低频

On the basis of previously research, this paper re-probe into the mechanism of electro-chemist mechanical manufacturing process, making the rational technological parameter, and developing the manufacturing equipment. Through a lot of technology tests, get a lot of labratory data, accordingly, researched the surface feature of the electro-chemist manufacturing process, and deeply discussed its influence on the work piece feature. The last result is that: the electro-chemist mechanical manufacturing process can reduce the low-frequency component significantly, but on high-frequency component, it has little influence, having obviously positive pole flat effect. After manufacture, the tip parts on the surface of the work piece is cut off, there is micro "high land" shape, the parameter for surface roughness is reduced a lot, the surface outline of the work piece is negative, the bearing length rate is cliffy. Also the surface quality of the work piece is improved. This can help to avoid changing the shape, improve the feature of rub, gear and reduce the time to suit. This would also ensure the precision and result in a longer work piece life.

在以前研究的基础上，本论文重新探讨了电化学机械复合光整加工工艺的机理，确定了较合理的工艺参数，对电化学机械复合光整加工设备进行了改进，通过工艺实验广泛地搜集了大量实验数据，依据实验数据，多角度地研究了电化学机械复合光整加工的表面形貌特点，并且从理论上深入讨论了电化学机械复合光整加工表面形貌对工件工作性能的影响，最后得出的结论为：电化学机械复合光整加工对工件原始表面的低频成分有较大程度的降低，而对高频成分影响较小，有明显的阳极整平作用，被加工工件表面的尖峰状凸起被去除，工件表面呈现出微观&高原型&，表面轮廓不平度高度特性参数大幅度降低，工件表面轮廓分布集中，且呈负偏态，轮廓偏斜度为负值，轮廓支承长度率曲线陡峭，工件的表面质量得到综合改善，这对提高零件的抗接触变形能力、改善摩擦、磨损性能、降低工件的磨合时间、提高工件的精度保持性、延长工件的寿命均有利。

Chapter four is devoted to plasma cloaking. The research status of dusty plasma physics is reviewed in chapter five.

因此本论文在第二部分专题研究中专门研究了尘粒对离子输运的影响和碰撞尘埃等离子体中的低频波。

The lower PBG exists in one third of the first Brilloin zone while the upper one can appear, simultaneously and complimentarily, in the rest two thirds of the first Brillouin zone.

低频光子带隙在1/3布里渊区内存在，而高频的光子能带在另外的2/3布里渊区内存在。

And the cathode heat appearance to also flap to concuss to have influence to the low frequency.

而阴极加热状态也对低频振荡有所影响。

For studying the exterior back track to the influence that the low frequency flaps to concuss, designing different back track parameter to match an experiment will carry on small wave a processing as a result also.

为了研究外部回路对低频振荡的影响，设计了不同回路参数匹配实验并将结果进行小波处理。

Taking a 3-machine system for example, the rational positions to configurate the PSS are selected, thus the correctness of the proposed method is verified.

特征向量分析法是由Demello F.P。等人于1980年提出的，其主要思想是：比较特征向量各分量模的大小，选出低频振荡的&主要振源&，然后

Based on the extended Phillips-Heffron model for the multi-machine power system and model control theory, a new model control analysis method of free eigensolution is proposed to select the rational position to configurate power system stabilizer in multi-machine power system.

引言 电力系统中的低频振荡是由于缺乏机械模式阻尼而引起的，为了抑制这种振荡，提高电力系统的阻尼及其稳定性，在电力系统中设置电力系统稳定器(Power system Stabi一izer，Pss)是一种经济而有效的方法〔'，2。

Low-frequency covibration experiments of four kinds of fluid-saturated feldspar sandstones which have different viscosity coefficients respectively were conducted so as to know how fluid viscosity coefficient influences attenuation, modulus and velocity dispersion in fluid-saturated sandstone.

为了探讨孔隙流体的黏滞系数对饱和砂岩的衰减、模量和速度色散的影响，本文进行了四种不同黏滞系数的饱和长石砂岩的低频共振实验，结果发现在0.01～10Hz频带范围内，无论是衰减温度话还是衰减频率谱，都显示出衰减随黏滞系数的增大成良好的线性增长关系，黏滞系数越大楼量越大；同时还具有明显的模量与速度色激，而且随着黏滞系数的增大，模量与速度色权有增强的趋势。

All these characteristics can extend frequency band , reduce antennaelectric size and improve impedance characteristics. In order to miniaturization ofantenna, impedance complete compensate and matching optimization of electricallysmall antenna are brought forward, and this method is applied to the discage antennas.

从阻抗特性和辐射特性的实测数据表明，水加载单极振子天线的谐振频率能很好地向低端下移，局部水加载单极圆锥天线在保持原有宽频带特性的前提下，以较少的效率损失实现了较大范围向低频区扩展，即天线小型化，这将为短波超短波波段天线进一步的小型化设计提供很好的思路。

Objective: To examine the therapeutic effects of dual dorsolateral prefrontal repetitive transcranial magnetic stimulation on auditory hallucinations experienced by schizophrenic patients.

目的：初步探讨双背侧前额叶低频重复经颅磁刺激治疗精神分裂症顽固性幻听的疗效和安全性，并观察其副反应。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。