93 research outputs found

    Enhancement of superconducting properties in FeSe wires using a quenching technique

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    Enhancements of superconducting properties were observed in FeSe wires using a quenching technique. Zero resistivity was achieved at about 10 K in quenched wires, which is about 2 K higher than that of polycrystalline FeSe bulk. Furthermore, transport Jc of quenched wires showed three times higher than that of furnace-cooled wires. In contrast, the quenched polycrystalline FeSe bulks did not show the enhancement of Tc. The quenching technique is a greatly promising for fabricating FeSe wires with high Tc and high Jc, and quenched FeSe wires have high potential for superconducting wire applications

    Study on the Teaching Strategy of an Junior High School and Improving the Program for Training Students to be Teachers of University (2) : In the Case of Music, Health and Physical Education, Art, Technology and Home Economics (Field of Technology)

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     本研究は,教科内容構成の考え方に基づいて中学校の授業づくりのあり方を検討するとともに,それをふまえることで大学の教員養成プログラムの授業が具体的にどのように改善されるかを明らかにしようとしたものである。教科内容構成とは,教員養成において従来から課題とされてきた教科の内容に関わる知識・技能と教科の指導法に関わる知識・技能の分離という問題を克服するために提案されたものである。教科内容構成は,教科の内容と指導法に関わる知識・技能を統合し,それらを応用して,教師が自ら「どのような内容をどのように教えるべきか」を考え,授業づくりに取り組むことができるようになるための考え方を示すものであり,本研究では教員養成プログラムにおける具体的な授業プランを提示してそれを明らかにしていく。本稿では,特に,中学校の音楽科,保健体育科,美術科,技術・家庭科(技術分野)を事例として論じていくことにしたい

    Ambient fine and coarse particles in Japan affect nasal and bronchial epithelial cells differently and elicit varying immune response

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    Ambient particulate matter (PM) epidemiologically exacerbates respiratory and immune health, including allergic rhinitis (AR) and bronchial asthma (BA). Although fine and coarse particles can affect respiratory tract, the differences in their effects on the upper and lower respiratory tract and immune system, their underlying mechanism, and the components responsible for the adverse health effects have not been yet completely elucidated. In this study, ambient fine and coarse particles were collected at three different locations in Japan by cyclone technique. Both particles collected at all locations decreased the viability of nasal epithelial cells and antigen presenting cells (APCs), increased the production of IL-6, IL-8, and IL-1β from bronchial epithelial cells and APCs, and induced expression of dendritic and epithelial cell (DEC) 205 on APCs. Differences in inflammatory responses, but not in cytotoxicity, were shown between both particles, and among three locations. Some components such as Ti, Co, Zn, Pb, As, OC (organic carbon) and EC (elemental carbon) showed significant correlations to inflammatory responses or cytotoxicity. These results suggest that ambient fine and coarse particles differently affect nasal and bronchial epithelial cells and immune response, which may depend on particles size diameter, chemical composition and source related particles types

    Evolution of superconductivity in isovalent Te-substituted KxFe2-ySe2 crystals

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    We report the evolution of superconductivity and the phase diagram of the KxFe2-ySe2-zTez (z=0-0.6) crystals grown by a simple one-step synthesis. No structural transition is observed in any crystals, while lattice parameters exhibit a systematic expansion with Te content. The Tc exhibits a gradual decrease with increasing Te content from Tconset = 32.9 K at z = 0 to Tconset = 27.9 K at z = 0.5, followed by a sudden suppression of superconductivity at z = 0.6. Upon approaching a Te concentration of 0.6, the shielding volume fraction decreases and eventually drops to zero. Simultaneously, hump positions in r-T curve shift to lower temperatures. These results suggest that isovalent substitution of Te for Se in KxFe2-ySe2 crystals suppresses the superconductivity in this system.Comment: 10 pages, 1 table, 8 figure

    Uniaxial strain effects on the superconducting transition in Re-doped Hg-1223 cuprate superconductors

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    The effects of uniaxial strain and hydrostatic pressure on Hg0.83Re0.18Ba2Ca2.4Cu3.6O14 [Hg0.83(Re0.18)-1223] were investigated by ac magnetic measurements under stress corresponding to a pressure of 20 GPa at maximum. According to a previous thermal study based on the Ehrenfest relation, in-plane contraction should increase the superconducting transition temperature Tc, whereas out-of-plane contraction should decrease Tc. This suggests that the increase in Tc under hydrostatic-pressure contraction must be smaller than that under in-plane contraction. However, the present uniaxial-strain experiments revealed enhancement of Tc under both in-plane and out-of-plane contraction, and the largest enhancement was observed under hydrostatic-pressure contraction. According to a band calculation, all contraction styles induce hole doping from the HgO blocks to the CuO2 blocks, and hydrostatic-pressure contraction yields the largest hole doping among three contractions. This behavior explains well a series of changes in Tc in the stress region of below 8 GPa. More specifically, under hydrostatic-pressure contraction, Tc exhibited an increase, a decrease, and another increase with increasing pressure, and this multistep change is similar to that observed in Bi-2223-type cuprate superconductors, suggesting that it is necessary to distinguish the effect of strain on the middle CuO2 plane in the three-CuO2-plane package from that on the outer planes
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