Volume 09, No.1

目次 / Table of Contents

January issue 2004

小林　庄一郎　KOBAYASHI Shoichiro

（財）高輝度光科学研究センター　会長　Chairman, JASRI

Page 1 Download PDF (14.32 KB)

1. SPring-8の現状／PRESENT STATUS OF SPring-8

第13回（2004A）利用研究課題の採択について
The Proposals Accepted for Beamtimes in the 13th Public Use Term 2004A

放射光利用研究促進機構（財）高輝度光科学研究センター　利用業務部　Organization for the Promotion of Synchrotron Radiation Research . User Administration Division, JASRI

Pages 2 - 19 Download PDF (110.61 KB)

「長期利用2002A採択課題中間評価」について
Intermediate Evaluation of 2002A Long-term Proposal

（財）高輝度光科学研究センター　利用業務部　User Administration Division, JASRI

Pages 20 - 21 Download PDF (17.61 KB)

SPring-8運転・利用状況
SPring-8 Operational News

（財）高輝度光科学研究センター　所長室　計画調整グループ　Planning and Coordination Section, Director's Office, JASRI

Pages 22 - 23 Download PDF (14.65 KB)

論文発表の現状
Publications Resulting from Experiments at SPring-8

（財）高輝度光科学研究センター　利用業務部　User Administration Division, JASRI

Pages 24 - 25 Download PDF (21.85 KB)

2. ビームライン／BEAMLINES

共用ビームライン評価委員会の報告概要（平成14年度）
Report of the Public Beamline Review Committees in 2002

壽榮松　宏仁　SUEMATSU Hiroyoshi

（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

Pages 26 -29 Download PDF (22.57 KB)

3. 最近の研究から／FROM LATEST RESEARCH

脂質結合タンパク質を輸送するタンパク質、LolAとLolBの結晶構造
Crystal Structures of Bacterial Lipoprotein Localization Factors, LolA and LolB

竹田　一旗　TAKEDA Kazuki^[1]、三木　邦夫　MIKI Kunio^[2]

^[1]理化学研究所　播磨研究所　Harima Institute, RIKEN、^[2]京都大学　大学院理学研究科　Graduate School of Science, Kyoto University

Abstract: Five Lol proteins are involved in the lipoprotein transport in Gram-negative bacteria. Crystal structures of a lipoprotein-specific periplasmic chaperone, LolA, and an outer membrane lipoprotein receptor, LolB from Escherichia coli were determined using diffraction data collected at the beamlines of SPring-8. Despite their dissimilar amino acid sequences (identity ~ 8%), the structures of LolA and LolB are strikingly similar to each other. Both have a hydrophobic cavity consisting of an unclosed β-barrel and an α-helical lid. The cavity represents a possible binding site for the lipid moiety of lipoproteins. However, the structural differences in size and shape of hydrophobic inner spaces between LolA and LolB are highly connected to the functional differences between two proteins. Furthermore, these structural differences between two proteins provide significant insights into the molecular mechanisms underlying the energy-independent transfer of lipoproteins from LolA to LolB, and from LolB to the outer membrane.

Pages 30 - 35 Download PDF (226.66 KB)

シリコン同位体で色分けされたナノクラスタによる新ナノデバイスの創製の可能性
− 超伝導から量子コンピュータまで −
Possibility of New Nano Devices Using Nano Clusters Colored by Silicon Isotopes
−From Superconductors to Quantum Computers −

谷垣　勝己　TANIGAKI Katsumi^[1]、寺岡　淳二　TERAOKA Junji^[1]、伊藤　公平　ITOH Kohei^[2]、清水　智子　SHIMIZU Tomoko^[2]、守友　浩　MORITOMO Hiroshi^[3]、山中　昭司　YAMANAKA Shoji^[4]

^[1]大阪市立大学大学院　理学研究科　Graduate School of Science, Osaka City University、^[2]慶應義塾大学　理工学部　Faculty of Science and Technology, Keio University、^[3]名古屋大学大学院　工学研究科　Graduate School of Engineering, Nagoya University、^[4]広島大学大学院　工学研究科　Graduate School of Engineering, Hiroshima University

Abstract: VI^th group elements like C, Si, Ge and Sn make clusters consisting of pentagonal and/or hexagonal plolyhedra. A avarious crystals having hierachical structure can be constructed on a basis of these clusters. Recent strong demand from the field of isotope engineering for semiconductors has spurred on efforts that have led to the successful separation of stable Si isotopes. The combination of nano clusters and pure isotopes may open a new field of materials science. The present paper describnes, as such examples, the clarification of superconducting mechanism of the first discovered silicon-network Si₄₆superconductor. An approach of all silicon quantum computors using ²⁸Si isotope is also demonstrated.

Pages 36 - 41 Download PDF (256.43 KB)

高圧下における窒化ガリウムの一致溶融
− 単結晶窒化ガリウム育成の新手法 −
Congruent Melting of Gallium Nitride at High Pressure and Its Application to Single Crystal Growth

内海　渉　UTSUMI Wataru^[1]、齋藤　寛之　SAITOH Hiroyuki^[1]、青木　勝敏　AOKI Katsutoshi^[1]、金子　洋　KANEKO Hiroshi^[2]

^[1]日本原子力研究所　関西研究所　放射光科学研究センター　Synchrotron Radiation Research Center, Kansai Research Establishment, JAERI、^[2]スプリングエイトサービス㈱　SPring-8 Service Co., Ltd

Abstract: The decomposition and melting behaviors of GaN under high pressures and temperatures were studied by in situ x-ray diffraction experiments using a large volume multi-anvil high-pressure apparatus at beamline BL14B1. GaN decomposed into Ga melt and N₂ at lower pressures than 5.5 GPa. At pressures above 6.0 GPa, however, congruent melting of GaN occurred around 2220 ℃, and decreasing the temperature allowed the GaN melt to crystallize to the original structure. Single crystals of GaN were formed by cooling the melt slowly under high pressures and were recovered at ambient conditions. The present results have great potential in providing high quality bulk single crystals of GaN, which are desirable substrates for fabricating optoelectronic devices.

Pages 42 - 45 Download PDF (148.72 KB)