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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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Fatigue crack growth rate test using a frequency sweep method


Fatigue crack propagation characteristics of a diesel engine crankshaft are studied by measuring the fatigue crack growth rate using a frequency sweep method on a resonant fatigue test rig.


A novel criterion for the thermorheologically simple material, and a procedure to calculate the shift factor from the angular frequency sweep and temperature ramp data were presented.


Various dynamic mechanical tests (strain sweep, frequency sweep, and time sweep) were performed to estimate viscoelastic characteristics and fatigue behavior.


Active head oscillations were performed at four discrete frequencies (0.12, 0.32, 0.80, 2.0 Hz) and over a frequency sweep between 0.1 and 2.0 Hz.

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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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 Based on the requirements for flight control system stability margin. Especially a new method, derived from the minimum singular value concepts of return difference matrix (RDM), can be applied to the flight validation of multi channel/loop complex system stability. Furthermore, basic element determining open /close loop system frequency response by using frequency sweep technique, involved in a variety of methods, is fully verified to be correct, through both manual and automatic frequency sweep at different... Based on the requirements for flight control system stability margin. Especially a new method, derived from the minimum singular value concepts of return difference matrix (RDM), can be applied to the flight validation of multi channel/loop complex system stability. Furthermore, basic element determining open /close loop system frequency response by using frequency sweep technique, involved in a variety of methods, is fully verified to be correct, through both manual and automatic frequency sweep at different input position in the control loop with BW 1 variable stability aircraft. So that the various methods of measuring stability margin are ensured to be effective and feasible.  根据飞控系统稳定裕度的要求，给出了几种求取稳定裕度的方法，尤其是提出的基于返回误差阵奇异值的稳定裕度判定方法，可解决多通道多回路复杂交联系统的稳定裕度评价问题。并就各种方法的基本环节——频率扫描确定开环／闭环系统频率响应的具体方法，通过ＢＷ－１变稳机人工手动扫频和试验信号发生器不同位置扫频激励试飞进行了验证，结果是正确的，从而确保了各种测取稳定裕度方法的有效可行。  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。  The tests of frequency sweeping and dynamic displacement sweeping at different temperatures for the viscoelastic material silicon rubber were conducted.The predication capability of the frequency response behavior for Burgers model and RT model was evaluated.Based on RT model,MRT model was proposed and considered the influence of temperature,frequency and dynamic displacement was considered.The comparison between the experimental and predicted results shows that the proposed model in the paper can predict the... The tests of frequency sweeping and dynamic displacement sweeping at different temperatures for the viscoelastic material silicon rubber were conducted.The predication capability of the frequency response behavior for Burgers model and RT model was evaluated.Based on RT model,MRT model was proposed and considered the influence of temperature,frequency and dynamic displacement was considered.The comparison between the experimental and predicted results shows that the proposed model in the paper can predict the dynamic constitutive behavior very well under broad temperature,frequency and dynamic displacement.  对硅橡胶粘弹性阻尼材料进行不同温度的频率扫描和动态位移扫描实验.采用经典Burgers模型和RT模型对该材料频率响应曲线的预言能力进行评估;基于RT模型,本文提出改进的MRT模型同时考虑了温度、频率和动态位移对材料动态力学行为的影响,通过与实验结果的比较分析,表明该模型能很好地描述该材料在宽温、宽频和宽动态位移的动态本构行为.  
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