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Spin wave resonance frequency in bilayer ferromagnetic films with the biquadratic exchange interaction
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作者 Xiaojie Zhang Yuting Wang +3 位作者 Yanqiu Chang Huan Wang Jianhong Rong Guohong Yun 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期607-613,共7页
The dependences of spin wave resonance(SWR)frequency on the surface anisotropy field,interface exchange coupling,symmetry,biquadratic exchange(BQE)interaction,film thickness,and the external magnetic field in bilayer ... The dependences of spin wave resonance(SWR)frequency on the surface anisotropy field,interface exchange coupling,symmetry,biquadratic exchange(BQE)interaction,film thickness,and the external magnetic field in bilayer ferromagnetic films are theoretically analyzed by employing the linear spin wave approximation and Green’s function method.A remarkable increase of SWR frequency,except for energetically lower two modes,can be obtained in our model that takes the BQE interaction into account.Again,the effect of the external magnetic field on SWR frequency can be increased by increasing the biquadratic to interlayer exchange ratio.It has been identified that the BQE interaction is of utmost importance in improving the SWR frequency of the bilayer ferromagnetic films.In addition,for bilayer ferromagnetic films,the frequency gap between the energetically highest mode and lowest mode is found to increase by increasing the biquadratic to interlayer exchange ratio and film thickness and destroying the symmetry of the system.These results can be used to improve the understanding of magnetic properties in bilayer ferromagnetic films and thus may have prominent implications for future magnetic devices. 展开更多
关键词 spin wave resonance frequency biquadratic exchange interaction interface exchange coupling surface anisotropy
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Enhanced resonance frequency in Co2FeAl thin film with different thicknesses grown on flexible graphene substrate
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作者 周偲 袁少康 +8 位作者 朱登玉 白宇明 王韬 刘福福 潘禄禄 冯存芳 张博涵 何大平 汪胜祥 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期618-622,共5页
The flexible materials exhibit more favorable properties than most rigid substrates in flexibility,weight saving,mechanical reliability,and excellent environmental toughness.Particularly,flexible graphene film with un... The flexible materials exhibit more favorable properties than most rigid substrates in flexibility,weight saving,mechanical reliability,and excellent environmental toughness.Particularly,flexible graphene film with unique mechanical properties was extensively explored in high frequency devices.Herein,we report the characteristics of structure and magnetic properties at high frequency of Co2FeAl thin film with different thicknesses grown on flexible graphene substrate at room temperature.The exciting finding for the columnar structure of Co2FeAl thin film lays the foundation for excellent high frequency property of Co2FeAl/flexible graphene structure.In-plane magnetic anisotropy field varying with increasing thickness of Co2FeAl thin film can be obtained by measurement of ferromagnetic resonance,which can be ascribed to the enhancement of crystallinity and the increase of grain size.Meanwhile,the resonance frequency which can be achieved by the measurement of vector network analyzer with the microstrip method increases with increasing thickness of Co2FeAl thin film.Moreover,in our case with graphene film,the resonance magnetic field is quite stable though folded for twenty cycles,which demonstrates that good flexibility of graphene film and the stability of high frequency magnetic property of Co2FeAl thin film grown on flexible graphene substrate.These results are promising for the design of microwave devices and wireless communication equipment. 展开更多
关键词 enhanced resonance frequency magnetic resonance field flexible graphene substrate
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Modal Frequency Prediction of Chladni Patterns Using Machine Learning
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作者 Atul Kumar K. P. Wani 《Open Journal of Acoustics》 2024年第1期1-16,共16页
