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Resonant acoustic modes of ultrathin CdS and CdSe colloidal nanoplatelets (NPLs) with varying thicknesses were probed using low frequency Raman scattering. The spectra are dominated by an intense band ascribed to the thickness breathing mode of the 2D nanostructures. The measured Raman frequencies show strong deviations with respect to the values expected for simple bare plates, all the more so as the thickness is reduced. The deviation is shown to arise from the additional mass of the organic ligands that are bound to the free surfaces of the nanoplatelets. The calculated eigen frequencies of vibrating platelets weighed down by the mass of the organic ligands are in very good agreement with the observed experimental behaviours. This finding opens up a new possibility of nanomechanical sensing such as nanobalances.
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http://dx.doi.org/10.1039/c5nr07383a | DOI Listing |
J Acoust Soc Am
September 2025
Department of Head and Neck Surgery, University of California, Los Angeles, 31-24 Rehab Center, 1000 Veteran Avenue, Los Angeles, California 90095-1794, USA.
The goal of this study was to understand the interaction between the voice source spectral shape, formant tuning, and fundamental frequency in determining the vocal tract contribution to vocal intensity. Computational voice simulations were performed with parametric variations in both vocal fold and vocal tract configurations. The vocal tract contribution to vocal intensity was quantified as the difference in the A-weighted sound pressure level between the radiated sound pressure and the sound pressure at the glottis.
View Article and Find Full Text PDFAnal Chem
September 2025
National Key Laboratory of Laser Spatial Information, Harbin Institute of Technology, Harbin 150001, China.
In this paper, a single-quartz-enhanced photoacoustic-photothermal dual spectroscopy sensor based on a spherical acoustic resonator (SAR) is reported for the first time. The dual spectroscopy of quartz-enhanced photoacoustic spectroscopy (QEPAS) and quartz-enhanced photothermal spectroscopy (QEPTS), utilizing a single quartz tuning fork (QTF), eliminates the frequency mismatch issue that occurs when multiple QTFs are used. The dual spectroscopy model was constructed using the finite element method, which provides numerical simulation support for subsequent experiments.
View Article and Find Full Text PDFJ Voice
September 2025
Department of Speech and Language Therapy, Faculty of Health Sciences, Hacettepe University, Ankara, Turkey. Electronic address:
Objectives: In individuals over 65, age is an essential factor in voice changes. Acoustic and aerodynamic norms guide clinicians in interpreting clinical voice assessment results. This study aimed to present aerodynamic-acoustic voice measurements in older individuals with no voice complaints.
View Article and Find Full Text PDFMagn Reson Med
September 2025
A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland.
Since its introduction more than 30 years ago, the blood oxygenation level-dependent (BOLD) contrast remains the most widely used method for functional MRI (fMRI) in humans and animal models. The BOLD contrast is typically acquired with echo planar imaging (EPI) to obtain sensitization of the signal during the echo time (TE) to dynamic changes in deoxyhemoglobin content, while achieving high spatiotemporal resolution and full brain coverage. However, EPI-based fMRI also faces multiple shortcomings, including sensitivity to body motion, susceptibility-related signal dropouts, interference with multimodal sensors, and loud acoustic noise.
View Article and Find Full Text PDFJ Acoust Soc Am
September 2025
State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240, China.
This paper presents a semi-analytical method, referred to as the linear-velocity-profile fast field program (LFFP), for predicting two-dimensional sound fields in ambient parallel mean flows. The proposed method incorporates the linear velocity layering method into the fundamental framework of fast field program (FFP) to achieve reduced computational costs and enhanced precision, particularly under high-velocity gradient conditions. The accuracy of LFFP is validated through a two-dimensional jet case by comparison with the linearized Euler equation in frequency-domain.
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