大轴

A torsional oscillation observer based on the general observer was discussed to estimate the speed of the turbine generator. The dynamic characteristics of standard Luenberger observer with quantization effects were studied by Lyapunov stability criterion. It is concluded that the state estimate error can not asymptotically converge to zero in-the-large in presence of quantization effects.

讨论了基于状态观测器的汽轮机轴系扭振测量方法，采用李亚普诺夫稳定性判据分析存在量化效应的条件下标准龙贝格观测器的动态特性，指出由于数字系统中的有限字长效应会使观测器的跟踪性能恶化，估计误差不能在大范围内渐进收敛。

The torsional oscillation problem will make the shaft endure big torque time and again, which produces the fatigue life loss and even makes the shaft broken.

机网扭振相互作用会使机组轴系反复承受较大的扭矩，从而造成疲劳寿命损耗、甚至直接损坏。

With establishing dynamic model of gun system, the effects of stiffness and damping of the main parts, i.e. elevating mechanism, trail, and soil as well as the effects of parity of recoil mass and parity of trunnion position of firing stability are systematically studied.

在建立火炮动力学模型的基础上，利用虚拟样机技术系统地研究了高低机刚度和阻尼、大架刚度和阻尼、土壤介质刚度和阻尼、后坐质量偏心和耳轴位置偏心对火炮射击稳定性的影响。

Trunnion bearing is rolling bearing with low speed and high load, if faults such as point erosion, peeling and roller fragmentation, happen in the manufacture process, it will bring vast economic losses, and will take much time and costs to maintain it.

耳轴轴承为低速重载滚动轴承，在其运行过程中一旦发生局部点蚀、剥落以及滚动体破碎等故障，会引起较大的经济损失，而对其进行检修往往要花费大量的时间和费用。

The coming forth of virtual prototyping technology presents a new approach to study gun stability, and based on establishment of dynamic model of selections of structure parameters, the effects of stiffness and damper of elevating mechanism, stiffness and damper of trail, stiffness and damper of soil, parity of recoil mass and parity of trunnion position on firing stability are first studied with virtual prototype of gun in this paper. An improved equation of sensitivity analysis is provided, and the important degrees of factors with different dimensions can be compared.

虚拟样机技术的出现为火炮射击稳定性研究提供了新的方法，文中在建立火炮动力学模型的基础上，通过选取火炮结构参数对火炮射击稳定性进行研究，利用虚拟样机分析高低机刚度和阻尼、大架刚度和阻尼、土壤介质刚度和阻尼、后坐品质偏心和耳轴位置偏心对火炮射击稳定性的影响。

A new stimulus-response method with two sample ports has been developed for experimental study of column performance.

本文对实验室大柱径萃取柱在有传质条件下研究了轴向混合和传质性能实验方法。

Slipper type universal coupling"s fork joint and palm end are the weak parts of the main transmission system. In this article, the two parts" intensity values are obtained through finite element analysis . After making three-dimensional computer simulation analysis by ANSYS, the results show that the middle arc of the fork joint in loaded side and the intersection of fork bore and the arc are the danger location, where the stress is largest and stress concentration is serious.

本文对轧机主传动系统机械部分的薄弱部件进行强度计算，即对滑块式万向联轴器的主要零部件的强度进行有限元分析，通过ANSYS有限元分析软件进行三维计算机仿真，由计算结果可知，在叉头受载侧过渡圆弧段中部、叉头镗孔与过渡圆弧交接处这两个部位的应力最大且存在严重的应力集中，考虑到单元总数限制及计算时间等因素，整体模型的网格划分较疏，不能反映倒圆角等细节。

The excessive gap is the main cause of the rupture destroys of the universal joint.

过大的间隙是造成万向联轴器断裂破坏的主要原因之一。

With the aid of Zemax software, a three-mirror, unobscured, high-resolution optical system with large aperture, long focal length was successfully aligned by first collecting interferograms from several fields of all image plane, and obtaining the wavefront error, namely, obtained wavefront Zernike polynomials; then using the self-made program package to calculate the optical system misalignment.

利用Zemax光学设计软件与自编计算机辅助装调软件，实现了对大口径、长焦距、无中心遮拦离轴三反射镜光学系统的装调。通过Zemax软件模拟光学系统的失调模式，得到整个光学系统的波前像差，把波前像差代入到自编的复杂光学系统计算机辅助装调软件中，计算出光学系统的失调量，与引入的失调量对比，证明了其正确性。在实际的装调过程中，用小型球面干涉仪分别收集3个视场的干涉图，得到失调光学系统的失调量，用Zemax软件验证失调量数据的正确性，从而指导装调。

As he watched it made a 180 degree turn through its vertical axis.

当他看着它发了180度大转弯通过其垂直轴。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。