• 제목/요약/키워드: H.A.Z

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$Ho_2O_3$가 첨가된 Mn-Zn ferrite의 전자기적인 특성연구 (A study on the electromagnetic properties of Mn-Zn Ferrite doped with $Ho_2O_3$)

  • 김성수;김태원;정승우;백승철;최우성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
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    • pp.265-268
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    • 1999
  • In this study, we investigated the electromagnetic Properties of M $n_{Y}$Z $n_{1-x}$ F $e_{x}$ $O_4$(X=0.67~0.69, Y=0.13~0.19) doped with and without H $o_2$ $O_3$(each of 0.05~ 0.2wt%, step 0.05wt%). The greatest initial permeability of composition is M $n_{0.17}$Z $n_{0.16}$F $e_{0.67}$ $O_4$. As X and Y components, increased. generally resistivity slightly change by the various X and Y components. The initial permeability of M $n_{0.17}$Z $n_{0.16}$F $e_{0.67}$ $O_4$ doped with H $o_2$ $O_3$ showed the about 2.5 times higher than that of M $n_{0.17}$Z $n_{0.16}$F $e_{0.67}$ $O_4$ doped without H $o_2$ $O_3$EX>EX>EX>X>>EX>EX>EX>X>

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Salmonella typhimurium의 금속이온에 대한 유전적 반응 (Genetic Responses to Metal ion in Aslmonella typhimurium)

  • 정주리;박경량;고상균;박용근;이인수
    • 생명과학회지
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    • 제8권2호
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    • pp.216-225
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    • 1998
  • Metal ion-induced and it’s regulatory genes were screened in virulent salmonella typhimurium UK1 and tested cross-regulation with various stresses. Using the techniqud of P22-MudJ(Km, lacZ)-directed lacZ operon fusion, LF40 cuiA::MudJ and Lf153 cuiD::MudJ which were induced by copper were selected. cuia and cuiD were determined anaerobic coper inducible and copper tolerance response gene, respectively. Also cuiA and cuiD locus were determined at 81 and 8min, respectively, on salmonella Genetic Map. The two regulators were identified as cuaR, and cudR, which controls cuiA and cuiD, respectively. cuaR, and cudR appeared as negative regulators because the expression of cuiA-lac-Z and cuiD-lacZ were increased. Copper adapted UK1 showed high resistance to H$_{2}$O$_{2}$, but cuiD did not. The product of the cudR locus was responsible for decreasing the tolerance to copper and H$_{2}$O$_{2}$. Furthemore cuiA and cuiD locus were found to be part of a regulon under the control of a trans-acting regulators, rpoS, oxyR and relA. Therefore, the results suggest CTR participate with oxidative stress on Salmonella.

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SOME PROPERTIES OF $D^n$-GROUPS

  • Kim, In-Su
    • 대한수학회보
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    • 제26권1호
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    • pp.1-9
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    • 1989
  • In 1980 and 1983, it was proved that P $D^{2}$-groups are surface groups ([2], [3]). Since then, topologists have been positively studying about P $D^{n}$ -groups (or $D^{n}$ -groups). For example, let a topological space X have a right .pi.-action, where .pi. is a multiplicative group. If each x.memX has an open neighborhood U such that for each u.mem..pi., u.neq.1, U.cap. $U_{u}$ =.phi., this right .pi.-action is said to be proper. In this case, if X/.pi. is compact then (1) .pi.$_{1}$(X/.pi).iden..pi.(X:connected, .pi.$_{1}$: fundamental group) ([4]), (2) if X is a differentiable orientable manifold with demension n and .rho.X (the boundary of X)=.phi. then $H^{k}$ (X;Z).iden. $H_{n-k}$(X;Z), ([6]), where Z is the set of all integers.s.

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Antioxidative Activity of Urushiol Derivatives from the Sap of Lacquer Tree (Rhus vernicifera Stokes)

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    • 한국자원식물학회지
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    • 제10권3호
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    • pp.227-230
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    • 1997
  • The authors isolated four olefinic catechols, commonly referred to as urushiol, from the sap of Korean lacquer tree(Rhus vernicifera STOKES) with stronger antioxidative activities than $\alpha-tocopherol$. The hexane extract with a free radical scavenging activity was purified by silica and ODS gel column chromatography. The active compounds were identified by MS and $^1H-NMR$ as 3-[8'(Z),11'(Z),14'-pentadecatrienyl]catechol, 3-[8'(Z),11'(Z)-pentadecadienyl]catechol, 3-[8'(Z)-pentadecenyl] catechol, and 3-pentadecylcatechol. All of these compounds showed strong free radical scavenging activities on 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical, in which 3-pentadecylacatechol exhibited the highest activity ($IC_{50}$: $1.2{\mu}g/ml$). They also showed a significant inhibitory activity on lipid peroxidation ($IC_{50}$: 2.1 - 3.5 ${\mu}g/ml$). The antioxidative activity of 3-pentadecylcatechol on DPPH radical and lipid peroxidation is approximately two times greater than that of $\alpha$-tocopherol. The results suggest that the urushiol derivatices may contribute to the preservative characteristics effective against oxidative stress and could be a good source for industrial applications including a coating material.

