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The high resolution spectra are measured tuning the length of a CO2 waveguide laser by means of a PZT yielding a frequency scan of 230 MHz around the CO2 laser lines.


Our frequency scan data, as well as our data for the time course of resistance and capacitance, show that the fast change is associated with both the underthecells and betweenthecells resistance.


The high sensitivity of the intracavity arrangement allowed very strong doubleresonance and twophoton transition signals to be observed with high microwavefrequency scanrates (1 GHz/min), and low microwave pumping powers (≦10mW/cm2).


In this way an idler frequency scan of 100150?GHz could be obtained, after which the signal frequency hops ahead over the FSR of the intracavity etalon of the OPO (207?GHz).


Low noise, modebymode absorption spectra are recorded at a high acquisition rate (laser frequency scan greater than 400?GHz/s) and covering four orders of magnitude in absorption coefficient.

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In the second case, the Brewster reflection conditions are not realized, and the variations in the intensity of the reflected light observed upon frequency scanning are smaller.


A diplexer of this type can be used for discrete frequency scanning of highpower wave beams in systems for the suppression of the hydrodynamic instabilities of plasma in magnetic traps.


Amorphous carbon films were examined by low frequency scanningprobe acoustic microscopy (LFSPAM).


Our results showed that the low frequency scanningprobe acoustic microscopy is a useful method for imaging subsurface defects with high resolution.


Frequency scanning of the laser is provided by acoustooptic modulation.

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 In view of the differential equations for free vibration of thin plate, according to elastic thin plate theory and vibration theory, Boundary Element Method (BEM) is used to analyze the dynamic characteristic of thin plate in lateral free vibration. In the process of calculation, the fundamental solution in the lateral free vibration is adopted, and the characteristic equation on boundary for free vibration of homogeneous and isotropic thin plate is deduced, the natural frequency is obtained by using the method... In view of the differential equations for free vibration of thin plate, according to elastic thin plate theory and vibration theory, Boundary Element Method (BEM) is used to analyze the dynamic characteristic of thin plate in lateral free vibration. In the process of calculation, the fundamental solution in the lateral free vibration is adopted, and the characteristic equation on boundary for free vibration of homogeneous and isotropic thin plate is deduced, the natural frequency is obtained by using the method of frequency scan. The calculated examples indicate that the methods suggested in this paper are simple with enough analytical accuracy.  从薄板自由振动的微分方程式出发,依据弹性薄板理论和振动理论,运用边界元法(BEM)研究了薄板横向自由振动的动态特性。计算中采用薄板横向振动问题的基本解,推导了均匀、各向同性薄板的边界特性方程,应用频率扫描的方法求解其固有频率。算例表明采用本文的方法计算简便,具有足够的解析精度。  According to the elastic thin plate theory and vibration theory, a boundary element method (BEM) was used to analyze the frequency characteristics of a thin plate in lateral free vibration. In view of the differential equations for free vibration of thin plate, the dynamic fundamental solutions in lateral free vibration are adapted to deduce the corresponding boundary integral equations. The amount of equations are reduced in the process of calculation. An approach of frequency scanning is used to research the... According to the elastic thin plate theory and vibration theory, a boundary element method (BEM) was used to analyze the frequency characteristics of a thin plate in lateral free vibration. In view of the differential equations for free vibration of thin plate, the dynamic fundamental solutions in lateral free vibration are adapted to deduce the corresponding boundary integral equations. The amount of equations are reduced in the process of calculation. An approach of frequency scanning is used to research the dynamic characteristics of thin plate. The corresponding natural frequencies are gotten accurately and effectively. By numerical examples given, the method introduced is simple and feasible, and it has good calculating precision.  根据弹性薄板理论和振动理论,运用边界元法(BEM)分析了薄板弯曲自由振动的频率特性。从薄板自由振动的微分方程式出发,采用动态基本解推导出其相应的边界积分方程式,计算中对边界积分方程进行缩减,应用频率扫描的方法研究薄板的动态特性,准确、有效地得到了其相应的固有频率。给出的数值算例证明了本文的方法简单、可行,且具有良好的解析计算精度。  Dynamic characteristics of a thin assembled plate structure are analyzed.Based on dynamic fundamental solutions for free vibration of the thin plate,governing boundary equations in the lateral and internal vibration of the thin plate are established by using a boundary element method(BEM).In order to increase the model accuracy and efficiency,dynamic equations of the thin assembled plate structure are deduced based on the thoughts of coupling.An approach of frequency scanning is presented to calculate a series... Dynamic characteristics of a thin assembled plate structure are analyzed.Based on dynamic fundamental solutions for free vibration of the thin plate,governing boundary equations in the lateral and internal vibration of the thin plate are established by using a boundary element method(BEM).In order to increase the model accuracy and efficiency,dynamic equations of the thin assembled plate structure are deduced based on the thoughts of coupling.An approach of frequency scanning is presented to calculate a series of natural frequencies of the thin assembled plate structure rapidly and accurately,and the corresponding modal shapes are obtained too.The numerical examples and experiments show that the established method not only feasibility but also have good precision.  研究薄板组合结构的动力学特性。基于薄板自由振动问题的动态基本解,运用边界元法建立薄板在横向和面内方向的边界控制方程式,为了提高解析建模的精度和效率,根据耦合的思想推导出薄板组合结构的动力学方程,采用频率扫描的方法,准确、快速地求解出薄板组合结构的频率,并得到其相应的振型。数值算例表明本建模方法的可行性和良好的解析计算精度。  
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