旋转运动

The larger subharmonic component will be introduced into the system after the instability of system periodic motions, the motion of systems will be nonsynchronous precession and the amplitude of alternate stress in the rotor shaft is high. The long-term existence of instability will directly threaten the safe running of the rotor systems. Research on the influence of the change of system parameters on the system dynamical behaviors, the stability of system periodic solutions with the change of system rotational speed and the system motion after instability will have the theoretical and engineering-oriented significance for the long-term safe running of large-scale rotating machinery.

转子系统失稳后会产生较大的低频振动分量，系统运动出现非协调进动，系统转轴中会产生幅值很大的交变应力，转子失稳状态的存在直接影响系统的安全运行，因此研究转子系统自身参数的变化对系统动力稳定性的影响，研究系统周期解随工作转速的变化情况及其失稳后的运动规律，对大型旋转机械的安全稳定运行具有重要的理论意义和工程实用价值。

This method can make sure the structure radiant sound status in total noise and the detail phonate part quickly and correctly.(3) Study on the control mechanism of structure noise radiated from rotary machines, we build a common model of rotary machine structure noise analysis relied on the general characters of rotary machines. Based on this model, we analyzed various influence factors to structure radiant noise using the union of revolution and numerical calculation method. We found that the joint stiffness between the rotor and the frame is the most sensitive parameter of structure radiant noise by calculating and analyzing.

根据本文对于旋转机械结构噪声控制技术的研究结果和惯性振动筛工作的特殊要求，对有关参数的选择进行了讨论，并通过试验为降低惯性振动筛噪声找到了两个新的方法：即，在轴间相对运动要求不高的情况下，可以在激振器与筛体之间安装一组减振器，通过适当选取减振器参数，既可以使机体在工作频率附近获得稳定振幅，保证振动筛正常工作，又可以使机体的高频响应减小，降噪效果显著；反之，如果轴间相对运动精度要求(来源：1aABC论文网www.abclunwen.com)较高，可以采用空心滚动体轴承，在保证滚动体强度的条件下也可以获得较好的降噪效果。

The calculation results shows that ,(1) when the rotor rotates at the working speed, a local regurgitant whirlpool that is rightabout to the rotor"s rotating direction appears in the classifying region, which makes the separated granules come back to the outside of the classification district and influences the classification efficiency of the turbine classifier;(2) in the condition of a low rotating speed of turbo rotor, ultrafine particles can follow the gas phase by and large, but when the rotating speed increases, a phenomenon of velocity slippage between two phases appears evidently;(3) A operating parameter, air flow rate is so important that can directly influence the stability of flow field in classifying chamber, the bigger the air flowrate is , the steadier the flow field is;(4) Compared with straight blades, the new shape of blades with backward crooked elbow are helpful to improve the stability of flow field and form whole stream easily, also beneficial to advance the classification accuracy and classification efficiency;(5) The motion trace of particles are very complicated when the turbo rotor rotates at a high speed, the constant bounce of the particles appear between the blades and the coarse particles are even bounce back from the inlet, only the finer can pass through the classification area from the oulet;(6) Along with the increase of the rotor"s rotating speed, radiah axial and tangential velocity all begain to fluctuate repetitively like sine-wave, the smaller the particles are, the more violently they fluctuates.

数值模拟结果表明，(1)在涡轮达到工作转速时，在分级区域形成了一个与涡轮旋转方向相反的局部回流涡，它使得分离出来的细粒重又被带回分级轮外边缘，从而严重影响分级机的分级效率；(2)粉尘粒子在涡轮低速运动情况下，基本上能跟随气体运动，但随着转速加大，两相之间出现了明显的速度滑移现象；(3)分级机工作时的风量也是一个比较重要的操作参数，它可以直接影响到分级机内腔流场的稳定性，风量越大，流场越稳定；(4)同直叶片形状相比较，带后弯导板的叶片，有利于改善流场的稳定性，流场容易形成整体流，对提高分级效率和分级精度都非常有利；(5)粒子轨迹线在涡轮转速较高时十分复杂，有的出现了反复的弹跳现象，大颗粒不能通过分级区域而从进口返流了，只有细小的颗粒才从出口处流出；(6)涡轮转速加大时，粒子的径向、轴向和切向速率出现了明显的类似于正弦波的脉动现象，颗粒越小，脉动程度越为剧烈。

When the ultrasound probe is moving on the surface of the body, the moving patter can linear or circumrotated, the acquired image sequences comprise the space position information.

当超声波探头在人体表面均速运动时，运动形式可为直线或旋转，所获取的图像序列包含一定空间位置信息。

A lot of plates, the relative motion between the plate is the most basic rigid body sport

岩石圈被断裂分割成许多板块，板块之间的相对运动是最基本的刚体运动，包括直移和旋转。

In his publications, Newton rephrased his ideas to suit the mathematical idiom of the time, replacing calculations with infinitesimals by equivalent geometrical arguments which were considered beyond reproach.

他用微积分的方法来解决问题的行星运动，形状，表面旋转流体，在地球的扁率，运动，体重滑动的摆线，并讨论了许多其他问题，他的数学原理。

They are, however, known to develop out of the leftover, typically disk-shaped mass of gas and dust that swirls around a newborn star, so whatever direction that material is moving, which is the direction of the star's rotation, becomes the direction of the planet's orbit.

不过，据认为它们是有残留物产生，通常残留物是在新生恒星周围旋转的碟型气体和尘埃团，所以，那种物质做什么运动--即恒星的自转方向--都会成为卫星轨道环绕运动方向。

Motor driven ball screw to achieve the main cutting me up and down the movement; the main movement is driven by the hydraulic motor rotating the spindle in order to achieve the cutting tool on the workpiece; radial feed through the nut and screw to achieve manually.

电机带动滚珠丝杠实现主切削箱的上下运动；主运动是由液压马达带动主轴的旋转，从而实现刀具对工件的切削；径向进给是通过螺母与丝杠手动实现的。

After knee joint replacement, the artificial joint should bear the weight of the body, furthermore, when it is flexing or whirling, it must be flexible and have a good stability. To make a coordinated movement between the joint prosthesis and the retained soft tissue, the geometry of joint prosthesis must match human body.

膝关节置换后，要求患肢达到负重、伸屈及旋转活动，稳定性好，这就要求假体的几何形状要与人体相匹配并使其植入后与人体运动规律相一致，才能使假体与周围保留的软组织协调运动，这一切都得依赖于精确的膝关节假体设计与制造。

A new way of exchange between rotation and reciprocating motion through planetary driving was introduced, which was different from the one realized by piton pump moving with cam, brace and link.

采用行星齿轮传动方式实现从旋转到直线的往复运动，不同于现有柱塞泵由凸轮、曲柄连杆或斜盘实现往复运动的方式，没有滑靴等高压力作用下高速滑移的元件。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失