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On the $Z_p$-extensions over $Q(sqrt{m})$

  • Kim, Jae-Moon
    • 대한수학회논문집
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    • 제13권2호
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    • pp.233-242
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    • 1998
  • Let $k = Q(\sqrt{m})$ be a real quadratic field. In this paper, the following theorems on p-divisibility of the class number h of k are studied for each prime pp. Theorem 1. If the discriminant of k has at least three distinct prime divisors, then 2 divides h. Theorem 2. If an odd prime p divides h, then p divides $B_{a,\chi\omega^{-1}}$, where $\chi$ is the nontrivial character of k, and $\omega$ is the Teichmuller character for pp. Theorem 3. Let $h_n$ be the class number of $k_n$, the nth layer of the $Z_p$-extension $k_\infty$ of k. If p does not divide $B_{a,\chi\omega^{-1}}$, then $p \notmid h_n$ for all $n \geq 0$.

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COMPOSITION OPERATORS FROM HARDY SPACES INTO α-BLOCH SPACES ON THE POLYDISK

  • SONGXIAO LI
    • 대한수학회논문집
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    • 제20권4호
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    • pp.703-708
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    • 2005
  • Let ${\varphi}(z)\;=\;({\varphi}_1(Z),{\cdots},{\varphi}_n(Z))$ be a holomorphic self­map of $\mathbb{D}^n$, where $\mathbb{D}^n$ is the unit polydisk of $\mathbb{C}^n$. The sufficient and necessary conditions for a composition operator to be bounded and compact from the Hardy space $H^2(\mathbb{D}^n)$ into $\alpha$-Bloch space $\beta^{\alpha}(\mathbb{D}^n)$ on the polydisk are given.

A Class of Bilateral Generating Functions for the Jacobi Polynomial

  • SRIVASTAVA, H M.
    • 대한수학회지
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    • 제8권1호
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    • pp.25-30
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    • 1971
  • Put ($$^*$$) $$G[x,y]={\sum}\limits^{p+q=n}_{p,q=0}[-n]_{p+q}c_{p,q}x^py^q$$, where $[{\lambda}]_m$ is the Pocbhammer symbol and the $c_{p,q}$ are arbitrary constants. Making use of the specialized forms of some of his earlier results (see [8] and [9] the author derives here bilateral generating functions of the type ($$^{**}$$) $${\sum}\limits^{\infty}_{n=0}{\frac{[\lambda]_n}{n!}}_2F_1[\array{{\rho}-n,\;{\alpha};\\{\lambda}+{\rho};}x]\;G[y,z]t^n$$ where ${\alpha}$, ${\rho}$ and ${\lambda}$ are arbitrary complex numbers. In particular, it is shown that when G[y, z] is a double hypergeometric polynomial, the right-band member of ($^{**}$) belongs to a class of general triple hypergeometric functions introduced by the author [7]. An interesting special case of ($^{**}$) when ${\rho}=-m,\;m$ being a nonnegative integer, yields a class of bilateral generating functions for the Jacobi polynomials $\{P_n{^{{\alpha},{\beta}}}(x)\}$ in the form ($$^{***}$$) $${\sum\limits^{\infty}_{n=0}}\(\array{m+n\\n}\)P{^{({\alpha}-n,{\beta}-n)}_{m+n}(x)\;G[y,z]{\frac{t^n}{n!}}$$, which provides a unification of several known results. Further extensions of ($^{**}$) and ($^{***}$) with G[y, z] replaced by an analogous multiple sum $H\[y_1,{\cdots},y_m\]$ are also discussed.

