For the enhancement of high temperature performance of the Mg-Zn based alloys, Sn element has been alloyed. However, the effect of Sn on the thermal conductivity of the Mg-Zn based alloys has been barely studied. In this study, pure Mg and -Zn alloys are alloyed with a 1, 3, and 5 mass% of Sn, respectively, and the heat capacity, thermal diffusivity and thermal conductivity of the alloys are then evaluated in a temperature range of 298 to 573 K. In the Mg-Sn binary alloys, the heat capacity and thermal diffusivity gradually decrease with increasing the volume fraction of the Mg₂Sn phase. In the Mg-Zn-Sn based alloys (ZT alloy), since the adding Sn element is mostly located at the MgZn₂ phases, thermal diffusivity is not affected with an increment of Sn content. Furthermore, the thermal conductivity of the ZT55 alloy at elevated temperatures is slightly higher than that of the ZT53 alloys.

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The effects of Ga content on the electrochemical behavior of - at%Hg alloys which contain a small amount of Ga was investigated by the measurement of polarization curves and galvanostatic test. The microstructure of the alloys and the surface of the specimens corroded in galvanostatic test were observed by using scanning electron microscopy, energy spectrum analysis and X-ray diffraction analysis. It can be concluded that with the content of Ga increasing, the alloys come into Mg-Mg₃Hg, Mg-Mg_7.2(Hg, Ga)_2.8 and Mg- binary phase fields sequentially. The best electrochemical activity occur in the - at%Hg-1 at%Ga alloy, with open circle potential −2.124 V and mean potential −1.992 V. The corrosion resistance of the alloys is in the sequential order from big to small: - at%Hg-5 at%Ga, - at%Hg-22 at%Ga, - at%Hg-1 at%Ga, - at%Hg. The lowest corrosion current density is 0.418 mA·cm⁻². The activation mechanism of the magnesium alloy produced by Hg and Ga was concluded: the dissolution of Hg and Ga atoms leads to the back accumulation of liquid Hg and Ga, which makes a true metallic contact with a-Mg. Magnesium atoms diffuse through the liquid mercury and gallium to form magnesium amalgam and undergo severe oxidation at the amalgam/electrolyte interface. The reaction produces pure Hg and Ga again which continue the activation process.

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A comprehensive research program on the creep of a die-cast

–Al–2Ca (mass%) alloy, which has been conducted in the last two decades by our group, is overviewed. The obtained results are summarized into the following categories: microstructure and creep strength, creep parameters, dislocation analysis, and life assessment. The creep strength of the alloy is predominantly ascribed to the interconnected skeleton of C36–(Mg,Al)₂Ca phase, while the fine C15–Al₂Ca precipitates have limited effects on creep strength. The change in creep parameters, n and Q_c, results from the decreased creep strength driven by the divorce of the interconnected skeleton of C36 phase during creep. At stress levels below the yield stress, the dislocation climb in the primary α-Mg grains is inferred as the rate-controlling process for the alloy. Mostly 〈a〉 type dislocations are introduced within the primary α-Mg grains during die-casting, and the dislocation segments are mainly located on the basal plane. The basal segments of dislocations bow out and glide on the basal planes under stress, and the jogs follow the basal segments with the help of climb during creep. The minimum creep rate and creep rupture life follow the phenomenological Monkman–Grant relationship for the alloy. When the Larson–Miller constant is set at 20, the value of Larson–Miller parameter is uniquely described by the logarithm of the applied stress.

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Hardness measurements and electron microscopic observations were employed to study the effects of additions of 0.04 and 0.13 wt% silver on the direct aging and the two-step aging characteristics of -.5 wt%Zn alloys. The aging processes are changed by the intersection temperatures of 100°C and about 50°C, which are obtained from the C-curves analyzed kinematically, but the silver addition raises these temperatures by 10°∼20°C. The final hardening is due to the genaral precipitation of the transition phase β′ in the form of a long thin rod. This system indicates the quenching rate dependence and effectiveness of the two-step aging; the pre-β′ region in the C-curve diagram gives the optimum condition of pre-aging, and the addition of 0.04 wt% silver is most suitable for these phenomena. Electron microscopic observations show that the silver addition little affects the direct aging, but it accelrates the refinment of the β′ phase in the two-step aging. As regards the direct aging and the two-step aging, it may be concluded that the silver atom plays a significant role as a positive action of nucleation for the pre-β′ or the β′ phase.

