• 제목/요약/키워드: acyclic

검색결과 245건 처리시간 0.03초

Acyclic eposidations (I)

  • Kim, Deuk-Joon
    • Archives of Pharmacal Research
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    • 제5권2호
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    • pp.107-108
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    • 1982
  • Some examples of stereoselective epoxidation of acyclic allylic and homoallylic systems will be presented.

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Lipophilic Acyclic Polyether Dicarboxylic Acid 에 의한 액체막을 통한 금속이온의 이동 (Transport of Metal Ions Across Bulk Liquid Membrane by Lipophilic Acyclic Polyether Dicarboxylic Acids)

  • 조문환;조성호;이인종
    • 대한화학회지
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    • 제38권2호
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    • pp.129-135
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    • 1994
  • Acyclic polyether dicarboxylic acid는 액체막계에서 금속이온의 운반체로 연구되었다. 수소이온이 이온화될 수 있는 리간드는 금속이온의 이동에 수소이온이 반대방향으로 이동된다. 이와 같은 리간드는 pH를 변화시키면 효과적으로 금속이온을 분리할 수 있고 농축시킬 수도 있다. 금속이온의 이동은 source phase의 염기의 농도와 receiving phase의 산의 농도를 증가시키면 증가된다. Acyclic polyether dicarboxylic acids를 운반체로 사용한 경쟁이동반응에서 칼슘이온을 선택적으로 분리할 가능성이 있다.

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Acyclic Eposidations (II)

  • Kim, Deuk-Joon
    • Archives of Pharmacal Research
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    • 제5권2호
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    • pp.109-110
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    • 1982
  • Conveersion of vinylogous glycidic ester 1 to 2 by a stereoselective acyclic allylic epoxidation will be presented.

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Classification by feedback structure and partitioning into acyclic subgraphs for a cyclic workflow graph

  • Choi, Yong-Sun
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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    • pp.718-721
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    • 2004
  • This paper introduces a novel method of partitioning a cyclic workflow graph into the subgraphs of acyclic flows. The way of iterative classification of nodes according to feedback structures and deriving subgraphs of acyclic flows is described with illustrative examples. The proposed method allows a cyclic workflow model to be analyzed further, if necessary, with several smaller subflows, which are all acyclic.

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Synthesis and Antiviral Evaluation of Novel Acyclic Nucleosides

  • Hong, Joon-Hee;Ko, Ok-Hyun
    • Bulletin of the Korean Chemical Society
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    • 제24권9호
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    • pp.1284-1288
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    • 2003
  • A very short and concise synthetic route for a novel acyclic version of d4T is described. The required quaternary carbon was successfully installed using a [3,3]-sigmatropic rearrangement. The condensation of the mesylates 16-18 with an adenine base under standard nucleophilic substitution conditions ($K_2CO_3$, 18-Crown- 6, DMF) in addition to deblocking afforded the target acyclic nucleosides 22-24. In addition, the antiviral evaluations against various viruses were performed.

THE ORDER OF CYCLICITY OF BIPARTITE TOURNAMENTS AND (0, 1) MATRICES

  • Berman, Abraham;Kotzig, Anton
    • Kyungpook Mathematical Journal
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    • 제19권1호
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    • pp.127-134
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    • 1979
  • A (0,1) matrix is acyclic if it does not have a permutation matrix of order 2 as a submatrix. A bipartite tournament is acyclic if and only if its adjacency matrix is acyclic. The concepts of (maximal) order of cyclicity of a matrix and a bipartite tournament are introduced and studied.

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Theoretical Determination of Geometrical Structures of the Nitric Oxide Dimer, (NO)₂

  • 박종근;선호성
    • Bulletin of the Korean Chemical Society
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    • 제20권12호
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    • pp.1399-1408
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    • 1999
  • Geometrical structures for the dimerization of (NO)₂ from (NO + NO) have been calculated using ab initio Har-tree-Fock (SCF), second-order Møller-Plesset perturbation (MP2), and coupled cluster with the single, double, and triple substitution [CCSD(T)] methods with a triple zeta plus polarization (TZP) basis set including diffuse Rydberg basis functions. The structure of (NO)₂ can be described by two interactions (N…N, N…O). One is the ONNO structure with an (N…N) interaction. In this structure, acyclic cis-ONNO with $C_{2v}$-symmetry, acyclic trans-ONNO with $C_{2h}$, and cyclic ONNO with trapezoidal structure ($C_{2v}$) are optimized at the MP2 level. The other structure is the ONON structure with an (N…O) interaction. In the structure, acyclic cis-ONON with Cs$^{-symmetry}$ and cyclic ONON of the rectangular ($C_{2h}$), square $(D_{2h})$, rhombic $(D_{2h})$, and parallelogramic $(D_{2h})$ geometries are also optimized. It is found that acyclic cis-ONNO (¹A₁) is the most stable structure and cyclic ONNO (³A₁) is the least stable. Acyclic trans-ONNO (³A₁) with an (N…N) interaction, acyclic trans-ONON and bicyclic ONON $(C_{2v})$ with (N…O) interaction, and acyclic cis- and trans-NOON with an (O…O) interaction can not be optimized at the MP2 level. Particularly, acyclic trans-ONNO with $C_{2h}$-symmetry can not be optimized at the CCSD(T) level. Meanwhile, acyclic NNOO (¹A₁, $C_s)$ and trianglic NNOO (¹A₁,$C_{2v})$ formed by the (O…N) interaction between O₂ and N₂ are optimized at the MP2 level. The binding energies and the relative energy gaps among the isomers are found to be relatively small./sec. Spiral CT scans during the arterial phase were obtained 35 seconds after the injection of contrast medium. CT findings of 78 lesions less than 4cm in diameter were correlated with angiographic findings. Results : The attenuation of lesions was high(n = 69), iso(n = 5), and low(n = 4) compared with liver parenchyma during the arterial phase of spiral CT. In lesions with high-, iso-, and low-attenuation during the arterial phase of spiral CT, hypervascularity on angiograms was found in 63 of 69(91.3%), three of five(60%), and three of four lesions(75%), respectively. Six lesions with high-attenuation on the arterial phase of spiral CT were not seen on angiography. Two iso-attenuated and one low-attenuated lesion were hypovascular on angiograms. Conclusion : The results of this study suggest that with some exceptions there was good correlation between the arterial phase of spiral CT and angiography.

ON A GENERALIZED BERGE STRONG EQUILIBRIUM

  • Kim, Won Kyu
    • 대한수학회논문집
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    • 제29권2호
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    • pp.367-377
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    • 2014
  • In this paper, we first introduce a generalized concept of Berge strong equilibrium for a generalized game $\mathcal{G}=(X_i;T_i,f_i)_{i{\in}I}$ of normal form, and using a fixed point theorem for compact acyclic maps in admissible convex sets, we establish the existence theorem of generalized Berge strong equilibrium for the game $\mathcal{G}$ with acyclic values. Also, we have demonstrated by examples that our new approach is useful to produce generalized Berge strong equilibria.