• 제목/요약/키워드: exchange property

검색결과 274건 처리시간 0.026초

Effect of Magnetic Property Modification on Current-Induced Magnetization Switching with Perpendicular Magnetic Layers and Polarization-Enhancement Layers

  • Kim, Woo-Jin;Lee, Kyung-Jin;Lee, Taek-Dong
    • Journal of Magnetics
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    • 제14권3호
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    • pp.104-107
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    • 2009
  • The effects of the magnetic property variation on current-induced magnetization switching in magnetic tunnel junction with perpendicular magnetic anistoropy (PMA) and the soft magnetic polarization-enhancement layers (PELs) inserted between the layers with PMA and the MgO layer was studied. A micromatnetic model was used to estimate the switching time of the free layer by different applied current densities, with changing saturation magnetization ($M_s$) of the PELs, interlayer exchange coupling between PMA layers and PELs. The switching time could be significantly reduced at low current densities, by increasing $M_s$ of PELs and decreasing interlayer exchange coupling.

RINGS AND MODULES WHICH ARE STABLE UNDER NILPOTENTS OF THEIR INJECTIVE HULLS

  • Nguyen Thi Thu Ha
    • 대한수학회보
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    • 제60권2호
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    • pp.339-348
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    • 2023
  • It is shown that every nilpotent-invariant module can be decomposed into a direct sum of a quasi-injective module and a square-free module that are relatively injective and orthogonal. This paper is also concerned with rings satisfying every cyclic right R-module is nilpotent-invariant. We prove that R ≅ R1 × R2, where R1, R2 are rings which satisfy R1 is a semi-simple Artinian ring and R2 is square-free as a right R2-module and all idempotents of R2 is central. The paper concludes with a structure theorem for cyclic nilpotent-invariant right R-modules. Such a module is shown to have isomorphic simple modules eR and fR, where e, f are orthogonal primitive idempotents such that eRf ≠ 0.

중온형 고체산화물 연료전지를 위한 YSZ 전해질에서의 고성능 공기극 연구 (Study on high performance cathode on YSZ electrolyte for intermediate-temperature solid oxide fuel cells(IT-SOFC))

  • 이창보;배중면
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 추계학술대회
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    • pp.368-371
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    • 2006
  • [ $La_{0.8}Sr_{0.2}Co_{1-x}Mn_xO_3$ ] cathode as a high performance cathode on YSZ electrolyte was studied by analyzing impedance spectra. It was shown that cathode property of $La_{0.8}Sr_{0.2}Co_{1-x}Mn_xO_3$ is bet ter than that of$La_{0.8}Sr_{0.2}CoO_3$. At $700^{\circ}C$ in air environment, $La_{0.8}Sr_{0.2}Co_{0.4}Mn_{0.6}O_3$ cathode on CGO- layered YSZ electrolyte showed very low area specific resistance of $0.14{\Omega}cm^2$, which is low enough for intermediate-temperature sol id oxide fuel cells. This is because material properties of ionic conductivity and thermal expansion compatibility with electrolyte were optimized. Judging from activation energy and oxygen part i al pressure dependance of cathode property, it was noted that oxygen surface exchange kinetics is dominantly influential on cathode property in higher temperature region than $700^{\circ}C$ and oxygen self-diffusion in cathode material is more influential in lower temperature region.

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Synthesis and Chromatographic Characteristics of Multidentate Ligand-Boned Silica Stationary Phases

  • Li, Rong;Wang, Yan;Chen, Guo-Liang;Shi, Mei;Wang, Xiao-Gang;Zheng, Jian-Bin
    • Bulletin of the Korean Chemical Society
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    • 제31권8호
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    • pp.2201-2206
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    • 2010
  • To improve the separation property and stability of metal chelate Cu(II) column, three new kinds of multidentate aminocarboxy silica columns with cation-exchange properties were synthesized using glutamic acid (Glu), glutamic acidbromoacetic acid (Glu-BAA), glutamic acid-bromosuccinic acid (Glu-BSUA) as ligands and silica gel as matrix. The standard proteins were separated with prepared chromatographic columns. The stationary phases exhibited the metal chelate property after fixing copper ion (II) on the synthesized multidentate ligand silica columns. The binding capacity of immobilized metal ion was related with the dentate number of multidentate ligands. Chromatographic behavior of proteins and the leakage of immobilized metal ion on multidentate chelate Cu(II) columns were affected by the dentate number of multidentate ligands and competitive elution system directly. The results showed that quinquedentate Glu-BSUA-Cu(II) column exhibited better chromatographic property and stability as compared with tridentate Glu-Cu(II) column, tetradentate Glu-BAA-Cu(II) column and commonly used IDA-Cu(II) column.

BULK 선용자동 Ballast Water Management Plan 개발 (Optimized Ballast Water Exchange Management for Bulk Carrier)

  • 홍충유;박제웅
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2004년도 학술대회지
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    • pp.67-72
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    • 2004
  • Many port states such as New Zealand, the USA, Australia and Canada have strict regulations to prevent ships which arrive in their port from discharging polluted ballast water which contain harmful aquatic organism and pathogens. They are notified that transfer of polluted ballast water can cause serious injury to public health and damage to property and environment. For this reason, they perceived that the ballast exchange in deep sea is the most effective method, together with submitting the ballast management plan which contains the effective exchange method, ballast system and safety consideration. In this study, we pursued both nautical engineering analysis and optimization of algorithm in order to generate the sequence of stability and rapidity. Heuristic Algorithm was chosen on the basis of optimality and applicability to a sequential exchange problem. We have built an optimized algorithm, for automatic exchange of ballast water, by redefining core elements of the $A^\ast$ algorithm, such as node, operator and evaluation function. Final version of the optimized algorithm has been applied to existing bulk carrier and the performance of the algorithm has been verified successfully.

