Structural Elucidation of an Elicitor-Active Oligosaccharide,LN-3, Prepared from Algal Laminaran

Abstract

The primary structure of an elicitor-active oligosaccharide, LN-3, prepared from partially hydrolyzed algal laminaran was determined by means of the analyses of glycosyl-linkage, fragments by acetolysis, and glycosyl-sequence. The elicitor-active oligosaccharide, LN-3, is a pyridylaminated hepta-β-d-glucoside which was shown to have the following linear structure: β-d-Glcp(1→6)-β-d-Glcp(1→3)-β-d-Glcp(1→3)-β-d-Glcp(1→3)-β-d-Glcp(1→6)-β-d-Glcp(1→3)-Glc-PA.     

Structures of xantholides A and B,two new guaianolides from xanthium canadense mill.

The structures of xantholides A and B were deduced on the basis of IR and NMR spectra, and confirmed by X-ray analysis. Xantholide A inhibited the larval growth of Drosophila melanogaster.     

Landau levels in a novel two-dimensional electron system interacting with charged quantum dots

Landau levels have been theoretically investigated in a two-dimensional electron gas near a quantum dot (QD) layer. By a diagrammatical method, we have formulated the self-energy for the Landau level and deduced its relation to the AC conductivity σ_loc(ω) in the QD layer. As an example, we have examined the density of states in the case where σ_loc(ω) is described by Aω^S(S=0.8). It is found that the Landau levels are broadened due to the interaction with the localized electrons in the QDs.     

A laser system for counting cloth filaments

A simple, high speed and high accuracy counter system for cloth filament has been constructed. The principle is based on the laser light attenuation through the cloth. The system is composed of semiconductor laser, objective lens, focusing lens PIN photodiode and processing system including amplifier, Δ V detector, counter, comparator, preset and marker. The counting accuracy is above 99% and the maximum counting speed is beyond 5 kHz, which will be enough for practical use.     

Control of Optical Properties of Thin Films Doped with Au Fine Particles by the Sol-Gel Method

We have developed tinted glasses with thin films doped with Au particles by the sol-gel method for automotive windows. Pink-colored glasses are mass-produced. The observed color is from absorption due to surface plasma resonance of Au particles. The squeeze-out of fine Au particles out of gel films was restrained by an organic additive. The index of the matrix was adjusted by the mixing ratio of TiO₂ (refractive index n = 2.20) to SiO₂ (n = 1.46). The absorption of Au particles is more intense with the higher index of the matrix, and its peak varies from 530 nm for n = 1.46 to 630 nm for n = 2.20, which yields a transmission color from pink to blue. The combination of the color of the glass substrate and the absorption by the Au particles in the thin films with various indices yields a variety of tinted glasses such as pink, orange, blue, blue-green and gray.     

Analysis of inelastic scattering processes of electrons by localized electrons in quantum dots

The inelastic Coulomb scattering rate 1/τ_in of conduction electrons has been theoretically evaluated in the presence of localized states such as quantum dots. By a diagrammatical method, we have formulated 1/τ_in and its relation to the conductivity σ_loc(ω) through localized states. The dependence of τ_in on temperature T is examined in the case that σ_loc(ω) follows the Mott's model. It is found that 1/τ_in varies as T²(ln Δ/T)^d+1 where d is the dimensionality and Δ is tunneling energy between the localized states in the asymptonic T = 0 limit, in agreement with Imry's calculation. It is also found that calculated 1/τ_in deviates from T²(ln Δ/T)^d+1 as T increases, suggesting the importance of correction term at high temperature.     

A limit theorem for branching one-dimensional periodic diffusion processes

We give almost sure convergence of appropriately normalized particle numbers in bounded domains of locally supercritical branching diffusion processes with one-dimensional periodic diffusions as their non-branching part processes. Some spectral properties of periodic diffusion operators including Hill's ones are also studied.