研究者詳細 - 寺﨑　英紀

論文 - 寺﨑　英紀

分割表示 148 件中 61 - 80 件目／全件表示 >>

Superconducting properties of SmFeAsO1-x prepared under high-pressure condition 査読

Jing Ju, Khuong Huynh, Jun Tang, Zhaofei Li, Masanori Watahiki, Kazumi Sato, Hidenori Terasaki, Eiji Ohtani, Hirotsugu Takizawa, Katsumi Tanigaki

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS 71 ( 4 ) 491 - 494 2010年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

Synthetic conditions such as stoichiometries, temperature and pressure are optimized to achieve a high quality oxygen deficient SmFeAsO0.6 superconductor. Both electric and magnetic measurements show a sharp superconducting transition at about 55 K. Several important physical parameters are deduced. The apparent superconducting gap observed in heat capacity with 2 Delta(o)/k(B)T(c) of 4.57 larger than that of previous fluorine replaced samples indicate that this superconductivity will not strongly conflict with the phonon-mediated BCS mechanism. The mean free length l = 18.8 nm and the coherent length xi = 2.3-3.3 nm show that the superconductivity is in the clean limit. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jpcs.2009.12.019

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In situ observation of the formation of intragranular acicular ferrite at non-metallic inclusions in C-Mn steel 査読

Di Zhang, Hidenori Terasaki, Yu-ichi Komizo

ACTA MATERIALIA 58 ( 4 ) 1369 - 1378 2010年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

Intragranular acicular ferrite is regarded as a most desirable microstructure feature, in view of its strength and toughness, both in weld metals and in the heat-affected zone. This paper systematically investigated the effect of Ti addition on the evolution of intragranular acicular ferrite in the heat-affected zone of C-Mn steel. We also systematically studied the effects of austenite grain size, alloy content and the characteristic of inclusions on the formation of intragranular acicular ferrite. The nucleation and growth of intragranular acicular ferrite was directly observed by laser scanning confocal microscopy. Subsequently, microscopy analysis was used to quantitatively determine and distinguish the potent and inactive inclusions with respect to the nucleation of intragranular acicular ferrite. Finally, some possible reasons are given to explain the formation of intragranular acicular ferrite in the C-Mn steel. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.actamat.2009.10.043

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Ｘ線吸収法による高温高圧下における珪酸塩メルトの密度測定．

大谷栄治, 鈴木昭夫, 寺崎英紀, 坂巻竜也, 浦川啓, 片山芳則

SPring-8 User Experiment Report No.23 (2009A) 23 2009A3785 2010年1月

Viscosity of lunar high-Ti magma at high pressure.

Suzuki, A, Ohtani, E, Nishida, K, Tateyama, R, Terasaki, H, Shibazaki, Y, Shiraishi, R, Kikegawa, T

Photon Factory Activity Report 2008 (KEK Progress Report 2009-3) 26 ( Part B ) 181 2010年1月

Density measurements of liquid Fe-S at high pressure using sink-float method.

Tateyama, R, Suzuki, A, Ohtani, E, Terasaki, H, Nishida, K, Shimazaki, Y, Kikegawa, T

Photon Factory Activity Report 2008 (KEK Progress Report 2009-3) 26 ( Part B ) 178 2010年1月

Density measurements of liquid FeS at high pressure using X-ray absorption image.

Nishida, K, Suzuki, A, Ohtani, E, Terasaki, H, Sakamaki, T, Shibazaki, Y, Hayashi, H, Funayama, M, Kikegawa, T

Photon Factory Activity Report 2008 (KEK Progress Report 2009-3) 26 ( Part B ) 179 2010年1月

高温高圧下における玄武岩マグマの構造解析．

坂巻竜也, 大谷栄治, 鈴木昭夫, 寺崎英紀, 柴崎裕樹, 林宏美, 舟越賢一, 立山隆二

SPring-8 User Experiment Report No.23 (2009A) 23 2009A1661 2010年1月

Report on "Global network symposium on earth's dynamics" 査読

Hidenori Terasaki

Review of High Pressure Science and Technology/Koatsuryoku No Kagaku To Gijutsu 20 ( 2 ) 181 - 182 2010年

Performance of semi-sintered ceramics as pressure-transmitting media up to 30 GPa 査読

Anton Shatskiy, Konstantin D. Litasov, Hidenori Terasaki, Tomoo Katsura, Eiji Ohtani

HIGH PRESSURE RESEARCH 30 ( 3 ) 443 - 450 2010年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：TAYLOR & FRANCIS LTD

Semi-sintered MgO-and ZrO(2)-based ceramics are the conventional materials used as a pressure-transmitting medium (PM) for large-volume high-pressure experiments. Our experimental data for both MgO and ZrO(2) provide similar pressure generation efficiency. The major requirement for a PM material is low compressibility. However, our experimental data suggest that semi-sintered types of these ceramics are more compressible than can be expected. For instance, the apparent compressibility of semi-sintered magnesia is 35% and 60% higher than the lattice compressibility of MgO at 15 and 30 GPa, respectively. The difference in lattice and apparent compressibilities of semi-sintered ceramics is most probably caused by a residual porosity. The use of a low-porous pressure medium should be considered as an improvement of pressure generation efficiency of high-pressure apparatuses.