The introduction of machine learning (ML) in the research domain is a new era technique. The machine learning algorithm is developed for frequency predication of patterns that are formed on the Chladni plate and focus... The introduction of machine learning (ML) in the research domain is a new era technique. The machine learning algorithm is developed for frequency predication of patterns that are formed on the Chladni plate and focused on the application of machine learning algorithms in image processing. In the Chladni plate, nodes and antinodes are demonstrated at various excited frequencies. Sand on the plate creates specific patterns when it is excited by vibrations from a mechanical oscillator. In the experimental setup, a rectangular aluminum plate of 16 cm x 16 cm and 0.61 mm thickness was placed over the mechanical oscillator, which was driven by a sine wave signal generator. 14 Chladni patterns are obtained on a Chladni plate and validation is done with modal analysis in Ansys. For machine learning, a large number of data sets are required, as captured around 200 photos of each modal frequency and around 3000 photos with a camera of all 14 Chladni patterns for supervised learning. The current model is written in Python language and model has one convolution layer. The main modules used in this are Tensor Flow Keras, NumPy, CV2 and Maxpooling. The fed reference data is taken for 14 frequencies between 330 Hz to 3910 Hz. In the model, all the images are converted to grayscale and canny edge detected. All patterns of frequencies have an almost 80% - 99% correlation with test sample experimental data. This approach is to form a directory of Chladni patterns for future reference purpose in real-life application. A machine learning algorithm can predict the resonant frequency based on the patterns formed on the Chladni plate. 展开更多
关键词 Chaldni Pattern Modal Analysis Machine Learning Resonant frequency Image Processing
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Small-current grounding fault location method based on transient main resonance frequency analysis 被引量:2
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作者 Yongjie Zhang Xiaojun Wang +2 位作者 Junjuan Li Yin Xu Guohong Wu 《Global Energy Interconnection》 2020年第4期324-334,共11页
The small-current grounding fault in distribution network is hard to be located because of its weak fault features.To accurately locate the faults,the transient process is analyzed in this paper.Through the study we t... The small-current grounding fault in distribution network is hard to be located because of its weak fault features.To accurately locate the faults,the transient process is analyzed in this paper.Through the study we take that the main resonant frequency and its corresponding component is related to the fault distance.Based on this,a fault location method based on double-end wavelet energy ratio at the scale corresponding to the main resonant frequency is proposed.And back propagation neural network(BPNN)is selected to fit the non-linear relationship between the wavelet energy ratio and fault distance.The performance of this proposed method has been verified in different scenarios of a simulation model in PSCAD/EMTDC. 展开更多
关键词 Small-current grounding fault location Main resonant frequency Double-end wavelet energy ratio Backpropagation neural network(BPNN)
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Diffusion Coefficient at Resonance Frequency as Applied to n+/p/p+ Silicon Solar Cell Optimum Base Thickness Determination 被引量:1
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作者 Amadou Mar Ndiaye Sega Gueye +6 位作者 Mame Faty Mbaye Fall Gora Diop Amadou Mamour Ba Mamadou Lamine Ba Ibrahima Diatta Lemrabott Habiboullah Gregoire Sissoko 《Journal of Electromagnetic Analysis and Applications》 2020年第10期145-158,共14页
The modelling and determination of the geometric parameters of a solar cell are important data, which influence the evaluation of its performance under specific operating conditions, as well as its industrial developm... The modelling and determination of the geometric parameters of a solar cell are important data, which influence the evaluation of its performance under specific operating conditions, as well as its industrial development for a low cost. In this work, an n+/p/p+ crystalline silicon solar cell is studied under monochromatic illumination in modulation and placed in a constant magnetic field. The minority carriers’ diffusion coefficient (<em>D</em>(<em>ω</em>, <em>B</em>), in the (<em>p</em>) base leads to maximum values (Dmax) at resonance frequencies (<em>ωr</em>). These values are used in expressions of AC minority carriers recombination velocity (Sb(Dmax, H)) in the rear of the base, to extract the optimum thickness while solar cell is subjected to these specific conditions. Optimum thickness modelling relationships, depending respectively on Dmax, <em>ωr</em> and <em>B</em>, are then established, and will be data for industrial development of low-cost solar cells for specific use. 展开更多
关键词 Silicon Solar Cell resonance frequency Magnetic Field Recombination Velocity Base Thickness
