Chemical effects in high-resolution nickel Kalpha X-ray fluorescence spectra.

The nickel Kalpha spectra of oxides, halides (NiF2, K2NiF6, NiCl2, NiBr2), complex compounds, and metal are measured with two different double-crystal X-ray fluorescence spectrometers. The peak shifts and line width changes due to the changes in the chemical states are reported. High reproducibility has been shown for the chemical shift and line width measurements. The DV-Xalpha molecular orbital calculation at the ground and the 1s(-1) hole states was performed to prove that the chemical effect originats from the charge-transfer mechanism.     

Mechanical fabrication of metal nano-contacts showing conductance quantization under electrochemical potential control

We have mechanically fabricated Ni and Cu nano-constrictions in solution to study their quantized conductance behavior under electrochemical potential control. Conductance quantization was observed at both metals in solution at room temperature for the first time. The conductance of Cu nano-constriction was quantized in units of G₀(=2e²/h). A sharp 1G₀ peak was observed in the conductance histogram. For Ni, a rather broad peak at 1–1.5G₀ was observed in the histogram. The conductance quantization behavior was discussed by comparing previously documented results of nano-constrictions fabricated in air or ultra-high vacuum conditions, with those fabricated in solution.     

One-pot synthesis of 4-substituted 4-alkoxy-1,4-dihydro-3,1-benzoxazine-2-thiones by the reaction of 2-isothiocyanatobenzoates with organolithiums

An efficient one-pot procedure for the preparation of 4-substituted 4-alkoxy-1,4-dihydro-3,1-benzoxazine-2-thiones from 2-isothiocyanatobenzoates has been developed. Thus, 2-isothiocyanatobenzoates were reacted with organolithiums including lithium enolates of acetates and tertiary acetamides in THF at −78 °C to give the desired products in generally good yields.     

Size-dependent inclusion of organic molecules into elastic pillared carbons

Size selective inclusion of organic molecules into pillared carbons accompanied by large interlayer expansions was observed for the first time. In order to achieve this, the distance between two adjacent pillars should be between 0.36 and 0.40 nm and they should align in the same direction.     

Synthesis of heterosegment-junctioned hybrid nanotubes of polythiophene and heterometallic nanoparticles by sequential template-based electropolymerization

New heterosegment-junctioned hybrid nanotubes of polythiophene and heterometallic nanoparticles (Pd, Au NPs) have been synthesized by sequential electropolymerization of terthiophene-modified Pd and Au NPs in a nanoporous template.     

New acylated anthocyanins and other flavonoids from the red flowers of Clematis cultivars

Six new acylated cyanidin glycosides, cyanidin 3-O-beta-(2'-E-caffeoylglucopyranosyl)-(1 --> 2)-O-beta-galactopyranoside (1), cyanidin 3-O-beta-(2'-E-caffeoylglucopyranosyl)-(1 --> 2)-O-beta-(6'-malonylgalactopyranoside) (2), cyanidin 3-O-beta-(2'-E-caffeoylglucopyranosyl)-(1 --> 2)-O-beta-(6'-succinylgalactopyranoside) (3), cyanidin 3-O-beta-(2'-E-caffeoylglucopyranosyl)-(1 --> 2)-O-beta-galactopyranoside-3'- O-beta-glucuronopyranoside (4), cyanidin 3-O-beta-(2'-E-caffeoylglucopyranosyl)-(1 --> 2)-O-beta-(6'-malonylgalactopyranoside)-3'-O-beta-glucuronopyranoside (5), and cyanidin 3-O-beta-(2'-E-feruloylglucopyranosyl)-(1 --> 2)-O-beta-(6'-malonylgalactoside)-3' -O-beta-glucuronopyranoside (6), were isolated from the red flowers of two Clematis cultivars, 'Niobe'and 'Madame Julia Correvon'. The chemical structures of the isolated anthocyanins were determined by UV, LC-MS, HPLC, TLC, characterization of hydrolysates, and 1H and 13C NMR spectroscopy, including H-H COSY, C-H COSY, HMBC, HMQC and NOESY. The last three anthocyanins were widely distributed in 37 red flower Clematis cultivars. On the other hand, the first three compounds were found only in two cultivars. Five known flavonol glycosides, kaempferol 3-O-glucoside, kaempferol 3-O-rutinoside, quercetin 3-O-galactoside, quercetin 3-O-glucoside and quercetin 3-O-rutinoside, were isolated from the flowers of'Madame Julia Correvon'.     

Polynomial solutions of q-Heun equation and ultradiscrete limit

We study polynomial-type solutions of the q-Heun equation, which is related with quasi-exact solvability. The condition that the q-Heun equation has a non-zero polynomial-type solution is described by the roots of the spectral polynomial, whose variable is the accessory parameter E. We obtain sufficient conditions that the roots of the spectral polynomial are all real and distinct. We consider the ultradiscrete limit to clarify the roots of the spectral polynomial and the zeros of the polynomial-type solution of the q-Heun equation.     

Normalizing and variance stabilizing transformations for intraclass correlations

Summary A concept of normalizing transformations of statistics is constructed on the basis of the rate of convergence to normality. The concept is applied to derive a normalizing transformation of a maximum likelihood estimate of intraclass correlation coefficient in ap-variate normal sample. Numerical comparisons are made to examine whether the proposed transformation is efficient to achieve normality. The relationship between normalization and variance stabilization is also considered. The Institute of Statistical Mathematics