Journal articles: 'Resonant'

1

Liu, Zeng, and Shi-Jun Liao. "Steady-state resonance of multiple wave interactions in deep water." Journal of Fluid Mechanics 742 (February 24, 2014): 664–700. http://dx.doi.org/10.1017/jfm.2014.2.

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AbstractThe steady-state resonance of multiple surface gravity waves in deep water was investigated in detail to extend the existing results due to Liao (Commun. Nonlinear Sci. Numer. Simul., vol. 16, 2011, pp. 1274–1303) and Xu et al. (J. Fluid Mech., vol. 710, 2012, pp. 379–418) on steady-state resonance from a quartet to more general and coupled resonant quartets, together with higher-order resonant interactions. The exact nonlinear wave equations are solved without assumptions on the existence of small physical parameters. Multiple steady-state resonant waves are obtained for all the considered cases, and it is found that the number of multiple solutions tends to increase when more wave components are involved in the resonance sets. The topology of wave energy distribution in the parameter space is analysed, and it is found that the steady-state resonant waves indeed form a continuum in the parameter space. The significant roles of the near-resonance and nonlinearity were also revealed. It is found that all of the near-resonant components as a whole contain more and more wave energy, as the wave patterns tend from two dimensions to one dimension, or as the nonlinearity of the steady-state resonant wave system increases. In addition, the linear stability of the steady-state resonant waves is analysed. It is found that the steady-state resonant waves are stable, as long as the disturbance does not resonate with any components of the basic wave. All of these findings are helpful to enrich and deepen our understanding about resonant gravity waves.

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Fen Bai, Fen Bai, Qingpu Wang Qingpu Wang, Zhaojun Liu Zhaojun Liu, Zhiyong Jiao Zhiyong Jiao, Xianfeng Xu Xianfeng Xu, and and Hui Zhang and Hui Zhang. "Comparison of signal-resonant and idler-resonant KTA-SROs." Chinese Optics Letters 14, no. 7 (2016): 071402–71406. http://dx.doi.org/10.3788/col201614.071402.

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Sangoi Mendonça, Lucas, and Fábio Ecke Bisogno. "RESONANCE-BASED NORMALIZATION THEORY FOR ANALYSIS AND DESIGN OF RESONANT POWER CONVERTERS." Eletrônica de Potência 24, no. 3 (September 30, 2019): 356–65. http://dx.doi.org/10.18618/rep.2019.3.0018.

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Jinhua Hu, Jinhua Hu, Xiuhong Liu Xiuhong Liu, Jijun Zhao Jijun Zhao, and and Jun Zou and Jun Zou. "Investigation of Fano resonance in compound resonant waveguide gratings for optical sensing." Chinese Optics Letters 15, no. 3 (2017): 030502–30505. http://dx.doi.org/10.3788/col201715.030502.

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5

Yang, Xiaoyan, Jie Yang, and Zeng Liu. "On the steady-state exactly resonant, nearly resonant, and non-resonant waves and their relationships." Physics of Fluids 34, no. 8 (August 2022): 082107. http://dx.doi.org/10.1063/5.0102814.

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The steady-state exactly resonant, nearly resonant, and non-resonant waves in infinite water depth are investigated, and their relationships are revealed. In the framework of homotopy analysis method (HAM), the two primary wave components' amplitudes in the initial guess of the velocity potential are fixed and the actual frequencies of the primary waves are unknown. For different wavenumber ratio ([Formula: see text]) values, three groups of steady-state wave systems are obtained with the proper auxiliary linear operator and the initial guess. It is found that when the third-order resonance occurs accurately, the energy of each wave group is mainly concentrated in the primary and third-order resonant wave components. When the value of the wavenumber ratio ([Formula: see text]) moves away from the exact resonance, the energy of the whole wave system is either gradually transferred to the two primary or one resonant wave components that finally evolves into the trivial non-resonant wave system, or the energy is more evenly distributed among more wave components that evolves into multiple nearly resonant wave systems. In addition, the results obtained based on HAM are verified and confirmed by means of the Zakharov equation. This work illustrate that the steady-state wave systems are continuous in wavevector space, the normal non-resonant solution on either side of the resonance point comes from the different third-order resonant solutions, and the occurrence of multiple near resonances can significantly increase the nonlinearity of the wave system.

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Bostwick, Kimberly S., Damian O. Elias, Andrew Mason, and Fernando Montealegre-Z. "Resonating feathers produce courtship song." Proceedings of the Royal Society B: Biological Sciences 277, no. 1683 (November 11, 2009): 835–41. http://dx.doi.org/10.1098/rspb.2009.1576.

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Male Club-winged Manakins, Machaeropterus deliciosus (Aves: Pipridae), produce a sustained tonal sound with specialized wing feathers. The fundamental frequency of the sound produced in nature is approximately 1500 Hz and is hypothesized to result from excitation of resonance in the feathers' hypertrophied shafts. We used laser Doppler vibrometry to determine the resonant properties of male Club-winged Manakin's wing feathers, as well as those of two unspecialized manakin species. The modified wing feathers exhibit a response peak near 1500 Hz, and unusually high Q -values (a measure of resonant tuning) for biological objects ( Q up to 27). The unmodified wing feathers of the Club-winged Manakin do not exhibit strong resonant properties when measured in isolation. However, when measured still attached to the modified feathers (nine feathers held adjacent by an intact ligament), they resonate together as a unit near 1500 Hz, and the wing produces a second harmonic of similar or greater amplitude than the fundamental. The feathers of the control species also exhibit resonant peaks around 1500 Hz, but these are significantly weaker, the wing does not resonate as a unit and no harmonics are produced. These results lend critical support to the resonant stridulation hypothesis of sound production in M. deliciosus .

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ZHAO, X. D., H. YAMAMOTO, and K. TANIGUCHI. "UNITY RESONANCE AND UNDER-UNITY RESONANCE CONDITIONS IN ASYMMETRICAL DOUBLE-BARRIER STRUCTURES." International Journal of Modern Physics B 09, no. 17 (July 30, 1995): 2119–37. http://dx.doi.org/10.1142/s0217979295000847.

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Resonant tunneling is studied theoretically in asymmetrical double-barrier structures with arbitrary potential profile. Analytical expressions of the transmission coefficient and resonance condition are derived by taking into account the mass difference between the well and barrier layers. It is confirmed that resonant tunneling with unity resonant transmission or under-unity resonant transmission may occur in asymmetrical double-barrier structures. Two independent conditions are required for unity resonant transmission: one is the Phase Difference Condition for Resonance (PDCR) and the other is the Maximum Condition for the Peak Value (MCPV). The under-unity resonant transmission occurs when only PDCR holds. Furthermore, wave functions of an electron at resonance level are calculated and the confining phenomenon is studied.

