特征方程

Within this context, four specific areas are addressed:(1) By means of finite integration technique, a new kind of the first order partial difference equation is derived from the original disperse transmission line equation of the uniform waveguide's. As it is the kind of one dimension Dirichlet's boundary problem, it is convenient for us to solve this equation from the leapfrog scheme. Because computation is carried out in one dimension, both high calculation efficiency and precision have been obtained in this method. Meanwhile, this method provide us a different selection to simulate the transient response of waveguide with non-simplical, for examples cylinder and elliptic waveguide, and avoid solving the second order equation, or using finite difference time domain to simulate a three dimension problem, sometimes the latter precision is not satisfied with the need, or low efficiency.

在这一研究内容下，主要研究四个方面的问题：(1)在完成金属波导传输线方程时域形式的基础之上，应用有限积分技术，把波导特征模式的色散传输线方程，化简为一组新的一阶偏微分方程组，该边值问题属一维Dirichlet边值问题，从而便于用蛙跳格式求解，由于是在一维中计算，该方法具有很高计算效率和精度，从而避免了以往为得到金属波导中特征模的时域响应特性，须要求解二阶方程，或用时域有限差分方法求解三维问题的方法，对于后者来说，计算有时是不准确的，或是很耗时的例如计算诸如圆波导、椭圆波导等其它复杂形状的波导。

Neutral differential equations with variable sign coefficients are separated into neutral differential equations with positive and negative coefficients by transformation. According to the characteristic of these equations, a real number set with supremum is constructed, and sufficient conditions for oscillation of all solutions to neutral equations with variable sign coefficients are obtained.

通过变换将具有变号系数的中立型微分方程分解为具有正负系数的中立型微分方程；分析具有正负系数中立型微分方程的特征，构造存在上确界的实数集；并对中立型微分方程的解作细致分析，得到了具有变号系数中立型微分方程所有解振动的充分条件。

In this thesis,we first consider the stability of the trivial solution to a three-unit ring network with multiple delays and without self-feedback.Most impor-tantly,we know how the number of the eigenvalues with positive real parts changes,which is fundamental for the discussion of bifurcation.

本文首先讨论了具多个时滞的不带自反馈的3元环状神经网络系统平凡解的稳定性，并得到了平凡解对应特征方程正实部根个数的变化规律。

The characteristics equation for the distance is derived by using the variational formulation for a generalized resonator.

应用谐振腔的变分公式，导出了确定短路面之间距离的特征方程。

It is found that the characteristic equations for right hand and left hand circularly polarized waves are identical.

在这种波导中，右旋和左旋圆极化波的特征方程是相同的，因此，它们的传播常数也是一样的；而当线极化波通过这种波导时，不出现极化面的旋转。

A character-codes model based pattern recognition method by using amplitude data of targets frequency response is proposed after the establishment of high frequency response equation of radar targets. The method uses the same unvariant character-codes to express the same target of different angles and uses sequential separating of regions of target's reference variables to obtain multiple coding vectors of all regions for every target. The category and pose of target can be determined after a two-staged classification processing such as coding processing of target range profile data and errors correcting processing of coded data. The two-stage classification results are used to target identification as posterior hypothesis to be tested by sufficient convincing and necessary convincing. The character-codes model based pattern recognition method is also adaptive to variation of target angles and controllable in error probability. Time-consuming and complicated iterative computation is not necessary in the train process of pattern recognition.

首先建立了雷达目标的高频频率响应方程，这种方程将目标多散射中心理论与目标局部谐振理论有机地结合起来；进而提出了目标多频响应结构成像方法，这种方法将瑞利区频率响应或谐振区频率响应曲线的不同部位用各种不同的近似方法去逼近，通过特征谱估计方法将目标的局部频响特征与宽带距离响应特征结合起来；然后提出了一种基于姿态角变化区域的序贯划分与多模匹配的特征编码识别方法，这种方法具有能适应目标姿态角的变化以及能控制识别的差错概率α等优点，在目标识别时只需要目标在少数有限个频率激励下的幅频响应数据。

ABSTRACT Theoretical analysis of the feed pipe inflow of self-excited pulsating and cavitating jet is given on the basis of fluid transient...

利用流体瞬变流和水声学理论分析了自激振荡气蚀射流喷管内的流动规律，建立了喷管内水声学特性的特征方程，并给出了数值解。

Basic hydro-equipments for transition process, namely movement equipment and continuity equipment, are introduced; characteristic line equipment is detruded and finite difference equipments are gained.

介绍流体过渡过程的基本方程组即运动方程和连续方程；推导了的特征线方程，得出了有限差分方程即特征线方程。

To set the coefficient determinant for zero to solve the characteristic equation of one-layered plate, and to calculate the dispersion equation of any layered plates with recursive matrix method.

层状板当上下表面为自由边界面时板中将会产生板波，文中通过求解行列式和采用传递矩阵法分别得到了单层板和任意层板的特征方程，研究了单层板和双层板中板波的频散特性和板中位移和应力的分布，讨论了板波的动力响应，对测点的布置有一定的指导意义。

If the first row interval numbers take zero as a Lower bound, then the character equation has pairs of conjugated imaginary radixes, and the system is in critical stability.

如果第一列区间数以零为下界，则特征方程有成对虚根，系统临界稳定。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失