Nonlinear absorption characteristics and micro flow physics of resonator under high sound intensity

2014 ◽  
Author(s):  
Jun Xu ◽  
Xiaodong Li ◽  
Yueping Guo
Keyword(s):  
Nonlinear Absorption ◽  
Sound Intensity ◽  
Flow Physics ◽  
Micro Flow ◽  
High Sound ◽  
Absorption Characteristics

scholarly journals Wavelength-Dependent Nonlinear Absorption in Palladium Nanoparticles

2021 ◽  
Vol 11 (4) ◽  
pp. 1640
Author(s):  
Chunyu Chen ◽  
Jun Wang ◽  
Yachen Gao
Keyword(s):  
Surface Plasmon Resonance ◽  
Excitation Energy ◽  
Systematic Study ◽  
Nonlinear Absorption ◽  
Palladium Nanoparticles ◽  
Excitation Wavelength ◽  
Saturated Absorption ◽  
Multi Wavelength ◽  
Resonant Region ◽  
Absorption Characteristics

This paper aims to study the nonlinear absorption characteristics of palladium nanoparticles (PdNPs) at off-resonant wavelengths. For this purpose, multi-wavelength (500–650 nm) nanosecond Z-scan technique was used. The experimental results indicate that saturated absorption (SA) and the transition from SA to reverse saturated absorption (RSA) can occur, and depends on the excitation wavelength and energy. When the excitation wavelength is constant, with the increase of excitation energy, PdNPs change from SA to RSA. When the excitation energy is constant, with the excitation wavelength approaching surface plasmon resonance (SPR), PdNPs change from SA to RSA. This phenomenon of SA and RSA under multi-wavelength excitation in the off-resonant region provides a supplement for the systematic study of the nonlinear absorption of PdNPs.

scholarly journals Modulatory Effects of Regional Cortical Activation on the Onset Responses of the Cat Medial Geniculate Neurons

1997 ◽  
Vol 77 (2) ◽  
pp. 896-908 ◽  
Author(s):  
Jufang He
Keyword(s):  
Sound Intensity ◽  
Noise Burst ◽  
Inhibitory Effect ◽  
Cortical Activation ◽  
Facilitatory Effect ◽  
Stimulation Site ◽  
Inhibitory Effects ◽  
Medial Geniculate ◽  
High Sound ◽  
Onset Responses

He, Jufang. Modulatory effects of regional cortical activation on the onset responses of the cat medial geniculate neurons. J. Neurophysiol. 77: 896–908, 1997. Corticofugal modulation on activity of the medial geniculate body (MGB) was examined by locally activating the primary auditory cortex (AI) and looking for effects on the onset responses of MGB neurons to acoustic stimuli. Of 103 MGB neurons recorded from 13 hemispheres of 11 animals, 91 neurons (88%) showed either a facilitatory or inhibitory effect or both; of these neurons, 72 showed facilitatory effects and 25 inhibitory effects. The average facilitatory effect was large, with a mean increase of 62.4%. Small inhibitory effects (mean: −16.2%) were obtained from a few neurons (6 of 103) when a pure tone stimulus was used, whereas the effect became larger and more frequent when a noise burst stimulus was used (mean: −27.3%, n = 22 of 27 neurons). Activation of an AI site having the same best frequency (BF) as the MGB neuron being recorded from produced mainly a facilitatory effect on MGB neuronal responses to pure tones. Activation of AI at a site neighboring the BF site produced inhibitory effects on the MGB response when noise burst stimuli were used. We found that the effective stimulation sites in AI that could modulate MGB activity formed patchlike maps with a diameter of 1.13 ± 0.09 (SE) mm (range 0.6–1.9 mm, n = 15) being larger than the patches of thalamocortical terminal fields. Examining the effects of sound intensities, of 18 neurons tested 9 neurons showed a larger effect for low-sound-intensity stimuli and small or no effects for high-sound-intensity stimuli. These were named low-sound-intensity effective neurons. Five neurons showed high sound intensity effectiveness and four were non-intensity specific. Most low-sound-intensity effective neurons were monotonic rate-intensity function neurons. The AI cortical modulatory effect was frequency specific, because 15 of 27 neurons showed a larger facilitatory effect when a BF stimulus was used rather than a stimulus of any other frequency. The corticothalamic connection between the recording site in MGB and the most effective stimulation site in AI was confirmed by injecting wheat germ agglutinin–horseradish peroxidase tracer at the stimulation site and producing a small lesion in the recording site. The results suggest that 1) the large facilitation effects obtained by AI activation at the region that directly projected to the MGB could be the result mainly of the direct projection terminals to the MGB relay neurons; 2) the large size patches of the effective stimulation site in AI could be due to widely ramifying corticothalamic projections; and 3) the corticofugal projection selectively gates auditory information mainly by a facilitatory effect, although there is also an inhibitory effect that depends on the sound stimulus used.

