Volume 10（2005）
放射光利用研究促進機構 （財）高輝度光科学研究センター 理事長 Organization for the Promotion of Synchrotron Radiation Research, President of JASRI
1. SPring-8の現状／PRESENT STATUS OF SPring-8
東京工業大学 応用セラミックス研究所 Materials and Structures Laboratory, Tokyo Institute of Technology
名古屋大学 大学院工学研究科 Graduate School of Engineering, Nagoya University
2. ビームライン／BEAMLINES
[1]名古屋大学大学院 工学研究科 Graduate School of Engineering, Nagoya University、[2]岡山大学大学院 自然科学研究科／CREST (JST) Graduate School of Natural Science and Technology, Okayama University / CREST (JST)、[3]大阪府立大学大学院 理学系研究科 Graduate School of Science, Osaka Prefecture University、[4]（財）高輝度光科学研究センター 利用研究促進部門／CREST (JST) Research & Utilization Division, JASRI / CREST (JST)
[1]放射線医学総合研究所 National Institute of Radiological Sciences、[2]北里大学 獣医畜産学部 Kitasato University, School of Veterinary Medicine & Animal Sciences、[3]（財）高輝度光科学研究センター JASRI
- Abstract
- Organotin compounds are widely used in industry and its environmental contamination by these compounds has recently become a concern. It is known that they act as endocrine disruptors but details of the dynamics of Sn in reproductive organs are still unknown. In the present study, we attempted to determine Sn in the testis of rats exposed to tributyltin chloride (TBTC) cell-selectively by synchrotron radiation X-ray florescence analysis with nanoprobe. TBTC was orally administered to rats at a dose of 45 µmol/kg per day for 3 days. One day later, Sn was detected in spermatozoa at the stage VIII seminiferous tubule, which are the final step of spermatogenesis in the testis. Sn levels in the microdissectioned seminiferous tubules determined by inductively coupled argon plasma-mass spectrometry were approximately equivalent to that in the testis. These data indicate that Sn accumulates in germ cells as well as in spermatozoa in a short period of TBTC exposure.
（独）理化学研究所 播磨研究所 Harima Institute, RIKEN
- Abstract
- Diffraction studies of magnetic materials subjected to extreme conditions are illustrated with observations made by non-resonant X-ray diffraction, using beam-line BL19LXU at SPring-8, on materials held in high magnetic fields and low temperatures. The first observation is that of a giant magneto-volume effect in solid oxygen. From this finding, we confirm that magnetic interactions between oxygen molecules are a vital ingredient in determining the crystal structure. A second example is the determination of the high-field phase of a spin-Peierls system CuGeO3. The X-ray diffraction pattern was measured in a magnetic field, H, up to 15 T. We find that the temperature dependence of the incommensurate peak is quite different at lower H from that at higher H, which is interpreted as stabilization of the incommensurate state by suppression of thermal fluctuations that is brought about by application of a magnetic field. The third example entails diffraction measurements on a sample held at a very low temperature. We observed a jump in the lattice constant of the ladder-like compound Cu2(C5H12N2)2Cl4 at about 40 mK associated with the field-induced magnetic ordering from the non-magnetic spin-liquid state. This is the first experimental confirmation of the theoretical prediction on the generalized spin-Peierls phenomenon in quantum magnets. Finally, future prospects are given.
神戸大学 発達科学部 Faculty of Human Development, kobe University
- Abstract
- Circular dichroism spectra of evaporated films of two amino acids (Phenylalanine and Serine) were measured at the soft X-ray energy region for the first time. Magnitude of signal was 0.1 % of the absorption coefficient. Asymmetric reaction will be explored from a view point of origin of life.
[1]（独）日本原子力研究開発機構 量子ビーム応用研究部門 Quantum Beam Science Directorate, Japan Atomic Energy Agancy、[2]東北大学 金属材料研究所 Institute for Materials Research, Tohoku University、[3]（財）高輝度光科学研究センター 利用研究促進部門 Research & Utilization Division, JASRI
北陸先端科学技術大学院大学 材料科学研究科 School of Materials Science, Japan Advanced Institute of Science and Technology
- Abstract
- Gold shows diamagnetic property in the bulk state. However, this property might be different in the nano-sized region because the electronic structure may be modified significantly. This article reports the first direct observation of ferromagnetic spin polarization of Au nanoparticles with a mean diameter of 1.9 nm using X-ray magnetic circular dichroism (XMCD). Owing to the element selectivity of XMCD, only the gold magnetization is explored. Magnetization of gold atoms estimated by XMCD shows a good agreement with the results obtained by conventional magnetometry. This result is evidence of intrinsic spin polarization in nano-sized gold.
[1]大阪女子大学 理学部 Department of Environmental Sciences, Osaka Women’s University、[2]（財）高輝度光科学研究センター 利用研究促進部門Ⅰ／CREST (JST) Materials Science Division, JASRI / CREST、[3]京都大学大学院 工学研究科 Department of Synthetic Chemistry and Biological Chemistry, Kyoto University、[4]（財）高輝度光科学研究センター 利用研究促進部門Ⅰ／CREST (JST)、Materials Science Division, JASRI / CREST、[5]岡山大学 理学部 Department of Physics, Okayama University、[6]名古屋大学大学院 工学研究科 Department of Applied Physics, Nagoya University
- Abstract
- Hydrogen storage is one of the most important technologies, which is indispensable for the establishment of clean hydrogen energy system. Adsorption of H2 molecules in the metal-organic porous materials is one of the most promising candidates to store and release H2 molecules efficiently. To develop a rational synthetic strategy for novel metal-organic porous materials as hydrogen storages, the elucidation of the intermolecular interaction between H2 molecules and pore walls is essential and the fundamental structural characteristics of H2 molecules are required. Although the weakest X-ray scattering amplitude of hydrogen made it difficult to determine the structure, we have succeeded in direct observation of H2 molecules adsorbed in the nano-channels of the metal-organic porous material by in-situ synchrotron powder diffraction experiment of gas adsorption and MEM(maximum entropy method)/Rietveld analysis. The result could give us promising guidelines for designing hydrogen gas storage materials.
（財）高輝度光科学研究センター 利用研究促進部門Ⅰ Materials Science Division, JASRI
3. 研究会等報告／WORKSHOP AND COMMITTEE REPORT
大阪大学大学院 基礎工学研究科 Graduate School of Engineering Science, Osaka University
（財）高輝度光科学研究センター 利用研究促進部門 Research & Utilization Division, JASRI
（財）高輝度光科学研究センター 産業利用推進室 Industrial Application Division, JASRI
日本原子力研究所 放射光科学研究センター／（財）高輝度光科学研究センター Synchrotron Radiation Research Center, JAERI / JASRI
東京大学 分子細胞生物学研究所 Institute of Molecular and Cellular Biosciences, The University of Tokyo
- Abstract
- Calcium ATPase is an ATP-powered calcium pump and the best studied member of the P-type ion-transporting ATPases. Its crystal structures have been determined using SPring-8 for 5 different states that cover the whole reaction cycle. These structures show how the ion pump works and reveal what ATP and phosphorylation do.
4. 研究会等報告／WORKSHOP AND COMMITTEE REPORT
（財）高輝度光科学研究センター 利用研究促進部門 Research & Utilization Division, JASRI
5. 談話室・ユーザー便り／OPEN HOUSE･A LETTERS FROM SPring-8 USERS
SPring-8利用推進協議会 研究開発委員会 Research and Development Committee, Industrial Users Society of SPring-8
名古屋大学大学院 工学研究科 Graduate School of Engineering, Nagoya University
