查询词典 critical damping

Shear force scanning near-field optical microscopy on biological materials is more critical to implement in liquid than in air because of viscous damping and sample softness.

基于剪切力的探针-试样间距控制扫描近场光学显微镜用于生物材料在液体中的成像比在空气中难得多。

Because the central difference method is conditional stable, the critical time step and damping were estimated by model analysis, which can guarantee the computation stability. In this paper, the mesh method was used to described the tool surface.

由于中心差分法的计算是有条件稳定，作者对确定系统临界时间步长和阻尼系数的方法进行了研究，采用模态分析理论估计临界时间步长和阻尼，保证了计算的稳定性。

Numerical method is used to investigate the bogie's ateral stability under diverse nonlinear factors. The influence of nonlinearities and conicity on the critical speed is investigated. The nonlinear forces considered in the bogie system include creep-force between the rail and wheel, longitudinal damping and the flange contact force.

利用数值方法研究了不同非线性力作用下转向架的横向稳定性，得到轮轨饱和力、蠕滑力、纵、横向阻尼力、轮缘死区接触力、踏面斜率以及轮轨间隙对转向架系统线性、非线性临界速度的影响规律。

Adjusting some parameters of the system can change the threshold speed, distribution of the critical speed and the damping characteristics of the system.

在此基础上，详细研究了齿轮参数、轴承参数和结构参数对二平行转子—轴承系统和DH型透平压缩机的失稳转速、临界转速和不平衡响应的影响。

In order to raise the critical temperature for damping applications of damping alloys in the high temperature environment, the as-cast microstructure of Mn-Cu alloys is investigated which is characteristic of the dendrite microstructure with a composition fluctuation.

为解决Mn—Cu阻尼合金使用温度的局限性，本研究选用凝固过程控制的方法在铸造组织中来获得较大幅度的Mn含量分布。从而在Mn-Cu合金得到较高的高阻尼特性温度。

The amplitude has a critical value in its effect on BBD damping, when the amplitude is in excess of the critical value, the damping property of BBD is very good, otherwise, the damping property of BBD is poor.

振幅对BBD阻尼特性的影响有一临界值，当振幅大于此临界值时，BBD的阻尼性能迅速增大，而当振幅小于此临界值时，BBD的阻尼性能较小。

Based on theory of simple harmonic oscillation in physics, this paper presents a novel model for production decline prediction given by deformation of critical damping oscillation equation which is predigested to Arps exponential decline form.

基于物理学中的简谐振动原理，提出了把阻尼振动方程中的临界阻尼振动方程变形得到一种新的产量递减模型，可简化为Arps指数递减形式，经实例计算，可以用来预测油田产量，以此指导油田开发和管理。

Chapter four studies the chaotic responses in a system consisting of simple pendulum and harmonic oscillator under bounded noise excitation. Firstly, the Melnikov function of the two-degree-of-freedom system under Hamiltonian perturbation is derived. The essential condition of the autonomous system for the probable onset of chaos is obtained, the Poincare maps of the system under small Hamiltonian perturbation and the effect of increasing perturbation on the Poincare maps are studies. Then for the non-autonomous system under damping and harmonic or bounded noise excitation, the largest Lyapunov exponent and Poincare maps are calculated. From the analysis of the largest Lyapunov exponent, the critical criterion for the onset of chaos, and the conclusion that the threshold of bounded noise amplitude for the onset of chaos in the system increases as the intensity parameter of Wiener process increases are obtained. The result from the analysis of Poincare maps is in agreement with that obtained from the Largest Lyapunov exponent. The effect of varying damping coefficient and intensity parameter of Wiener process is also analyzed.

第四章研究了有界噪声激励下的两自由度单摆—谐振子系统的混沌运动，首先推导了该两自由度系统仅在Hamilton扰动下的Melnikov函数，得到该自治系统可能产生混沌的必要条件；研究了该系统在小的Hamilton扰动和增大摄动情形下的Poincare截面；然后对有阻尼、谐和或有界噪声激励下的非自治系统数值计算了其最大Lyapunov指数和Poincare截面；从Lyapunov指数分析得到了这个两自由度系统产生混沌运动的临界条件及产生混沌的临界激励幅值随Wiener过程强度参数值的增大而增大的结论，Poincare截面分析的结果亦符合Lyapunov指数分析的结论；研究了Wiener过程强度参数、阻尼系数变化对Poincare截面的影响。

In this paper the nonstationary vibration behavior of an unbalanced rotor system, which is assumed to be bending flexible but torsionally rigid, during acceleration or deceleration through the critical speeds is investigated. Influencing factors such as gyrascopic effects, external and internal damping, Supporting mass, damping and stiffness, asymmetry of the shaft crass section as well as anisotropy of the supports are considered.

在理论分析方面，本文考虑了转子的陀螺效应，内外阻尼，轴截面的非对称性，支承的貭量、阻尼、刚度和支承的各向异性等因素的影响，使用分析动力学，建立起严格的运动方程，并考虑了弯曲自由度与转动自由度间的耦合，因而能较精确地分析和描述转子通过临界点时的非定常振动和转速变化規律。

The analysis results indicate that the vibration fractional factor with rotating frequency has a close relationship with both rotating speed of rotor and damping of bearing under constant acceleration. When rotating acceleration is small and damping is large, the transient response is not sensitive to the variation of rotating speed; otherwise the imbalance response with constant acceleration and the response in stable state will build up obvious differences near critical rotating speed.

研究结果表明：在恒加速条件下，转子同频振动分量与转子的转速、支承阻尼等因素密切相关，当角加速度较小且阻尼较大时，其瞬态响应对转速的波动不敏感；而当角加速度较大或阻尼较小时，恒加速过程不平衡响应与稳态响应在临界转速附近将产生明显的差异。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。