• 제목/요약/키워드: Scale of vacuum

검색결과 439건 처리시간 0.042초

Charge Redistribution of Pt-based Alloys

  • Lim, K.Y.;Chung, Y.D.;Kwon, S.Y.;Lee, Y.S.;C.N.Whang;Y.Jeon;Park, B.S.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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    • pp.171-171
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    • 1999

  • We studied the charge redistribution in the Pt-M (M=Cu, Co) alloys by X-ray Absorption Near Edge Spectroscopy(XANES) and X-ray Photoelectron Spectroscopy(XPS). These analysis tools provide us information about the charge transfer in the valence band of intermetallic bonding. The samples were prepared by arc-melting method. After annealing this samples in vacuum for several hours, we cold get the ordered samples, which were confirmed with XRD analysis. the core and valence level energy shift in these system were investigated by Mg $K\alpha$(1253.6eV) x-ray source for Pt-Co alloys and monochromatized Al $K\alpha$ (1486.6eV) for Pt-Cu alloys. Pt L2, L3-edge, and Cu, Co K-edge XANES spectra were measured with the total electron-yield mode detector at the 3Cl beam line of the PLS (Pohang light source0. from the changes of White line (WL) area and the core level shifts of the each metal sites, we can obtain the information about the electrons participating in the intermetallic bonding of the Pt-Cu and Pt-Co alloys.

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아진공 터널에서 초고속 열차의 속도향상에 관한 실험적 연구 (Experimental Study for the Speed-up of a Super-speed Train Model in the Partial Vacuum Tunnel)

  • 김동현;김재흥
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.2064-2071
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    • 2011

  • We are developing an innovative super-speed land transportation system running in a partial vacuum in tunnels with small inside diameter to reduce the aerodynamic drag forces. This paper presents the experimental results obtained on a small scale model when a super-speed train model passing through a tunnel with small inside diameter and a partial vacuum to reduce the aerodynamic drag forces. The experiments were performed on a 1/52-scale moving model rig in which a train model with a diameter of 58 mm and a length of 603 mm was accelerated in a launching tube with 12.27 m length by means of the compressed air launcher and then passed through a tunnel model with 17.149 m length. The partial vacuum was maintained in the tunnel in order to reduce the energy consumption of the propulsion system of the super-speed tube train at super-speed of 700 km/h. In this study, the blockage ratio of train to tunnel model is 0.336. Experimental results show the nonlinear effects of the vacuum on the speed-up of the train model in the tunnel model under the partial vacuum up to 0.21 atm and at the velocity up to 684 km/h. This paper is first study for experiments on the speed-up of a super-speed train model in the partial vacuum tunnels.

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The effect of ion irradiation on magnetic thin films

  • Kim, I.S.;Sung, M.C.;You, D.G.;Park, H.S.;Kim, T.H.;Ye, W.T.;Kim, H.J.;Jung, Y.S.;Lee, J.C.;Yang, J.S.;Kim, T.G.;Song, J.H.;Jeong, K.;Lee, J.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2001년도 창립10주년 제20회 학술발표회
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    • pp.214-214
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    • 2001

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