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Structural changes of precipitates in an - at%Gd (Mg₉₅Gd₅) alloy by aging at 200°C and 250°C have been studied by ordinary high-resolution transmission electron microscopy (HRTEM) and high-angle annular detector dark-field scanning transmission electron microscopy (HAADF-STEM). In the early stage of precipitation by aging at 200°C up to 5 h, a short-range ordered structure exists in Gd-enriched regions with an about 2 nm size, and nuclei of an Mg₇Gd structure (β′ phase) occur in the short-range ordered structure by aging at 200°C for 5 h. The β′ phase with the Mg₇Gd structure is formed as definite precipitates by aging at 200°C for 10 h. The β′ precipitates are joined along the b-axis and form a plate-shape with a thickness of about 20 nm along the a-axis, and lengths of about 200 nm along the b-axis and 200 nm along the c-axis, and the connection of planar precipitates along the three directions, which are parallel to the [210]_m-typed directions of the Mg-matrix, forms a two-dimensional cell structure, by top-aging at 200°C for 100 h.

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With a purpose of obtaining materials showing high specific tensile strength, -mass%Ca-Al-Zn quaternary alloys of varied Al and Zn compositions were rapidly solidified and subsequently consolidated to the P/M (powder metallurgy) materials by cold-pressing and hot-extrusion. In the tested alloys, Al and Zn contents were varied while Al+Zn content was kept to 12mass%. The results of X-ray diffraction revealed that formation of Ca₂Mg₆Zn₃ ternary compound increased while that of Al₂Ca decreased with an increase of Zn/Al content ratio. In as-extruded P/M materials, fine Ca₂Mg₆Zn₃ and Al₂Ca compound particles of 100 to 200 nm in size were dispersed uniformly in the Mg matrix. The P/M materials of all tested alloys showed high tensile strength above 450 MPa and density not higher than 1.9 Mg/m³. Moreover, tensile strength increased with increasing Zn/Al ratio and -Ca-10Zn-2Al alloy showed the highest tensile strength of 600 MPa at RT and 311 MPa at 473 K. In Mg-Ca-Al-Zn alloys, thus, formation of Ca₂Mg₆Zn₃ is more effective in increasing strength than that of Al₂Ca since volume fraction of Ca₂Mg₆Zn₃ is higher than that of Al₂Ca for the same Ca content.

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The effect of adding up to 4 mass% of strontium to -Al-3Ca alloys was investigated in terms of microstructural and mechanical properties. The major interdendritic intermetallic compounds of as-cast alloys changed from the Mg₂Ca phase to a combination of the (Mg,Al)₂Ca and Al₄Sr phases. The morphology of the interdendritic α-Mg/Al₄Sr eutectic phase also changed from a coarse lamellar structure at a low strontium concentration to a bulk-like ultrafine lamellar structure at a high strontium concentration (4 mass%). The creep resistance was improved by the addition of up to 2 mass% strontium but it was saturated at a higher strontium concentration.

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降圧薬1剤のみならず、作用機序が異なる降圧薬を併用しても降圧目標に到達しない管理不良の高血圧症患者は一定数存在するなど、我が国における現状の高血圧症の薬物治療にはアンメットメディカルニーズが存在する。このような背景から、当社は2006年より米国Exelixis社と共同研究を開始し、非ステロイド骨格を有する選択的ミネラルコルチコイド受容体ブロッカーであるミネブロ^®錠を見出した。

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The microstructures and mechanical properties of the –(mass%) Sn alloy subjected to a solution heat treatment (SHT) were investigated by using equal channel angular extrusion (ECAE). The average grain size was significantly refined from 147 µm (as-cast) to 16 µm by ECAE four passes. Further, the fine Mg₂Sn particles were uniformly distributed in the matrix by dynamic precipitation after ECAE four passes. The yield strength (YS), ultimate tensile strength (UTS) and elongations also showed notable improvements at room temperature and high temperatures (100 and 200°C) on account of the ECAE process. Further, the tensile strength and elongations were better than those of the ECAE without SHT alloy. Those results show that SHT is a useful way to enhance the effect of ECAE on the mechanical properties of –(mass%) Sn alloy.

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The microstructure and tensile properties of a rolled specimen of -.5 mass%Zn-0.6 mass%Zr alloy are investigated. A relatively small grain size of 15.9 μm was obtained in the rolled specimen. The rolled magnesium alloy exhibited higher strength than the annealed specimen at room temperature, while the elongation was almost the same as the annealed specimen. Also, a large elongation of 501% was obtained at 573 K for the rolled specimen. A smaller grain size of 9.6 μm was obtained due to dynamic recrystallization during the tensile test at 573 K.

