edge point of image.

首先，在3×3象素的窗口中，如果中心值为最小值，则以该点为基础，以±45°、0°和90°方向作为近似法线带，然后判断该法线上的象素最小值是否在切点上（即是否在法线的中心点上），再通过检验切点与轮廓法线上亮度极大值的差值是否超过阈值，来判断切点是否为边缘轮廓上的点。

While it is usually impractical for the marshallate to measure blade weight directly by weighing the sword before the basket hilt, cross, or pommel weight is attached, the linear density of the blade (its weight divided by its length) can be estimated fairly easily by weighing the finished sword, locating the point on the blade at which it balances, and measuring the distance from the point of balance to the tip, from the point of balance to the hilt, and from the point of balance to the point where the additional weight (the basket hilt, cross, or cross plus pommel weight) is attached to the blade.

而这通常是不切实际的为marshallate来衡量的刀身Weight直接由称重剑前一篮子的Hilt ，交叉，或pommel重量是重视，线性密度的刀片可估计相当容易称重成品剑，定位点的叶片在它的结余，以及测量距离平衡点，以尖端性，从平衡点到极限和从平衡点以点的额外重量（篮子的Hilt ，交叉，或跨加pommel重量）是连接到刀片。

Subline matching method based on binary system small wave transform is proposed, which expliots the character that the model maximum point of spline binary small wave transform coefficient at different scales can provide position information of signal's fast changing point. The matching scheme from thick to thin for point matching is adapted. Then, the point to point matching is calculated with the sequence consistent principle in each subline.

设计基于二进小波变换的子线段匹配方法，通过求解样条二进小波变换系数在不同尺度下的模极大点确定不同尺度下信号急速变化点位置，采用由粗到细的匹配策略匹配端点，再对端点之间的每一个子线段采用顺序一致的原则，进行点对点匹配。

This study is to give a solution for the estimation of flash point for mixtures, the necessity for classification of flammable liquids. The traditional models for predicting flash point of mixtures usually by the activity coefficient approach. However, the parameters of activity coefficient were regressed from phase equilibrium data in the literatures. If there is no such parameter in literatures for the desired mixture, the model cannot predict the flash point oft hat mixture. Thus, this research aims at the improvement of deficiency of the flash point prediction models in the literatures by useing UNIFAC (Universal Quasi-chemical Functional Group Activity Coefficient) equation, Dortmund-UNIFAC equation and Lyngby-UNIFAC equation. In this study, we were aim at the prediction model for miscible mixtures.From the result, it is suggested to use different type of UNIFAC equation to estimast activivity coefficient in the predition of flash point for different mixture type.

易燃液体分类的主要依据参数为闪火点值，因此本研究目的为解决易燃液体中混合物分类时所面临到的闪火点值缺乏的问题，而在过去文献中所提出的闪火点预测模式会使用到活性系数，但这些模式使用到的活性系数均需要相平衡的数据以回归其所需参数，若所欲估算闪火点的混合溶液文献上未有相关参数，则无法有效利用闪火点预测模式估算其闪火点，因此针对文献中现有闪火点预测模式的缺点，利用描述液体混合物活性系数UNIFAC (Universal Quasi-chemical Functional Group Activity Coefficient)方程式、Dortmund-UNIFAC方程式和 Lyngby-UNIFAC方程式，建立发展一闪火点预测模式，而本研究以互溶溶液为对象。

"Yes, now you can give yourself airs," she said, you have got what you wanted.

"对了，您现在高兴了，"她说道，这是您所期待的。

Then the LORD said to me: Rebel Israel is inwardly more just than traitorous Judah.

上主于是对我说：＂失节的以色列比失信的犹大，更显得正义。