A canonical module characterization of Serre’s (R1)

In this short note, we give a characterization of domains satisfying Serre’s condition (R₁) in terms of their canonical modules. In the special case of toric rings, this generalizes a result of the second author [9 Yanagawa, K. (2015). Dualizing complexes of seminormal a?ne semigroup rings and toric face rings. J. Algebra 425:367–391.[Crossref], [Web of Science ®] , [Google Scholar]] where the normality is described in terms of the “shape” of the canonical module.     

Synthesis,Redox Properties,and Electronic Spectra of Sterically Crowded Triarylphosphines Conjugated with Electron Acceptors

Abstract

Synthesis, redox properties, and electronic spectra of the sterically crowded triarylphosphines conjugated with π-electron systems, especially electron acceptors such as carbonyl group, are briefly reviewed. The sterically crowded triarylphosphines conjugated with various π-electron systems were synthesized from the common synthetic intermediate, (bromoaryl)phosphine, by conventional manner. The sterically crowded triarylphosphines conjugated with the electron acceptors exhibit visible absorption and fluorescence with large Stokes shift. Large solvent effect, redshift in polar solvent, and good correlation with the difference of the oxidation potential of the phosphine moiety and the reduction potential of the acceptor moiety suggest polar excited state resulting from HOMO-LUMO transition.     

Investigation of structural changes related to temperature: An understanding of H-bond based proton transfer in 4(5)-vinylimidazole and acrylic acid copolymer membrane

An attempt to understand how proton transfer proceeds in poly (acrylic acid-co-4(5)-vinylimidazole) has been carried out based on the temperature dependent characterization techniques, i.e., Fourier transform infrared spectroscopy (FTIR), wide angle X-ray diffraction (WAXD), Raman spectroscopy, including the atomic distance calculations. Systematical studies are achieved from a series of poly (acrylic acid-co-4(5)-vinylimidazole) with different acrylic acid content. When the copolymer is almost an ideal in equimolar ratio of an alternating structure, the hydrogen bond between carboxylic acid and imidazole is maintained and initiates the proton conductivity even at 120 °C. Whereas when the copolymer is carboxylic acid rich, the dehydration to form anhydride proceeds resulting in the decrease in proton conductivity at high temperature. The radial distribution function (RDF) calculated from the WAXD pattern shows that the inter-atomic distances reflect how the increase in temperature induces a favorable packing structure under the hydrogen bond network and the chain mobility to enhance the proton transfer at high temperature, especially in the case of the copolymer with an ideal alternating structure.     

Magnetic structures of exchange bias Ni/FeF2(1 1 0) interface

Electronic and magnetic structures of ferromagnetic (FM)/antiferromagnetic (AFM), Ni/FeF₂(1 1 0), with a compensated AFM interface are investigated by using the full-potential linearized augmented plane-wave method. We find that magnetic structures at the AFM interface are perturbed by a contact with the FM material, where the superexchange interaction through the interface F excites and induces a small net moment at the AFM interface. These results predicted may play an important role for explaining the exchange bias in this system, and rule out the exchange bias mechanisms with the spin-flop coupling and the magnetic moment reorientation.     

Comparison of standard materials for the establishment of calibration curves in solid sampling graphite furnace atomic absorption spectrometry. Direct determination of copper in powdered biological samples

Summary The selection of standard materials for the establishment of calibration curves is one of the most important problems in the direct analysis of biological samples by GFAAS. Three kinds of standard materials, NBS tomato leaves, coprecipitates with magnesium oxinate and Ni/DMG/PAN were investigated. It was found that it is possible to use both the NBS-SRM and the synthetic reference material prepared by coprecipitation with magnesium oxinate as standard materials for the direct determination of copper in several biological samples issued from NBS and NIES. However, too low results are obtained when the synthetic reference material prepared by coprecipitation with Ni/DMG/PAN is used. In order to clarify this, the effects of nickel and magnesium were examined and the role of magnesium was discussed.