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8

Oh, Yongseung, Jaeeul Yeon, Jayoon Kang, Ilya Galkin, Wonsoek Oh, and Kyumin Cho. "Sensorless Control of Voltage Peaks in Class-E Single-Ended Resonant Inverter for Induction Heating Rice Cooker." Energies 14, no. 15 (July 28, 2021): 4545. http://dx.doi.org/10.3390/en14154545.

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Single-ended (SE) resonant inverters are widely used as power converters for high-pressure rice cooker induction, with 1200 V insulated-gate bipolar transistors (IGBTs) being used as switching devices for kW-class products. When voltage fluctuations occur at the input stage of an SE resonant inverter, the resonant voltage applied to the IGBT can be directly affected, potentially exceeding the breakdown voltage of the IGBT, resulting in its failure. Consequently, the resonant voltage should be limited to below a safety threshold—hardware resonant voltage limiting methods are generally used to do so. This paper proposes a sensorless resonant voltage control method that limits the increase in the resonant voltage caused by overvoltage or supply voltage fluctuations. By calculating and predicting the resonance voltage through the analysis of the resonance circuit, the resonance voltage is controlled not to exceed the breakdown voltage of the IGBT. The experimental results of a 1.35 kW SE resonant inverter for a high-pressure induction heating rice cooker were used to verify the validity of the proposed sensorless resonant voltage limiting method.

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9

Schmitt, C., B. Dybiec, P. Hänggi, and C. Bechinger. "Stochastic resonance vs. resonant activation." Europhysics Letters (EPL) 74, no. 6 (June 2006): 937–43. http://dx.doi.org/10.1209/epl/i2006-10052-6.

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10

DOROBANTU, V., and C. HATEGAN. "APPROACH TO QUASI-RESONANT PROCESSES." Modern Physics Letters A 06, no. 27 (September 7, 1991): 2463–66. http://dx.doi.org/10.1142/s021773239100289x.

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An approach to quasi-resonant processes is presented, by developing a method of generalized reduced (K)- and collision-matrices. It is proved that a single channel resonance can induce, via direct interaction coupling, quasi-resonant structures in competing reaction channels. The magnitude of the quasi-resonant process is proportional both to strengths of single channel resonance and of direct coupling. A direct compression of the quasi-resonance's width is evidenced. Its width is smaller than the width of originating single channel resonance.

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11

Tonoian, D. S., A. V. Artemyev, X. J. Zhang, M. M. Shevelev, and D. L. Vainchtein. "Resonance broadening effect for relativistic electron interaction with electromagnetic ion cyclotron waves." Physics of Plasmas 29, no. 8 (August 2022): 082903. http://dx.doi.org/10.1063/5.0101792.

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Relativistic electron scattering by electromagnetic ion cyclotron (EMIC) waves is one of the most effective mechanisms for >1 MeV electron flux depletion in the Earth's radiation belts. Resonant electron interaction with EMIC waves is traditionally described by quasi-linear diffusion equations, although spacecraft observations often report EMIC waves with intensities sufficiently large to trigger nonlinear resonant interaction with electrons. An important consequence of such nonlinear interaction is the resonance broadening effect due to high wave amplitudes. In this study, we quantify this resonance broadening effect in electron pitch-angle diffusion rates. We show that resonance broadening can significantly increase the pitch-angle range of EMIC-scattered electrons. This increase is especially important for [Formula: see text] MeV electrons, where, without the resonance broadening, only those near the loss cone (with low fluxes) can resonate with EMIC waves.

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12

Healey, J. J. "A new boundary layer resonance enhanced by wave modulation: theory and experiment." Journal of Fluid Mechanics 304 (December 10, 1995): 231–62. http://dx.doi.org/10.1017/s0022112095004411.

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When more than one wave is present in a system there exists the possibilty of a resonant interaction. Resonant modes become nonlinear at smaller amplitudes than nonresonant modes. If the nonlinearity causes increased growth rates then it may be that, for a time at least, the behaviour of the resonant modes will be the dominant feature. In shear layers resonant triads can be found where two oblique modes resonate with a plane wave and this case has received much attention in the literature. For a given plane wave, the resonance condition selects oblique modes of a certain wave angle and agreement has been found between predicted wave angles and those measured in experiments.In this paper it is shown that resonance conditions can also be met between two planar waves in a Blasius boundary layer, where one of the waves is the usual unstable mode, and the other is a higher-order damped mode. The effects of wave modulation are modelled by performing a spatial analysis but allowing the frequency to become complex. It is found that for certain complex frequencies the strength of the nonlinear resonant interaction coefficients is greatly increased. Experiments have been performed in a low-turbulence wind tunnel in which disturbances with modulated and unmodulated sections were introduced into the boundary layer over a flat plate. It was found that disturbances with the frequency and modulation predicted by the theory do indeed show a much greater susceptibility to nonlinear breakdown than nonresonant disturbances.

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13

Nishiguchi, Katsuhiko, Hiroshi Yamaguchi, Akira Fujiwara, Herre S. J. van der Zant, and Gary A. Steele. "Room-temperature several-hundred-of-megahertz charge sensing with single-electron resolution using a silicon transistor." Applied Physics Letters 122, no. 4 (January 23, 2023): 043502. http://dx.doi.org/10.1063/5.0131808.

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We demonstrate charge detection with single-electron resolution at high readout frequency using a silicon field-effect transistor (FET) integrated with double resonant circuits. A FET, whose channel of 10-nm width enables a single electron to be detected at room temperature, is connected to resonant circuits composed of coupled inductors and capacitors, and these double resonant circuits provide two resonance frequencies. When the FET is driven by a carrier signal at the lower resonance frequency, a small signal applied to the FET's gate modulates the resonance condition, resulting in a reflected signal appearing near the higher resonance frequency. Such operation utilizing the double resonant circuits enables charge detection with a single-electron resolution of 3 × 10−3 e/Hz0.5 and a readout frequency of 200 MHz at room temperature. In addition, a variable capacitor used in the double resonant circuits allows charge-sensing characteristics to be controlled in situ.

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14

WAKE, GEOFFREY W., EMIL J. HOPFINGER, and GREGORY N. IVEY. "Experimental study on resonantly forced interfacial waves in a stratified circular cylindrical basin." Journal of Fluid Mechanics 582 (June 14, 2007): 203–22. http://dx.doi.org/10.1017/s002211200700585x.

