• 제목/요약/키워드: basic properties

검색결과 3,857건 처리시간 0.035초

원통형 결함을 포함한 Ramp-Edge Junction의 수송특성 (Transport Properties of Ramp-Edge Junction with Columnar Defects)

  • Lee, C. W.;Kim, D. H.;Lee, T. W.;Sung, Gun-Yong;Kim, Sang-Hyeob
    • Progress in Superconductivity
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    • 제3권1호
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    • pp.65-69
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    • 2001
  • We measured the transport properties of$ YBa_2$$Cu_3$$O_{x}$ ramp-edge junction fabricated with interface-engineered barrier. The current-voltage characteristics show a typical resistively-shunted junction like behavior Voltage noise measurement revealed that the main source of the 1/f noise is the critical current and resistance fluctuations. The analysis of the noise data showed that the critical current fluctuations increase with temperature, whereas the resistance fluctuations are almost constant, and both fluctuations are almost correlated. The smaller magnitude of the critical current and resistance fluctuations seems to result from the columnar-deflects.s.

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입도분급을 실시한 폐광미 미립분의 시멘트 혼화재로의 활용 (Utilization of waste fine tailing separated coarse materials as cement mineral admixture)

  • 안양진;유승완;문경주;박원춘;소양섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.297-300
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    • 2004
  • The purpose of this study reutilization of waste fine tailing as admixture for cement. We observe tailing's basic properties such as shape, physical and chemical basic features. Also, various admixtures were made of 2 Types of tailings, OPC, fly-ash and blast furnace slag. The basic properties of the cement mortars incorporation with these admixtures were examined and analyzed under a verity of experimental conditions. This work showed that the tailing separated coarse materials could be effectively utilized as replacement materials of cement without any decrease in the strength if we can control the blaine of materials like OPC, slag and fly ash.

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Recent advances of 17O NMR spectroscopy

  • Lin, Yuxi;Kim, Hak Nam;Lee, Young-Ho
    • 한국자기공명학회논문지
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    • 제23권2호
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    • pp.56-60
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    • 2019
  • Study on the structure and dynamics of molecules at the atomic level is of great significance for understanding their function and stability as well as roles for various chemico-physical and biological processes. $^{17}O$ NMR spectroscopy has appeared as an elegant technique for investigating of the physicochemical and structural properties of oxygen-containing compounds such as metal organic frameworks and nanosized oxides. This method has drawn much attention as it provides unique insights into the properties of targets based on atomistic information of local oxygen environments which is otherwise difficult to obtain using other methods. In this mini review, we introduce and discuss the recent study and developments of $^{17}O$ NMR techniques which are tailored for the investigation on the structure and dynamics of water and inorganic materials.

탄산칼슘계 분말 첨가에 따른 외단열 미장 마감재의 기초물성에 관한 연구 (A Study on the Basic Properties of Exterior Insulation Plasterer Finishing Materials by Addition of Calcium Carbonate Powder)

  • 신종현;조수연;정의인;김봉주
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 봄 학술논문 발표대회
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    • pp.213-214
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    • 2021
  • External insulation method is used to conserve energy of buildings. However, the current external insulation method uses organic insulating materials to become a diffusion path in case of fire. In this study, the purpose of this study is to provide basic data on the required performance of the plastering material according to the CaCO3 powder addition of the finishing material of the external insulation method. In Figure 1, when powder was added, the adhesion strength decreased by 30% to 35% at 10% and 0% to 50% at 20% compared to Plain. In Figure 2, the moisture permeability increases approximately twice when powder is added. The results for the water absorption coefficient are shown in Figure 3.

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Deformation performance analysis of thin plates based on a deformation decomposition method

  • Wang, Dongwei;Liang, Kaixuan;Sun, Panxu
    • Structural Engineering and Mechanics
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    • 제84권4호
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    • pp.453-464
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    • 2022
  • Thin plates are the most common spatially stressed members in engineering structures that bear out-of-plane loads. Therefore, it is of great significance to study the deformation performance characteristics of thin plates for structural design. By constructing 12 basic displacement and deformation basis vectors of the four-node square thin plate element, a deformation decomposition method based on the complete orthogonal mechanical basis matrix is proposed in this paper. Based on the deformation decomposition method, the deformation properties of the thin plate can be quantitatively analyzed, and the areas dominated by each basic deformation can be visualized. In addition, the method can not only obtain more deformation information of the structure, but also identify macroscopic basic deformations, such as bending, shear and warping deformations. Finally, the deformation properties of the bidirectional thin plates with different sizes of central holes are analyzed, and the changing rules are obtained.

