绝对

A threshold current which brings about the transition to absolute instability was investigated.

分析表明，绝对不稳定性的起振存在一定阈值，起振电流对电子注参数和电路参数极其敏感，确定起振电流是稳定器件工作的前提条件。

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。

The numerical results show that lossy dielectric-load can heighten the start oscillation current of absolute instability, and increase depends on the magnetic field strength and the perpendicular-to-parallel velocity ratio of the electrons; The thickness of the lossy waveguide increases the start oscillation length of backward wave oscillation.

结果表明：损耗介质的加载，可以提高绝对不稳定性起振电流，提高的幅度依赖于工作磁场偏离饱和磁场的程度、电子束横纵速度比等；增加波导损耗介质加载的厚度，可以提高竞争模式的回旋返波起振长度。

In addition,Various methods of stability analysis of wakes behind bluff bodies arediscussed,among which the general theory of absolute/convective instability is strictlyformulized from stability equations of viscous flow;the theoretical foundation of stabil-ity analysis of time-average flows is also discussed from basic equations of fluids,andthe reason for the stability analysis of time-average flow can predict the frequency inthe saturation state is explaned.

此外，讨论了钝体尾迹稳定性分析的各种方法，其中从粘性流的稳定性方程出发严格推导了绝对/对流不稳定性的理论公式；从基本方程出发探讨了采用时均流场作稳定性分析的可行性，并解释了用时均流场作稳定性分析可以更好地预示饱和频率的原因。

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。

In the second chapter, we investigate propagations of desynchronous disturbances in synchronized chaotic one-way coupled map lattices. It is well known that spatiotemporally chaotic systems with large gradient couplings may show convective instability under the absolute stability condition of chaos synchronization. This convective instability is the key reason for the effective propagation of control signals.

时空混沌在不同的耦合系数情况下会表现出不同的动力学行为，用驱动实现具有强梯度耦合系数的时空混沌同步时，会观察到在绝对稳定条件下被驱动系统表现出对流不稳定性，这种对流不稳定性是在单个信号驱动下实现混沌同步的关键原因。

The formation mechanism of the absolute instability and gyrotron backward wave oscillations is analyzed, and the methods to suppress the parasitical modes are discussed.The nonlinear theory model of gyro-TWT is consummated by considering the influence of tapered magnetic field and waveguide radius, electron velocity spread, and waveguide loss on electron beam-wave interaction. The large-signal characteristic of gyro-TWT, such as launching loss and absolute instability, are also analyzed in detail. This work establishes the foundation for the development of a gyro-TWT amplifier.

重点研究了两段损耗波导结构和损耗陶瓷结构回旋行波管中的电子注-波互作用，分析了绝对不稳定性和回旋返波振荡的形成机制和抑制寄生模式的方法；完善了回旋行波管的非线性理论模型，并考虑了磁场和波导半径渐变、速度零散、波导损耗等因素对注-波互作用的影响；详细分析了发射损耗、相位稳定性等回旋行波管的大信号特征，为回旋行波管放大器的研制奠定了基础。

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。

This paper, with the analysis of the propagation characteristics in a lossy cylindrical waveguide and using small-signal theoretical dispersion relation, presents study on the device stability with influence of the absolute instability and the backward wave oscillation in TE01-mode lossy dielectric-load gyrotron traveling wave amplifier.

摘要该文从分析损耗介质加载金属圆波导中电磁波传输特性出发，应用回旋行波管放大器小信号色散方程，研究损耗介质加载结构TE01模回旋行波管放大器绝对不稳定性振荡和回旋返波振荡对器件稳定性的影响。

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。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。