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Influence of surface micro-beams with large deflection on the resonance frequency of a quartz crystal resonator in thickness-shear mode vibrations 被引量:1
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作者 Chi Luo Jiemin Xie Yuantai Hu 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2017年第2期72-75,共4页
We study the dynamic behavior of a quartz crystal resonator (QCR) in thickness-shear vibrations with the upper surface covered by an array of micro-beams (MBs) under large deflection. Through taking into account t... We study the dynamic behavior of a quartz crystal resonator (QCR) in thickness-shear vibrations with the upper surface covered by an array of micro-beams (MBs) under large deflection. Through taking into account the continuous conditions of shear force and bending moment at the interface of MBs/resonator, dependences of frequency shift of the compound QCR system versus material parameter and geometrical parameter are illustrated in detail for nonlinear and linear vibrations. It is found that the frequency shift produces a little right (left) translation for increasing elastic modulus (length/radius ratio) of MBs. Moreover, the frequency right (left) translation distance caused by nonlinear deformation becomes more serious in the second-order mode than in the first-order one, 展开更多
关键词 Quartz crystal resonator Nonlinear deformation Micro-beams frequency shift
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Tunable characteristics of bending resonance frequency in magnetoelectric laminated composites
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作者 陈蕾 李平 +1 位作者 文玉梅 朱永 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第7期511-515,共5页
As the magnetoelectric (ME) effect in piezoelectric/magnetostrictive laminated composites is mediated by mechanical deformation, the ME effect is significantly enhanced in the vicinity of resonance frequency. The be... As the magnetoelectric (ME) effect in piezoelectric/magnetostrictive laminated composites is mediated by mechanical deformation, the ME effect is significantly enhanced in the vicinity of resonance frequency. The bending resonance frequency (fr) of bilayered Terfenol-D/PZT (MP) laminated composites is studied, and our analysis predicts that (i) the bending resonance frequency of an MP laminated composite can be tuned by an applied dc magnetic bias (Hdc) due to the E effect; (ii) the bending resonance frequency of the MP laminated composite can be controlled by incorporating FeCuNbSiB layers with different thicknesses. The experimental results show that with H dc increasing from 0 Oe (1 Oe=79.5775 A/m) to 700 Oe, the bending resonance frequency can be shifted in a range of 32.68 kHz≤fr≤33.96 kHz. In addition, with the thickness of the FeCuNbSiB layer increasing from 0 μm to 90 μm, the bending resonance frequency of the MP laminated composite gradually increases from 33.66 kHz to 39.18 kHz. This study offers a method of adjusting the strength of dc magnetic bias or the thicknesses of the FeCuNbSiB layer to tune the bending resonance frequency for ME composite, which plays a guiding role in the ME composite design for real applications. 展开更多
关键词 magnetoelectric effect bending resonance frequency composite materials
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ANALYSIS OF PIEZOELECTRIC ENERGY HARVESTING DEVICE WITH ADJUSTABLE RESONANCE FREQUENCY
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作者 Jiang Lei Li Yuejuan Marvin Cheng 《Journal of Electronics(China)》 2012年第3期310-318,共9页
This paper presents an analytic method that adjusts resonance frequency of a piezoelectric vibration energy harvester. A mathematical model that estimates resonance frequency of cantilever is also proposed. Through mo... This paper presents an analytic method that adjusts resonance frequency of a piezoelectric vibration energy harvester. A mathematical model that estimates resonance frequency of cantilever is also proposed. Through moving an attached mass and changing its weight on the cantilever beam, resonance frequency of adopted piezoelectric device can be adjusted to match the frequency of ambient vibration sources, which is critical in order to harvest maximum amount of energy. The theoretical results are validated by experiments that move different masses along experimental cantilever beams. The results demonstrate that resonance frequency can be adjusted by an attached mass located at different positions on the cantilever beam. Different combinations of operational conditions that harvest maximum amount of energy are also discussed in this paper. 展开更多
关键词 PIEZOELECTRIC Energy harvesting resonance frequency