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Laboratory experiments have been performed on resonantly forced interfacial waves in a circular cylindrical basin containing a two-layer stratified fluid. The results of this shallow-water study exhibit a number of similarities to previous shallow-water studies performed in single-layer fluids, such as the generation of a large-amplitude response over a frequency bandwidth offset from the primary resonance, generation of a swirling mode at the observed resonant condition, and the significant contribution of higher harmonics. The two-layer experiments also produce results that are unique to stratified domains. In particular, the observed negative nonlinearity of the resonant condition at shallow water depth, mixing of the density interface resulting in detuning the forced response from the resonant condition, the enhanced role of viscous dissipation, and an alternative pathway for the nonlinear generation of higher-frequency waves when the layer depths are disparate. The results of this study are considered with regard to their implications for enclosed basins at the geophysical scale that are subject to near resonant forcing.

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15

Sazonov, S. V. "Resonant quasi-resonant solitons." Bulletin of the Russian Academy of Sciences: Physics 76, no. 3 (March 2012): 245–47. http://dx.doi.org/10.3103/s1062873812030252.

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16

Li, Guang Yu, Hong Min Gao, Xiang Zhi Yu, and Yuan Chun Fei. "Study of Determination of Microwave Dielectric Properties Based on Resonance Cavity Perturbation Method." Applied Mechanics and Materials 347-350 (August 2013): 241–47. http://dx.doi.org/10.4028/www.scientific.net/amm.347-350.241.

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For the study of effects of perturbation, such as the change in the resonant frequency and in the other parameters of a rectangular cavity, the resonance condition, the resonant wavelength and the resonant frequency are analyzed in this paper, with the help of perturbation method in a resonance cavity of the reflection type. The relation is deduced in detail under two suppose conditions, which is between the resonant frequency and the dielectric constant or the permeability of the medium filled in the cavity. The accurate relation between the changes in the resonant frequency and in the dielectric constant or the permeability is established. This paper provides the scientific basis for research on the intrinsic characteristic of medium.

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17

Raupp, Carlos F. M., Pedro L. Silva Dias, Esteban G. Tabak, and Paul Milewski. "Resonant Wave Interactions in the Equatorial Waveguide." Journal of the Atmospheric Sciences 65, no. 11 (November 1, 2008): 3398–418. http://dx.doi.org/10.1175/2008jas2387.1.

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Abstract Weakly nonlinear interactions among equatorial waves have been explored in this paper using the adiabatic version of the equatorial β-plane primitive equations in isobaric coordinates. Assuming rigid lid vertical boundary conditions, the conditions imposed at the surface and at the top of the troposphere were expanded in a Taylor series around two isobaric surfaces in an approach similar to that used in the theory of surface–gravity waves in deep water and capillary–gravity waves. By adopting the asymptotic method of multiple time scales, the equatorial Rossby, mixed Rossby–gravity, inertio-gravity, and Kelvin waves, as well as their vertical structures, were obtained as leading-order solutions. These waves were shown to interact resonantly in a triad configuration at the O(ɛ) approximation. The resonant triads whose wave components satisfy a resonance condition for their vertical structures were found to have the most significant interactions, although this condition is not excluding, unlike the resonant conditions for the zonal wavenumbers and meridional modes. Thus, the analysis has focused on such resonant triads. In general, it was found that for these resonant triads satisfying the resonance condition in the vertical direction, the wave with the highest absolute frequency always acts as an energy source (or sink) for the remaining triad components, as usually occurs in several other physical problems in fluid dynamics. In addition, the zonally symmetric geostrophic modes act as catalyst modes for the energy exchanges between two dispersive waves in a resonant triad. The integration of the reduced asymptotic equations for a single resonant triad shows that, for the initial mode amplitudes characterizing realistic magnitudes of atmospheric flow perturbations, the modes in general exchange energy on low-frequency (intraseasonal and/or even longer) time scales, with the interaction period being dependent upon the initial mode amplitudes. Potential future applications of the present theory to the real atmosphere with the inclusion of diabatic forcing, dissipation, and a more realistic background state are also discussed.

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Han, Jian Qiang, Xiao Fei Wang, and Ri Sheng Feng. "Dependence of the Resonance Frequency of Mircobridge Resonators on the Thermal Power and Vacuum." Advanced Materials Research 465 (February 2012): 14–22. http://dx.doi.org/10.4028/www.scientific.net/amr.465.14.

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Microbridge resonators have been widely used as sensing elements to measure various parameters, such as pressure, acceleration, biochemical adsorption and reactions, mass-flow, infrared ray et al. But no model has been built to calculate quantitatively the shift of resonance frequency due to heat convection, incident infrared ray, excited thermal power drift and ambient air pressure. In this paper, a theoretical analysis is given to calculate the resonance frequency shift due to the thermal power (static heating power and dynamic heating power) fluctuation and the added mass of the ambient air. The model can be used to design resonant sensors based on microbridge resonator, such as resonant mass-flow sensors, resonant IR detectors, resonant biochemical sensors and resonant vacuum gauge, et al.

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Madunil, Siddihalu Lakshitha, Totaro Imasaka, and Tomoko Imasaka. "Resonant and non-resonant femtosecond ionization mass spectrometry of organochlorine pesticides." Analyst 145, no. 3 (2020): 777–83. http://dx.doi.org/10.1039/c9an01861a.

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20

Bar-David, Jonathan, Noa Mazurski, and Uriel Levy. "Resonance Trimming in Dielectric Resonant Metasurfaces." IEEE Journal of Selected Topics in Quantum Electronics 25, no. 3 (May 2019): 1–5. http://dx.doi.org/10.1109/jstqe.2019.2902911.

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21

Zhao, Xinying, and Kun Luo. "Automatic Calculation Method of Load Resonant Frequency of Photovoltaic Power Supply." International Journal of Circuits, Systems and Signal Processing 15 (August 12, 2021): 945–52. http://dx.doi.org/10.46300/9106.2021.15.101.

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The resonance phenomenon of photovoltaic power supply load makes the output voltage of grid-connected photovoltaic power supply system difficult to keep stable, which brings trouble to power supply. Therefore, it is necessary to study the automatic calculation method of load resonance frequency of photovoltaic power supply, so as to detect the load resonance frequency of photovoltaic power supply in real time, thereby ensuring the normal operation of photovoltaic power supply system. The load resonance frequency of photovoltaic power supply is divided into steady-state load resonance frequency and dynamic load resonance frequency. The mathematical model of load resonant circuit of photovoltaic power supply is established by calculating algorithm of load resonant frequency of photovoltaic power supply in steady state, and load resonant frequency of photovoltaic power supply in steady state is calculated. The resonance detection algorithm based on wavelet transform and Hilbert-Huang transform is used to analyze and calculate the load resonance frequency after detecting the resonance signal of photovoltaic power system. The experimental results show that the resonant frequency of photovoltaic power supply load calculated by this method is not much different from the actual resonant frequency of photovoltaic power supply load, and the error range is between-0.30% and 0.49%. Therefore, this method can keep the load resonance frequency of the photovoltaic power supply the same as the RF transmission resonance frequency, and can ensure the normal operation of the photovoltaic power supply.