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옥수수수염에 함유된 Flavonoids의 분리 및 동정 (Isolation and Identification of Flavonoids from Corn Silk)

  • 김선림;김미정;이유영;정건호;손범영;이진석;권영업;박용일
    • 한국작물학회지
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    • 제59권4호
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    • pp.435-444
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    • 2014
  • 본 연구는 옥수수수염에 함유된 flavonoid 계열의 물질인 maysin, luteolin 7-O-neohesperidoside, luteolin 3'-methyl ether 7-glucuronosyl-($1{\rightarrow}2$)-glucuronide 및 polyphenol성 물질인 chlorogenic acid을 추출 및 분리하는 방법에 관한 것으로, 얻어진 결과를 요약하면 다음과 같다. 1. 수정되지 않은 옥수수수염의 메이신 함량은 출사 후 3일에 함량이 최대치에 도달하고, 그 후 감소되는 것으로 나타났으며, 방임수분된 옥수수수염의 메이신 함량은 출사후 지속적으로 감소되는 것으로 나타나 화분의 수분 여부에 따라 메이신 함량에 많은 차이가 있음을 알 수 있었다. 2. 채취한 옥수수수염에 에탄올을 가하여 9일간 상온에서 추출 후 엽록소, 지질 및 당질 등을 제거시키고, $C_{18}$ column chromatography를 수행하여 분취물 I, II, III, IV를 얻었다. 3. 분취물의 흡광도를 분석한 결과 분취물 I은 327 nm 및 239 nm에서 최대 흡수 파장(${\lambda}_{max}$)을 나타내었고, 분취물 II는 339 nm 및 274 nm, 분취물 III는 345 nm 및 277 nm, 분취물 IV는 352 nm, 270 nm, 및 257 nm 에서 최대 흡수파장을 나타내었다. 4. 분취물 I은 m/z $355[M+H]^+$인 chlorogenic acid(3-(3,4-dihydroxycinnamoyl)quinic acid, $C_{16}H_{18}O_9$)이었으며, 분취물 II는 chlorogenic acid와 m/z $653[M+H]^+$인 luteolin 3'-methyl ether 7-glucuronosyl-($1{\rightarrow}2$)-glucuronide ($C_{28}H_{28}O_{18}$)를 함유한 혼합물, 분취물 III는 chlorogenic acid와 m/z $595[M+H]^+$인 luteolin 7-O-neohesperidoside ($C_{27}H_{30}O_{15}$) 및 luteolin 3'-methyl ether 7-glucuronosyl-($1{\rightarrow}2$)-glucuronide를 함유한 혼합물이었고, 분취물 IV는 m/z $577[M+H]^+$인 maysin ($C_{27}H_{28}O_{14}$, 2"-O-${\alpha}$-L-rhamnosyl-6-C-(6-deoxy-xylo-hexose-4-ulosyl)luteolin 임을 각각 확인 하였다. 5. 옥수수수염의 알코올 추출물로부터 분리된 분취물 I은 옥수수수염 생체 100 g 당 (수분함량 약 92%) 35 mg/100 g, 분취물 II는 48 mg/100 g, 분취물 III는 46 mg/100 g, 분취물 IV는 138 mg/100 g을 얻을 수 있었다.

COMMUTING ELEMENTS WITH RESPECT TO THE OPERATOR Λ IN INFINITE GROUPS

  • Rezaei, Rashid;Russo, Francesco G.
    • 대한수학회보
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    • 제53권5호
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    • pp.1353-1362
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    • 2016
  • Using the notion of complete nonabelian exterior square $G\hat{\wedge}G$ of a pro-p-group G (p prime), we develop the theory of the exterior degree $\hat{d}(G)$ in the infinite case, focusing on its relations with the probability of commuting pairs d(G). Among the main results of this paper, we describe upper and lower bounds for $\hat{d}(G)$ with respect to d(G). Here the size of the second homology group $H_2(G,\mathbb{Z}_p)$ (over the p-adic integers $\mathbb{Z}_p$) plays a fundamental role. A further result of homological nature is placed at the end, in order to emphasize the influence of $H_2(G,\mathbb{Z}_p)$ both on G and $\hat{d}(G)$.

Inhibitory Effects of the Extract of Rhus verniciflua Stokes on the Reverse Transcriptase of AIDS

  • Kim, Myong-Jo;Choi, Won-Cheol;Barshinikov, A. M.;Kobayashi, A.
    • 한국약용작물학회지
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    • 제10권4호
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    • pp.284-287
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    • 2002
  • Four olefinic catechols, commonly referred to as urushiol were isolated from the sap of Korean Rhus verniciflua Stokes and had the stronger inhibitory effects on the reverse transcriptase of AIDS. The hexane extract with a inhibitory effects on reverse transcriptase was purified by silica and ODS gel column chromatography. The active compounds were identified by MS and $^1H-NMR$ as 3-[8' (Z), 11' (Z), 14' -pentadecatrienyl]catechol, 3-[8' (Z), 11' (Z)-pentadecadienyl]catechol, 3-[8' (Z)-penta- decenyl]catechol, and 3-pentadecylcatechol. All of these compounds showed strong inhibitory effects on reverse transcriptase of AIDS, in which 3-pentadecylcatechol exhibited the highest activity $(IC_{50}\;:\;10.87\;{\mu}g/ml)$.