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  • Author or Editor: H. Sato x
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Abstract  

Radiation effects on the extraction of americium(III) with several dialkylphosphoric and monoalkylphosphoric acids have been studied comparatively. The extractants were exposed to60Co γ-rays in the absence and presence of diluent and HNO3. The Df of Am(III) was measured and the yield of radiolytic products was determined after γ-irradiation as a function of the absorbed dose. Di(hexoxyethyl)phosphoric acid was the most susceptible to radiation among the extractants studied and its extractability was weakened by radiation regardless of the presence or absence of diluent or HNO3. Diisodecylphosphoric acid itself showed an enhancement upon irradiation but incurred a depressant effect upon intimate contact with HNO3·Mono(2-ethylhexyl)phosphoric acid showed a decrease of the Df of Am(III), similarly to DIDPA in the presence of HNO3 during γ-irradiation. All the above extractants gave H3PO4 as the principal radiolytic product upon γ-irradiation upon intimate contact with HNO3 causing decreasing solely the extraction of Am(III). Di(2-ethylhexyl)phosphoric acid proved to be the most stable extractant to radiation among those studied.

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Abstract  

Photolytic products of tetramethylstannane in low temperature argon matrix were studied by Mössbauer, IR, and UV spectroscopy. At an early stage of the reaction, an unstable tin compound possibly with a tin-carbon double bond was formed in low temperature argon matrix, which might not exist in ordinary conditions. In subsequent reaction, cyclic tin compounds with large quadrupole splittings might be produced.

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Abstract  

Unusually broad119Sn-Mössbauer absorption was observed in pure Sn(CH3)4 or Sn(CH3)4/argon condensed at low temperatures by pulsed deposition. Such broadening of the Mössbauer linewidth suggested the presence of large quadrupole splitting due to possible distortion of molecular structure as deposited in the argon matrix.

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Abstract  

The structure of chlorotrimethylstannane was studied by Mössbauer spectroscopy in solids, frozen solution, and argon matrices at low temperatures. In frozen solutions, quadrupole splitting was very similar to the value in solid phase, and strong intermolecular interaction may exist between Sn/CH3/3Cl and solvent molecules. In argon matrices, the quadrupole splitting of Sn/CH3/3Cl was much smaller. Comparison of the observed quadrupole splitting with the predicted value based on the point charge model suggests that the Sn/CH3/3Cl molecule may have a tetrahedral structure and be isolated well from each other in the argon matrix.

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Abstract  

Emission Mössbauer spectra of mixedvalence trinuclear complexes,57Co-labelled [CoFe2O(CH3CO2)6(H2O)3] and [CoFe2O(CH3CO2)6 (py)3]py were compared with that of [CoCr2O(CH3CO2)6 (py)3]py. It was found that the57Fe atoms produced in57Co-labelled [CoFe2O(CH3CO2)6(H2O)3] and [CoFe2O(CH3CO2)6 (py)3]py showed a temperature-dependent mixed-valence state as observed in the absorption Mössbauer spectra of [Fe3O(CH3CO2)6 (H2O)3] and [Fe3O(CH3CO2)6 (py)3]py, respectively, while57Co-labelled [CoCr2O(CH3CO2)6 (py)3]py showed a temperature-independent divalent iron/II/ state. The results indicate that the decayed atoms keep their position at the sites of original57Co atoms and that the valence electrons are transferred through the intramolcular bondings.

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Abstract  

A simplified method for the substoichiometric analysis of phosphorus has been developed and applied to determine the concentration distribution of phosphorus in the region of a SiO2–Si interface in order to explain why phosphorus is lost from the ion-implanted silicon surface throughout the oxidation and oxide removal processes. It is revealed that phosphorus piles up on the SiO2 side at the interface by the thermal oxidation of silicon surface and is removed with the oxide by wet etching and with the resulting silicon by RCA cleaning. This results in a total loss of ion-implanted phosphorus of 3.5%.

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Abstract  

Radiochemical techniques have been applied in various ways to the study of fullerenes and metallofullerenes for the past several years, and they have provided invaluable information pertaining to the stability, structures, and formation of the novel carbon material. This paper reviews those experimental results that have fully shown the usefulness and uniqueness of radionuclides demonstrated in the field of fullerene science.

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Abstract  

In order to obtain the information about plutonium contamination in ocean environment, plutonium in the internal organs of squid collected from Japanese inshore were determined by HR-ICP-MS. Although the plutonium was detected in all samples collected in 1980"""s, the concentration is almost the same level as the detection limit (1 to 3 mBq/kg wet) in recent years. The atomic ratio of 240Pu/239Pu in all samples was slightly higher than the value of global fallout.

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Abstract  

A novel nitrido technetium complex was synthesized by the reaction of the KYCAR (lysyl-tyrosyl-cystyl-alanyl-arginine) ligand with [(n-C4H9)4N][99TcNCl4]. The structure of the complex was analyzed by 1H- and 13C-NMR and IR spectroscopy as well as by elemental analysis. The nitrido technetium complex with KYCAR has a square pyramidal structure in which two KYCARs coordinate to the Tc atom through both an N and a deprotonated S atom of cysteine. The complex possesses a trans configuration.

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