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22

Zaveri, Nihaal, and Renu Malhotra. "Pluto’s Resonant Orbit Visualized in 4D." Research Notes of the AAS 5, no. 10 (October 20, 2021): 235. http://dx.doi.org/10.3847/2515-5172/ac3086.

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Abstract Orbital resonance phenomena are notoriously difficult to communicate in words due to the complex dynamics arising from the interplay of gravity and orbital angular momentum. A well known example is Pluto’s 3:2 mean motion resonance with Neptune. We have developed a python software tool to visualize the full three-dimensional aspects of Pluto’s resonant orbital dynamics over time. The visualizations include still images and animated movies. By contrasting Pluto’s resonant dynamics with the dynamics of a nearby non-resonant orbit, this tool enables better understanding and exploration of complex planetary dynamics phenomena.

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Clark di Leoni, Patricio, and Pablo D. Mininni. "Quantifying resonant and near-resonant interactions in rotating turbulence." Journal of Fluid Mechanics 809 (November 18, 2016): 821–42. http://dx.doi.org/10.1017/jfm.2016.713.

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Nonlinear triadic interactions are at the heart of our understanding of turbulence. In flows where waves are present, modes must not only be in a triad to interact, but their frequencies must also satisfy an extra condition: the interactions that dominate the energy transfer are expected to be resonant. We derive equations that allow direct measurement of the actual degree of resonance of each triad in a turbulent flow. We then apply the method to the case of rotating turbulence, where eddies coexist with inertial waves. We show that for a range of wavenumbers, resonant and near-resonant triads are dominant, the latter allowing a transfer of net energy towards two-dimensional modes that would be inaccessible otherwise. The results are in good agreement with approximations often done in theories of rotating turbulence, and with the mechanism of parametric instability proposed to explain the development of anisotropy in such flows. We also observe that, at least for the moderate Rossby numbers studied here, marginally near-resonant and non-resonant triads play a non-negligible role in the coupling of modes.

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24

Brunel, F. "Not-so-resonant, resonant absorption." Physical Review Letters 59, no. 1 (July 6, 1987): 52–55. http://dx.doi.org/10.1103/physrevlett.59.52.

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Yang, Jian, Meng Zhang, Yurong He, Yan Su, Guowei Han, Chaowei Si, Jin Ning, Fuhua Yang, and Xiaodong Wang. "A Resonant Z-Axis Aluminum Nitride Thin-Film Piezoelectric MEMS Accelerometer." Micromachines 10, no. 9 (September 6, 2019): 589. http://dx.doi.org/10.3390/mi10090589.

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In this paper, we report a novel aluminum nitride (AlN) thin-film piezoelectric resonant accelerometer. Different from the ordinary MEMS (micro-electro-mechanical systems) resonant accelerometers, the entire structure of the accelerometer, including the mass and the springs, is excited to resonate in-plane, and the resonance frequency is sensitive to the out-plane acceleration. The structure is centrosymmetrical with serpentine electrodes laid on supporting beams for driving and sensing. The stiffness of the supporting beams changes when an out-plane inertial force is applied on the structure. Therefore, the resonance frequency of the accelerometer will also change under the inertial force. The working principle is analyzed and the properties are simulated in the paper. The proposed AlN accelerometer is fabricated by the MEMS technology, and the structure is released by an ICP isotropic etching. The resonance frequency is 24.66 kHz at a static state. The quality factor is 1868. The relative sensitivity of this accelerometer, defined as the shift in the resonance frequency per gravity unit (1 g = 9.8 m/s2) is 346 ppm/g. The linearity of the accelerometer is 0.9988. The temperature coefficient of frequency (TCF) of this accelerometer is −2.628 Hz/°C (i.e., −106 ppm/°C), tested from −40 °C to 85 °C.

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Kumar, Ashok, and A. L. Verma. "Nonlinear absorption of intense short pulse laser over a metal surface embedded with nanoparticles." Laser and Particle Beams 29, no. 3 (July 11, 2011): 333–38. http://dx.doi.org/10.1017/s0263034611000383.

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AbstractThe anomalous absorption of laser, incident at an arbitrary angle of incidence on a metal surface embedded with nanoparticles, is studied. The electrons inside a nanoparticle resonantly absorb laser energy when the laser frequency equals the frequency of surface charge oscillations of the nanoparticle. A monolayer of nanoparticles of radius rnp0 ≈ 50 A with inter-particle separation d ~ 10rnp0 can cause up to 40% reduction of the reflection of p-polarized laser light. The absorption coefficient increases with the angle of incidence and has a sharp peak at a resonant frequency width of about 1%. At high laser power, even if the nanoparticles are initially off resonant with the laser, the particle heating and subsequent expansion reduces the resonance frequency, and the resonance absorption is realized after a time delay. The delay is found to be directly proportional to the cluster size and inversely proportional to the laser intensities.

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GUO, ZHI-WEI, and DE-JUN SUN. "RESONANCE OF NONMODAL PERTURBATIONS IN THE BATCHELOR VORTEX." Modern Physics Letters B 24, no. 13 (May 30, 2010): 1449–52. http://dx.doi.org/10.1142/s0217984910023840.

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The resonance phenomenon for nonmodal perturbation of Batchelor vortex is studied. For azimuthal wavenumber n = - 1, two resonant peaks appear and the left one is always dominant. For n = 1, the resonant character becomes very complicated. There is a resonant mode switch from right peak to left peak as swirl parameter q increases from 2 to infinity. The resonant wavenumber k is the largest when q approaches to infinity for n = - 1 while it is the smallest for n = 1. The maximum value of the optimal energy growth for n = 1 is at q approaches to infinity, whereas it decreases monotonically as q increases for n = - 1. The resonance for n = - 1 is the more important one.

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Cao, Wu, Kangli Liu, Haotian Kang, Shunyu Wang, Dongchen Fan, and Jianfeng Zhao. "Resonance Detection Strategy for Multi-Parallel Inverter-Based Grid-Connected Renewable Power System Using Cascaded SOGI-FLL." Sustainability 11, no. 18 (September 4, 2019): 4839. http://dx.doi.org/10.3390/su11184839.

