低频

It is found that traveling waves with either lower frequency or higher frequency can both eliminate the anti-spiral waves, while only the target waves with lower absolute value of frequency can eliminate the anti-spiral waves.

数值计算表明，对于行波，无论是低频行波还是高频行波，都可以成功地消除系统中的反螺旋波；而对于靶波，只有低频靶波才可以消除反螺旋波。

Wavelet modulus maxima with high frequency and low frequency coefficients were obtained firstly through multiscale decomposition of well logging data;then important wavelet coefficients were chosen according to the fusion principle where high frequency coefficients were taken as maximal absolute values and low frequency coefficients were selected by edge detection principle;finally alternating projection algorithm was applied to reconstruct the fusion curve.

首先对原始测井曲线进行多尺度分解，得到不同尺度下的小波低频系数和高频模极大值；然后选用高频系数取绝对值极大、低频系数采用边缘法的融合规则，选取重要的小波系数；最后利用交替投影算法重构融合曲线。

The preparation of electromagnetic shielding concrete adulterated short carbon fibers and graphite respectively have been introduced in this paper.

介绍了分别掺杂短碳纤维和石墨的电磁屏蔽混凝土的制备，研究了短碳纤维和石墨的含量对混凝土低频电磁屏蔽效能的影响，最后分析了短碳纤维的加入对石墨混凝土电磁屏蔽性能的影响机理，为将来设计高性能低频电磁屏蔽混凝土提供了依据。

The result shows that large airgun source excited in reservoir environment is rich in low frequencies (0 Hz), and is effective to produce waves with long-offset and deep crustal penetration.

试验结果表明，大容量气枪震源是具有丰富的10Hz以下低频信号的低频震源，其激发的地震波具有传播距离远，穿透深度深的特点。

It was found that with the increase in the oscillating frequency for a fixed oscillating angle, the film thickness increases, which may contribute to the formation of the oil film; however, the maximum pressure and the pressure scope during an oscillation cycle also increase; which may shorten the fatigue life of the bounding surface in the latter situation.

结果表明：在摆程不变的条件下，膜厚随摆动频率增加而增大，有利于润滑膜的建立，但同时会增加1个周期中的最大压力及压力波动幅度，使工件易于疲劳；对于相同凸度量，在低频摆动工况下边缘效应较高频工况下的严重，因此在低频摆动工况下使用滚子设计时需要增大其凸度量。

The dependence of resistance on the curing temperature illustrated that-codoped BST was capable of exhibiting the positive temperature coefficient effect at low frequency; nevertheless,it might display the negative temperature coefficient effect at other frequencies. The relationships between the resistance and applied voltage revealed that the resistance property of-codoped BST appeared at low frequencies, but its property of capacitive reactance might present at high frequency.

阻温特性曲线显示，在低频时它显示正温度系数效应，在其它频率则显示负温度系数效应电阻与电压关系显示，低频时它呈现电阻特性，而高频时则显示容抗特性。

Experiments shows that it can detect the carrier frequency and the low frequency of modulation signal as expected, the resolution of the carrier frequency is 0.3Hz,the detecting error is within ±0.5Hz, and the resolution of the low modulation frequency is 0.07Hz, the detecting error is within ±0.05Hz.

实验结果表明该检测仪能很好地检测出信号的载频和信号的低频调制信息，其中信号载频的分辨率为0.3Hz，误差范围在±0.5Hz 以内，低频信息的分辨率可达0.07Hz，信号的误差在±0.05Hz。

Besides, another reason of the heavy rain may be that the kinetic energy perturbation is released concentrically in South China.

在对大气低频扰动动能的分析中也发现，华南前汛期降水伴随着低频扰动动能在该地区的集中释放。

Based on description method of damping motion in mechanical vibration, variables movement of generator are divided into two basic motion models: damping oscillation and critical damping motion. Detail methods of extracting damping parameters from simulation data is introduced to establish variable motion models. An approximate method is put forward to simulate low-frequency signal and generator response characteristic, from which motion models and damping parameters of main variables are obtained. The influences of oscillation amplitude, frequency and initial operating point of power system to the motion damping parameters are analyzed.

借鉴机械振动中阻尼运动的描述方法，将低频振荡下发电机主要变量的运动归纳为阻尼振荡和临界阻尼两种基本运动形态；介绍了从仿真数据提取阻尼参数建立参数运动模型的方法，实现对发电机振荡特性的量化分析；提出一种系统侧低频振荡信号的近似模拟方法，并应用于发电机响应仿真，获得了主要变量的运动模型和阻尼参数；分析了系统侧振荡幅度、频率以及初始工况对发电机功角振荡的影响。

Actually ,signals are processed from low frequency domain to high one by modulation firstly and alternating current amplification secondly.It can also improve anti-interference抗干扰 ability of circuit and signal to noise ratio of signals.

实际中往往采用更有效的先调制而后交流放大，将信号从低频区推移到高频区，也可以提高电路的抗干扰能力和信实际中往往采用更有效的先调制而后交流放大，将信号从低频区推移到高频区，号的信噪比。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失