Otoacoustic emission (OAE) data recorded for tone bursts presented separately and as a two-tone burst complex, that had been reported previously [Yoshikawa, H., Smurzynski, J., Probst R., 2000. Suppression of tone burst evoked otoacoustic emissions in relation to frequency separation. Hear. Res. 148, 95-106], were re-processed using the method of adaptive approximations by matching pursuit (MP). Two types of stimuli were applied to record tone burst OAEs (TBOAEs): (a) cosine-windowed tone bursts of 5-ms duration with center frequencies of 1, 1.5, 2 and 3kHz, (b) complex stimuli consisting of a digital addition of the 1-kHz tone burst together with either the 1.5-, 2- or 3-kHz tone burst. The MP method allowed decomposition of signals into waveforms of defined frequency, latency, time span, and amplitude. This approach provided a high time-frequency (t-f) resolution and identified patterns of resonance modes that were characteristic for TBOAEs recorded in each individual ear. Individual responses to single-tone bursts were processed off-line to form 'sum of singles' responses. The results confirmed linear superposition behavior for a frequency separation of two-tone bursts of 2kHz (the 1-kHz and 3-kHz condition). For the 1, 1.5-kHz condition, the MP results revealed the existence of closely positioned resonance modes associated with responses recorded individually with the stimuli differing in frequency by 500Hz. Then, the differences between t-f distributions calculated for dual (two-tone bursts) and sum-of-singles conditions exhibited mutual suppression of resonance modes common to both stimuli. The degree of attenuation depended on the individual pattern of characteristic resonance modes, i.e., suppression occurred when two resonant modes excited by both stimuli overlapped. It was postulated that the suppression observed in case of dual stimuli with closely-spaced components is due to mutual attenuation of the overlapping resonance modes.
In a previous study [H. Shintaku et al., Sensors and Actuators A: Physical 158 (2010): 183-192], an artificially developed auditory sensor device showed a frequency selectivity in the range from 6.
This article studies the synthesis, as well as the structural, vibrational, and optical properties of Eu-doped ZnO quantum dots (QDs) and investigates the energy transfer mechanism from the ZnO host to Eu ions using Reisfeld's approximation. Eu-doped ZnO QDs at varying concentrations (0-7%) were successfully prepared using a wet chemical method. The successful doping of Eu ions into the ZnO host lattice, as well as the composition and valence states of the elements present in the sample, were confirmed through X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses.
Piezoelectric resonance sensors are essential to many diverse applications associated with chemical and biological sensing. In general, they rely on continuously detecting the resonant frequency shift of piezoelectric resonators due to analytes accreting on their surfaces in vacuum, gas or fluid. Resolving the small analyte changes requires the resonators with a high quality factor.
In this Letter, we present a theoretical study based on the Lorentz function and harmonic oscillator model to explore temporal dynamics of charge transfer plasmon (CTP) resonances. By fitting scattering curves and near-field oscillations, we determine the dephasing time of CTP modes in conductively connected gold nanodisk dimers. We show that, compared with the well-known particle plasmon and dimer plasmon modes, the CTP mode has a narrow spectral width and longer lifetime.
Fluorescence emission regulation is of great interest for its promising applications in various fields such as microscopy, chemical analysis, encryption, and sensing. Most studies focus on the regulation of the fluorescence emission process. However, the spectral separation of excitation and emission of fluorophores requires careful design of resonances to cover both emission and excitation wavelengths, which is a better choice to enhance fluorescence intensity.