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Electromagnetic Resonance of Astigmatic Gaussian Beam to the High Frequency Gravitational Waves
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作者 仲元红 李瑾 +1 位作者 周瑶 雷绮仑 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第10期11-14,共4页
The high frequency gravitational waves (around lOS-lO12 Hz) could interact with a specially designed electro- magnetic resonance system. It is found that the power of transverse perturbative photon flux (PPF) of a... The high frequency gravitational waves (around lOS-lO12 Hz) could interact with a specially designed electro- magnetic resonance system. It is found that the power of transverse perturbative photon flux (PPF) of an electromagnetic resonance system can be improved significantly by virtue of an astigmatic Caussian beam. Cor- respondingly the signal-to-noise ratio (SNR) would also be improved. When the eccentric ratio of waist satisfying w0x : w0y 〉 1, the peak value of signal photon flux could be raised by 2-4 times with typical systematic parameters, while the background photon flux would be depressed. Therefore, the ratio of transverse PPF to background photon flux (i.e., SNR) can be further improved 3-8 times with dimensionless amplitude of relic gravitational wave ht = 10-36. 展开更多
关键词 of on IS in PPF Electromagnetic resonance of Astigmatic Gaussian Beam to the High frequency Gravitational Waves
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A Method for Measuring LC Resonance Frequency by Impulse Response
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作者 Mingwei Xu Jiuxin Gong Yuechang Shi 《Modern Electronic Technology》 2020年第1期16-18,共3页
LC circuit resonance frequency measurement often requires the use of professional analysis instruments such as LCR meters,vector network analyzers,but currently such instruments on the market are expensive,and it is d... LC circuit resonance frequency measurement often requires the use of professional analysis instruments such as LCR meters,vector network analyzers,but currently such instruments on the market are expensive,and it is difficult for non-professional institute personnel to access.Here comes unnecessary trouble.In view of this situation,a test method for measuring the resonance frequency using only a digital storage oscilloscope is proposed.Using the impulse signal to obtain the system response,the response waveform period can be observed through the oscilloscope. 展开更多
关键词 LC circuit Resonant frequency Digital Storage Oscilloscope Impulse signal
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Frequency response of a new kind of silicon nanoelectromechanical systems resonators
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作者 于虹 袁为民 +5 位作者 刘春胜 岳东旭 吴士杰 顾勇 陈志远 黄庆安 《Journal of Southeast University(English Edition)》 EI CAS 2012年第3期310-314,共5页
Diffraction effects will bring about more difficulties in actuating resonators,which are electrostatically actuated ones with sub-micrometer or nanometer dimensions,and in detecting the frequency of the resonator by o... Diffraction effects will bring about more difficulties in actuating resonators,which are electrostatically actuated ones with sub-micrometer or nanometer dimensions,and in detecting the frequency of the resonator by optical detection.To avoid the effects of diffraction,a new type of nanoelectromechanical systems(NEMS) resonators is fabricated and actuated to oscillate.As a comparison,a doubly clamped silicon beam is also fabricated and studied.The smallest width and thickness of the resonators are 180 and 200 nm,respectively.The mechanical oscillation responses of these two kinds of resonators are studied experimentally.Results show that the resonant frequencies are from 6.8 to 20 MHz,much lower than the theoretical values.Based on the simulation,it is found that over-etching is one of the important factors which results in lower frequencies than the theoretical values.It is also found that the difference between resonance frequencies of two types of resonators decreases with the increase in beam length.The quality factor is improved greatly by lowering the pressure in the sample chamber at room temperature. 展开更多
关键词 nanoelectromechanical system resonant frequency over-etching nano-beam
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Fuzzy control on automatic frequency tracking of ultrasonic vibration system with high power and high quality factor Q 被引量:4
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作者 朱武 张佳民 +2 位作者 刘洪利 孟逢逢 张智明 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第2期275-278,共4页