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The increasing use of multi-parallel grid-connected inverters introduces both high-quality and high-capacity power, while it tends to cause a resonance instability problem. A resonance damper can virtualize a resistor at resonant frequency to suppress the instability effectively, but the resonant frequency should be detected primarily. However, the resonant current or voltage is severely distorted and oscillating, which will lead to the resonant frequency extraction being more difficult. To address it, this paper proposes a resonance detection strategy based on the cascaded second-order generalized integrators (SOGI) and the normalized frequency locked loop (FLL). The cascaded structure ensures the accuracy by completely filtering the fundamental component from the detected voltage or current, and the normalization accelerates the frequency detection. The proposed method can be used as a crucial unit of the resonance damping controller. Finally, the performance of the proposed method is verified by the MATLAB-based simulation and Hardware-in-the-Loop (HIL)-based emulation results.

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Cheng, Ran, Zhihua Liu, Guodong Zhai, Qi Lv, Ming Yang, and Chenguang Cai. "High-Acceleration Vibration Calibration System Based on Phase-Locked Resonance Control." Sensors 22, no. 19 (September 23, 2022): 7208. http://dx.doi.org/10.3390/s22197208.

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In order to ensure the measurement accuracy of high-acceleration vibration sensors used in engineering applications, it is necessary to calibrate their key performance parameters at high acceleration. The high-acceleration vibration calibration system produces high-acceleration vibration by utilizing the resonance amplification principle; however, the resonance frequency of the resonant beam changes with increasing amplitude, affected by the influences of nonlinear and other factors. In this study, a phase-locked resonance tracking control method based on the phase resonance principle is proposed to accurately and quickly track the resonance frequency of the resonant beam, which can improve the accuracy and stability of resonance control. The resonant beam is able to produce stable vibration with an amplitude exceeding 7500 m/s2 by phase-locking and tracking the resonant frequency. A calibration system built with this method can provide stable vibration with an amplitude of 500–10,000 m/s2 in the range of 80–4000 Hz. Comparison experiments with the commonly used amplitude iteration amplification method demonstrate that the proposed method can give an acceleration stability control index of less than 0.5% and a resonance tracking time of less than 0.1 s.

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DMITRIENKO, I. S. "Spatio-temporal evolution of thin Alfven resonance layer." Journal of Plasma Physics 76, no. 5 (May 7, 2010): 709–34. http://dx.doi.org/10.1017/s002237781000022x.

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AbstractWe describe the spatio-temporal evolution of one-dimensional Alfven resonance disturbance in the presence of various factors of resonance detuning: dispersion and absorption of Alfven disturbance, nonstationarity of large-scale wave generating resonant disturbance. Using analytical solutions to the resonance equation, we determine conditions for forming qualitatively different spatial and temporal structures of resonant Alfven disturbances. We also present analytical descriptions of quasi-stationary and non-stationary spatial structures formed in the resonant layer, and their evolution over time for cases of drivers of different types corresponding to large-scale waves localized in the direction of inhomogeneity and to nonlocalized large-scale waves.

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Filimonikhin, Gennadiy, Volodymyr Amosov, Antonina Haleeva, Iryna Ienina, Mareks Mezitis, Yuriy Nevdakha, Guntis Strautmanis, and Oleksii Vasylkovskyi. "Estimating the stability of steady motion of vibration machines operating on the somerfeld effect using an empirical method." Eastern-European Journal of Enterprise Technologies 6, no. 7 (120) (December 30, 2022): 45–53. http://dx.doi.org/10.15587/1729-4061.2022.268718.

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One-, two-, and three-mass vibration machines with translational motion of platforms and a vibration exciter of a ball, roller, or pendulum type with several loads were studied. The empirical criterion for the onset of auto-balancing was applied in the extended formulation. It has been established that a single-mass vibration machine has one resonant speed, and: – at the after-resonance speeds of rotation of loads synchronously with the rotor, the auto-balancing mode becomes stable; – at the pre-resonance speeds of rotation of loads, loads tend to gather together. In a dual-mass vibration machine, there are two resonant speeds and one additional speed located between two resonant ones. The auto-balancing mode is stable when the loads rotate synchronously with the rotor at the following speeds: – between the first resonant speed and the additional speed; – greater than the second resonant speed. At other speeds of rotation of loads, loads tend to gather together. The three-mass vibration machine has three resonant speeds and two additional speeds, located one by one between adjacent resonant speeds. The auto-balancing mode is stable when the loads rotate synchronously with the rotor at the following speeds: – between the first resonant speed and the first additional speed; – between the second resonant speed and the second additional speed; – greater than the third resonant speed. At other speeds of rotation of loads, loads tend to gather together. In a single-mass vibration machine, the value of the resonant speed does not depend on the viscosity of supports. In dual-mass and three-mass vibration machines, all characteristic speeds depend on the viscosity of supports. With small forces of viscous resistance, the values of these speeds are close to the characteristic speeds found in the absence of resistance forces.

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Tolley, N. S., K. Ison, and A. Mirza. "Experimental studies on the acoustic properties of mastoid cavities." Journal of Laryngology & Otology 106, no. 7 (July 1992): 597–99. http://dx.doi.org/10.1017/s0022215100120286.

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AbstractThis study investigated the effects of open-mastoid surgery upon ear canal resonance. In particular an attempt was made to alter resonant properties by obliterating each cavity with silastic foam. The results from this study showed that open-mastoid surgery significantly decreased resonant frequency without producing an effect upon either the peak amplitude or the quality of the resonant peak as defined by the Q-factor.Restoring the natural resonance properties of an operated ear, if indicated, is likely to be a difficult objective to achieve in surgical terms.

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Hao, Honggang, Dexu Wang, Zhu Wang, Bo Yin, and Wei Ruan. "Design of a High Sensitivity Microwave Sensor for Liquid Dielectric Constant Measurement." Sensors 20, no. 19 (September 29, 2020): 5598. http://dx.doi.org/10.3390/s20195598.

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In order to improve the sensitivity of liquid dielectric constant measurements, a liquid dielectric constant sensor based on a cubic container structure is proposed for the first time. The cubic container, which consists of a dielectric substrate with a split resonant ring (SRR) and microstrip lines, can enhance the electric field intensity in the measuring area. High sensitivity can be obtained from measuring the dielectric constant with the characteristics of the structure resonate. The research results show that the resonant frequency of the sensor is shifted from 7.69 GHz to 5.70 GHz, with about a 2 GHz frequency offset, when the dielectric constant of the sample varied from 1 to 10. A resonance frequency offset of 200 MHz for the per unit dielectric constant is achieved, which is excellent regarding performance. The permittivity of oil with a different metal content is measured by using the relation between the fitted permittivity and the resonant frequency. The relative error is less than 1.5% and the sensitivity of measuring is up to 3.45%.

