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Purpose: This study set out to investigate whether individuals with dysphonia, as determined by either self-assessment or clinician-based auditory-perceptual judgment, exhibited differences in perilaryngeal muscle activities using surface electromyography (sEMG) during various phonatory tasks. Additionally, the study aimed to assess the effectiveness of sEMG in identifying dysphonic cases. Method: A total of 77 adults (44 women, 33 men, Mage = 30.4 years) participated in this study, with dysphonic cases identified separately using either a 10-item Voice Handicap Index (VHI-10) or clinician-based auditory-perceptual voice quality (APVQ) evaluation. sEMG activities were measured from the areas of suprahyoid and sternocleidomastoid muscles during prolonged vowel /i/ phonations at different pitch and loudness levels. Normalized root-mean-square value against the maximal voluntary contraction (RMS %MVC) of the sEMG signals was obtained for each phonation and compared between subject groups and across phonatory tasks. Additionally, binary logistic regression analysis was performed to determine how the sEMG measures could predict the VHI-10-based or APVQ-based dysphonic cases. Results: Participants who scored above the criteria on either the VHI-10 (n = 29) or APVQ judgment (n = 17) exhibited significantly higher RMS %MVC in the right suprahyoid muscles compared to the corresponding control groups. Although the RMS %MVC value from the right suprahyoid muscles alone was not a significant predictor of self-evaluated dysphonic cases, a combination of the RMS %MVC values from both the right and left suprahyoid muscles significantly predicted APVQ-based dysphonic cases with a 69.66% fair level. Conclusions: This study found that individuals with dysphonia, as determined by either self-assessment or APVQ judgment, displayed more imbalanced suprahyoid muscle activities in voice production compared to nondysphonic groups. The combination of the sEMG measures from both left and right suprahyoid muscles showed potential as a predictor of dysphonia with a fair level of confidence. Supplemental Material: https://doi.org/10.23641/asha.25112804 [ABSTRACT FROM AUTHOR]

Mechanistic studies on lead halide perovskites (LHPs) in recent years have suggested charge carrier screening as partially responsible for long carrier diffusion lengths and lifetimes that are key to superior optoelectronic properties. These findings have led to the ferroelectric large polaron proposal, which attributes efficient charge carrier screening to the extended ordering of dipoles from symmetry-breaking unit cells that undergo local structural distortion and break inversion symmetry. It remains an open question whether this proposal applies in general to semiconductors with LHP-like anharmonic and dynamically disordered phonons. Here, we study electron-phonon coupling in Bi2O2Se, a semiconductor which bears resemblance to LHPs in ionic bonding, spinorbit coupling, band transport with long carrier diffusion lengths and lifetimes, and phonon disorder as revealed by temperature-dependent Raman spectroscopy. Using coherent phonon spectroscopy, we show the strong coupling of an anharmonic phonon mode at 1.50 THz to photo-excited charge carriers, while the Raman excitation of this mode is symmetry-forbidden in the ground-state. Density functional theory calculations show that this mode, originating from the A1g phonon of out-of-plane Bi/Se motion, gains oscillator strength from symmetry-lowering in polaron formation. Specifically, lattice distortion upon ultrafast charge localization results in extended ordering of symmetry-breaking unit cells and a planar polaron wavefunction, namely a two dimensional polaron in a three-dimensional lattice. This study provides experimental and theoretical insights into charge interaction with anharmonic phonons in Bi2O2Se and suggests ferroelectric polaron formation may be a general principle for efficient charge carrier screening and for defect-tolerant semiconductors. [ABSTRACT FROM AUTHOR]

Community structure, one of the most attention attracting properties in complex net-works, has been a cornerstone in advances of various scientific branches. A number of tools have been involved in recent studies concentrating on the community detection algorithms. In this paper, we propose a support vector clustering method based on a proximity graph, owing to which the introduced algorithm surpasses the traditional support vector approach both in accuracy and complexity. Results of extensive experiments undertaken on computer generated networks and real world data sets illustrate competent performances in comparison with the other counterparts. [ABSTRACT FROM AUTHOR]

Copper-catalyzed ortho-acyloxylation of the sp² C-H bond of aryl amides with carboxylic acids is reported. Benzoic acids, cinnamic acids, and aliphatic acids can be involved, and the desired products were obtained in moderate to good yields. This procedure is compatible with a wide range of functional groups and heteroarenes without the use of any ligands or additives. This method provides an operationally simple approach for the synthesis of benzoate and cinnamate. [ABSTRACT FROM AUTHOR]

