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We have proposed and demonstrated a weak acoustic signal detection technology based on phase-sensitive optical time-domain reflectometry (Φ-OTDR). Non-contact acoustic signals transmitting through air gap between the sound source and the receiver are difficult to detect due to fast attenuation. In order to improve the detection ability of non-contact weak acoustic signals, we demonstrate that multi-mode fiber (MMF) is a better solution than single-mode fiber (SMF) benefiting from its larger core and higher Rayleigh backscattering (RBS) capture coefficient. The frequency signal-to-noise ratio (SNR) has been enhanced by 9.26 dB. Then, with the help of 3D printing technology, elastomers have been designed to further enhance the detection ability due to the high-sensitive response to acoustic signals. Compared with the previous reported "I" type elastomer, the location and frequency SNR enhancement caused by our new proposed "n" type elastomer are 8.39 dB and 11.02 dB in SMF based system. The values are further improved to 10.51 dB and 13.38 dB in MMF and "n" type elastomer integrated system. And a phase-pressure sensitivity of -94.62 dB re rad/µPa has been achieved at 2.5 kHz. This non-contact weak acoustic signal detection technique has great application potential in the quasi-distributed partial discharge (PD) detection of smart grid.
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http://dx.doi.org/10.1364/OE.499806 | DOI Listing |
J Acoust Soc Am
September 2025
School of Ocean Engineering and Technology, Sun Yat-sen University, Zhuhai 519000, China.
This study establishes a quantitative framework using field observations and normal mode theory to reveal wind field control mechanisms over ambient noise vertical directionality in shallow water. Acoustic data from a vertical line array in the northern South China Sea, combined with sound speed profiles, seabed properties, and multi-source wind fields (ERA5 reanalysis/Weibull-distributed synthetics), demonstrate: (1) A 20-km spatial noise-energy threshold (>90% energy contribution), challenging conventional near-field assumptions (1-2 km); (2) frequency-dependent distribution: low-frequency (50-200 Hz) directionality depends on near-field sources, while high-frequency (>400 Hz) energy shifts seaward due to modal cutoff variations; (3) model validation shows 0.96 correlation at 100 Hz/100 km (stratified medium accuracy), but seabed interface waves induce 3.
View Article and Find Full Text PDFRSC Chem Biol
August 2025
Department of Chemistry - BMC, Uppsala University Sweden
Analysis of ligand-induced structural changes in proteins is challenging due to the lack of experimental methods suited for detection and characterisation of both ligand binding and induced structural changes. We have explored biosensors with different detection principles to study interactions between ligands and acetylcholine binding proteins (AChBPs), soluble homologues of Cys-loop ligand gated ion channels (LGICs) that undergo similar structural changes as LGICs upon ligand binding. X-ray crystallography was used to identify binding sites and establish if the detected conformational changes involved small changes in loop C or major structural changes in the pentamer associated with ion channel opening.
View Article and Find Full Text PDFPhys Chem Chem Phys
September 2025
College of Materials Science and Engineering, Liaoning Technical University, Zhonghua Road. #47, Fuxin, Liaoning, 123000, China.
The thermoelectric performance of the SrZnSbF compound is comprehensively evaluated using first-principles calculations and Boltzmann transport theory in present study. The electronic band structure shows that the SrZnSbF compound is semiconductor with a direct bandgap of 0.64 eV.
View Article and Find Full Text PDFSheng Wu Yi Xue Gong Cheng Xue Za Zhi
August 2025
Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, P. R. China.
In recent years, hybrid brain-computer interfaces (BCIs) have gained significant attention due to their demonstrated advantages in increasing the number of targets and enhancing robustness of the systems. However, Existing studies usually construct BCI systems using intense auditory stimulation and strong central visual stimulation, which lead to poor user experience and indicate a need for improving system comfort. Studies have proved that the use of peripheral visual stimulation and lower intensity of auditory stimulation can effectively boost the user's comfort.
View Article and Find Full Text PDFGenes (Basel)
July 2025
Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy.
: Perceptual analysis has highlighted that the voice characteristics of patients with rare congenital genetic syndromes differ from those of normophonic subjects. In this paper, we describe the voice phenotype, also called the phonotype, of patients with Crisponi/cold-induced sweating syndrome type 1 (CS/CISS1). : We conducted an observational study at the Department of Life Sciences and Public Health, Rome.
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