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Waseda, Takuji, Takeshi Kinoshita, and Hitoshi Tamura. "Interplay of Resonant and Quasi-Resonant Interaction of the Directional Ocean Waves." Journal of Physical Oceanography 39, no. 9 (September 1, 2009): 2351–62. http://dx.doi.org/10.1175/2009jpo4147.1.

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Abstract Recent experimental study of the evolution of random directional gravity waves in deep water provides new insight into the nature of the spectral evolution of the ocean waves and the relative significance of resonant and quasi-resonant wave interaction. When the directional angle containing half the total energy is broader than ∼20°, the spectrum evolves following the energy transfer that can be described by the four-wave resonant interaction alone. In contrast, in the case of a directionally confined spectrum, the effect of quasi-resonant wave–wave interaction becomes important, and the wave system becomes unstable. When the temporal change of the spectral shape due to quasi resonance becomes irreversible owing to energetic breaking dissipation, the spectrum rapidly downshifts. Under such extreme conditions, the likelihood of a freak wave is high.

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Chen, Wei Ping, Yu Gang Guo, Xiao Liang Chen, Hong Chen, and Zhen Gang Zhao. "Analysis of Temperature Effects on a Fully-Symmetrical Micromachined Gyroscope." Advanced Materials Research 60-61 (January 2009): 31–35. http://dx.doi.org/10.4028/www.scientific.net/amr.60-61.31.

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This paper researches on the temperature effects of a fully-symmetrical micromachined gyroscope. The Young’s modulus and thermal expansion coefficient of silicon vary with the environment temperature, which affects the modes’ resonant frequencies of micromachined gyroscopes. The effects of temperature fluctuation on the modes’ resonant frequencies is simulated by the FEM software ANSYS. The simulation results show that the fully-symmetrical gyroscope’s resonance frequencies decrease with the increase of temperature and the decrease degree nearly 0.256Hz/°C, but the two modes’ resonance frequencies matches well. The micromachined gyroscope’s dynamic characteristics are tested. The resonant frequencies and the quality factor are reduced with the increase of temperature and the decrease degree of the fit linear about the resonant frequencies is 0.276 Hz/°C. The test results are in good accordance with the simulation results.

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Li, Wei Xin, and He Zhang. "Analysis of Wireless Energy Transfer System Using Magnetic Resonant Coupling." Advanced Materials Research 591-593 (November 2012): 1164–67. http://dx.doi.org/10.4028/www.scientific.net/amr.591-593.1164.

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In order to research the relationship between coupling distance and transmission efficiency, study on the transmission characteristics of magnetic resonant coupling for wireless power transmission system, simulation model of wireless power transmission system via magnetic resonance coupling were established based on the theory of two ports network analysis method. The frequency expression of maximum efficiency and the resonant frequency splitting phenomenon condition of a contact-less power transmission system were derived. In a weak coupling at resonance, magnetic resonant coupling can transfer energy with high efficiency. The resonant frequency changes from two to one depending on the critical condition. Until a certain distance, maximum efficiencies are not got. The transmission characteristics of this system were researched by simulation software and experiments. The results show that the transmission characteristics are consistent with theoretical analysis and simulation.

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Wang, X., S. Briguglio, C. Di Troia, M. Falessi, G. Fogaccia, V. Fusco, G. Vlad, and F. Zonca. "Analysis of the nonlinear dynamics of a chirping-frequency Alfvén mode in a tokamak equilibrium." Physics of Plasmas 29, no. 3 (March 2022): 032512. http://dx.doi.org/10.1063/5.0080785.

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Chirping Alfvén modes are considered as potentially harmful for the confinement of energetic particles in burning tokamak plasmas. In fact, by changing their frequency, they are able to extract as much power as possible from these particles, possibly increasing their transport. In this paper, the nonlinear evolution of a single-toroidal-number chirping mode is analyzed by numerical particle simulation. The relevant resonant structures are identified by numerical techniques based on the use of a coordinate system including two constants of motion: the magnetic moment and a suitable function of the initial particle coordinates. The analysis is focused on the dynamics of two different resonant structures in the particle phase space: those yielding the largest drive during the linear and the nonlinear phase, respectively. It is shown that, for each resonant structure, a density-flattening region is formed around the respective resonance radius, with a radial width that increases as the mode amplitude grows. It is delimited by two steepened negative density gradients, drifting inwards and outward. If the mode frequency were constant, phase-space density flattening would quench the resonant-structure drive as the steepened gradients leave the original resonance region. The frequency chirping, however, causes the resonance radius and the resonance region to drift inwards. This drift, along with a relevant increase in the resonance width, delays the moment in which the inner density gradient reaches the inner boundary of the resonance region, leaving it. On the other hand, the island evolves consistently with the resonance radius; as a consequence, the steepened density gradient further moves inward. This process continues as long as it allows to keep the steepened gradient within the resonance region. When this is no longer possible, the resonant structure ceases to be effective in driving the mode. To further extract energy from the particles, the mode has to tap a different resonant structure, possibly making use of additional frequency variations.

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Vazifehkhah Ghaffari, Babak, Mojgan Kouhnavard, Takeshi Aihara, and Tatsuo Kitajima. "Mathematical Modeling of Subthreshold Resonant Properties in Pyloric Dilator Neurons." BioMed Research International 2015 (2015): 1–21. http://dx.doi.org/10.1155/2015/135787.

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Various types of neurons exhibit subthreshold resonance oscillation (preferred frequency response) to fluctuating sinusoidal input currents. This phenomenon is well known to influence the synaptic plasticity and frequency of neural network oscillation. This study evaluates the resonant properties of pacemaker pyloric dilator (PD) neurons in the central pattern generator network through mathematical modeling. From the pharmacological point of view, calcium currents cannot be blocked in PD neurons without removing the calcium-dependent potassium current. Thus, the effects of calciumICaand calcium-dependent potassiumIKCacurrents on resonant properties remain unclear. By taking advantage of Hodgkin-Huxley-type model of neuron and its equivalent RLC circuit, we examine the effects of changing resting membrane potential and those ionic currents on the resonance. Results show that changing the resting membrane potential influences the amplitude and frequency of resonance so that the strength of resonance (Q-value) increases by both depolarization and hyperpolarization of the resting membrane potential. Moreover, hyperpolarization-activated inward currentIhandICa(in association withIKCa) are dominant factors on resonant properties at hyperpolarized and depolarized potentials, respectively. Through mathematical analysis, results indicate thatIhandIKCaaffect the resonant properties of PD neurons. However,ICaonly has an amplifying effect on the resonance amplitude of these neurons.

