揭示出冷空气的向南传播主要是一种低频模态的10—20天周期的振荡。
It has been revealed that the propagation of cold air mainly shows a mode of 10—20 day period oscillation.
三波共振相互作用低频振荡周期与初始扰动振幅有很强的相关关系；
The low-frequency fluctuation periods and the initial amplitudes have close relationship in the resonance interaction.
反映滚动轴承故障的特征周期信号处于较低频带内，容易被噪声淹没，难以检测。
The fault characteristic periodic signals of the rolling bearing are in low frequency band and often buried in the noise.
对于相同的初始扰动振幅，随着波数的增加，低频振荡周期缩短，三波逐渐变得不稳定，三波之间较强的相互作用时间缩短。
For the same initial amplitudes, the periods are becoming short, the three waves are gradually becoming instability, and the time of strong interaction is shorting with increasing of wave Numbers.
电力系统强迫功率振荡为持续的周期性小扰动所引起低频振荡现象。
Power System forced power oscillation is a kind of low frequency oscillation caused by persistent periodic small disturbance.
也许“震荡”一词并不准确，因为它们的设计是低频震荡，而且周期是间断性的。
Perhaps the term "vibrating" is not quite accurate since they are designed for low frequency vibration and the vibration cycle is intermittent.
外源强度越强（弱），大气低频振荡周期将缩短（延长）；
The stronger (weaker) the external source , the periods of LFO the shorter (longer);
谱分析显示，两岸的水位低频变化均以年周期为主，但两岸间的水位差却以半年周期为主。
Spectrum analysis showed that the main period of low frequency sea level variations at both coasts was annual, while that of sea level differences between the two coasts was semiannual.
采用流式细胞分析法检测了低频脉冲电场对人真皮成纤维细胞细胞周期的影响。
The effect of low frequency pulsed electric field on dermal fibroblast was examined by flow cytometry analysis.
它能精确测量任意波形的低频模拟周期信号并同时显示其有效值和分贝值。
It not only can measure the discretionary low frequency analog signals exactly, but also can simultaneously show their virtual values and decibels.
研究结果表明：改变周期结构单元的几何尺寸和材料特性，能将带隙频率范围扩大并延伸至低频。
The results show that the stop band can be tuned by modifying material and geometric parameters of periodic mounts.
实验结果表明该检测系统可有效地避开空间的电晕及周期性脉冲干扰信号等低频段干扰。
The results indicate that the UHF system of detecting PD can effectively detect partial discharge and avoid outer corona interfere and Periodic pulse interfere.
它能精确测量任意波形的低频模拟周期信号并同时显示其有效值和分贝值。具有智能量程转换功能。
It not only can measure discretionary low-frequency analog signals exactly, but also can show their virtual values and decibels synchronously, which has the intelligent selectiveness of measure.
结果显示，青海南部高原地区春季最高气温的变化存在较明显的31~54年低频和2~4年高频准周期波动特征。
The result shows that there exist pronounced lower-frequency periodicities of 31~54 years and higher-frequency variations of 2~4 years.
由于低频振荡频率较低、周期较长、波及面较广，给电力系统带来的危害也较大。
This paper describes the mechanism of power system low frequency oscillation production, and discusses the current common analysis methods. Through comparative ana…
由于低频振荡频率较低、周期较长、波及面较广，给电力系统带来的危害也较大。
This paper describes the mechanism of power system low frequency oscillation production, and discusses the current common analysis methods. Through comparative ana…
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