DOI： 10.1080/08957959.2010.515079

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Development of high pressure apparatus for X-ray microtomography at SPring-8 査読

S. Urakawa, H. P. Terasaki, K. Funakoshi, K. Uesugi, S. Yamamoto

INTERNATIONAL CONFERENCE ON HIGH PRESSURE SCIENCE AND TECHNOLOGY, JOINT AIRAPT-22 AND HPCJ-50 215 012026- 2010年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IOP PUBLISHING LTD

A new high-pressure apparatus has been developed for studies of synchrotron radiation-based X-ray microtomography at SPring-8 of Japan. The high pressure tomography apparatus at SPring-8 is a compact hydraulic press with a 0.8 MN capacity and is equipped with an opposed anvil device. It has two wide windows for X-ray access with a 160-degree opening in the equatorial plane to the compression axis. Radiographs are acquired over 180 degree rotation for reconstruction of 3D image, in which some shadows occur, because the press frame blocks a 20-degree angular region. 3D tomography image computed from radiographs obtained using the high pressure tomography apparatus has a reasonably good quality enough to measure physical properties of materials.

DOI： 10.1088/1742-6596/215/1/012026

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Pressure and temperature dependence of the viscosity of a NaAlSi2O6 melt 査読

Suzuki A, E. Ohtani, H. Terasaki, K. Nishida,H. Hayashi, T. Sakamaki, Y. Shibazaki, K. Funakoshi, T. Kikegawa

Physics and Chemistry of Minerals 10.1007/s00269-010-0381-4- 2010年

Stress measurement under high pressure using Kawai-type multi-anvil apparatus combined with synchrotron radiation 査読

Nishihara Yu, Funakoshi Ken-ichi, Higo Yuji, Terasaki Hidenori, Nishiyama Norimasa, Kubo Tomoaki, Shimojuku Akira, Tsujino Noriyoshi

JOURNAL OF SYNCHROTRON RADIATION 16 ( 6 ) 757 - 761 2009年11月

Stress measurement under high pressure using Kawai-type multi-anvil apparatus combined with synchrotron radiation 査読

Yu Nishihara, Ken-ichi Funakoshi, Yuji Higo, Hidenori Terasaki, Norimasa Nishiyama, Tomoaki Kubo, Akira Shimojuku, Noriyoshi Tsujino

JOURNAL OF SYNCHROTRON RADIATION 16 757 - 761 2009年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

A system for stress measurement under high pressure has been developed at beamline BL04B1, SPring-8, Japan. A Kawai-type multi-anvil apparatus, SPEED-1500, was used to pressurize polycrystalline KCl to 9.9 GPa in a mechanically anisotropic cell assembly with the KCl sample sandwiched between dense Al2O3 pistons. The variation of deviatoric stress was determined from the lattice distortion measured using two-dimensional X-ray diffraction with monochromatic synchrotron X-rays. The low-pressure B1 phase transformed to the high-pressure polymorph B2 during compression. The deviatoric stress increased with increasing pressure in both the B1 and B2 phases except for the two-phase-coexisting region at a pressure of 2-3 GPa. This new system provides one of the technical foundations for conducting precise rheological measurements at conditions of the Earth's lower mantle.

DOI： 10.1107/S0909049509034955

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Hydrogen partitioning between iron and ringwoodite: Implications for water transport into the Martian core 査読

Yuki Shibazaki, Eiji Ohtani, Hidenori Terasaki, Akio Suzuki, Ken ichi Funakoshi

Earth and Planetary Science Letters 287 ( 3-4 ) 463 - 470 2009年10月

掲載種別：研究論文（学術雑誌）

We determined the exchange partition coefficients of hydrogen between solid iron and ringwoodite between 16.6 and 20.9 GPa at temperatures up to 1273 K using a Kawai-type multianvil high-pressure apparatus with synchrotron X-ray radiation at the BL04B1 beamline at SPring-8, Japan. The hydrogen concentration in iron hydride was estimated from the volume expansion of iron caused by hydrogenation determined by in situ X-ray diffractions at high pressure and high temperature, and the water content of ringwoodite in the recovered samples was estimated using the Fourier transform infrared spectroscopy (FTIR). According to our results, the exchange partition coefficients of hydrogen between the solid iron and ringwoodite were almost constant, 26, with pressure between 16.6 and 20.9 GPa and 1273 K. These results revealed that hydrogen was strongly partitioned to metallic iron and that iron hydride formed, coexisting with dry ringwoodite under the experimental pressures. Ringwoodite, found in the Martian core-mantle boundary region, is an important hydrogen reservoir. The pattern of quasi-parallel bands of uniformly magnetized crust with alternating positive and negative polarity measured by the Mars Global Surveyor spacecraft strongly shows that a magnetic field did exist in ancient Mars suggesting a possible plate tectonic activity on ancient Mars. Thus, water could have been transported to the deep Martian interior by hydrous minerals during the plate subduction process and stored in ringwoodite in the deep Martian slabs, as is suggested on the Earth today. Our experiments suggested that hydrogen stored in ringwoodite was absorbed by the Martian core at the Martian core-mantle boundary. Thus, water from the ancient Martian ocean may be stored now in the Martian core. © 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.epsl.2009.08.034

