绝对不稳定

According to the understanding of the flow characteristics, a mechanism of formation of vortex streets has been proposed to be the absolute instability of the wake, and several methods of flow control have been developed and shown successful.

根据表面流动及尾流特性的研究结果，从流动稳定性的角度提出了尾流中涡街产生的机理，在于尾流中存在着绝对不稳定的区域。基于对流动特性的理解，从改变流动稳定性的角度，寻求各种流动控制方法。试验结果表明这些方法是成功的。

In addition, the absolute/convective instability is studied, and the governing region in the parameter plane is declared. It is shown that the absolute instability may become predominant when the electric field or the surface tension is sufficiently large.

另外，研究了单流体射流的绝对和对流不稳定性，在参数平面上给出了它们的控制区域，发现在电场强度足够大或表面张力足够大时，射流可能由对流不稳定状态进入绝对不稳定状态。

The unstable fracture of scapular neck can be divided into two main types: absolute instability and relative instability, based on the stability of the glenoid fragment in the scapular neck fracture. The former needs early operation.

根据不稳定性肩胛颈骨折中的关节盂骨折块的稳定程度，可将其分为关节盂骨折块绝对不稳定和相对不稳定两类。

Start-oscillation current will be down by absolute instability of TE02 and TE01 modes and electron velocity ratio and interaction section, it can be suppressed by the distributed wall losses.

模拟结果显示，TE02、TE01模式绝对不稳定的引发使得原有操作电流降低，其起振电流明显受电子速率比、作用段长度的影响，但此模式可藉由损耗来抑制，此结论与线性理论结果一致。

Therefore, the interaction structures with distributed wall losses and attenuating severs were more stability for absolute instability and gyrotron backward oscillations.

藉由引用非线性程式进行磁旋行波放大器稳定分析，结果显示散布式损耗(distributed-losses)的设计对绝对不稳定有明显的抑制作用，而隔离管结构亦具有减短磁旋返波振荡作用长度的效用，因此我们采用兼具隔离管及散布式损耗结构的磁旋行波放大器，同时提升绝对不稳定和磁旋返波振荡的稳定性。

However, operating of the high current, the output power, gain, and efficiency of gyro-TWT will be degraded where the absolute instability, gyrotron backward oscillation and reflective oscillation occur to cause mode competition. Stability issues comprise the key factors limiting the performance of the gyro-TWT.

对於高电流的影响，磁旋行波放大器将有可能引发绝对不稳定、磁旋返波振荡(gyrotron backward oscillation；gyro-BWO)及反射振荡，造成模式竞争而抑制原先操作模式的放大波，进而影响其输出功率、增益及效率。

Therefore, the multi-stage interaction structures with losses and severed structure were more stability for absolute instability and gyrotron backward oscillations. This study presents a nonlinear analysis of typical oscillations, including absolute instability, gyrotron backward oscillation and reflective oscillation. The multi-stage gyro-TWT seem to increase effectively the start-oscillation currents of the absolute instability, gyro-BWO, and reflection oscillation.

所以在本研究分析中，藉由了解磁旋行波放大器中的自发振荡物理原因及特性，将有助於高功率放大器的设计，并且引用非线性程式进行磁旋行波放大器稳定分析，并且采用兼具隔离管及散布式损耗结构的磁旋行波放大器，同时提升绝对不稳定、磁旋返波振荡及反射振荡的稳定性能有效提升磁旋行波放大器输出功率和频宽。

Therefore, the moist potential vorticity analysis associated with the mesoscale convective system was researched in the paper, so as to reveal the moist potential characteristics of mesoscale convective system in typhoon circulation. The results showed that, during the generation stage, convective instability characterized by MPV1 was a favorable condition for forming MCS, while the vorticity which was caused by the slantwise isentropic surface and the vertical shear of the horizontal wind characterized by MPV2 was an inspiring mechanism. The specific process was that, the atmosphere exhibited the feature of strong convective instability at the low level of convection areas and the southeast areas, which included plenty of erratic energy. The slantwise ascended the stream transfer the erratic energy to northwest, where the stratification stability was small. As decreased, the cyclonic vorticity increased. On the other hand, the vorticity caused by the slantwise isentropic surface and the vertical shear of the horizontal wind inspired the release of convective instability and as a result that the MCS formed. During the development stage, the cyclonic vorticity increased quickly with the persistent decreasing of . Meanwhile, the inclination of isentropic linewas bigger than the absolute momentum line at middle level, which exhibited the feature of conditional symmetric instability , then the conditional symmetric instability was forced to release by the vorticity resulted from the slantwise isentropic surface and the vertical shear of horizontal wind, and the MCS developed.

结果表明，在对流形成阶段，MPV1即对流不稳定为MCS的形成提供背景不稳定条件，由MPV2即湿等熵面的倾斜和水平风的垂直切变而引起的涡旋发展作为强迫机制：MCS形成的区域及东南区域中低层是强对流不稳定层，蕴含丰富的不稳定能量，倾斜上升运动把对流不稳定区具有强不稳定能量的暖湿空气向西北中层的中性层结区输送，由于的减小，气旋性涡度增强，有利于形成对流，另一方面，由于湿等熵面倾斜和低空急流加强而引起的涡旋发展作为一种强迫机制激发对流不稳定能量得到释放，从而形成对流；在对流系统地发展阶段，由于低层的对流不稳定性进一步减弱，进一步减小，气旋性涡度进一步增强，有利于MCS的增强，中层等θe 线的倾斜度比绝对动量M 等值线的倾斜度大，对应有条件对称不稳定区域，满足条件对称不稳定条件，在湿等熵面倾斜和台风低空急流作用下引起的涡旋发展强迫对称不稳定能量释放，从而使得对流得以维持和加强。

It is difficult to control a single inverted pendulum system because of the characteristics of multi-variable, nonlinear and absolutely instability of the system. A controller based on adaptative neuro-fuzzy inference system is designed by using Matlab/Simulink software in the paper. For the sampling data the hybrid algorithm of back propagation algorithm and least squares algorithm is applied in the paper. Thus the parameters of membership function are adjusted and all of the fuzzy rules are generated automatically.

摘 要：针对单级倒立摆系统具有多变量、非线性、绝对不稳定的特点，本文应用Matlab/Simulink 设计了用于倒立摆系统的基于自适应神经模糊推理系统的ANFIS控制器，采用反向传播算法和最小二乘算法的混合算法对倒立摆控制样本数据进行学习，调整各变量的隶属度函数，自动产生模糊规则。

The control system for parallel-type double inverted pendulumthat features multi-variable,strong coupling,hish order and absolutely unstable in open loop,is studied.

赵万青，魏利胜，费敏锐研究了一种具有多变量、强耦合、高阶次和开环绝对不稳定等复杂特性的双并联倒立摆控制系统。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。