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ミロガバリンベシル酸塩（タリージェ^®）は、第一三共(株)が創製した電位依存性カルシウムチャネルα₂δサブユニットのリガンドであり、特に神経障害性疼痛において重要な役割を担うα₂δ-1サブユニットに対して持続的に結合する末梢性神経障害性疼痛治療剤である。糖尿病性末梢神経障害性疼痛患者および帯状疱疹後神経痛患者を対象とした第Ⅲ相二重盲検試験において、本剤の有効性が検証され、承認された。

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Various motor using transportation system in land-sea-air, high speed mobile terminal with 5G specification, and renewable energy storage equipment have required innovative metal rechargeable batteries compared with lithium ones. In particular, magnesium has huge potentialities as an anode material from the standpoint of its theoretical volumetric capacity superior to that of lithium. Secondly, magnesium has been one of the most abundant elements in the Earth’s crust. Moreover, the potential safety by short-circuiting evading with non-dendritic deposition of magnesium. In general, magnesium-based ribbon as an anode has been manufactured by cold rolling which requires multistage process including heat treatment. We have studied rapid liquid quenching process in order to develop low-cost manufacturing technique. On the other hand, we have focused Mg–6 mass%Al–3 mass%Ca alloy due to this unique microstructure which consist of primary crystals and intermetallic compounds along grain boundary. In addition, calcium has affected to prevent of molten magnesium burning in air atmosphere. The structural properties and surface morphology are investigated by XRD and Digital Microscope, respectively. Microstructure has been observed by FE-SEM and FE-TEM. Moreover, these electrochemical properties have been examined by constant current charge - discharge tests using 3 electrodes type cell. Mg–3 mass%Al–1 mass%Zn alloy cold rolled thin plate has been investigated as comparison. The ribbons that exhibited electrochemical properties had a fine microstructure. It is suggested that the grain refinement and dispersion of the second phase are important to improve the charge-discharge properties of Mg–Al–Ca based anode materials.

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High-strength Mg–Y–Zn alloy plate was obtained by friction stir processing (FSP) after casting. In this study, the Mg–Y–Zn alloy by FSP showed sufficiently high performance with low cost. As-cast material was held at 723 K for 95 h. It then showed a lamellar structure, which might have resulted from long-range periodic structure. However, this lamellar structure showed very low hardness, as did the as-cast material. Plates cut from heat-treated ingot were processed as single, overlapped double, and multiple pass FSP. After FSP, each processed materials was cut for microscopic measurement and hardness testing. Ultra-fine-grained microstructures are obtainable using the FSP. Micro-Vickers hardness tests for each pass result in the occurrence of strengthening for FSP of Mg–Y–Zn alloy. There was little change in grain size and hardness of pre-stirred zone by the next pass of stirring.

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高温状態におけるhydromagnesite の相変化を明らかにするために，その場高温粉末XDR 測定を行った．測定は室温から320℃まで30℃刻みで行われた．170℃までピークに大きな変化はみられなかったが，200℃からピークの強度が減少しはじめた．最終的に290℃では，ほとんどのピークが消失し，320℃において出現したピークはpericlase であった．従って，hydromagnesite は，300℃を超える高温下において次の反応が進行するものと示唆される．(CO₃)₄(OH)₂・4H₂O → 5MgO + 4CO₂ + 5H₂O.

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Single crystals of a magnesium niobium oxide were prepared at 1673 K. This compound has an orthorhombic pseudobrookite-type structure (space group Cmcm). The single-crystal structure refinement was carried out in the temperature range from 293 to 1173 K. The final R-factors were R = 0.025-0.038 and R_w = 0.031-0.044. The lattice parameters were a = 3.806(3), b = 10.057(3) and c = 10.260(4) Å at 293 K and a = 3.810(6), b = 10.188(5) and c = 10.398(5) Å at 1117 K. The linear thermal expansion coefficients were α_a = 1.28 × 10^-6, α_b = 15.8 × 10^-6 and α_c = 16.3 × 10^-6 K^-1. Thermal expansion anisotropy in the bond distances and angles is consistent with the thermal expansion anisotropy in the lattice parameters.

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Nanostructured -%Al-x%Nd (x=0.5,1 and 5 wt.%) alloys were prepared by mechanical alloying. Microstructural characterisation revealed average crystalline size to be about 90 nm after sintering and extrusion. Mechanical properties showed increase in 0.2% yield stress, ultimate tensile strength and ductility after 20 h of mechanical alloying. The increase in yield stress and ultimate tensile strength was attributed to reduction in grain size as well as to the enhanced diffusion after mechanical activation. Although ultra high yield stress was observed from the specimen with 5%Nd, its ductility was reduced to about 1.6%.