Controllable synthesis of copper chalcogenide nanocrystals (NCs), including desired geometry, composition and surrounding environment, is of high significance for the modulation of their optoelectronic response and the corresponding applications. Herein, copper nitride nanoparticles have been used as "uncontaminated" copper precursors to synthesize copper chalcogenide NCs with high monodispersity through a one-pot strategy. In this protocol, the sizes and compositions of NCs can be readily controlled by varying the ratio of the precursors. For Cu2-xS NCs with different diameters, the size variations are all smaller than 5.6%. Furthermore, the plasmonic properties of the copper chalcogenide NCs are investigated under a steady state by tuning the plasmonic resonance absorption band to a limiting condition (denoted "pinning" phenomena). It is observed that the pinning frequency increases (from 1.09 to 1.23 eV) with the increment of the NC size (from 5.4 ± 0.3 to 11.1 ± 0.4 nm), explained by introducing surface scattering. Meanwhile, the frequencies of ternary alloyed copper sulfide selenide NCs blue-shift from 0.90 to 1.00 eV with the increase of selenium content from 11% to 66%, which is related to the effective mass of free carriers. Additionally, the plasmonic absorption bands of Cu2-xS NCs encapsulated by two single-layer graphene pin at 1525-1550 nm during the oxidation process, which is influenced by both the dielectric constant and redox potential of the surrounding environment. This study demonstrates the controllable synthesis and precise fundamental plasmonic properties of the copper chalcogenide NCs, ensuring the potential plasmonic-related techniques with high efficiency, accuracy and excellent spatial resolution. [ABSTRACT FROM AUTHOR]

Purpose: This study set out to quantify the fatigue-related changes in surface electromyographic (sEMG) activities of the perilaryngeal muscles following a vocal loading task. Method: Thirty-six young healthy participants (Mage = 22.4 years) with normal voice performed karaoke singing for at least 100 min. Before the singing task, all participants underwent the sEMG measure and completed a Perceived Vocal Fatigue Score (P-VFS) questionnaire. After the singing task, all participants were immediately measured with the P-VFS again. Half of the participants were then measured for their sEMG immediately after their karaoke singing task, and the other half were given 20 min of rest before undertaking the sEMG measure. The P-VFS and the median frequency (MDF) of the sEMG signals collected from the suprahyoid, infrahyoid, and sternocleidomastoid muscles before and after the singing task were compared using a linear mixed-effects model. Results: All participants reported a perceived vocal fatigue after singing, with a significantly increased P-VFS. Compared with the presinging baseline, the MDF of the sEMG signals in perilaryngeal muscles was significantly lower immediately after the singing task. Such a significant difference was also found after 20 min following the singing task. Conclusions: The MDF analysis of the sEMG signals could identify and quantify the performance vocal fatigue contributed by perilaryngeal muscles following a vocal loading task. The findings also showed that such fatigue in perilaryngeal muscles, as far as sEMG activities are concerned, can last for at least 20 min. [ABSTRACT FROM AUTHOR]

This paper addresses the upset prediction problem of friction welded joints. Based on finite element simulations of inertia friction welding (IFW), a radial basis function (RBF) neural network was developed initially to predict the final upset for a number of welding parameters. The predicted joint upset by the RBF neural network was compared to validated finite element simulations, producing an error of less than 8.16% which is reasonable. Furthermore, the effects of initial rotational speed and axial pressure on the upset were investigated in relation to energy conversion with the RBF neural network. The developed RBF neural network was also applied to linear friction welding (LFW) and continuous drive friction welding (CDFW). The correlation coefficients of RBF prediction for LFW and CDFW were 0.963 and 0.998, respectively, which further suggest that an RBF neural network is an effective method for upset prediction of friction welded joints. [ABSTRACT FROM AUTHOR]

