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Abstract  

Thermal stability of para (p--) and ortho (o-) isomers was investigated by CRTG and reaction kinetic analysis. The temperature started the mass decrease of o-isomer was about 20C lower than that of p-isomer by CRTG. The activation energies of thermal decomposition of o- and p-isomers were 136.9 and 153.4 kJ mol–1, respectively. The effect of steric hindrance on heat of formation was calculated by AM1 method using Win MOPAC3.0 for the model compound of p- and o-isomers. The lower stability of o-isomer was the results of the steric hindrance between the ethylene unit of aromatic ring and three alkyl chains.

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Abstract  

The annihilation behavior of irradiation defects induced in neutron-irradiated Li2TiO3 and Li2ZrO3 were investigated with the tritium release behavior. It was revealed that the common characteristics in both samples were that the annihilation process of irradiation defects consisted of two first-order processes and E’-center could act as tritium trapping site, and otherwise was the way how the E’-center annihilated. The difference was suggested to attribute to the mobility of M as M4+ (or M3+, etc.).

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Abstract  

The D2 + was irradiated into SiC up to the saturation and thereafter He+ irradiation was performed to elucidate interaction mechanism between hydrogen isotope retained in SiC and irradiated energetic He+ by means of X-ray photoelectron spectroscopy (XPS) and thermal desorption spectroscopy (TDS). It was found that D was trapped by both of Si and C by D2 + irradiation and only D bound to Si interacted with irradiated He+ in the initial He+ irradiation stage. Some damaged structures were introduced into SiC by both of D2 + and He+ irradiation. By heating after the irradiation experiments, most of SiC structure was recovered at the temperature above 1000 K. However, some free C was migrated toward the surface and aggregated on the surface of SiC. This fact indicates that the C impurity would contaminate the plasma and/or the tritium breeding materials, which is thought to be contacted with the SiC inserts.

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Abstract  

The effect of thermal treatment on the electrical conductivity was studied for a quasi-one-dimensional organic conductor, (DIMET)2I3 (DIMET=dimethyl(ethylenedithio)tetrathiafulvalene). After heating the samples up to a temperature between 340 and 370 K, the electric resistivity was measured at low temperature down to 2 K and under pressure up to 1.6 Gpa. (DIMET)2I3 shows irreversible decrease in the electric resistivity between 350 and 356 K on heating. It was found that the heating above 350 K suppresses the spin-density-wave transition at 40 K and another metal-insulator transition appears at 18 K.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
Y. Oura
,
A. Saito
,
K. Sueki
,
H. Nakahara
,
T. Tomizawa
,
T. Nishikawa
,
C. Yonezawa
,
H. Matsue
, and
H. Sawahata

Abstract  

Prompt γ-ray analysis using the internal monostandard method was applied to voluminous archaeological bronze mirrors produced in ancient China. Sn/Cu content ratios were determined nondestructively by this method. Furthermore, Au/Cu, As/Cu, and Sb/Cu content ratios were determined by means of measuring decay γ-rays emitted from radioactive nuclides produced within samples via (n,γ) reactions. It is clear that the Sn/Cu content ratios in bronze mirrors produced in the Sung era is smaller than in ones produced in between the Han and the Tung era.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
S. Akahori
,
E. Tega
,
Y. Morimoto
,
K. Okuno
,
M. Nishikawa
,
K. Munkata
,
H. Moriyama
,
K. Kawamoto
, and
M. Okada

Abstract  

The effects of irradiation damages induced by neutron irradiation on tritium release processes were studied in Li4SiO4. It was shown that the thermal annealing process of the damages consisted of two processes of a fast and a slow process. The activation energies were determined to be 0.21 eV and 1.1 eV, respectively. From the experimental results, it was suggested that the migration of tritium and displaced oxygen into the damages plays an important role in both thermal annealing processes.

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