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Examines the diabatic potential crossings leading to electron transitions in moderate-energy collisions of closed-shell particles using charge-overlap of electron clouds. Evaluation of the differential scattering experiments and calculations; Origin of the potential crossing; Account on one- and two-electron transitions.

Presents a study that measured demagnetizing curves after field cooling in melt processed yttrium-barium-copper-oxygen superconductors. Use of vibrating sample magnetometer and superconducting quantum interference device; Impact of field-cooling technique on magnets; Background on high temperature superconductors.

Substitution of Co[SUP2+] for a small part of Fe[SUP2+] in (MnZn)Fe[SUB2]O[SUB3] results in much smaller temperature variation in core loss, compared with that of conventional MnZn ferrite used for transformers. This effect appears in the temperature dependence of hysteresis loss rather than two other contributions of loss, eddy current loss, and residual loss. The total loss not exceeding 370 kW/m[SUP3]at 100 kHz/200 mT is obtained in the wide temperature range from 0 to 100 °C. However, excess substitution gives rise to a steep increase of loss below room temperature. Both the improvement of temperature dependence and the abrupt changes in loss in a lower-temperature region accompanying Co[SUP2+] substitution could result from a change in the magnetocrystalline anisotropy constant K[SUB1]. [ABSTRACT FROM AUTHOR]

Frequency dependence of power loss of MnZn ferrite was investigated in relation with the absolute complex permeability, μ[sub a](=μ[sub a]-jμ[sub a][sup ″]), in the frequency range 10 kHz–5 MHz and the temperature range 23–120 °C. Residual loss, P[sub r] contributes more than half of the total power loss, P[sub c], at a frequency above 1 MHz and exhibits a close relationship with μ[sub a][sup ″]. The specimen with grain size of 4 μm and ZnO content of 0 mol % indicates μ[sub a][sup ′] of 1280 and P[sub c] of 140 kW/m[sup 3] at 1 MHz and 50 mT. In the second measurement at the remanent state after the dc magnetization of 400 A/m, these values, however, increased and then gradually recovered with time. This behavior is considered to be related to the diffusion of Fe[sup 2+] through cation vacancy. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We measured the spectral and spatial intensity distributions of synchrotron radiation (SR) in the soft x-ray region using an energy-dispersive method with a Si (Li) detector at the Photon Factory. By measuring the intensity of x rays scattered by helium gas, we could reduce the high SR intensity to the sensitivity range of a Si (Li) detector and, by selecting the scattering angle, we used this method as a polarimeter. In the soft x-ray region above 2 keV, the measured spectral and spatial profiles of the direct beam transmitted through a Be window were almost the same as the calculated values, but absolute intensity was about 30% less than calculated. This is largely due to the geometric errors of the measuring system. We also measured the intensity distribution of the beam reflected from fused quartz mirrors. The spectrum profiles agreed with the calculated values, but absolute intensity was somewhat less than expected, and the spatial distribution had a complicated profile because of imperfections in the mirrors. [ABSTRACT FROM AUTHOR]

A new type of thermal treatment for air-exposed AlGaAs surfaces, in situ low-temperature H2 annealing, has been developed regrowing AlGaAs in metalorganic vapor phase epitaxy. The quality of regrown interface was evaluated by photoluminescence (PL) spectrum from Al0.3Ga0.7As/GaAs/Al 0.3Ga0.7As quantum wells near the interface of the initial AlGaAs layer. Remarkable recovery of PL intensity was observed by this newly developed process, indicating that initial air-exposed AlGaAs surface states are reduced. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

This paper describes the effect of two types of temporal permutations of the speech waveform on speech intelligibility. Using an overlap-add procedure with triangular-shaped windows for frame lengths of 1/8 to 2048 ms, the temporal order of the speech samples within each frame was subjected to either of two types of permutations: time-reversal or randomization. For both permutations, speech intelligibility tests expectantly show 100% intelligibility for the very short frame lengths containing only a few speech samples. Intelligibility drops to essentially zero toward longer frame lengths of around 1 ms. Interestingly, only for the reverse condition, intelligibility recovers to essentially 100% for frame lengths in the 4-32 ms range, dropping again to zero for frame lengths exceeding about 100 ms. Tests for the Japanese and the English language show essentially similar results. The data are interpreted along the lines of a previous paper by Kazama and the present authors [J. Acoust. Soc. Am. 127(3), 1432-1439 (2010)]. As in that previous paper, the loss of temporal envelope correlation shows a pattern very similar to that of the intelligibility data, illustrating again the importance of the preservation of narrow-band envelopes for speech intelligibility.

This paper investigates the significance of the magnitude or the phase in the short term Fourier spectrum for speech intelligibility as a function of the time-window length. For a wide range of window lengths (1/16-2048 ms), two hybrid signals were obtained by a cross-wise combination of the magnitude and phase spectra of speech and white noise. Speech intelligibility data showed the significance of the phase spectrum for longer windows (>256 ms) and for very short windows (<4 ms), and that of the magnitude spectrum for medium-range window lengths. The hybrid signals used in the intelligibility test were analyzed in terms of the preservation of the original narrow-band speech envelopes. Correlations between the narrow-band envelopes of the original speech and the hybrid signals show a similar pattern as a function of window length. This result illustrates the importance of the preservation of narrow-band envelopes for speech intelligibility. The observed significance of the phase spectrum in recovering the narrow-band envelopes for the long term windows and for the very short term windows is discussed.