查询词典 instability

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。

We estimated the conditional symmetry instability by absolute and geostrophic momentem and comparative potential temperature.

利用角动量和相当位温对条件性对称不稳定进行定性判断，此次降雨过程的确存在对称不稳定和对流不稳定。

The physical interpretations,character and suppressing methods of absolute instability were analyzed and verified by a W-band TE_(01) experiment.

通过回旋行波管色散方程，详细分析了W波段基波回旋行波管绝对不稳定性的形成和特征，提出了采用多段损耗波导来抑制绝对不稳定性的方法。

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。

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。

The basicflows are computed by a low-dimensional Galerkin method.The results confirm thattwo times global mode switching occur with increasing Re up to which the Hopf bifur-cation occurs when the absolutely unstable region cover the whole reversed flow region,and the first explanation of this phenomenon with absolute/convective instability theoryis given.

结果证实了只有当绝对不稳定性区域完全覆盖了回流区才会形成整体的Hopf分叉，此前随着Re数的增加整体模态经历了两次跳跃；并首次用绝对/对流不稳定性理论解释了这一现象。

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。

A carrier gas such as nitrogen is directed through line 20 and valve 22 to connect with line 26 and mix with the gas sample.

如氮气之类的载体通过管线20和阀22引入，与管线26相通，与气体样品混合。

But for the most part, knaves and parasites had the command of his fortune

然而支配他的家产的大多是恶棍和寄生虫。