In order to realize automatic tracking drift of resonance frequency of ultrasonic vibration system with high power and high quality factor Q, adaptive fuzzy control was studied with a self-fabricated ultrasonic plasti... In order to realize automatic tracking drift of resonance frequency of ultrasonic vibration system with high power and high quality factor Q, adaptive fuzzy control was studied with a self-fabricated ultrasonic plastic welding machine. At first, relations between amplitude of vibration and frequency as well as main loop current and amplitude of vibration were analyzed. From this analysis, we deduced that frequency tracking process of the vibration system can be concluded as an optimizing problem of one dimensional fluctuant extremum of main loop current in vibration system. Then a method of self-optimizing fuzzy control, used for the realization of automatic frequency tracking in vibration system, is presented on the basis of serf-optimizing adaptive control approach and fuzzy control approach. The result of experiments shows that the fuzzy self-optimizing method can solve the problem of tracking frequency drift very well. Response time of tracking in the system is less than 50 ms, which basically meets the requirements of frequency tracking in ultrasonic plastic welding machine. 展开更多
关键词 automatic frequency tracking fuzzy control ultrasonic vibration system resonant frequency
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Non-contact evaluation of the resonant frequency of a microstructure using ultrasonic wave 被引量:1
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作者 X. Kang X. Y. He +1 位作者 C.J. Tay C. Quan 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2010年第2期317-323,共7页
This paper presents a novel non-contact method for evaluating the resonant frequency of a microstructure, Firstly, the microstructure under test is excited by ultrasonic waves. This excitation method does not impose a... This paper presents a novel non-contact method for evaluating the resonant frequency of a microstructure, Firstly, the microstructure under test is excited by ultrasonic waves. This excitation method does not impose any undefined load on the specimen like the electrostatic excitation and also this is the first actual use of ultrasonic wave for exciting a microstructure in the literature. Secondly, the amplitudes of the microstructure are determined by image edge detection using a Mexican hat wavelet transform on the vibrating images of the microstructure. The vibrating images are captured by a CCD camera when the microstructure is vibrated by ultrasonic waves at a series of discrete high frequencies (〉30 kHz). Upon processing the vibrating images, the amplitudes at various excitation frequencies are obtained and an amplitude-frequency spectrum is obtained from which the resonant frequency is subsequently evaluated. A micro silicon structure consisting of a perforated plate (192 × 192 μm) and two cantilever beams (76 × 43 μm) which is about 4 μm thickness is tested. Since laser interferometry is not required, thermal effects on a test object can be avoided. Hence, the setup is relatively simple. Results show that the proposed method is a simple and effective approach for evaluating the dynamic characteristics of microstructures. 展开更多
关键词 NON-CONTACT Microstructure· Resonant frequency Ultrasonic wave Image processing
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High sum-frequency generation in dielectric/antiferromagnet/Ag sandwich structures 被引量:1
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作者 付淑芳 梁红 +1 位作者 周胜 王选章 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第5期556-562,共7页
We present a method to increase the sum-frequency (SF) outputs in dielectric/antiferromagnet(AF)/Ag sandwich structures for a fixed input power. Two incident waves simultaneously illuminate the upper surface, one ... We present a method to increase the sum-frequency (SF) outputs in dielectric/antiferromagnet(AF)/Ag sandwich structures for a fixed input power. Two incident waves simultaneously illuminate the upper surface, one is oblique and the other is normal to it. Numerical calculations based on the SiO2/MnF2/Ag and ZnF2/MnF2/Ag structures show that the SF outputs on the upper film increase a few times as compared to those of a single AF film when the thickness of the AF film is one-quarter of the vacuum wavelength. Moreover, the SF outputs generated near the higher resonant frequency will be higher than those obtained near the lower resonant frequency. An optimum AF film thickness is achieved through investigating its effect on the SF outputs in the two different dielectric sandwich structures. 展开更多
关键词 sum-frequency generation antiferromagnetic film resonant frequency nonlinear response
