阻尼法

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。

Firstly, based on the wave equation, determining reasonably its initial boundary condition, the paper establishes a computer diagnostic model of oil pumping mechanical well, the damping factor in the model has been reasonably determined, the implicit difference solutionis conducted to the model by changing of step width expression difference solves, and the half analytical solution is explored to the model - fine integral method; and realizes the transformation from dot indicator diagram to indicator diagram of any section.

首先从抽油机井计算机诊断技术的理论基础入手，考虑多级抽油杆连续性，建立了粘滞阻尼波动方程，合理确定模型中的阻尼系数，采用无条件稳定的隐式差分法及半解析方法求解方程，获得抽油杆柱任意断面和抽油泵处的示功图。

In this paper, by using complex configuration optimization method, we calculate the optimum parameters for a given mass TMD to meet the condition of minimum variance of displacement .

本文利用复形调优法进行TMD参数设计的优化计算，研究在满足结构最小均方位移条件下，对于给定质量比的调质阻尼器的最优参数，即最优频率和最优阻尼比。

Based on the concept of the non-proportional damping which may be divided into the proportional part for dissipation of energy and the nonproportional part for transformation of energy, a new modal superposition pseudo-force method is presented if the approximate decoupling method is not suitable. In this method the coupled modal equations are solved by iteration in which the coupling terms are treated as pseudo-force and set to the right side of the equations.

在不能进行近似解耦分析时，基于非比例阻尼可分为耗散能量的比例部分和转换能量的非比例部分这种概念，建立了一种拟力实模态叠加法，即把正则化的耦合模态方程中代表非比例阻尼部分的耦合项作为虚力，放到方程的右端，再运用迭代法求解。

According to structural characteristics of floating slab tracks, a track segment element was taken between two adjacent fasteners. For each element, rails were regarded as Euler beams supported by discrete viscoelastic supports. The fasteners and rubber supports were replaced by a linear spring and damp. So the vibration model of the floating slab track was established. In constructing vibration model of a metro train, each car of the metro train with two suspensions was modeled as a multi-rigid body system, in which rigid bodies were connected with each other by a linear spring and damp. Combining the potential energy of vertical vibration of the track with that of the metro train, the total potential energy of vertical vibration of the train and track was obtained. And then, the matrix equation of vertical vibration of the system was established using the principle of total potential energy with stationary value in elastic system dynamics and the "set-in-right-position" rule for formulating system matrices. The vibration responses of the system can be obtained by solving the matrix equation with the direct time integration such as Wilson-θ method.

摘 要：针对浮置板式轨道结构特点，取相邻2个扣件之间的轨道为1个轨段单元，钢轨视为连续弹性点支承Euler梁，浮置板视为弹性薄板，扣件系统及橡胶支座均模拟为线性弹簧及粘滞阻尼器，建立浮置板式轨道振动模型；将城轨列车中的车辆均离散为多刚体系统，各刚体之间通过线性弹簧及粘滞阻尼器相连，建立列车振动模型；将浮置板式轨道及列车振动势能叠加，得到系统竖向振动总势能；基于弹性系统动力学总势能不变值原理及形成系统矩阵的"对号入座"法则，建立此系统竖向振动矩阵方程；采用Wilson-θ逐步积分法求解此矩阵方程，得出此系统竖向振动响应。

Thirdly, based on the continuum model, the natural modes of undamped complex framed structures are proved to be orthogonal with each other in a generalized sense. This leads to an alternative method for transient response analysis of undamped framed structures via the expansion of normal modes.

再次，基于MRRM列式，从连续模型的角度证明无阻尼复杂框架结构的固有模态具有正交性，并以此为基础构造模态叠加法来求解无阻尼复杂框架结构的瞬态响应。

In orderto improve the complex subspace iteration method for solving undamped gyroscopiceigenvalue problems, we apply the special properties of undamped gyroscopiceigenvalues to it, so we propose double inverse iteration method and double subspaceiteration method.

为了利用无阻尼陀螺特征值的特殊性质，我们进一步讨论了复子空间迭代法在无阻尼陀螺特征值问题中的应用，并给出了双逆迭代算法和双子空间迭代算法。

Unstable solution that may exist in SIRT or SART which converges to the Solution of a least-square problem is avoided.

阻尼代数重建技术，这种方法收敛于阻尼最小二乘解，因而克服了收敛于最小二乘问题的SIRT、SART法可能出现的不稳定解。

The influences of the stiffness and damping of front spring,rear spring and seat cushion were analyzed by orthogonal tests.The seat cushion is the most important for the seat vibration,and the front spring makes a more important effect on seat vibration and hand vibration than the rear spring, the effect of the front spring on seat vibration and hand vibration is not consentaneous.

利用正交优化法分析了悬架、坐垫参数对平顺性的影响，结果表明：坐垫参数对座位处振动影响最大，相比后悬架，前悬架参数对座位处和手把处振动的影响大，前悬架小刚度大阻尼对座位处振动有利，前悬架大刚度小阻尼对手把处振动有利。

The approximation solution of the biomathematical model of muscular blood vessel under the condition of the nonresonant case is obtained. The expansion method for two variables of perturbation theory is used and the approximation solutions are given to the biomathematical model of muscular blood vessel under two cases.

求得了具有小阻尼、硬外激励的肌型血管生物数学模型在非共振情形下的一次近似解，并利用两变量展开法，经方程演化，求得了具有小阻尼、弱外激励的肌型血管生物数学模型在非共振和共振两种情况下的首次渐近解。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。