• 제목/요약/키워드: $k_h$

검색결과 87,764건 처리시간 0.088초

Surface Impedance and Complex Conductivity of $MgB_2$ Films

  • Lee, Sang-Young;Lee, J.H.;Ko, Y.B.;Moon, S.H.;Kim, M.H.;Kim, K.B.;Lee, H.N,;Oh, B.;Leong, K.;Booth, James C.;Claassen, J.H.
    • 한국초전도학회:학술대회논문집
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    • 한국초전도학회 2003년도 High Temperature Superconductivity Vol.XIII
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    • pp.39-39
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    • 2003
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Column Chromatography에 의한 바르비탈류 분리 정량법에 관한 연구 (Quantitative Determination of Barbiturates by Column Chromatographic Method)

  • 정인명;심수일;최광식;전성환;고미혜;부인향
    • Journal of Pharmaceutical Investigation
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    • 제9권4호
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    • pp.1-7
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    • 1979
  • The analytical method of phenobarbital and mephobarbital in the pharmaceutical preparation were investigated by the partition chromatographic method. The influence of 13 kinds of excipients and various kinds of ingredients such as 8 kinds of antipyretics and 5 kinds of antacids on the partition chromatographic analysis of phenobarbital and mephobarbital in the preparation were investigated. The results were not affected by materials with the exception of caffeine, aspirin and sulpyrin.

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히스톤 메틸화와 유전자 전사 (Histone methylation and transcription)

  • 김애리
    • 생명과학회지
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    • 제17권4호
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    • pp.593-598
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    • 2007
  • Amino acids of histone tail are covalently modified in eukaryotic cells. Lysine residues in histone H3 and H4 are methylated at three levels; mono-, di- or trimethylation. Methylation in histones is related with transcription of the genes in distinct pattern depending on lysine residues and methylated levels. Relation between transcription and methylation has been relatively well understood at three lysines H3K4, H3K9 and H3K36. H3K4 is methylated in active or potentially active chromatin and its methylation associates with active transcription. H3K9 is generally methylated in heterochromatin or repressed gene, but trimethylation of this lysine occur in actively transcribed genes also. Methylation at H3K36 generally correlates with active chromatin/transcription, but the correlation of its dimethylation with transcription is controversial. All together methylation patterns of individual lysine residues in histone relate with activation or repression of transcription and may provide distinctive roles in transcriptional regulation of the eukaryotic genes.

SOME FIXED POINTTHEOREMS ON H-SPACES(I)

  • Lee, Byung-Soo;Lee, Sang-Chul
    • 대한수학회논문집
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    • 제10권2호
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    • pp.325-330
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    • 1995
  • In this paper we obtain some fixed point theorems on H-spaces by using H-KKM theorems.

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Effects of pH on Fertilization and the Hatching Rates of Far Eastern Catfish Silurus asotus

  • Gao, Yang;Kim, Sun-Gyu;Lee, Jeong-Yeol
    • Fisheries and Aquatic Sciences
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    • 제14권4호
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    • pp.417-420
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    • 2011
  • In this experiment, we examined the survival, fertilization, hatching times, and hatching rates of Far Eastern catfish Silurus asotus at pH ranging from 2 to 13 under laboratory conditions. Eggs could be fertilized at pH 3-12. In a hatching experiment, mortality was first observed at pH 13, when all fertilized eggs died within 8 min, followed by pH 2 (30 min), pH 12 (60 min), pH 3 (4 h), and pH 11 (5 h). Hatching only occurred at pH 4-10, with the highest hatching rate at pH 7 (52%) and the lowest at pH 10 (24%). Hatching rates in acid solutions were higher than in alkaline solutions, although the difference was not significant. Hatching was first observed at pH 10, beginning 27 h after fertilization and ending at the 31 h. A clear difference was observed between hatching times, ranging from 31 to 64 h and increasing in order with descending pH.

