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Decay of amplitude-modulation property of song and an analysis of sounding mechanism in mottled cicade (Gaeana maculata Drury)
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作者 JIANG Jinchang LIU Xianqun +2 位作者 YANG Xinyu CHEN Hao XU Muling and TANG Huan(Institute of Biophysics. A cademia Sinica. Beijing 100101) 《Chinese Journal of Acoustics》 1994年第4期365-375,共11页
In the natural song of the mottled cicada, the prelude and loud song of the prolonging and repctition songs consist separatcly of several pulses containing the three subpulscs (SP1-3). The principal frequencies (PFban... In the natural song of the mottled cicada, the prelude and loud song of the prolonging and repctition songs consist separatcly of several pulses containing the three subpulscs (SP1-3). The principal frequencies (PFband PFc) of the basic sound and carricr frcquency band are 338±20 Hz and 3617±87 Hz, respectively.The prelude or the prolonging song contains 22 pulses (P1-22),and their amplitude-modulation propertics gradually decay. The carrier-wave oscillations gradually lose symmetrics and overlap with basic waves of the SP1, and the SP2,3 are similar to sine waves. Moreover, a dominant tone of the song gradually changes from PFc into PFb. In the loud song of the prolonging song, the prelude and loud song of repetition songs, the amplitude-modulation propcrties are lost.The carrier-wave oscillations mainly overlap with basic waves of the SP2, and the amplitudes of the PFc arc 10 dB over lower than those of the PFb, and the songs are the PFb of basic sounds as a dominant tone. In view of the structure of the sounding membrane, the vibration frequencies of the three long ribs may be gradually changed from mass controlling to mechanical resistance controlling, and corresponding songs are gradually changed from the prolonging prelude with the PFc as a dominant tone to the loud song and repetition songs with the PFb as a dominant tone. 展开更多
关键词 Mottled cicada Decay of amplitude-modulation property Mechanism of sound-production
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Time-Fractal Modulation—Possible Modulation Effects in Human Therapy 被引量:2
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作者 Andras Szasz 《Open Journal of Biophysics》 2022年第1期38-87,共50页
The malignant processes deviate from the healthy homeostatic control, and various “tricks” enable malignant cells to avoid the healthy regulation. Consequently, the malignant structures miss the apoptosis and prolif... The malignant processes deviate from the healthy homeostatic control, and various “tricks” enable malignant cells to avoid the healthy regulation. Consequently, the malignant structures miss the apoptosis and proliferate without restriction, and without the formation of communication networks in the newly formed cells. The modulation supports the homeostatic control to rearrange the health regulation processes in various ways. The modulation acts with stochastic processes, using stochastic resonances for molecular excitations, supporting the regulative enzymatic processes. The number of stochastic resonant frequencies is as many as the number of enzymatic reactions. The malignant cells differ structurally and dynamically in their connections and interactions from their healthy host tissues. The radiofrequency carrier is modulated with an appropriate time-fractal (1/f) noise to select the autonomic cancer-cells, destroy them, or force the precancerous, semi-individual cells to participate in the networking connections. The modulation in this way limits the cellular autonomy of malignant cells and boosts the healthy control. The resonant energy triggers apoptotic processes and helps immunogenic actions deliver extracellular genetic information for antigen-presentation. The modulation is applied in clinical practice. The therapy (modulated electro-hyperthermia, mEHT) is intensively used in oncology in complementary applications and for palliative stages, and occasionally even as a monotherapy. 展开更多
关键词 Pink-Noise Homeostasis amplitude-modulation Cellular-Communication Antigen-Presentation Stochastic Resonances Resonance Frequencies Cellular Networking
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Damping Identification of Bridges Under Nonstationary Ambient Vibration 被引量:5
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作者 Sunjoong Kim Ho-Kyung Kim 《Engineering》 SCIE EI 2017年第6期839-844,共6页
