查询词典 natural oscillation

Physics The increase in amplitude of oscillation of an electric or mechanical system exposed to a periodic force whose frequency is equal or very close to the natural undamped frequency of the system.

磁共振：受周期力作用的电动或机械系统的振荡幅度的增加，该周期力的频率等于或非常接近系统固有的不减弱的频率

About 1976, Alaska's ocean underwent a "regime shift," in the latest turn of a long-running natural climate cycle called the Pacific Decadal Oscillation.

大约1976 年，阿拉斯加的海洋进行了&政权转移，&在一个长期运行的自然气候周期的最新的轮中称和平的Decadal 动摆。

As a further studying, the "beat" oscillation phenomenon appearing beforce the chatter occurs is analyzed and it is found that there is a self-excited vibration frequency f during the rilling. Farthermore, if the frequency f is infinitively close to one of the natural frequencies of the rolling mill system then an instability will occur.

作为颤振振因的深化研究，对颤振出现前的&拍振&现象进行了分析，推证了轧制过程中有一个自激频率f存在，而且当它与轧机系统的某个固有频率无限接近时会立即引起轧机工作的不稳定。

Based on two kinds of control strategies of VSR under unbalanced grid condition,the introduction of a new VSR control strategy featuring undamped -oscillation that simplifies the controller structure and effectively improves VSR"s performance under unbalanced grid condition.· A systematic description of the state switching in trilogic PWM signal generation of three-phase CSR by using the conversion between bilogic and trilogic switching functions.· Referenced to the CSR"s trilogic PWM signal generation, an approach to achieve low-stress natural commutation of switching devices by reshuffling the vector composition sequence, resulting reduced switching loss.

在研究了两类电网不平衡时的VSR控制策略基础上，提出了一种新型的基于无阻尼振荡控制器的VSR不平衡控制策略，在简化控制结构的同时，有效地改善了电网不平衡时的VSR控制性能；·通过二、三值逻辑开关函数间的转换，系统地描述了三相CSR三值逻辑PWM信号发生中的状态切换；·结合三相CSR三值逻辑PWM信号发生规律，提出了通过调整矢量合成顺序而使功率管获得自然换相的低电压应力SVPWM控制，从而有效地降低了功率管的开关损耗。

These data,especially the seiches with relatively large amplitudes,were examined by using statistics and natural period analysis.Basic chracteristics of seiches,such as monthly and annual occurrences,oscillation period, occurrence duration and occurrence time of the peak,were derived. Among these 20 tide-gauge stations...

结果表明，该海域主要港湾假潮出现具有明显的局地性、季节性和年际变化；夏季是大振幅假潮(振幅1 )≥ 80cm的多发期，冬季基本上不出现；龙口港湾的大振幅假潮最为突出，最大振幅可达 2 93cm ；气压和风速、风向突变的良好配合，是发生大振幅假潮的主要原因

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