不动地

The authors find coupling mechanism of momentum of nutations between solar and earth. It is caused by solar radiation, earth's rotation and revolution, angle between ecliptic and equator, irregularity of oceans and continents between northen hemisphere and southen hemisphere and layer structure of earth's core.

作者发现：太阳辐射，地球自转与公转，黄、赤交角的存在，陆地和海洋在地球表面南、北半球的不规则、不对称地理分布，及地球内部因〖ZZ〗形成的分层结构，构成了一套天然的能使地球产生自由章动的日、地间动量相耦合的物理机制。

The multi-gear pump ultimately solves some important problems such as unbalanced radial force and high flow pulsation of the common gear pump.

多齿轮泵部分地解决了普通齿轮泵径向力不平衡及流量脉动大等问题。

Finally, the adaptive control strategy of active balancing for a strictly positive and real rotor with actuator time delay is successfully extended to a flexible rotor with single collocated plane and a flexible rotor with multiple collocated planes. A series of numerical simulations demonstrate that the proposed controller is valid to suppress the imbalance-induced vibration of these rotor systems.

最后，把带作动器时迟的严格正实转子系统的自适应控制策略成功地推广到具有单并置平面的柔性转子及具有多并置平面的柔性转子，一系列数值模拟验证了该控制律对抑制这些转子不平衡振动的有效性。

Joe gasped out loud and stood frozen to the spot.

乔喘着粗气大叫着，僵硬地站在那里不敢动。

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％。