Nonlinear absorption characteristics of piezopolar semiconductor plasmas

2020 ◽  
Author(s):  
Ratna Agrawal ◽  
Ravi Vanshpal ◽  
Swati Dubey ◽  
S. Ghosh
Keyword(s):  
Nonlinear Absorption ◽  
Semiconductor Plasmas ◽  
Absorption Characteristics

Controlling the nonlinear absorption characteristics of TiO2/carbon nanocomposites on films

2018 ◽  
Vol 108 ◽  
pp. 510-514 ◽  
Author(s):  
Ahmet Karatay ◽  
Yusuf Osman Donar ◽  
Ali Sınağ ◽  
Ayhan Elmali
Keyword(s):  
Nonlinear Absorption ◽  
Carbon Nanocomposites ◽  
Absorption Characteristics

scholarly journals High sound absorption characteristics of foamed alumina ceramics fabricated by gelcasting-foaming process

2020 ◽  
Vol 128 (7) ◽  
pp. 387-394
Author(s):  
Guo-Rui LI ◽  
Chen-Hui LI ◽  
Jiang-An LIU ◽  
Yang ZOU ◽  
Liang HU ◽  
...  
Keyword(s):  
Sound Absorption ◽  
Alumina Ceramics ◽  
Foaming Process ◽  
High Sound ◽  
Absorption Characteristics

Realizing broadband sub-wavelength focusing and a high intensity enhancement with a space-time synergetic modulated acoustic prison

2020 ◽  
Vol 8 (28) ◽  
pp. 9511-9519
Author(s):  
Fuyin Ma ◽  
Jianyu Chen ◽  
Jiu Hui Wu ◽  
Han Jia
Keyword(s):  
High Intensity ◽  
Sound Intensity ◽  
Space Time ◽  
Intensity Enhancement ◽  
High Sound ◽  
Sub Wavelength

We experimentally demonstrate broadband sub-wavelength focusing and a high sound intensity enhancement using an acoustic prison.

Latency of unit responses in cochlear nucleus determined in two different ways

1975 ◽  
Vol 38 (4) ◽  
pp. 812-821 ◽  
Author(s):  
A. R. Moller
Keyword(s):  
Cochlear Nucleus ◽  
Time Integration ◽  
Sound Intensity ◽  
Propagation Delay ◽  
Step Response ◽  
Spike Density ◽  
Cross Covariance ◽  
Statistical Signal Analysis ◽  
Small Increments ◽  
High Sound

The latency revealed by poststimulus time histograms of the responses of single units in the cochlear nucleus to tone bursts was compared with the latency of the change in discharge frequency in response to small increments in the amplitude of the stimulus. The latter was derived on the basis of statistical signal analysis of the discharge pattern in response to tones amplitude modulated with pseudorandom noise. The "step response" of the system was computed by time integration of the cross covariance between modulation and spike density. The following observations can be made: 1. The latency of the responses to tone bursts always decreased with increasing sound intensity, whereas the latency of the step response was almost constant for intensities from immediately above threshold to the highest intensity used (60-70 dB above threshold). 2. In most units the latency revealed by the PST histogram of the responses to tone bursts approached the value of latency of the step response asymptotically. 3. In some units with longer latency, the latency of the response to tone bursts was many times greater than the latency of the step response, even at high sound intensities. 4. A histogram of latency values of the step response of the units studied showed narrow peaks at 2.8 and 4.7 ms. 5. On the basis of the present results it is concluded that the latency values of the step response represent the true sum of synaptic and axon dendritical propagation delay, whereas the latency of the responses to tone bursts also includes the temporal summation at the synaptic level.

scholarly journals Sound absorption characteristics of KGM-based aerogel

2020 ◽  
Vol 15 (3) ◽  
pp. 450-457
Author(s):  
Yixin Wang ◽  
Fei Xiang ◽  
Wei Wang ◽  
Weiling Wang ◽  
Yuehong Su ◽  
...  
Keyword(s):  
Pore Structure ◽  
Sound Absorption ◽  
Freeze Drying ◽  
Drying Method ◽  
Absorption Potential ◽  
Absorption Performance ◽  
Property Characterization ◽  
High Sound ◽  
Absorption Characteristics

Abstract This study presents the preparation and property characterization of biomass aerogels as sound absorption materials. Biomasses were chosen to prepare aerogels through the freeze-drying method. Results indicated that four components may have different effects on the aerogel pore structure, and the aerogel formula was thus optimized to reach the best sound absorption. Within the experimental range, biomass aerogel with the optimized formula had an average sound efficiency 0.352, density 0.047 g/cm3 and porosity 94.46 ± 0.04%. It shows better sound absorption performance than traditional sound absorption cotton. These results demonstrate the high sound absorption potential of biomass aerogels for building applications.

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