转动中心

To live in Beijing is a little like being in the center of a wheel turning at full speed.

他说，住在北京，有点像是处于一个全速转动的轮子的中心。

He burns at the centre of time, and he can see the turn of the universe.

他在时间的中心燃烧，他能看到宇宙的转动。

The spin of the Earth causes the winds within the storm to whirl around the center of the low pressure.

地球的转动引起这些暴风雨中流动的空气围绕低气压的中心旋转。

At the center of the observation wheel: Rolling bearings from FAG which ensure the wheel rotates reliably.

在观察车轮中心：从FAG的滚动轴承的车轮转动，确保可靠。

Driven by the valve stem to close one to wind the rotatory central point while rotating,the spheroid to the third a bit more separately, relative valve central point at this moment,from the third orbit a bit one cam form partial another,enter valve flat make valve it keep sealing to shut off down wards .

由阀杆带动关闭件绕旋转中心点转动时，球体由另点移至第三点，此时相对阀门中心点，从另点的第三点轨迹为一凸轮状偏心，向下进入阀座使阀门关闭保持密封。

A self-drilling anchor (10) for use in a friable material (1) comprises a body (12) having an axis (13), a flanged rear end (14), a drilling front end (16) and a generally cylindrical portion (18) therebetween having an outer surface (20) with a thread (22) disposed thereon, wherein the body forks, beginning at a predetermined distance from the flanged rear end, into a first leg (24) and a second leg (26), the first leg extending forwardly into a drilling tip (28) and having a generally rearward facing shoulder (30) angled obtusely outwardly with respect to the axis, wherein the body (12) has an axial bore (32) for receiving an elongate fastener (2), the axial bore (32) extending substantially through the flanged end (14) and the generally cylindrical portion (18) and leading to the generally rearward facing shoulder (30), wherein the anchor (10) has a drilling mode wherein the second leg (26) nests behind the generally rearward facing shoulder (30) of the first leg (24), and an anchoring mode wherein the legs are pivoted apart from one another.

一种用于易碎材料(1)中的自攻螺钉(10)，包括：主体(12)，其具有中心轴(13)、带有凸缘的后端部(14)、用于钻孔的前端部(16)和位于所述后端部和前端部之间的通常为圆柱状的部分(18)，所述圆柱状部分(18)的外表面(20)上布置有螺纹(22)，其中主体从距离带有凸缘的后端部的预定的距离处开始分叉为第一腿(24)和第二腿(26)，第一腿向前伸入钻孔尖端(28)，并且具有相对于中心轴向外成钝角的通常面向后的肩部(30)，主体(12)具有容纳细长状紧固件(2)的轴向孔(32)，轴向孔(32)基本延伸穿过带有凸缘的端部(14)和通常为圆柱状的部分(18)，并且通向通常面向后的肩部(30)，螺钉(10)具有钻孔状态和固定状态，在钻孔状态，第二腿(26)套在第一腿(24)的通常面向后的肩部(30)之后，并且在固定状态，腿彼此转动分离。

On the ship center line of the dock, a laser equipment (this laser equipment only can turn in same vertical face)is put on someplace between the Fr –3# and the Fr 7.5#.

在船坞底船体中心线上，-3#肋位与艉轴管后端面所在肋位之间某处放一激光仪（此激光仪只能在同一重垂面内转动），然后分别用激光打-3#肋位及艉轴管后端面两处的钢丝心，确定这两点在船中心面的内，及已确定了整根轴线在同一中心面上。

Utilized the correlative knowledge of mathematics and theoretical mechanics, the movement measure of the rolling forming of rectangle ring have been studied that based on the ring rolling theory. And the corresponding geometrical models and mathematical models have been established. It was revealed the variation law of ring in the cold rolling process.With the rolling processing, the inside and outside diameters of ring gradually increased with the cures similarly hyperbolic and the augment speed of the inside diameter was obviously larger than the augment speed of the outside diameter. With the rolling processing, the displacement, speed and acceleration of the ring centre gradually increased in the feeding direction in the horizontal and vertical ring rolling mill. With the rolling processing, the moment of inertia which ring reeled its centre and the whirligig of ring gradually increased. It caused the rotary speed gradually decreased. And it was benefit to decrease the circle tolerance and improve the precision of final molding.

本文基于环件轧制理论，运用相关的数学知识和理论力学知识，研究了冷轧过程中矩形截面环件轧制成形的运动测量，并建立相关的几何模型和数学模型，揭示了冷轧过程中环件的变化规律：随着轧制过程的进行，环件的内外径随类似于双曲线的曲线逐渐增大，且环件内径增大速度大于外径增大速度；在卧式轧环机和立式轧环机下，随着轧制过程的进行，环件中心的位移、速度及加速度不断增大；随着轧制过程的进行，环件绕其中心的转动惯量不断增大，导致环件的转速不断减小，这样有利于环件的整圆和最终成形环件的精度。

The influence of the excursion of the mass center of the torsional vibrating system of the three-string pendulum on the measurement of the moment of inertia is analyzed. A criterion for the mass center of the torsional vibrating system to be in alignment with the central axis of the three-string pendulum and a practical method to measure the moment of inertia of a body about a noncentral axis of mass using the three-string pendulum are proposed.

分析了三线摆扭振系统质心偏移对转动惯量测试的影响，给出了扭振系统质心与三线摆中心轴对齐的判别准则和用三线摆测定物体对非质心轴转动惯量的工程实用方法。

The dynamic constraints on the system are second-order nonholonomic constraints. It is assumed that the rigid bodies are hinged at the center of percussion. By the translational acceleration inputs at one of the rigid bodies, the system has two different kinds of rotation around the center of percussion.

该系统的动力学约束是二阶非完整的，通过给定其中一个刚体的加速度输入，并假设被动关节安装在刚体撞击中心处，系统可以产生两种不同形式的绕撞击中心的转动。

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。