振动周期

The kinematics parameters were firstly presented by establishing the mechanical model of relation between the vibration screen and particle to deduce periodicity condition of particle motion,then disturbing function of particle motion for periodic motion was educed by using Poincaré mapping method,and studied motion characteristics of particle in vibration screening in terms of numerical analysis.

利用振动筛与颗粒之间关系的运动学模型，导出颗粒运动的周期性条件；然后利用Poincaré映射方法，推导出颗粒的运动对周期运动的扰动方程；最后对振动筛分过程中颗粒运动特性进行了数值计算研究，得出了筛面上颗粒运动是经周期分叉和概周期分叉通向混沌的演化过程。

In this paper, the almost periodic solution for a class of two-degree-of-freedom nonlinear oscillating systems is studied by using the Leray-Schauder fixed point theorem and the method of Liapunov function.

运用Leray-Schauder不动点定理和Liapunov函数方法，研究了一类两自由度非线性振动系统的概周期解，得到了该振动系统概周期解存在的充分条件。

Firstly, the function sinx that appears in the simple pendulum equation is replaced with a polynomial of degree 3 using Maclaurin series expansion and Chebyshev polynomial approximation. Subsequently, the resulting equation which is a Duffing type equation is approximately solved with combing Newton's method and the harmonic balance method.

首先，利用Maclaurin展开和Chebyshev多项式加速技术将单摆振动方程中的正弦型恢复力用三次多项式近似代替，得到一个Duffing型方程；然后，将牛顿法与谐波平衡法结合起来建立Duffing方程的解析逼近周期及周期解，从而给出单摆振动的解析逼近解。

The results show that the variations of summer temperature and precipitation in Chongqing contain obvious staggered features. The variations of precipitation are more complex than that of temperature. Three\|year period\|oscillation of mean temperature variations is the strongest,...

结果表明，重庆市夏季气温及降水变化具有明显的阶段性，且降水变化较气温更复杂；重庆市夏季平均气温变化以3年周期振动最强，而降水变化则以10年周期振动最强。

It is pointed out that the solution of the differential equation is a periodic function.

建立了水平方向静电悬浮非线性系统微分方程形式的数学模型，指明了该微分方程的解是振动周期函数。

It is demonstrated that the system can exhibit unstable periodic 3 3 motion bifurcated from periodic 1 1 motion on the resonance condition, and the transition from subharmonic impacts to chaos is disscussed.

分析并证实了碰撞振动系统在此共振条件下可由稳定的周期 1 1振动分叉为不稳定的周期 3 3振动，讨论了亚谐振动向混沌运动的演化过程

The vibro-impact systems are familiar with the non-smooth dynamic systems.The dynamics research of the vibro-impact systems not only is significant in theory but also has practical values in engineering.Firstly,using the Poincaré map method,we get an existent criterion of single impact period-n motion in a two-degree-of-freedom vibro-impact system with damper.It is shown that our conclusions are valid through the numerical simulations.Moreover,the satiability of periodic motions is studied and the correspon...

基于Poincaré映射的方法，通过解析的方法导出了一类具有阻尼的两自由度碰撞振动系统的单碰周期n次谐运动存在性判据，经过数值模拟验证了理论分析的正确性，并给出了分析其稳定性的判别公式，通过数值模拟，讨论系统的局部分岔与全局分岔，同时比较了系统参数变化对其周期运动的影响，发现在强阻尼、弱激励、小质量比、较大恢复系数下系统将会出现较多的有规律的周期碰撞。

In this dissertation, periodic impact motions in vibro-impact systems are studied, and the existence and stability of superharmonic periodic impact motions are obtained. The critical bifurcation parameter intervals of superharmonic periodic impact motions are deduced, and numerical simulations are used to verify the results.

中文题名碰振或约束系统的全局分析及稳定性研究副题名外文题名 Studies on global analysis and stability in vibro-impact or constraint systems 论文作者张彦梅导师陆启韶教授学科专业一般力学与力学基础研究领域\研究方向学位级别博士学位授予单位北京航空航天大学学位授予日期2002 论文页码总数95页关键词碰振系统转子系统多体系统碰撞振动馆藏号BSLW /2003 /O322 /1 本论文讨论了碰撞振动系统的周期碰撞运动，得到了超谐周期碰撞运动的存在性和稳定性，推导出亚谐周期运动的临界分岔参数区间，并利用数值模拟进行验证。

For this purpose, from 2004 to 2006 Professor Zhang create uniform limit power function space and strong limit power function space that are large, nice spaces.

Sarason在1984年提出了遥远概周期函数和缓慢振动函数并提出了一个公开问题，本文对这两个函数主要做了以下工作第一，将在一维空间中定义的遥远概周期函数和缓慢振动函数推广到高维空间，并指出其与一致极限幂函数和强极限幂函数等新的极限幂函数的关系。

Pressure waves from continuous vibration look more like this

另一个声波的类型是周期波，当你击打一个铃时，击打下去的那一个瞬间跟拍手有一点相像，声音由铃的振动产生，当铃持续发出声音时，它的震动是以一个特别的频率进行的，这个频率与铃的大小和形状有关，而这个振动造成了铃周围的空气也以相同的频率振动，这使得铃声透过空气的压力波传递到更远的地方，以声音的既有速度进行，持续震动的压力波看起来跟以下这个图很像

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。