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The partitioning of Pt-Re-Os between solid and liquid metal in the Fe-Ni-S system at high pressure: Implications for inner core fractionation 査読

Hiromi Hayashi, Eiji Ohtani, Hidenori Terasaki, Yoshinori Ito

GEOCHIMICA ET COSMOCHIMICA ACTA 73 ( 16 ) 4836 - 4842 2009年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD

Coupled (186)Os/(188)Os and (187)Os/(188)Os enrichments of plume-derived lavas have been suggested to reflect contributions of materials from the outer core (Brandon et al., 1998). This hypothesis is based on the assumption that the Earth's liquid outer core has high Pt/Os and slightly high Re/Os ratios as a result of the crystallization of the solid inner core, and shows coupled enrichments in the (186)Os/(188)Os and (187)Os/(188)Os ratios, reflecting the decay of (190)Pt and (187)Re to (186)Os and (187)Os, respectively. Partitioning experiments of Pt-Re-Os between solid and liquid metal were performed at 5-20 GPa and 1250-1400 degrees C, to examine the effects of pressure in the Fe-Ni-S system. The ratios (D(Os)/D(Pt), D(Os)/D(Re)) of measured partition coefficients of Pt, Re and Os are almost constant with increasing pressure. D(Os)/D(Pt) increases significantly, whereas D(Os)/D(Re) decreases, with increasing sulphur content in the liquid metal. On the basis of the present experimental results, it is unlikely that the required Pt-Re-Os fractionation is generated during inner core crystallization, assuming that the light element in the Earth's core is sulphur. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.gca.2009.05.055

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Fe-Mg partitioning between perovskite and ferropericlase in the lower mantle 査読

Takeshi Sakai, Eiji Ohtani, Hidenori Terasaki, Naoki Sawada, Yusuke Kobayashi, Masaaki Miyahara, Masahiko Nishijima, Naohisa Hirao, Yasuo Ohishi, Takumi Kikegawa

AMERICAN MINERALOGIST 94 ( 7 ) 921 - 925 2009年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：MINERALOGICAL SOC AMER

Fe-Mg partitioning between perovskite and ferropericlase in the MgO-FeO-SiO2 system has been studied up to about 100 GPa at around 2000 K using a laser-heated diamond anvil cell (LHDAC). The compositions of both phases were determined by using analytical transmission electron microscopy (ATEM) on the recovered samples. Present results reveal that the Fe-Mg apparent partition coefficient between perovskite and ferropericlase [K-D(Pv/Fp) = ((XFeXMgFp)-X-Pv)/((XMgXFeFp)-X-Pv)] decreases with increasing pressure for a constant FeO of the system, and it decreases with increasing FeO content of ferropericlase. The gradual decrease of K-D(Pv/FP) with increasing pressure is consistent with the spin transition in ferropericlase Occurring in the broad pressure range from 50 to 100 GPa at around 2000 K.

DOI： 10.2138/am.2009.3123

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Density measurement of liquid FeS using X-ray absorption image.

Nishida, K, Ohtani E, Suzuki, A, Terasaki, H, Sakamaki, T, Shibazaki, Y, Kikegawa, T

Special Issue of the Review of High Pressure Science and Technology 19 448 2009年7月

Density and structure of basaltic magma under high pressure and high temperature.

Sakamaki, T, Ohtani E, Urakawa, S, Suzuki, A, Terasaki, H, Katayama, Y, Funakoshi, K

Special Issue of the Review of High Pressure Science and Technology 19 287 2009年7月

Density measurement of Fe-C liquid using X-ray absorption image under high pressure.

Terasaki, H, Nishida, K, Suzuki, A, Ohtani E, Shibazaki, Y, Sakamaki, T, Kikegawa, T

Special Issue of the Review of High Pressure Science and Technology 19 292 2009年7月

Effect of water on post-spinel transition and implication for 660 km seismic discontinuity at the Earth's mantle.

Ghosh, S, Ohtani E, Suzuki, A, Litasov, K.D, Terasaki, H, Funakoshi, K

Special Issue of the Review of High Pressure Science and Technology 19 461 2009年7月

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