小振动

According to the principle of gear modification, this paper presented a new method, which determines the modification of spur gear using the dynamic system identification and optimum control theory.

摘 要：提出了一种利用动态系统辨识与最优控制理论相结合确定齿轮修形量的方法：在实际工况下，通过实验采集直齿轮传动系统实际动态信号进行系统辨识，然后求取系统的最优控制，将其转换为振动最小的修形量。

Jump for the most common eyelid orbicularis oculi muscle of the "little muscle vibration syndrome", each jump a few seconds to several minutes; normal circumstances as long as a period of time after the automatic recovery, but also close your eyes a rest look, or deposited his eyes with hot towel, as well as with a balanced diet and adequate sleep, to shorten the eyelid beating time.

跳为最常见的眼睑眼轮匝肌的"小肌肉振动综合症"的肌肉，每几秒钟到几分钟的时间，如在一段时间内维持正常情况下，自动恢复后跳，也闭上你的眼睛休息一下看看，或用热毛巾存入他的眼睛，以及均衡饮食和充足的睡眠，以缩短眼皮跳动的时间。

Due to a "loss" of energy with each overshoot, the amplitude of the string diminishes.

由于每一次振动中的能量流失，弦的振幅越来越小。

An instantaneous optimal semi-active control method is put forward. Combined sliding mode control with lyapunov's stability theory, the control weights matrix, which can minimize structural instantaneous energy, is designed. Simulation and shaking table test is conducted to validated the method's effectiveness. To solve combination explosion of controlled structural state encountered in high-rise building control, the semi-active control strategy, which can drive structural state point to reach the sliding mode switching band, is designed by using sliding mode control theory, and genetic algorithm is used to find the optimal semi-active switching to drive the structural state point to sliding mode switching band at prestissimo speed.

提出了一种瞬时最优半主动结构控制方法，利用滑模变结构控制理论和Lyapunov稳定性理论设计使结构瞬时能量最小的半主动控制权矩阵，仿真实例和振动台试验验证了本文所提方法的有效性和实用性；为解决在高层建筑半主动控制中半主动控制器状态组合爆炸的问题，利用滑模变结构控制理论设计在Lapunov稳定意义下使结构在运动状态空间中任一相点于以最快速率到达滑模切换带的半主动控制策略，并用遗传算法找出了最快到达滑模切换带的半主动控制切换组合。

The minor principal stress of slab, the maximum acceleration in up-down stream direction and permanent deformation of the dam body for three-directional earthquake excitation are obviously different from those for unidirectional and two-directional earthquake loading.

计算表明，多向地震动下的面板峰值小主应力、顺河向峰值加速度及坝体的永久变形均与单向和双向输入时显著不同，实际工程计算时应同时考虑三个方向的地震动；振动型地震激励引起的坝体反应明显大于冲击型地震激励；随着地震动强度的增加，峰值加速度、峰值剪应变、面板应力和周边缝变形等增加；面板刚度对面板的应力值和周边缝的变位具有较大影响，当面板模量取值较低时，计算所得到的"面板"应力集中部位不甚明显，计算结论为新型的"土工膜面板堆石坝"提供了理论依据。

Based on the theory of analogy of structural mechanics and optimal control, the optimal induced norm γ-2 of state feedback H∞ control is shown to be the fundamental Rayleigh quotient eigen value in structural vibration or Euler stability problems.

文摘：根据结构力学与最优控制的模拟理论，指出状态反馈H∞控制黎卡提方程中的最优参数γ－2，实质上就是结构振动或稳定理论中的瑞利商最小本征值。

Calculating results show that variation of the propellant inlet pressure makes little impact on engine performance parameters, and the engine will transit to a new stable state. The parameter transition curves are smooth. When the engine thrust is adjusted in a small range within a short period, the parameter transition curves are also reposeful. But when the adjusting range becomes large, the parameter transition curves will fluctuate acutely. Thus, when large range adjusting is required, the time of adjusting should be lengthened or the adjusting should be divided into adequate steps.

计算结果表明，当发动机在某一个稳定工况工作时，发动机入口推进剂压强的变化对发动机性能参数的影响不大，发动机的参数都能比较平稳的过渡到一个新的稳定工况；当发动机在短时间内进行小范围的推力调节时，发动机参数的过渡过程的曲线也比较平稳，但是当在短时间内进行大范围推力调节时，参数的过渡过程的曲线振动比较剧烈，因此应当在进行大范围推力调节时，应当对调节时间进行适当延长，或者分级进行推力调节。

The experiments showed that both rotary belt cutter and the jagged chain cutter can realize high speed cut with high ground speed, the former cut speed and operating speed can reach 17 m/s and 15 km/h separately, and the latter can reach 7 m/s and 13 km/h responsively.

试验表明，回转带式切割器和齿形链式切割器均可实现高速切割和高速作业，前者(来源：ABC55论文网www.abclunwen.com)的切割速度和作业速度分别达17m/s和15km/h，后者的切割速度和作业速度分别达7m/s和13km/h；工作平稳，割台振动小，割茬整齐，无撕裂、漏割、重割和堵刀现象；适于收割小麦、水稻等细茎秆作物和牧草。

This product works on the principle that the inertial vibrating riddler almost reaches resonance. It had a high rate of screening and big swing of the screening machine that it does not jam the screen sieve. It is also of great adaptability to materials. The main vibrating spring uses cutting rubber spring which has low noise, and a long life. It is sealed to prevent environmental pollution. The working efficiency is 3 times than that of the original frequency. It has a good anti-vibrating effect.

该机采用惯性共振系统在近共振状态下工作，单位面积筛分效率高，筛机振幅大不堵筛，对物料适应性强，主振动弹簧选用剪切橡胶弹簧，设备噪音低，寿命长，机壳密闭性好，环境污染小，工作效率为阁振系统固有频率的三倍，有良好的隔振效果。

A new diagnosis method of rolling element bearing on railway rolling stock wheel axle is proposed and tested.

本文采用小波分析方法对铁路客车滚动轴承振动加速度信号进行处理，提出了新的诊断方法，并通过实验证明了该方法的有效性。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。