Development of an experimental database of EUV spectra from highly charged ions of medium to high Z elements in the Large Helical Device plasmas

We are developing an experimental database of extreme ultraviolet spectra from highly charged ions using optically thin high-temperature plasmas produced in the Large Helical Device. Spectra from a variety of elements with atomic numbers ranging from 36 to 83 have been systematically recorded in the range of 1–20 nm by a grazing incidence spectrometer. For higher Z elements from tin onward, discrete or quasicontinuum spectral features from n=4 (N-shell) ions are mainly observed depending upon the plasma temperature, which leads to some new experimental identifications of spectral lines. On the other hand, major emitters are n=3 (M-shell) ions for medium Z elements from krypton to ruthenium. The calculated wavelengths for Δn≠0 transitions agree well with the measurements and the calculated wavelengths are systematically shifted to shorter wavelengths for Δn=0 transitions associated with inner-subshell excited configurations.     

Antimony-121 mössbauer spectra of antimony (III) compounds with a stereochemically active lone pair

The Sb-121 Mössbauer parameters at 20 K for 23 antimony(III) compounds were obtained and the data are discussed in terms of known crystal structures. The isomer shifts and quadrupole coupling constants depend strongly on the type of configuration around the Sb(III) atoms with stereochemically active lone pair electrons.     

X-ray diffraction study of a structural phase transition in (NbSe4)3I

The second-order structural phase transition was observed by X-ray diffraction technique in (NbSe₄)₃I. The transition temperature (T_c) was 274.2 K. No evidence of the formation of the charge-density wave was found out. Temperature dependence of the intensity of (0,5,12) reflection obeys the Landau theory of the second kind of phase transition near T_c. Temperature dependence of the integral breadth of (0,0,12) reflection indicates the effect of the soft-phonon mode below T_c. The existence of the structural phase transition, probably not associated with charge-density-wave formation, suggests the unique nature of (NbSe₄)Z₃I in the new series of compounds (MSe₄)_xI (M=Nb, Ta).     

Mixed-valence states in TCNQ salts of monoalkylbiferrocenes and their mixed crystals with dialkyl derivative

TCNQ salts of 1-monoalkylbiferrocenes showed a temperature-independent trapped-valence state as expected for the unsymmetrical structure of cations. On the other hand, mixed crystals of 1-monobutyl- and 1.1-dibutylbiferrocenium⁺(TCNQ) ₃ ^– showed a temperature dependence of the mixed-valence states, showing that the lattice affects the mixed-valence states.     

Recent advances in immobilization of heteropolyacids

Freely water-soluble heteropolyacid could be made insoluble either by supporting on active carbon or by forming acidic cesium salts. In addition, 12-tungstophosphoric acid and its acidic cesium salt could be effectively immobilized in silica matrices by means of a sol-gel technique which involves the hydrolysis of ethyl orthosilicate to give insoluble, readily recoverable, and highly active solid acid catalysts for the hydrolysis of ethyl acetate.     

Immobilization of creatinine deiminase on a substituted poly(methylglutamate) membrane and its use in a creatinine sensor

A substituted poly(γ-methyl-l-glutamate) membrane is used for chemical immobilization of creatinine deiminase. The permeability of the membrane is controlled by the conditions used for membrane preparation. The creatinine sensor based on the immobilized enzyme membrane with immobilized nitrifying bacteria and an oxygen electrode exhibited greater sensitivity than the sensor previously reported which had a 1,8-diamino-4-amino-methyloctane membrane. The sensor gave a linear response to creatinine over the range 1–10 mg dl^?1; responses remained stable for two weeks.