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熱分解過程において，Hydromagenesite (CO₃)₄(OH)₂･4H₂Oが非晶質相を経てペリクレース(MgO)へと構造変化する過程について明らかにするためにX線全散乱測定を行った．PDF解析の結果，1 A付近のピークはC-O結合を示しており，温度の増加に伴い減少していく様子を示していた．一方，2 A付近のピークはMg-O結合を示しているが，温度の変化によってMg-O結合距離にほとんど変化はみられなかった．この結果は，Hydromagnesite が熱分解で非晶質化した後ペリクレースに変化する過程では，MgO₆八面体はほぼ維持されることを示唆している．

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Cast Mg-Y₂-Zn₁ alloy was friction stir (FS) processed to obtain fine grain structure. Then the elevated temperature tensile tests were carried out to investigate the deformation behavior of the FS processed alloy. The starting structure for FS processing was coarse dendritic microstructure (secondary dendrite arm spacing ca. 75 μm) with a plate-like second phase, which developed from inter-dendritic eutectic pockets after homogenization heat treatment. The α-Mg matrix and second phases were broken mechanically and distributed homogeneously by FS processing. The refined grain size at the fully stirred zone had the average size of ca. 2.0 μm. Different deformation behavior occurred as a result of varying microstructural evolution according to temperatures (623 K and 723 K).

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レミフェンタニルは，バランス麻酔用の全身麻酔薬に求められる迅速な鎮痛作用の発現ならびに消失を実現するため，非特異的エステラーゼによる代謝を受け易い構造を有するオピオイドとして英国Glaxo社（現英国GlaxoSmithKline社）により合成され，本邦では，その塩酸塩がアルチバｨとして2006年12月に承認された．レミフェンタニルのμ-オピオイド受容体に対する親和性は，δ-またはκ-オピオイド受容体のそれぞれ約25または2300倍であった．摘出モルモット回腸の経壁電気刺激誘発収縮に対するレミフェンタニルの抑制作用は，ナロキソンにより競合的に拮抗されたが，κ-またはδ-オピオイド受容体選択的拮抗薬で影響を受けなかった．レミフェンタニルの3 μg/kg以上をラットに単回静脈内投与すると，投与直後から鎮痛作用（tail-flick法）が発現し，30 μg/kg以上で全例に最大潜時が認められた．レミフェンタニルによる最大潜時持続時間（全例が最大潜時を示している時間）および作用持続時間（潜時が延長してから投与前値に戻るまでの時間）は用量依存的に延長したが，最大潜時に達した後の作用持続時間はフェンタニルと比較して明らかに短く，作用消失が早かった．レミフェンタニルを持続静脈内投与中は最大潜時を維持し，投与終了後の鎮痛作用の持続時間は数分間であり，フェンタニルと比較して作用消失が極めて早かった．鎮痛作用には蓄積性が認められず，回復が迅速であることは反復投与後にも確認されている．ウサギの侵害刺激による循環動態変動に対する，レミフェンタニルと静脈麻酔薬プロポフォールまたは吸入麻酔薬セボフルランとの併用による抑制作用は少なくとも相加的であった．本邦で実施した臨床試験のうち，プロポフォールの併用（4.5 mg/kg/時）による全静脈麻酔法を用いる手術患者を対象に実施した無作為化平行用量反応試験では，低用量群（1.0 μg/kg単回静脈内投与+0.5 μg/kg/分，挿管5分後より0.25 μg/kg/分）および高用量群（1.0 μg/kg単回静脈内投与+1.0 μg/kg/分，挿管5分後より0.5 μg/kg/分）の何れにおいても約80%以上の症例で気管挿管時および皮膚切開時の外科的侵襲による反応がみられなかった．また，気管挿管後5分以内および皮膚切開時の収縮期血圧ならびに心拍数は安定しており，麻酔からの覚醒は速やかであった．安全性解析対象の67.9%に副作用が認められ，主なものは血圧低下34例（40.5%），悪心19例（22.6%），徐脈17例（20.2%），嘔吐10例（11.9%）であった．また，セボフルランを併用（呼気終末濃度約1.0%）した全身麻酔下での手術患者を対象に実施した一般臨床試験では，麻酔維持期には約99%の症例で皮膚切開時の刺激に対する反応がみられず，循環動態は安定しており，麻酔終了後には速やかな覚醒が得られ，遅発性の呼吸抑制も認められなかった．以上より，レミフェンタニルは，選択的なμ-オピオイド受容体作動薬であり，鎮痛モデルにおいて速やかに強力な鎮痛作用を発現するが，その作用発現時間が極めて短く蓄積性が低いことが示された．これらの特徴は，他の麻酔薬との併用臨床試験において，手術中の侵襲刺激に対する十分な抑制と迅速な回復などにより確認されており，バランス麻酔においてレミフェンタニルを併用することは有用であることが示された．

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