Ab initio DFT studies on dimerization and one-dimensional (1-D) polymerization of M@$Au_{12}$ (M = W, Mo) clusters

  • Park, So-Ra;Kim, Gunn;Kwon, Young-Kyun
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.271-271
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    • 2010
  • Using ab initio density functional theory, we investigate the dimerization and one-dimensional (1-D) polymerization of metal-encapsulated gold nanoclusters, M@$Au_{12}$ (M=W, Mo) and their structural and electronic properties. M@$Au_{12}$ clusters with a magic number 13 can form icosahedral and cuboctahedral structures. We consider various dimer configurations with different compounds and symmetries to find the most stable dimer structure in each case. Au atoms in the one cluster, which participate directly in dimerization, tend to form triangular bonds together with counterpart Au atoms in the other. It is found that both M@$Au_{12}$ and M@$Au_{12}$ clusters are stabilized by about 3 eV due to dimerization. We also calculate and compare the electronic and magnetic properties of different dimerized clusters. Based on our investigation on dimerization, we further study on 1-D polymerization of M@$Au_{12}$ with different compounds and symmetries. We will also discuss their formation energies as well as their electronic and magnetic properties.

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Thermal Effect on Characteristics of IZTO Thin Films Deposited by Pulsed DC Magnetron Sputtering

  • Son, Dong-Jin;Ko, Yoon-Duk;Jung, Dong-Geun;Boo, Jin-Hyo;Choa, Sung-Hoon;Kim, Young-Sung
    • Bulletin of the Korean Chemical Society
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    • 제32권3호
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    • pp.847-851
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    • 2011
  • This study examined In-Zn-Sn-O (IZTO) films deposited on glass substrates by pulsed DC magnetron sputtering with various substrate temperatures. The structural, electrical, optical properties were analyzed. Xray diffraction showed that the IZTO films prepared at temperatures > $150^{\circ}C$ were crystalline which adversely affected the electrical properties. Amorphous IZTO films prepared at $100^{\circ}C$ showed the best properties, such as a low resistivity, high transmittance, figure of merit, and high work function of $4.07{\times}10^{-4}\;{\Omega}$, 85%, $10.57{\times}10^{-3}\;{\Omega}^{-1}$, and 5.37 eV, respectively. This suggests that amorphous IZTO films deposited at relatively low substrate temperatures ($100^{\circ}C$) are suitable for electrode applications, such as OLEDs as a substitute for conventional crystallized ITO films.

고대 벽화안료 재질분석 연구 - 봉정사 대웅전 후불벽화 및 고아동 고분벽화를 중심으로 (Scientific Analysis of Ancient Mural Pigments (Focus on Mural Pigments at Daeungjeon Hall of Bongjeongsa Temple and Ancient Tomb in Goadong))

  • 문환석;홍종욱;황진주;김순관;조남철
    • 헤리티지:역사와 과학
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    • 제35권
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    • pp.160-184
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    • 2002
  • The composition analysis of mural pigments at Daeungjeon Hall of Bongjeongsa Temple(Treasure No. 55) and ancient tomb with mural pigments in Goadong(Historic site No. 165) were carried out by XRF and MXRD. The analytical result showed that red pigments were Red Lead($Pb_3O_4$), Cinnabar(HgS) at Daeungjeon Hall of Bongjeongsa Temple and Cinnabar(HgS) in Goadong. The main composition identified in white pigments were Lead Carbonate Hydroxide[$PbCO_3{\cdot}Pb(OH)_2$]. Green pigments were basic copper chloride[Paratacamite $CuCl{\cdot}Cu(OH)_3$], celadonite[$K(Mg,Fe,Al)_2(Si, Al)_4O_{10}(OH)_2$] at Daeungjeon Hall of Bongjeongsa Temple and were basic copper chloride or basic copper carbonate in Goadong. Therefore it proved that mural pigments painted in use the mineral materials.