Of course, with the camera fixed to a tripod, the stars themselves produce concentric trails in long exposures, a reflection of the Earth's rotation around its axis.
当然用装在三角架上的照相机固定摄影，长时间曝光能拍到星星因地球自转而形成的同心圆轨迹。
2
A new measuring instrument of rotational inertia has been devised by the fixed - axisrotation principle and parallel axis theorem of compound pendulum.
利用复摆定轴转动原理和刚体平行轴定理设计的一种新型转动惯量测定仪。
3
From the Angle of relative equilibrium, the paper analysis the reason of the formation of the additional pressure on the axis of fixed-point rotation of rigid body.