振动的

There are various techniques for constructing analytical approximations to the nonlinear differential equation.

早期研究非线性振动的理论分析方法多局限於弱非线性振动系统，碰到强非线性振动系统就显的无能为力。

The effect of conventional audiphone for the treatment of conduction deafness is unsatisfactory.

颞骨振动器是利用声音－交变电磁场－机械振动的转换，由颞骨的振动引起听觉。

Moreover, combined with the instance of building, the finite element method for calculating building vibration from subway and its influencing factor is analyzed.

进一步结合实例分析了地铁振动影响下建筑物振动的有限元计算方法及建筑内振动传播的基本规律。

Characteristics of free vibration and forced vibration of a damped system with dry frictional damping,viscous damping and c x·2 damping are analyzed and calculated,acceleration response of free-vibration of the dry frictional damped system has a sudden change when x· is zero,the change value is constant and depends only on the natural frequency ωn and the displacement xk due to dry friction.

本文对存在干摩擦阻尼、粘性阻尼和c.x2阻尼系统的自由振动及受迫振动特性进行了解析及数值计算，得到干摩擦阻尼系统自由振动的加速度响应在速度零点有一突变，这一变化量为定值，且只与系统固有频率ωn及摩擦当量位移xk有关。

In this part, the characteristics of transient responses of flexible rotor systems with arbitrarily distributed mass on isotropic or anisotropic supports passing through several critical speeds seguencially are examined. Here, the current knowledge of rotor dynamics on the eigenproblem of damped free whirling vibration, the generaliged damped mode theary, the transient forced vibration and so on combined with KBM asymptotic method in the nonlinear vibration theory is employed and extended.

作者综合运用并引伸推广转子动力学关于阻尼自由回旋振动的特征问题、广义阻尼模态理论、瞬态强廹振动等現代理论和方法，结合非线性振动理论中的KBM渐近法，提出自己独創見解和覌点，成功地建立起正回旋和逆回旋两种情况下转子通过临界点的瞬态振动一阶微分方程组，可以在临界点的邻域内从事方程的数值积分计算。

Moreover, using two-dimension model, the vibration attenuation law of free field in thick-layered soft soil is analyzed, and the soil scopes requiring consider by various limit criterions is obtained for building.

利用二维模型分析了厚层软土情况地铁环境振动的自由场衰减规律，得出建筑在不同振动限值标准情况下需要考虑振动影响的范围。

Starting from the main meteorological factors impacting vibration of overhead line, the impact of conductor tension variety on self-damping feature of conductors is analyzed according to state equations of overhead line, and by use of energy balance principle the variation of vibration level is calculated and the vibration life under different meteorological conditions are obtained.

文章提出了一种基于短期测量数据评估线路全年振动状态和寿命的方法，从气象影响线路振动的主要因素出发，根据导线的状态方程分析导线因张力变化对导线自阻尼特性的影响，并采用功率平衡法计算出振动水平的变化，得到了不同气象条件下的振动寿命。

In the part of the vibration experiments and analysis, firstly, used the simple-beam theory to estimate the natural frequency of the beam of the 20-headed computerized embroidery machine.secondly, measured the beam of its low rank natural frequency, the beams horizontal vibrating acceleration amplitude, speed amplitude and the displacement amplitude in different rev and different turn parts. Found that it is sympathetic vibration, which bring on the thread-broken rate rise rapidly. On this base, established the finite element analysis modle of the vibrating beam, and took on hamonic analysis and modal analysis with the mold. The rusult of test and analysis offer the basis for farther improvement of the computerized embroidery machine.

振动分析部分，首先由简单梁理论出发，对横梁的固有频率进行估算；接着通过测振仪器对20头电脑刺绣机横梁进行了试验模态分析和不同工况振动测试；获得了横梁前四阶固有频率和模态振型，以及在不同工作转速、不同回转部件下横梁振动的加速度幅值、速度幅值和位移幅值；找到了横梁振动加剧的原因——共振；在此基础上建立了符合实际情况的横梁有限元模型，对模型进行了模态和谐响应计算，证实了模型的可靠性，为下一步的改进设计提供了依据。

The results show that the vibration intensity of the substructure has a connection with the depth of the well, the geological condition and the density of drilling fluid; the horizontal vibration of the substructure is mainly caused by bent kelly; the included angle between the axis of cardan shaft and the derrick floor is also the cause of the vibration in three directions, and the cause of t...

分析结果表明，底座的振动强度与井深、地质条件和钻井液密度有关；弯曲的方钻杆是造成底座水平方向振动的最主要原因；万向轴因与钻台面存在夹角，从而引起底座在三个方向的振动；采用四挡钻进时，万向轴的工频及其倍频接近底座垂直方向的固有频率是引起底座在该方向振动强烈的原因。

The non-uniform flow behind a rigid cylinder row with a small pitch ratio T/D= 1.5 is characterized by narrow and wide near wakes and multiple frequencies, and the vortex shedding behind a rigid cylinder row with T/D= 2.0 is replicated properly by the simulation results.

此外，还研究了单列自由振动的弹性圆柱在间隙比为2.0时的流体诱导振动问题，结果表明：在大振幅条件下，流体诱导力在x方向和y方向有较强烈的耦合；随着振幅的减小，x方向振动对y方向振动的影响可以忽略，可采用单自由度的动力学模型假设进行计算。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。