We measure the mechanical thermal noise of soft silicon atomic force microscope cantilevers. Using an interferometric setup, we obtain a resolution down to 10(-14) m Hz(-1/2) on a wide spectral range (3-10(5) Hz). The low frequency behavior depends dramatically on the presence of a reflective coating: almost flat spectra for uncoated cantilevers versus a 1/f like trend for coated ones. The addi...

We report time-domain measurements with subpicosecond resolution of optical tunneling of terahertz electromagnetic pulses undergoing frustrated total internal reflection. Measurements of the transmitted electromagnetic pulses over a 3 THz bandwidth permits direct determination of frequency-dependent phase and amplitude changes in both the thin and opaque barrier limits in a single measurement. ...

We use our recently developed beam-deflection technique to measure the dispersion of the nondegenerate nonlinear refraction (NLR) of direct-gap semiconductors. The magnitude and sign of the NLR coefficient n2(ωa; ωb) are determined over a broad spectral range for different values of nondegeneracy. In the extremely nondegenerate case, n2(ωa; ωb) is positively enhanced near ...

A pitch-synchronous method and system for speech coding using timbre vectors is disclosed. On the encoder side, speech signal is segmented into pitch-synchronous frames without overlap, then converted into a pitch-synchronous amplitude spectrum using FFT. Using Laguerre functions, the amplitude spectrum is transformed into a timbre vector. Using vector quantization, each timbre vector is conver...

A measurement-model-based error structure analysis was applied to impedance data collected under galvanostatic modulation for a single 5 cm2 polymer electrolyte membrane PEM fuel cell. The stochastic errors were found to be roughly independent of frequency and were similar for the two instruments used. The measurement-model approach was found to be capable of identifying both high-frequency and...

Within the envelop-function framework, we developed the finite element method to calculate theminibands in the realist Silicon nanocrystal array. This method clearly reveals the miniband formation and accurately calculates the E–K dispersion relationship. In the simple 1D array, the deduced miniband structure matches well with the analytic Kronig–Penney method. More importantly, it can better s...

The title paper [Spectrochim. Acta A 213 (2019): 391–396] reports an improvement of the ”Poor Man’s Kramers–Kronig analysis” and ”Kramers–Kronig constrained variational thanks to ad hoc modification some analytical formulas existing in literature. This is not based on mathematical grounds. In this comment we show that no required but a correction formula used by authors 391–396].

Recently, bootstrap methods from conformal field theory have been adapted for studying the energy spectrum of various quantum mechanical systems. In this paper, we consider application these in obtaining Schr\"odinger equation with periodic potentials, paying particular attention to Kronig-Penney model a particle one-dimensional lattice. With an appropriate choice operator basis involving posit...