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GHRIST, ROBERT W. "RESONANT GLUING BIFURCATIONS." International Journal of Bifurcation and Chaos 10, no. 09 (September 2000): 2141–60. http://dx.doi.org/10.1142/s021812740000133x.

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We consider the codimension-three phenomenon of homoclinic bifurcations of flows containing a pair of orbits homoclinic to a saddle point whose principal eigenvalues are in resonance. We concentrate upon the simplest possible configuration, the so-called "figure-of-eight," and reduce the dynamics near the homoclinic connections to those on a two-dimensional locally invariant centre manifold. The ensuing resonant gluing bifurcations exhibit features of both gluing bifurcations and resonant homoclinic bifurcations. Under certain twist conditions, the bifurcation structure is extremely rich, although describing zero-entropy flows. The analysis carefully exploits the topology of the orbits, the centre manifold and the parameter space.

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Farzbod, Farhad. "Resonant ultrasound spectroscopy: How much information lies in higher frequencies." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A88. http://dx.doi.org/10.1121/10.0015637.

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Resonance ultrasound spectroscopy (RUS) is a well-established experimental technique for measuring all the elastic properties and a few anelastic properties of a material. A sample with known geometry is excited to vibrate in a wide range of frequencies, and its resonant frequencies are detected. The resonant frequencies depend on elastic constants; as such, a complete set of elastic constants can be extracted from the resonant frequency values. In this work, we investigate first the sensitivity of resonant frequencies to some of the elastic constants, and second, how much data are in the resonant frequencies as they go higher. It has been speculated that the higher modes have more info about the off-diagonal elastic constants and shear modes of vibrations. We will investigate this hypothesis and study resonant frequencies' limiting behavior.

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DMITRIENKO, I. S. "Nonlinear non-stationary Alfvén resonance." Journal of Plasma Physics 62, no. 2 (August 1999): 145–64. http://dx.doi.org/10.1017/s0022377899007758.

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For a cold plasma that is inhomogeneous (in the direction across an external homogeneous magnetic field), the nonlinear equation describing the spatial structure and temporal behaviour of a non-stationary disturbance in a resonance layer is obtained. The matching conditions for a disturbance through the resonance layer are obtained, and in the linear limit give a well-known linear matching. It is shown that the spatial and temporal behaviour of the resonance disturbance and the evolution of the resonant absorption in terms of nonlinear theory are determined by the ratio of the nonlinear to linear non-stationary spatial scales. The spatial–temporal profile of the disturbance in the resonance layer and the resonant absorption for different values of this ratio are calculated. A nonlinear decrease in the resonant absorption and a stratification of the resonance disturbance are revealed.

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Haddara, M. R., and M. A. Younis. "Effect of Connecting Rod Obliquity on the Torsional Vibration of Marine Diesel Engines with Variable Inertia." Transactions of the Canadian Society for Mechanical Engineering 10, no. 4 (December 1986): 201–11. http://dx.doi.org/10.1139/tcsme-1986-0024.

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Recent instances of marine crankshaft failure were attributed to secondary resonance which is a consequence of variable inertia. More insight into the secondary resonance producing mechanism may be gained by considering the effect of connecting rod obliquity. In this work an analytical method for the study of the effect of variable inertia, taking into account the obliquity of the connecting rod, is developed. New resonant frequencies are found. Expressions defining the boundaries between resonant and non-resonant solutions are derived. Moreover, numerical solutions are obtained using a fourth order Runge-Kutta algorithm. Results obtained from both approaches are in agreement.

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Zheng, Jianxing, and Yanjie Wang. "Personalized Recommendations Based on Sentimental Interest Community Detection." Scientific Programming 2018 (August 5, 2018): 1–14. http://dx.doi.org/10.1155/2018/8503452.

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Communities have become a popular platform of mining interests for recommender systems. The semantics of topics reflect users’ implicit interests. Sentiments on topics imply users’ sentimental tendency. People with common sentiments can form resonant communities of interest. In this paper, a resonant sentimental interest community-based recommendation model is proposed to improve the accuracy performance of recommender systems. First, we learn the weighted semantics vector and sentiment vector to model semantic and sentimental user profiles. Then, by combining semantic and sentimental factors, resonance relationship is computed to evaluate the resonance relationship of users. Finally, based on resonance relationships, resonant community is detected to discover a resonance group to make personalized recommendations. Experimental results show that the proposed model is more effective in finding semantics-related sentimental interests than traditional methods.

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OKAMURA, MAKOTO. "Almost limiting short-crested gravity waves in deep water." Journal of Fluid Mechanics 646 (February 10, 2010): 481–503. http://dx.doi.org/10.1017/s0022112009992795.

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We investigate the properties of almost limiting short-crested gravity waves with harmonic resonance for various incident angles. When the incident angle is less than 47.5°, the enclosed crest angle in non-resonant limiting waves is 90°, which corresponds to that in standing waves. In contrast, when the incident angle exceeds 47.5°, the enclosed crest angle in non-resonant limiting waves is 120°, which corresponds to that in two-dimensional progressive waves. The enclosed crest angle is 90° in resonant limiting waves for all incident angles. The crest becomes flatter than the trough in resonant limiting waves if the fundamental mode has a different sign from its harmonic resonant mode. Bifurcation of short-crested waves is also investigated.

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LIU, YUMING, and DICK K. P. YUE. "On generalized Bragg scattering of surface waves by bottom ripples." Journal of Fluid Mechanics 356 (February 10, 1998): 297–326. http://dx.doi.org/10.1017/s0022112097007969.

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We study the generalized Bragg scattering of surface waves over a wavy bottom. We consider the problem in the general context of nonlinear wave–wave interactions, and write down and provide geometric constructions for the Bragg resonance conditions for second-order triad (class I) and third-order quartet (class II and class III) wave– bottom interactions. Class I resonance involving one bottom and two surface wave components is classical. Class II resonance manifests bottom nonlinearity (it involves two bottom and two surface wave components), and has been studied in the laboratory. Class III Bragg resonance is new and is a result of free-surface nonlinearity involving resonant interaction among one bottom and three surface wave components. The amplitude of the resonant wave is quadratic in the surface wave slope and linear in the bottom steepness, and, unlike the former two cases, the resonant wave may be either reflected or transmitted (relative to the incident waves) depending on the wave–bottom geometry. To predict the initial spatial/temporal growth of the Bragg resonant wave for these resonances, we also provide the regular perturbation solution up to third order. To confirm these predictions and to obtain an efficient computational tool for general wave–bottom problems with resonant interactions, we extend and develop a powerful high-order spectral method originally developed for nonlinear wave–wave and wave–body interactions. The efficacy of the method is illustrated in high-order Bragg resonance computations in two and three dimensions. These results compare well with existing experiments and perturbation theory for the known class I and class II Bragg resonance cases, and obtain and elucidate the new class III resonance. It is shown that under realistic conditions with moderate to small surface and bottom steepnesses, the amplitudes of third-order class II and class III Bragg resonant waves can be comparable in magnitude to those resulting from class I interactions and appreciable relative to the incident wave.