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A Novel Resonant Frequency Tracking Control for Linear Compressor Based on MRAS Method 被引量:3
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作者 Wei Xu Qizhe Wang +2 位作者 Xiang Li Yi Liu Jianguo Zhu 《CES Transactions on Electrical Machines and Systems》 CSCD 2020年第3期227-236,共10页
To optimize the efficiency of the linear compressor,its operating frequency must be controlled equal to the system resonant frequency.The traditional resonant frequency tracking control algorithm relies on the steady ... To optimize the efficiency of the linear compressor,its operating frequency must be controlled equal to the system resonant frequency.The traditional resonant frequency tracking control algorithm relies on the steady state characteristics of the system,which suffers from slow convergence speed,low accuracy and slow system response.In order to solve these problems,a novel resonant frequency tracking control for linear compressor based on model reference adaptive system(MRAS)is proposed in this paper,and the parameter adaptive rate is derived by the Popov's hyperstability theory,so that the system resonant frequency can be directly calculated through the parameter adaptive rate.Furthermore,the traditional algorithm needs to calculate the piston stroke signal by integrating the back-EMF,which has the problem of integral drift.The algorithm proposed in this paper only needs the velocity signal,and the accuracy of the velocity calculation can be ensured by utilizing the self-adaptive band-pass filter(SABPF),thereby greatly improving the accuracy of the resonance frequency calculation.Simulation results verify the effectiveness of the proposed algorithm. 展开更多
关键词 linear compressor linear oscillating motor(LOM) resonant frequency tracking control model reference adaptive system(MRAS)
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Ultrasonic Pulse Signal Resonance Features in Layered CFRP Within Voids 被引量:1
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作者 杨辰龙 陈越超 +1 位作者 WANG Zhe ZHENG Huifeng 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第3期695-702,共8页
The ultrasonic pulse signal resonance features in layered carbon fiber reinforced plastic(CFRP) within voids were researched. The frequency domain model of acoustic wave propagation in multilayered medium was establ... The ultrasonic pulse signal resonance features in layered carbon fiber reinforced plastic(CFRP) within voids were researched. The frequency domain model of acoustic wave propagation in multilayered medium was established. Then the reflection coefficient of multilayered CFRP within voids was numerically calculated. The results are as follows. When the CFRP laminate is tested by ultrasonic whose center frequency is close to the CFRP inherent resonant frequency, the ultrasonic may generate resonance phenomenon in CFRP. If CFRP contains evenly distributed voids, the frequency of resonant signal and its amplitude all decrease with the increase of porosity. For the thick section CFRP within local concentrated voids, the local concentrated voids near testing surface will cause signal frequency reduction and the decrease of its amplitude. But the voids which exist in layers far away from testing surface almost have no influence on signal resonance. The ultrasonic pulse echo testing was conducted for thick section CFRP specimen. The analysis results of testing signals were in accordance with the results of the numerical calculation, showing that the reflection coefficient frequency response model can effectively explain the ultrasonic resonance phenomenon in layered CFRP within voids. 展开更多
关键词 carbon fiber reinforced plastic void resonance reflection coefficient frequency response
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High frequency magnetic properties of ferromagnetic thin films and magnetization dynamics of coherent precession
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作者 蒋长军 范小龙 薛德胜 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第5期1-15,共15页
We focus on the ferromagnetic thin films and review progress in understanding the magnetization dynamic of coherent precession, its application in seeking better high frequency magnetic properties for magnetic materia... We focus on the ferromagnetic thin films and review progress in understanding the magnetization dynamic of coherent precession, its application in seeking better high frequency magnetic properties for magnetic materials at GHz frequency, as well as new approaches to these materials' characterization. High frequency magnetic properties of magnetic materials determined by the magnetization dynamics of coherent precession are described by the Landau-Lifshitz-Gitbert equation. However, the complexity of the equation results in a lack of analytically universal information between the high frequency magnetic properties and the magnetization dynamics of coherent precession. Consequently, searching for magnetic materials with higher permeability at higher working frequency is still done case by case. 展开更多
