Raman scattering in low wavenumber region as a new probe to structural properties of microcrystalline silicon

The structural properties of microcrystalline silicon (μc-Si) are studied by Raman scattering. It is found that the intensity of each Raman band closely correlates with the absorption coefficient in the interband region and that the Raman band at ca. 150 cm^?1 is a sensitive probe to randomness of Si-Si bonding structure in μc-Si.     

Mössbauer spectroscopic studies of (n-C n H2n +1NH3)2SnX6 (n=0-4; X = Cl or Br) and their related complexes

Complexes of the type (n-C _n H_2n +1NH₃)₂SnX₆ (0n 4 and X=Cl or Br) have been investigated with a variety of physico-chemical techniques. The structural phase transitions were found in some of these complexes. The temperature dependence of the Mössbauer spectral absorption area for (C₂H₅NH₃)₂SnCl₆ and (C₂H₅NH₃)₂SnBr₆ changed sharply at phase transition temperatures. The temperature dependences for (n-C₄H₉NH₃)₂SnCl₆ and (n-C₄H₉NH₃)₂SnBr₆ decreased gradually with an increase in temperature. The correlation between the temperature dependence of the spectral absorption area and the motion of n-C _n H_2n+1NH₃ ⁺ ions is discussed.     

Real-time processing using the frequency domain binaural model

There are many approaches to achieving high-performance speech enhancement. The modeling of the human auditory system is a good approach, since human beings can focus on target speech under concurrent speech conditions. One example of the binaural models is the time domain binaural model. However, this model has a high-calculation cost because the algorithm is based on auto-correlation, which is computationally intensive. Another example is the frequency domain binaural model proposed by Nakashima et al. [Nakashima H, Chisaki Y, Usagawa T, Ebata M. Frequency domain binaural model based on interaural phase and level differences. Acoust Sci Technol 2003;24(4):172-8]. Since the frequency domain binaural model uses the fast fourier transform, the calculation cost is much lower than that of the time domain binaural model. Therefore, it is not difficult to perform real-time processing using recent hardware such as digital signal processors and even laptop personal computers. However the quality of the segregated sound obtained using the frequency domain binaural model depends on system parameters such as frequency resolution and frame shift length for overlap adding in time domain. This paper introduces the construction of a prototype of a hearing assistant system based on the frequency domain binaural model. The detailed implementation techniques and parameter tuning are mentioned. The proposed system runs in real-time after parameter tuning. The directional attenuation levels, that is, the directivity patterns of the proposed system is measured. Finally, it is shown that the prototype can extract sounds coming from specific directions in real-time.     

The role of spin-orbit potential in nuclear prolate-shape dominance

It is confirmed, in terms of the Woods-Saxon-Strutinsky method, that the spin-orbit potential plays a decisive role in the predominance of prolate deformation, which has been a long standing problem in nuclear physics. It is originated from the combined effects of the spin-orbit coupling and the diffused surface of the potential, in agreement with the previous work based on a more schematic Nilsson-Strutinsky method. The degree of prolate-shape dominance exhibits an oscillatory behavior with respect to the strength of spin-orbit potential and, the prolate-shape dominance is realized at the proper strength of the spin-orbit potential together with the standard surface diffuseness; this oscillatory behavior disappears in case of small diffuseness corresponding to ellipsoidal cavity. The calculated energy differences between oblate and prolate minima in this Letter are consistent with those of our extensive self-consistent calculations of the Hartree-Fock + BCS method with the Skyrme interaction.     

Determination of the structure of {31}ne by a fully microscopic framework

We perform the first quantitative analysis of the reaction cross sections of {28-32}Ne by {12}C at 240 MeV/nucleon, using the double-folding model with the Melbourne g matrix and the deformed projectile density calculated by antisymmetrized molecular dynamics. To describe the tail of the last neutron of {31}Ne, we adopt the resonating group method combined with antisymmetrized molecular dynamics. The theoretical prediction excellently reproduces the measured cross sections of {28-32}Ne with no adjustable parameters. The ground state properties of {31}Ne, i.e., strong deformation and a halo structure with spin parity 3/2{-}, are clarified.     

The Microwave Spectrum of Methyl Formate (HCOOCH3) in the Frequency Range from 7 to 200 GHz

The rotational spectrum of methyl formate (HCOOCH₃) has been observed in the frequency range from 7 to 200 GHz. We newly assigned 1612 lines in the ground torsional state and simultaneously analyzed both A- and E-species data including previously reported lines on the basis of the internal axis method. A total of 3077 lines were fitted to a 1σ standard deviation of 139 kHz, and molecular parameters were determined.     

Language specificity in the perception of voiceless sibilant fricatives in Japanese and English: implications for cross-language differences in speech-sound development

Both English and Japanese have two voiceless sibilant fricatives, an anterior fricative /s/ contrasting with a more posterior fricative /∫/. When children acquire sibilant fricatives, English children typically substitute [s] for /∫/, whereas Japanese children typically substitute [∫] for /s/. This study examined English- and Japanese-speaking adults' perception of children's productions of voiceless sibilant fricatives to investigate whether the apparent asymmetry in the acquisition of voiceless sibilant fricatives reported previously in the two languages was due in part to how adults perceive children's speech. The results of this study show that adult speakers of English and Japanese weighed acoustic parameters differently when identifying fricatives produced by children and that these differences explain, in part, the apparent cross-language asymmetry in fricative acquisition. This study shows that generalizations about universal and language-specific patterns in speech-sound development cannot be determined without considering all sources of variation including speech perception.     

Controlling chaos in a satellite power supply subsystem

In this work, we show that chaos control techniques can be used to increase the region that can be efficiently used to supply the power requests for an artificial satellite. The core of a satellite power subsystem relies on its DC/DC converter. This is a very nonlinear system that presents a multitude of phenomena ranging from bifurcations, quasi-periodicity, chaos, coexistence of attractors, among others. The traditional power subsystem design techniques try to avoid these nonlinear phenomena so that it is possible to use linear system theory in small regions about the equilibrium points. Here, we show that chaos control can be used to efficiently extend the applicability region of the satellite power subsystem when it operates in regions of high nonlinearity.     

Mean-field gauge interactions in five dimensions II. The orbifold

We study Gauge–Higgs Unification in five dimensions on the lattice by means of the mean-field expansion. We formulate it for the case of an SU(2)$\mathit{SU}(2)$ pure gauge theory and orbifold boundary conditions along the extra dimension, which explicitly break the gauge symmetry to U(1)$U(1)$ on the boundaries. Our main result is that the gauge boson mass computed from the static potential along four-dimensional hyperplanes is non-zero implying spontaneous symmetry breaking. This observation supports earlier data from Monte Carlo simulations in Irges and Knechtli (2007) [12].