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벌크 화물선용 자동 밸러스트수 교환계획 시스템 개발 (Optimized Ballast Water Exchange Management for Bulk Carriers)

  • 홍충유;박제웅
    • 한국해양공학회지
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    • 제18권4호
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    • pp.65-70
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    • 2004
  • Many port states, such as New Zealand, U.S.A., Australia, and Canada, have strict regulations to prevent arriving ships from discharging polluted ballast water that contains harmful aquatic organisms and pathogens. They are notified that transfer of polluted ballast water can cause serious injury to public health and damage to property and environment. For this reason, ballast exchange in deep sea is perceived as the most effective method of emptying ballast water. The ballast management plan contains the effective exchange method, ballast system, and safety considerations. In this study, we pursued both nautical engineering analysis and optimization of the algorithm, in order to generate the sequence of stability and rapidity. A heuristic algorithm was chosen on the basis of optimality and applicability to a sequential exchange problem. We have built an optimized algorithm for the automatic exchange of ballast water, by redefining core elements of the A$\ast$ algorithm, such as node, operator, and evaluation function. The final version of the optimized algorithm has been applied to existing bulk carrier, and the performance of the algorithm has been successfully verified.

Synthesis of Selenoflavonoid and Selenoisoflavonoid.

  • Kim, Dong-Myung;Jeong, Jin-Hyun
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.351.1-351.1
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    • 2002
  • Heterocyclic compounds with oxygen atoms are known to have potent biological effect. The flavonoids. isoflavonoids. and coumarins which form the bulk of these compounds are very polar and have limited use as drugs which have to pass through membranes. The non-polar property is increased by exchange oxygen to selenium as a part of heterocyclic compound. Our group is focused on synthesizing selenoheterocyclic compound with the above property. (omitted)

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문학 경제학 -사용가치에서 교환가치로의 전이 (Economics of Literature: Transfer of 'Worth' to 'Value')

  • 양병현
    • 영어영문학
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    • 제55권5호
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    • pp.767-792
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    • 2009
  • The two fields, economics of art and literature, tend to be put together as part of cultural economic studies; yet the former has been widely popular as compared to the latter. Economics of art has been known as part of social science which studies art economically. Similarly, economics of literature is likely to be an interdisciplinary study of literature and economics. Literature is suggested usually to reflect the economic base of a society as a form of its superstructure in view of classical Marxism; so, it is interesting to see social, economic activities, such as individual values and social institutions, income, price and opportunity cost, in a particular way of analyzing economic ideas in literature. Capital seems to have an innate property of self-expansion in literature; this property thus features actual economic life since in capitalism money is the universal value between persons and literary works. Specifically, the field of economics of literature starts with such ideas: economics of literature is part of cultural economics; and economics of literature deals with the economic value of literature. Putting interdisciplinary fields of literature and economics together, this study is to examine the economic value of literature in which Karl Marx talked about commodities with exchange value, use value, and fetishism. The exchange value is commercial worth, the actual exchange value of a publication; yet, the use value is innate worth, the aesthetic use value of literature. With commodity fetishism, profit seems not as the outcome of a social relation, but of a work- "reification" as the would-be Marxists suggest. As a commodity, the literary work appears to be able to animate life and power in reality. As a result, this paper asserts that social, economical activities in literature as we may apply to the study of economics of literature increase its economic value, implying commercial and innate worth, as the capital in the marketplace.

Effect of composition and structure on exchange anisotropy of IrxMn(100-x)/NiFe films

  • Suh, Su-jung;Park, Young-suk;Ro, Jae-chul;Yong-sung;Yoon, Dae-ho
    • 한국결정성장학회:학술대회논문집
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    • 한국결정성장학회 1998년도 PROCEEDINGS OF THE 14TH KACG TECHNICAL MEETING AND THE 5TH KOREA-JAPAN EMGS (ELECTRONIC MATERIALS GROWTH SYMPOSIUM)
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    • pp.91-95
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    • 1998
  • Exchange anisotropy between IrMn antiferromagnetic layer and NiFe ferromagnetic layer has been studied in IrxMn(100-x)/NiFe/Buffr/Si(100) films deposited by D. C. magnetron sputtering method. Among Zr, Ta, and Cu used as buffer layer, Zr and Ta enhanced the fcc(111) texture of NiFe and IeMn layer, but Cu did not affect microstructure of those layer. Strong fcc(111) texture of IrMn layer was confirmed to be the origin of exchange anisotropy of IrMn. Ir composition control in IrMn layer showed that {{{{ gamma -phase}}}} IrMn is stabilized between 10 and 30 at % Ir, an 21 at. % Ir in IrMn layer was optimum composition that showed maximum exchange anisotropy field. above 200 ${\AA}$ thickness of IrMn, antiferromagnetic property is stabilzed to show saturated exchange anisotropy field. Based pressure was confirmed to be critical requisite in IrMn-based spin-valve GMR system.

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