关键词 magnetization dynamics PERMEABILITY resonance frequency thin films
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Analysis of iris-loaded resonance cavity in miniaturized maser
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作者 Zu-Gen Guo Yong Zhang +4 位作者 Tao Tang Zhan-Liang Wang Yu-Bin Gong Fei Xiao Hua-Rong Gong 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第5期188-193,共6页
The size reduction of atomic clocks is a long-standing research issue.Many atomic clocks such as passive hydrogen masers(PHMs)and compact rubidium masers(CRMs)use iris-loaded resonance cavities(IRCs)as their microwave... The size reduction of atomic clocks is a long-standing research issue.Many atomic clocks such as passive hydrogen masers(PHMs)and compact rubidium masers(CRMs)use iris-loaded resonance cavities(IRCs)as their microwave cavities because they can dramatically reduce the radical sizes of the atomic clocks.In this paper,the electromagnetic characteristic of the IRC is investigated by a theoretical model based on electromagnetic field theory.The formulas to calculate the resonance frequency,quality factor,and magnetic energy filling factor are presented.The relationship between the IRC structure and its electromagnetic characteristic is clarified.The theoretical calculation results accord well with the electromagnetic software simulations and experimental results.The results in this paper should be helpful in understanding the physical mechanism of the IRC and designing the atomic clocks. 展开更多
关键词 MASER iris-loaded resonance cavity resonance frequency quality factor magnetic energy filling factor
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Design of a low-frequency miniaturized piezoelectric antenna based on acoustically actuated principle
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作者 Yong Zhang Zhong-Ming Yan +3 位作者 Tian-Hao Han Shuang-Shuang Zhu Yu Wang Hong-Cheng Zhou 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第7期565-572,共8页
An acoustically actuated piezoelectric antenna is proposed for low frequency(LF)band in this paper.The proposed antenna is theoretically calculated,numerically optimized by the finite element method(FEM),and experimen... An acoustically actuated piezoelectric antenna is proposed for low frequency(LF)band in this paper.The proposed antenna is theoretically calculated,numerically optimized by the finite element method(FEM),and experimentally analyzed.The measurement results show that the near-field radiation pattern of the piezoelectric antenna is similar to that of the electric dipole antenna.The radiation efficiency of the piezoelectric antenna is 3-4 orders of magnitude higher than that of electrically small antenna(ESA),with their sizes being the same size,and the maximum transmission distance obtained experimentally is 100 cm,which can be improved by increasing the input power.In addition,the gain,directivity,and quality factor of piezoelectric antenna are also analyzed.In this paper,traditional antenna parameters are creatively used to analyze the performance of piezoelectric antenna.The research conclusions can provide reliable theoretical basis for realizing LF antenna miniaturization. 展开更多
关键词 piezoelectric low frequency antenna resonance frequency radiation quality factor antenna miniaturization
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Dual-Frequency Operation of Bow-Tie Microstrip Antenna
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作者 钟顺时 张需溥 《Journal of Shanghai University(English Edition)》 CAS 2005年第3期234-236,共3页
Characteristics of a single-feed dual-frequency bow-tie microstrip antenna are studied. By using the variation method, simple formulas for resonant frequencies of the bow-tie microstrip antenna are derived. It is show... Characteristics of a single-feed dual-frequency bow-tie microstrip antenna are studied. By using the variation method, simple formulas for resonant frequencies of the bow-tie microstrip antenna are derived. It is shown that the dual-frequency ratio can be controlled easily by choosing the parameters of the antenna. This design gives compact antenna size and simple antenna structure. Experimental results are presented, verifying the validity of the design. 展开更多
关键词 microstrip antennas resonant frequency DUAL-frequency miniature design.
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