Grating couplers that interconnect photonic chips to off-chip components are crucial for various optoelectronics applications. Despite numerous efforts in past decades, the existing grating couplers are still far from optimal in energy efficiency and thus hinder photonic integration toward a larger scale. Here, we propose a strategy to achieve ultralow-loss grating couplers by using unidirectional guided resonances (UGRs), suppressing the useless downward radiation with no mirror on the bottom. By engineering the dispersion and apodizing the geometry of grating, we experimentally realize a grating coupler with a record-low loss of -0.34 dB and 1-dB bandwidth exceeding 30 nm at the telecom wavelength of 1550 nm and further demonstrate an optic via with a loss of only -0.94 dB. Given that UGRs ubiquitously exist in a variety of grating geometries, our work sheds light on a systematic method to achieve energy-efficient optical interconnect and paves the way to large-scale photonic integration. [ABSTRACT FROM AUTHOR]

The article provides information on the use of intense THz electric fields to control lattice structures in lead halide perovskites (LHPs), which are promising semiconductors for solar cells and optoelectronic devices. The study focuses on the role of Raman-active phonons in governing the ultrafast THz-induced Kerr effect and highlights the potential for selective control of LHP's vibrational degrees of freedom.

Friction welding (FW) is a collection of a series of friction-based solid state joining processes which can produce high quality welds of different components with either similar or dissimilar materials and has been attracting increasing attention. Due to the extreme condition encountered during FW and the highly thermomechanical coupled nature of FW, finite element methods have been widely developed to study the FW process. In the light of reasonable simplification, we developed several effective methods based on the ABAQUS environment. Initially 2D models were developed to investigate the complete FW process, where an implicit method with remeshing and map solution techniques and an explicit method with the Arbitrary Lagrangian Eulerian (ALE) adaptive mesh controls were proposed to effectively overcome the excessive element distortion by using the ABAQUS Standard and Explicit packages, respectively. In addition, a 3D model was also developed to obtain better simulation results with the help of the ALE adaptive mesh controls in the ABAQUS/Explicit package and the map solution technique in the ABAQUS/Standard package combined with the HYPERWORKS software. The experiments validate the feasibility and accuracy of the developed models. [ABSTRACT FROM AUTHOR]

The ultrafast polarization response to incident light and ensuing exciton/carrier generation are essential to outstanding optoelectronic properties of lead halide perovskites (LHPs). A large number of mechanistic studies in the LHP field to date have focused on contributions to polarizability from organic cations and the highly polarizable inorganic lattice. For a comprehensive understanding of the ultrafast polarization response, we must additionally account for the nearly instantaneous hyperpolarizability response to the propagating light field itself. While light propagation is pivotal to optoelectronics and photonics, little is known about this in LHPs in the vicinity of the bandgap where stimulated emission, polariton condensation, superfluorescence, and photon recycling may take place. Here we develop two-dimensional optical Kerr effect (2D-OKE) spectroscopy to energetically dissect broadband light propagation and dispersive nonlinear polarization responses in LHPs. In contrast to earlier interpretations, the below-bandgap OKE responses in both hybrid CH3NH3PbBr3 and all-inorganic CsPbBr3 perovskites are found to originate from strong hyperpolarizability and highly anisotropic dispersions. In both materials, the nonlinear mixing of anisotropically propagating light fields results in convoluted oscillatory polarization dynamics. Based on a four-wave mixing model, we quantitatively derive dispersion anisotropies, reproduce 2D-OKE frequency correlations, and establish polarization-dressed light propagation in single-crystal LHPs. Moreover, our findings highlight the importance of distinguishing the often-neglected anisotropic light propagation from underlying coherent quasiparticle responses in various forms of ultrafast spectroscopy. [ABSTRACT FROM AUTHOR]

We achieved an ultralow-power Fano-like diode in integrated photonic circuits through two cascaded and uncoupled photonic-crystal microcavities, coated with a nonlinear layer constructed from polycrystalline indium-tin oxide doped with gold nanoparticles. The multicomponent nanocomposite layer helps to obtain an extremely large nonlinearity enhancement on account of the quantum confinement effect, hot-electron injection, and local-field enhancement effect. Thus, the strong nonlinearity enhancement, asymmetric Fano-like spectrum lineshape, and asymmetric light confinement for the forward and backward incidence cases guarantee the nonreciprocal transmission of signal light. A compact size of 7 μm is maintained for the photonic-crystal microcavities and the transmission contrast reached 15 dB. Besides, we achieved 1.5 kW cm−2 operating threshold intensity (cut down by a thousand times). This work assists chip-integrated optical computing on the basis of nonlinear photonic-crystal microcavities. [ABSTRACT FROM AUTHOR]