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Ren, Yijie, Changxiang Yan, Xiamiao Zhang, and Chunhui Hu. "Resonant Coupling of Hermite-Gaussian Transverse Modes in the Triangular Cavity of a Cavity Ring-down Spectroscope." Photonics 9, no. 9 (August 23, 2022): 595. http://dx.doi.org/10.3390/photonics9090595.

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During resonance in resonant cavities, such as those used in laser or cavity ring-down spectroscopes (CRDS), resonant coupling between higher-order transverse modes and fundamental modes can seriously affect the quality of the beam and introduce measurement errors. Several coupling models, such as thermal deformation coupling and scattering coupling, have been established according to existing coupling theory and specific application scenarios; however, these coupling models have not been attributed to a unified theory. In this paper, we reveal that the same resonant coupling excitation factors exist under different types of environmental perturbation. The conditions and range of resonant coupling in a CRDS ring-down cavity are systematically analyzed, and a preferential coupling model of the middle-order modes is proposed. The time-domain characteristics of the CRDS are used in experiments to analyze the resonant coupling between the modes in a weak energy system. The order and coupling range of the middle-order modes involved in resonant coupling are verified using the modal filtering characteristics of the triangular cavity; this paper presents a unified explanation for various types of resonant coupling and also provides a new approach to resonant coupling experiments performed in high-finesse resonant cavities.

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MA, TIANXING. "RESONANT SPIN POLARIZATION IN A TWO-DIMENSIONAL HOLE GAS." Modern Physics Letters B 25, no. 15 (June 20, 2011): 1259–70. http://dx.doi.org/10.1142/s0217984911026279.

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Within the Luttinger Hamiltonian, electric-field-induced resonant spin polarization of a two-dimensional hole gas in a perpendicular magnetic field was studied. The spin polarization arising from splitting between the light and the heavy hole bands shows a resonant peak at a certain magnetic field. Especially, the competition between the Luttinger term and the structural inversion asymmetry leads to a rich resonant peaks structure, and the required magnetic field for the resonance may be effectively reduced by enlarging the effective width of the quantum well. Furthermore, the Zeeman splitting tends to move the resonant spin polarization to a relative high magnetic field and destroy these rich resonant spin phenomena. Finally, both the height and the weight of the resonant peak increase as the temperature decreases. It is believed that such resonant spin phenomena may be verified in the sample of a two-dimensional hole gas, and it may provide an efficient way to control spin polarization by an external electric field.

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Pavlov, Gennadiy, Andrey Obrubov, and Irina Vinnichenko. "Optimizing the operation of charging self-generating resonant inverters." Eastern-European Journal of Enterprise Technologies 1, no. 5(115) (February 25, 2022): 23–34. http://dx.doi.org/10.15587/1729-4061.2022.252148.

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This paper reports a study of the electromagnetic processes in self-generating resonant inverters, as well as the derivation of analytical dependences of their operating frequency on the parameters of the resonance circuit and positive feedback circuits, in order to expand the range of their output power and optimize their operation. The object of research is electromagnetic processes in resonant inverters, in which autogeneration of resonant current oscillations is carried out in the process of operation. The results of studying the electromagnetic processes in sequential self-generating resonant inverters based on the characteristics of the resonant circuit are presented. The operating modes of the inverters have been optimized by setting certain ratios between the operating and resonant frequencies at unstable circuit parameters. The ratio of operating and resonant frequencies is set through the use of phase-shifting filters in a positive feedback loop along the circuit current and correspond to the autogenerator mode. The conditions of self-generation in converters with a sequential resonant circuit have been determined. Mathematical expressions have been built for determining the coefficients of positive feedback on the current and voltage of the resonant circuit, which made it possible to derive target analytical dependences. Analytical dependences of the established operating frequency on the parameters of the circuit and phase-shifting filters have been established. Based on the obtained dependences, the parameters of the positive feedback circuits have been determined in order to ensure a wide range of output power of the converters. The resulting dependences make it possible to carry out theoretical calculations whose results repeat the results of model experiments. Phase characteristics of the resonance circuit and various phase-shifting filters, which can be part of a serial resonant converter, have been constructed. The results of the analysis reported here could be used in the design of resonant inverters with unstable circuit parameters, in particular in inductive chargers.

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Lei, Hanlun. "Secular resonance of inner test particles in hierarchical planetary systems." Monthly Notices of the Royal Astronomical Society 506, no. 2 (June 25, 2021): 1879–88. http://dx.doi.org/10.1093/mnras/stab1789.

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ABSTRACT This work studies the secular resonance associated with the critical argument σ = ϖ (ϖ is the longitude of pericentre) for inner test particles moving in low-eccentricity region with inclination i smaller than 39°. To formulate the dynamical model, the double-averaged Hamiltonian is formulated up to an arbitrary order in the semimajor axial ratio, and then those high-order periodic terms are removed from the double-averaged Hamiltonian by means of Hori–Deprit transformation technique. The resulting Hamiltonian determines a resonant model with a single degree of freedom. Based on the resonant model, it becomes possible to explore the phase-space structure, resonant centre, and resonant width in an analytical manner. In particular, an excellent correspondence is found between the resonant width in terms of the eccentricity variation and the maximum variation of eccentricity (Δe) for test particles initially placed on quasi-circular orbits. It means that the secular dynamics in the low-eccentricity space with i < 39° is dominantly governed by the secular resonance associated with σ = ϖ.

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Kovernikova, Lidiia I. "Resonance Modes at Harmonics Frequencies in Electrical Networks." E3S Web of Conferences 209 (2020): 07006. http://dx.doi.org/10.1051/e3sconf/202020907006.

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Resonance modes at harmonic frequencies in electrical networks are a serious problem. They arise due to the availability of electrical equipment with capacitive and inductive elements. The values of the harmonics of currents and voltages increase at resonances. The voltage quality indices in resonant modes exceed the limit values. Harmonics cause energy losses in electrical equipment, reduce its service life, create economic damage. Capacitor banks are often damaged by resonances. Network nodes with resonant circuits and resonant harmonics can be determined using the frequency characteristics of the nodal reactance (susceptance). The paper presents an algorithm and HARMONICS software for the analysis and forecasting of resonance modes, the results of studies of resonance modes in the high-voltage networks of Eastern Siberia.

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Journal articles on the topic 'Resonant'

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