Quantitative analysis of inhomogeneous luminance effect on visibility of text

In the present study, we measured the visibility of several types of Japanese text on a liquid crystal display (LCD) with a spatially inhomogeneous luminance and extended the visibility index function (VIF) to explain the current experimental results with a higher degree of accuracy. We quantitatively analyzed the effect of an inhomogeneous luminance, which was produced by the graphical representation of a background without reflected light and by reflected light on a homogeneous background. These results showed that the visibility of text was influenced by the inhomogeneity of the background luminance in a domain that depended on text size. Then we applied a weighted average background luminance with a two dimensional Gaussian function, whose distribution width was related to the text size, to VIF. Finally, we proposed a modified VIF and showed that the new method was able to precisely estimate the actual visibility of text with an inhomogeneous luminance.     

Photo-electrochemical properties of multi-layered thin films composed of chalcogenide and superionic conductor glasses

Multi-layered thin films, which consisted of metallic silver, GeSe₃ glass, and silver oxyhalide superionic conductor glass were prepared. Photo- and electrochemical reaction of metallic silver with the chalcogenide glass layer was studied by optical absorbance and cyclic-voltammetry. Photo-doping of silver through the superionic glass layer was observed using evaporated AgI---Ag₂MoO₄ film and it was partly undoped by electrochemical treatment. However, no photo-doping was observed for the cell consisting of a AgI---AgPO₃ dip-coated layer. The doped silver was dissolved into the GeSe₃ layer during the photo-doping process. However, it formed another intermediate compound layer (probably silver selenide) during the electrodoping process.     

Charge transport study on single crystals of β-LiAl

Charge transport properties of β-LiAl were studied in the composition range of 48.0–50.2 at.% Li. Measurements were made on single crystal samples and down to the liquid He temperature. The resistivity changes linearly with temperature above 125 K, with a thermal coefficient of 72–95nΩ cm K^?1. The Matthiessen law was obeyed very well. A component dependent on temperature, which was described by the Grüneisen formula, is insensitive to a change of the chemical composition. On the other hand, the residual resistivity depends largely on the composition and contributes up to 58% of the total resistivity in Li_0.498. It is chiefly due to the substituted Li atoms on the Al sublattice.     

Raman scattering in the depletion region of GaAs

We have obtained spectra for the LO phonon mode by Raman scattering associated with surface quantization of the hole states in the depletion layer of highly doped n-type GaAs samples. When semi-transparent metal contacts are employed, the zone-center LO peak shifts to higher frequency due to plasmon-phonon interaction. The observed effects are not sensitive to the types of metal. The presence of the plasmon mode is thought to be due to the steady-state carrier injection from the incident laser light. The position of the peak is used to estimate the surface recombination rate of the excited electron-hole pairs.     

Determination of trace vanadium in petroleum oils by oxygen flask combustion and a catalytic method

The petroleum oil sample is combusted in an improved oxygen flask and vanadium (?0.1 ppm) is then determined by a catalytic method based on spectrophotometric monitoring of the gallic acid-bromate reaction. For most samples, there is no interference from other elements normally present, but an ion-exchange separation prior to catalytic determination is recommended in order to achieve reliable analyses of a wide variety of real petroleum samples.     

Carbon-13 NMR studies of the biologically active nor-diterpenoid dilactones from Podocarpus plants

Carbon-13 NMR signals of the biologically active norditerpenoid dilactones from Podocarpus plants were fully assigned by using selective ¹H decoupling, coupling constants (²J_CH), spin-lattice relaxation times (T₁) and correlation of the spectra of more than thirty dilactone congeners. The spectra of five nagilactones, B, C, D, E and F, which constitute representative members of three major structural types of the dilactones: (A) 8:14, 9:11-dienolide (α-pyrone) type, (B) 7α:8α-epoxy-9:11-enolide type, and (C) 7:8,9:11-dienolide type, were extensively analysed. Some characteristic steric interactions for the substituents on the ring system can be demonstrated from the spectral properties.     

Effects of trivalent phosphorus compounds on vinyl polymerization. III. Anionic polymerization of acrylonitrile with triethyl phosphite

The polymerization of acrylonitrile catalyzed by triethyl phosphite was studied. It was found that the order with respect to the monomer concentration varies from two to three, depending on the polymerization temperature. From the results obtained for the molecular weight of the polymer and the phosphorus content in the polymer, it was thought that the zwitterion formed by the addition of triethyl phosphite to acrylonitrile is responsible for the initiation of polymerization. The following equation was suggested for the rate of the polymerization: