自然振动

Buffeting is a kind of usual and stochastic vibration with limited amplitude under natural wind.

抖振是桥梁在自然风作用下的一种经常性的、随机的限幅振动。

Horizontal contraposition multistage piston compressor, designed in accordance with API standard, leads the trend of compressor field. Its advantages of unvibrating operating and durable using structure 、 continuous working and natural cooling attract more and more compressor users. In addition, that it can be wholly skid mounted makes transportation, installation and maintenance more convenient, that alters the traditional demanding for installation.

依据 API 标准设计的水平对置多级活塞压缩机代表着压缩机领域的潮流，其以无振动运转、平稳耐用的结构，持续工作及自然风冷的特点越来越被压缩机使用者所青睐，特别是它整体撬装使运输安装和维护更方便快捷，改变了传统的对安装基础的要求。

Firstly, the natural frequencies and normal mode shapes of the fluid-conveying pipe with zero fluid velocity (i.e. U=0) were determined with the transfer matrix method. Next, these natural frequencies and normal mode shapes were used to derive the equation of motion for the fluid-conveying pipe with fluid velocity U.neq.0 by using the expansion theorem. Finally, the free and forced vibration responses of the pipe with flowing fluid were obtained by means of the Jacobi method and the Newmark direct integration method.

首先吾人使用转移矩阵法来求取一流速等於零(即U=0)、跨距数为N之流体输送管的自然频率及其所对应之正规化振态，然后利用振态重叠法原理来推导流速不等於零(即U.neq.0)时，整个流体输送管在外力作用下的运动方程式，最后再以Jacobi法及Newmark直接积分法来计算该水平流体输送管的自然频率及强迫振动反应。

Then the paper analyzes the responses of the forced vibration under the considerations of the nature growth and the load of wind.

然后本文在考虑云杉的自然生长情况和风载作用的前提下，分析云杉的受迫振动响应。

If the excitation frequency is close to one of the natural frequencies of the bridge, further analysis is required to determine the dynamic amplification in what is known as a 'forced vibration' analysis.

如果激励频率接近一个自然频率的桥梁，进一步分析必须确定动态扩增什么是所谓的'强迫振动分析。

Therefore, we must first remove the vibration at natural frequency of geophone when underging information processing.

在作信息处理时，必须首先消去检波器自然频率的振动。

Sound is a mechanical disturbance of a wave nature that propagates through any elastic medium at a speed characteristic of that medium.

声音是一种自然波的机械振动，通过弹性介质传播，速度取决于由该介质的特性。

Application of proportional controller to active vibration control incorporated with passive vibration isolator to suppress its resonant oscillation of natural frequency is proposed in this paper. Vibration acceleration acquired from accelerator is inputted to controller as feedback signal. The processed signal from controller is transmitted to voice coil actuator to control vibration.

本文主要是运用比例控制器进行被动式隔振系统自然频率共振抑制之主动控制研究，控制回馈讯号采用加速规量得之振动加速度值，经由控制器计算输出控制讯号驱动音圈致动器进行主动控制。

In the experimental work, application of proportional controller to active vibration control incorporated with passive vibration isolator to suppress its resonant oscillation of natural frequency is studied in this project. Vibration acceleration acquired from accelerator is inputted to controller as feedback signal. The processed signal from controller is transmitted to voice coil actuator to control vibration. Firstly, based on the theoretical equations which govern the system vibration, the physical mechanism of active control in total system is studied.

在实验部分，则运用比例控制器进行被动式隔振系统自然频率共振抑制之主动控制实验，控制回馈讯号采用加速规量得之振动加速度值，经由控制器计算输出控制讯号驱动音圈致动器进行主动控制。

The main reason of wind vibration is a pulsant part of nature wind, unremitting vibration may bring large distortion and stress in the structure, and at the same time, it will bring fatigue damnification to the structure.

自然风中的脉动风分量是引起结构风激振动的主要因素，持续的振动可引起建筑幕墙结构产生较大的变形及应力，同时引起结构的疲劳损伤。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。