振

Structural natural period s are important indexes to reflect on absorbed seismic energy, a formula for structural frequency is deducted according to variation principle in this paper, various ap.

结构自振周期是直接反映结构吸收地震能量多少的重要指标，本文基于能量变分原理推导了结构频率的计算公式，介绍了工程中计算结构自振周期常用的几种近似方法，讨论了影响结构自振周期的主要因素。

This paper extends the analysis for axial-system torsional oscillation into the nonlinear domain,and the research for Hopf ramification phenomena in axial-system torsional oscillation has been made using the time-domain simulating results,it verified the analysis results of similar nonlinear differential equation describing the axial-system torsional oscillations.

文中把发电机轴系扭振的分析扩展到非线性领域，并对轴系扭振中的Hopf分歧现象进行了研究，利用时域仿真结果对从描述轴系扭振的近似非线性微分方程分析所得结果进行了验证。

In this paper, the natural characteristics of TSS will be analyzed firstly, and then the peculiarity of its frequency and vibration will be summarized.

本文第四章首先对张弦桁架结构的自振特性进行了分析，对其自振频率和振型的特点进行了总结。

Then the creative research work on ultra-low frequency and large amplitude elcectromagnetic vibrator based on moving magnet is done, improving exciting signal at ultra-low frequency, and, the theoretic analysis and experiment model are studied. Thus, the reference for establishing ultra-low frequency standard vibrator in future is provided. In chapter 5, two control strategies for ultra-low frequency standard vibrator test table waveform are studied.

首先采用机械振动隔振理论，研究设计了机械低通滤波器来滤除噪声信号，并运用等效的小振级信号进行了实验研究，得出了有益的结论；然后为提高超低频时激振信号，作者创造性地提出了动铁型大位移的电动振动台结构，进行了理论分析和实验模型研究，为将来建立大位移的超低频标准振动台提供了参考。

Artificial neural network classifiers are respec-tively built by wingbeat waveformti me series and wingbeat frequencies.

研究中分别以蚊虫翅振频率和翅振波形建立人工神经网络，结果发现以翅振频率为特征值的神经网络的识别准确率高。

The critical curves of linear shimmy systems are determined by optimizing the complex eigenvalues. This method can be used to analyse stability of linear shimmy systems with the arbitrary degrees of freedom and to extricate designers from the tedious algebraical derivation in the early shimmy stability analyses.

并使用&复特征值优化分析方法&确定线性摆振系统的各种临界参数曲线，这种方法可以分析任意多自由度的线性摆振系统的稳定性，免去了以往摆振稳定性分析中冗长的代数推导。

MA Zhihong, LI Jinguo. Designing technique for antivibrating and antishocking of military equipment ［J］.Equipment Environmental Engineering,2006, 3(5):7073.［3］ ZHAN Jiakai,DING Hui,NING He,et al.

由试验结果还得到，安装减振器前，A点响应的总均方根加速度值为4.205 g，安装减振器后，总均方根加速度值为1.779 g，减振效率达到57%。

It shows that it is possible to increase the start oscillation length by tailoring magnetic field's amplitude and its period without changing the synchronous condition of the fundamental wave;in the meantime, when there are two or more azimuthally asymmetric space harmonics in the high power broad-band helix TWT, the influences of the Pierce's gain parameter, space charge parameter, and loss parameter on the start oscillation length and real starting asynchronous velocity parameter are also analyzed.

研究结果表明：改变聚焦磁场的幅值或周期来增加起振长度是可能的，而且不会改变基波的互作用条件。与此同时，对起振长度、初始非同步速度参量随皮尔斯增益参量、空间电荷参量、损耗参量等的变化，以及在超宽带行波管中当存在两个或多个角向非对称空间谐波时，起振长度、初始非同步速度参量随周期永久聚焦磁场的变化进行了研究。

The calorigenic mechanism of the oil in the DCSA was analyzed,the related convective heat transfer coefficient and the heat conduction equation were derived.

车用减振装置中双筒式减振器应用较为普遍，但其散热效果并不理想，油液的温升对密封件的影响很大，是困扰减振器可靠性设计的关键性问题。

According as the four modes in a symmetric waveguide, that one of modes is symmetric or anti-symmetric about X axes or Y axes, are X polarized or Y polarized odd mode or even mode, we calculated the polarized coupling characteristics using Cassinian curves as boundaries of the couplers.

本文还根据对称波导中对称于或反对称于x轴或y轴的四个模式分别为x偏振或y偏振的奇模或偶模的原理，用Cassinian曲线表示耦合器介质波导的边界，计算了耦合器的偏振耦合特性。

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