An overview of the research conducted in the area of linear and nonlinear vibrations in the turning-point frequency range of loudspeakers and revolution shells is given in chapter 1.

第1章回顾了扬声器和旋转薄壳在转点频段的线性和非线性振动，发现旋转薄壳转点问题中尚有若干问题有待进一步研究。

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Then the author analyses the effect of the frame vibration and tries to make the natural frequency of vibration beyond the range of engine revolution rate.

分析了发动机振源对车架振动的影响，使车架主要模态的自振频率避开了发动机转速范围；

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The range of material is impressive: the chapters deal with the growth of European cities before the industrial revolution, corruption in post-Soviet Russia, privatisation in Eastern Europe, local government in the United States, and more.

ECONOMIST: Economics focus: The grabbing hand | The