查询词典 instability

Absolute instability is a major physics limitation in the realization of the ultimate capability of gyro-traveling-wave tube.

绝对不稳定性是制约回旋行波管性能的主要因素之一。

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。

PIC results show that the occurrence of absolute instability is determined by the operating current.

通过PIC模拟，给出了采用无损耗波导结构，且工作电流为25A和10A条件下的放大器频谱图和功率图，结果表明绝对不稳定性的出现与否主要由工作电流是否超过起振的阈值电流决定，损耗波导是抑制绝对不稳定性的有效手段。

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。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。