Psychological impression and listening score while listening to audio signal under meaningless steady noise

The indices for evaluating psychological impression and listening score are first introduced in the case of listening to a Japanese monosyllabic audio signal while subjected to meaningless steady noise. Hereupon, the mutual relationship between the power spectrum level of audio signal and that of external noise is reflected in the above evaluation indices. Next, estimation and/or prediction problems of the psychological impression and listening score are discussed. The predicted values of the psychological impression and listening score are compared with the experimental observed data. A useful index is discussed, considering consistency between predicted and observed values.     

A new tris-annulation reagent prepared from a butadiene telomer,and its application to steroid synthesis

Reaction of 1,7-octadien-3-one with dimethyl malonate, followed by the reduction of the ketone produced dimethyl (3-hydroxy-7-octenyl)malonate, which was converted to 9-decen-5-olide after hydrolysis and decarboxylation. Reaction of vinylmagnesium chloride with the lactone and the subsequent acylation afforded 7-acetoxy-1,11-dodecadien-3-one. This is a new tris-annulation reagent. (±)-D-homo-19-norandrosta-4-en-3-one was synthesized by using this tris-annulation reagent.     

Mössbauer spectra and molecular structure of spin-crossover iron (III) complexes of monoclinic form with hexadentate ligands derived form triethylenetetramine and salicylaldehyde [Fe(sal2trien)]BPh4·acetone

Iron (III) complexes of [FeL]BPh₄·acetone containing the hexadentate ligand derived from triethylenetetramine and salicylaldehyde have been synthesized. These complexes were grown in two crystalline forms; monoclinic and twin crystals. The spin-state interconversion rate of the monoclinic form is as fast as the inverse of the Mössbauer lifetime (1×10^?7 s) above 200 K. The crystal structure of the monoclinic form (complex a) was determined at 290 K and to be of space group P2₁/a, with a=27.418 (4), b=10.097 (2), c=14.726 (3) Å, β=98.00 (1)°, and Z=4. The average bond distances of Fe?O (1.875 Å), Fe?N_imine (1.988 Å) and Fe?N_amine (2.069 Å) are in good agreement with the expected values for the transition spin-state between high- and low-spin states. Twin crystals are in a high-spin state over the temperature range 78–320 K.     

One-carbon extrusion from carbohydrates via C1-alkoxy radical fragmentation. An easy access to erythrose and threose

Generation and fragmentation of the C1-alkoxy radicals of pyranose derivatives are nicely promoted by (diacetoxyiodo)benzene or lead tetraacetate in the presence of iodine catalyst under mild conditions to give the corresponding mixed-acetal formates which are further converted to the furanose derivatives by acid-catalysed transacetalization.     

Structures of modified nucleotides isolated from calf thymus DNA alkylated with reductively activated mitomycin C

The structures of modified nucleotides isolated from calf thymus DNA alkylated with reductively activated mitomycin C were determined.     

Log-T dependence in the low-temperature resistivity of Sb doped Si

We have studied temperature dependence of the resistivity of Sb doped Si at low temperature down to 10mK. In the vicinity of metal-nonmetal transition in Sb doped Si, the low-temperature resistivity in a just metallic side shows a logarithmic increase with lowering temperature. After thermal annealing the log-T dependence disappears and $\text{T}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ dependence is observed in the same temperature region. We find that the log-T dependence in the low-temperature resistivity comes from a surface-related conduction.     

Crystal and molecular structure of [i-Pr2Si]4 and [(Me3SICH2)2Si]4 and some structural properties of cyclopolysilanes, [R1R2Si]n (n = 3-6)

The crystal structures of octaisopropylcyclotetrasilane [i-Pr₂Si]₄ (1) and octakis(trimethylsilylmethyl)cyclotetrasilane [(Me₃SiCH₂)₂Si]₄ (2) have been determined by means of X-ray diffraction analysis. Various crystallographic and structural data for the two compounds were recorded. The Si₄ rings of the compounds are nonplanar with quite large dihedral angles of 37.1° in (1) and 36.6° in (2), being comparable to that (36.8)° for [t-BuMeSi]₄ reported previously and other characteristic features in the structures of (1) and (2) were described. Some structural properties of the cyclic catenation systems, [R¹R²Si]_n (n = 3–6), including (1) and (2) were also discussed from a comparative viewpoint with respect to the ring shape and the relationship between ring size and Si-Si bond length.