beat-frequency system 中文意思是什麼
beat-frequency system
解釋
拍頻系統-
Abstract : we have studied the polarization beats spectroscopy with phase - conjugation geometry in a cascade three - level system. it was found that the accuracy for the energy - level difference measurement is determined by the homogeneous linewidths of the optical transitions. under the condition for the occurrence of beating, the frequency difference of the beat between two independent light sources could exceed the laser linewidth. the measurement accuracy for laser absolute frequency could reach the same order of magnitude as the laser linewidth
文摘:研究了級聯三能級系統中的相位共軛極化拍頻光譜術.發現其對能級差的測量精度決定於光學躍遷的均勻增寬.在符合拍頻條件時，兩獨立光源拍頻的頻差可以超出激光線寬，激光絕對頻率的測量精度可達到與激光線寬同一量級 -
Base on review of existed study and application in suppressing cable vibration in the world, technique of mitigating cable vibration with viscous damper and mr damper has been investigated in this dissertation, and the main contents and progresses in form of summary are as following : 1 the motion differential equations of the cable - damper system are formatted, which take into account these factors, such as the inclined angle, sag, stiffness etc. coupling motion between cable and deck is studied with analytical and numerical method. numerical results show that large amplitude vibration of cable with beat rhythm will occur when exciting frequency of deck equals two times modal frequency of cable
本文在對國內外斜拉索振動控制研究與應用現狀進行綜合評述、分析的基礎上，針對上述問題進行了深入研究，具體的研究內容和取得的成果包括： 1 、建立了斜拉索-阻尼器系統運動方程，對拉索與橋面的耦合振動作了分析和研究，數值結果顯示當橋面激振頻率等於某階拉索模態頻率的兩倍時，很小的初始擾動將引起拉索的大幅振動，並呈現拍振的特徵，與實測的拍振信號一致。
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