This research focuses on identifying the damping ratio of bridges using nonstationary ambient vibration data. The damping ratios of bridges in service have generally been identified using operational modal analysis (... This research focuses on identifying the damping ratio of bridges using nonstationary ambient vibration data. The damping ratios of bridges in service have generally been identified using operational modal analysis (OMA) based on a stationary white noise assumption for input signals. However, most bridges are generally subjected to nonstationary excitations while in service, and this violation of the basic assumption can lead to uncertainties in damping identification. To deal with nonstationarity, an amplitude-modulating function was calculated from measured responses to eliminate global trends caused by nonstationary input. A natural excitation technique (NExT)-eigensystem realization algorithm (ERA) was applied to estimate the damping ratio for a stationarized process. To improve the accuracy of OMA-based damping estimates, a comparative analysis was performed between an extracted stationary process and nonstationary data to assess the effect of eliminating nonstationarity. The mean value and standard deviation of the damping ratio for the first vertical mode decreased after signal stationarization. 展开更多
关键词 DAMPING Operational modal analysis Traffic-induced vibration NONSTATIONARY Signal stationarization amplitude-modulating Bridge CABLE-STAYED SUSPENSION
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Parametric Instability of a Liquid Metal Sessile Drop Under a High Frequency Amplitude-Modulate Magnetic Field
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作者 LEI Zuo-sheng ZHANG Li-jie +4 位作者 CHEN Chao-yue GUO Jia-hong REN Zhong-ming FAUTRELLE Yves ETAY Jecqueline 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2012年第S1期491-494,共4页
The parametric instability behavior of a liquid mercury sessile drop under high frequency Amplitude-Modulate Magnetic Field(AMMF),i.e.a high frequency magnetic field(carder wave)modulated by a low frequency sine wave(... The parametric instability behavior of a liquid mercury sessile drop under high frequency Amplitude-Modulate Magnetic Field(AMMF),i.e.a high frequency magnetic field(carder wave)modulated by a low frequency sine wave(modulate wave),is investigated experimentally.The free surface contour of the mercury drop is observed by a CCD camera while varying the frequency and amplitude of the high frequency AMMF.At a given frequency and amplitude,the edge deformations with an azimuthal wave numbers(modes n=3,4,5,6)were excited. 展开更多
关键词 high frequency amplitude-modulate Magnetic Field liquid metal sessile drop parametric instability
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Probing the formation of ultrastable metallic glass from structural heterogeneity
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作者 Qijing Sun DavidM Miskovic Michael Ferry 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第9期214-223,共10页
Ultrastable metallic glasses(SMGs)exhibit enhanced stability comparable to those of conventional glasses aged for thousands of years.The ability to understand why certain alloy compositions and processing conditions g... Ultrastable metallic glasses(SMGs)exhibit enhanced stability comparable to those of conventional glasses aged for thousands of years.The ability to understand why certain alloy compositions and processing conditions generate an SMG is an emerging challenge.Herein,amplitude-modulation dynamic atomic force microscopy was utilized for tracking the structure of Zr_(50)Cu_(50),Zr_(50)Cu_(44.5)Al_(5.5)and Zr_(50)Cu_(41.5)Al_(5.5)Mo_(3) thin film metallic glasses(TFMGs)that were produced by direct current magnetron sputtering at room temperature with the rate of deposition being the only variable.The transition in stability from bulkto SMG-like behavior resides in the change of relaxation mechanism as the deposition rate is decreased.The formation of SMGs is directly linked with the degree of structural heterogeneity,whereby MGs with greater heterogeneity have a higher potential to form SMGs with more significant enhancement in stability.Slower deposition rates,however,are required to yield the more homogenous structure and lower energy state underlying the ultrastability.Ultrastability is closely linked with the geometric shape and distribution of loosely packed phases,whereby SMGs containing more slender loosely packed phases with a more skewed distribution achieve more significant improvements in stability.This work not only provides direct evidence of the structure of SMGs,but also opens new horizons for the design of SMGs. 展开更多
关键词 Ultrastable metallic glass Structural heterogeneity Relaxation dynamics amplitude-modulation dynamic atomic force microscopy
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