Synthesis and binding behaviors of monomethyl cucurbit[6]uril

By reacting 3a-methylglycoluril and glycoluril with paraformaldehyde, monomethyl cucurbit[6]uril was synthesized in 14% yield. The new host molecule forms stable inclusion complexes with diamine and hexylaminocarbazole derivatives.     

Numerical methods for the eigenvalue determination of second-order ordinary differential equations

An accurate method for the numerical solution of the eigenvalue problem of second-order ordinary differential equation using the shooting method is presented. The method has three steps. Firstly initial values for the eigenvalue and eigenfunction at both ends are obtained by using the discretized matrix eigenvalue method. Secondly the initial-value problem is solved using new, highly accurate formulas of the linear multistep method. Thirdly the eigenvalue is properly corrected at the matching point. The efficiency of the proposed methods is demonstrated by their applications to bound states for the one-dimensional harmonic oscillator, anharmonic oscillators, the Morse potential, and the modified Pöschl–Teller potential in quantum mechanics.     

Green polynomials at roots of unity and Springer modules for the symmetric groups

We consider the Green polynomials at roots of unity. We obtain a recursive formula for the Green polynomials at roots of unity whose orders do not exceed some positive integer. The formula is described in a combinatorial manner. The coefficients of the recursive formula are realized by the cardinality of a set of permutations. The formula gives an interpretation of a combinatorial property on a family of graded modules for the symmetric group in terms of representation theory.     

Magnetic susceptibility measurements of solutions by surface nanodisplacement detection.

A new principle to measure the magnetic susceptibility of a solution was proposed; it utilized the displacement of solution surface caused by the magnetic force applied to the solution. The interfacial displacement was measured with the sensitivity of 5 nm from a change of the interference fringes, so called Newton Ring, generated from the solution surface and an upper surface of a small plano-convex lens on the bottom wall of a cell. The surface displacement measurement was carried out in a homemade cell attached by one or two small Nd-Fe-B magnets. The performance of this method was investigated by the measurements of magnetic susceptibility of manganese(II) chloride solution and some lanthanide(III) solutions. An excellent linear relationship between the magnetic susceptibility and the interfacial displacement was observed for each solution system. Then, it was demonstrated that this relationship could be used for the determination of the magnetic susceptibility of solutions or the concentration of a solute by using the manganese(II) solution as a standard solution.     

Limitation of Color Samples for Spectral Estimation from Sensor Responses in Fine Art Painting

A new technique is proposed to improve the way of selecting samples used to estimate spectral reflectance from sensor responses in multi-band images. This technique limits the samples of reflectance spectra based on the spectral reflectance estimated by the conventional estimation method, and estimates it again using the limited samples. Vector angle and distance among reflectance spectra as the criteria for the limitation can be applied to improve the estimation of reflectance spectra.     

A new approach for controlling birefringent property of cyclic olefin copolymers

This article reports an original method to control the birefringent property of the cyclic olefin copolymer, which has been recently commercialized as a new type of optical resins, via introduction of a third monomer that possesses a negative birefringence into the cyclic olefin copolymer that exhibits an inherently positive birefringence. The mutual compensation between these opposite‐sign birefringences effectively reduced the birefringent magnitude of the corresponding terpolymer. In fact, terpolymerization of norbornene (N), ethylene (E), and styrene (S), in which S exhibits a negative birefringence regarding to the positive birefringence of the NE copolymer was successfully prepared using fluorenylamidodimethyltitanium‐based catalyst, yielding NES terpolymers with controllable birefringent property. Especially, when the S content in the NES terpolymer was controlled at optimum values, it is possible to synthesize a new type of the cyclic olefin copolymer that exhibits an extremely low birefringent magnitude close to zero regardless of high degrees of chain orientation. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7395–7400, 2008     

Measurement of low retardation using reflective optical system based on the photoelastic principle

A new measuring technique that can measure retardation and can output magnitude and direction of plane stress in each glass of a panel composed of double transparent pieces of glass has been developed using reflective confocal optics. The linear polarized probe beam is incident to the glass and we can detect a reflected beam converted to orthogonal polarization caused by the photoelastic phenomenon. Using the high extinction ratio (10⁶) beam-displacing prism as a polarization discriminator, we can measure the photoelasticity by rotating the polarization of the probe beam from 0 to π rad without disturbing the optical axis. This system has the ability to measure retardation. The lowest one is estimated as nearly 0.066 nm for 700 μm thickness glass which corresponds to 0.03 MPa stress from our calibration line.     

Behavior of hydrogen atom at Nafion-Pt interface

We present a mechanism depicting how a hydrogen atom migrates from a platinum catalyst to a Nafion membrane using ab initio calculations based on density functional theory (DFT). The H atom initially adsorbed on Pt is extracted by the sulfonate group (-SO₃⁻), which is a part of the side chain of Nafion. We found partial electron transfer from the H atom to the Pt, which directly binds to the -SO₃⁻ group, through this reaction. The electron-poor H atom conducts in Nafion, and the partial electron transfer from the H atom results in the generation of electric power in polymer electrolyte fuel cells (PEFCs).