$Cp^*Ru(CO)(PR_3)H$형 착물의 합성과 광반응에 의한 H/D 교환반응 (Synthesis of $Cp^*Ru(CO)(PR_3)H$ Type Complexes and Photo-Induced H/D Exchange Reaction)

  • 이동환;김승일;김장일;오영희;감상규
    • 대한화학회지
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    • 제41권12호
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    • pp.645-652
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    • 1997
  • 클로로착물 Cp*Ru(CO)(PR3)H (Cp*=η5-C5Me5, PR3=PMe3, PEt3, PMePh2, PPh3, PCy3)을 출발물질로 사용하여 다양한 히드리드화시약(NaBH4, LiAlH4, LiBEt3H)이나 NaOMe를 반응시켜서 대응하는 히드리드착물 Cp*Ru(CO)(PCy3)H(5)를 합성하였다. Cp*Ru(CO)(PCy3)H(5)착물의 C6D6ㅇ용액에 UV를 조사하면 분자간 및 분자내 C-H결합 활성화반응을 통하여 용매의 중수소와 착물의 배위 리간드인 Cp*, PCy3, Ru-H의 수소 사이에 H/D 교환반응이 진행되었으며 그 반응기구를 설명하였다.

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ON THE IDEAL CLASS GROUPS OF ℤp-EXTENSIONS OVER REAL ABELIAN FIELDS

  • Kim, Jae Moon;Ryu, Ja Do
    • Korean Journal of Mathematics
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    • 제7권2호
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    • pp.227-233
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    • 1999
  • Let $k$ be a real abelian field and $k_{\infty}={\bigcup}_{n{\geq}0}k_n$ be its $\mathbb{Z}_p$-extension for an odd prime $p$. For each $n{\geq}0$, we denote the class number of $k_n$ by $h_n$. The following is a well known theorem: Theorem. Suppose $p$ remains inert in $k$ and the prime ideal of $k$ above $p$ totally ramifies in $k_{\infty}$. Then $p{\nmid}h_0$ if and only if $p{\nmid}h_n$ for all $n{\geq}0$. The aim of this paper is to generalize above theorem: Theorem 1. Suppose $H^1(G_n,E_n){\simeq}(\mathbb{Z}/p^n\mathbb{Z})^l$, where $l$ is the number of prime ideals of $k$ above $p$. Then $p{\nmid}h_0$ if and only if $p{\nmid}h_n$. Theorem 2. Let $k$ be a real quadratic field. Suppose that $H^1(G_1,E_1){\simeq}(\mathbb{Z}/p\mathbb{Z})^l$. Then $p{\nmid}h_0$ if and only if $p{\nmid}h_n$ for all $n{\geq}0$.

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담배 배양세포에서 인간 히스톤 단백질 H1.5의 발현 (Expression of a Human Histone H1.5 in Transgenic Tobacco Cultured Cells)

  • 김기연;권석윤;송재영;이행순;곽상수
    • Journal of Plant Biotechnology
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    • 제31권2호
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    • pp.175-178
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    • 2004
  • Collagen에 의해 유도되는 류마티스 관절염을 저해하는 효과가 있는 인간 histone 단백질 Hl.5 (hHl.5)를 산화스트레스 유도성 SWPA2 프로모터에 연결하여 형질전환 담배(Nicotiana tabacum L. cv Bright Yellow-2) 배양세포주를 개발하였다. hH1.5 유전자는 Agrobacterium 매개 형질전환 방법으로 담배 BY-2 배양세포에 도입되었다. 형질전환 캘러스는 150mg/L kanamycin과 300mg/L claforan이 포함된 변형된 MS 선발배지에서 선발하여, PCR분석으로 hHl.5 유전자의 도입을 확인하였다. 형질전환 현탁배양세포에서 hH1.5 단백질의 발현은 northern 분석과 Western 분석으로 확인하였는데, 담배배양세포에서 재조합hHl.5 단백질 (42 kDa)은 인간의 것 (32 kDa)과는 다른 크기의 단백질이 확인되었다. 금후 재조합 hH1.5 단백질의 자세한 특성규명이 요구된다.

Iodine-Sulfur 수소 제조 공정에서 $H_2SO_4-HI-H_2O-I_2$ 계의 고온 상 분리 (High Temperature Phase Separation of $H_2SO_4-HI-H_2O-I_2$ System In Iodine-Sulfur Hydrogen Production Process)

  • 이동희;이광진;강영한;김영호;박주식;황갑진;배기광
    • 한국수소및신에너지학회논문집
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    • 제17권4호
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    • pp.395-402
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    • 2006
  • Iodine-sulfur(IS) hydrogenation production process consists of three sections, which are so called a Bunsen reaction section, a HI decomposition section and a $H_2SO_4$ decomposition section as a closed cycle. For highly efficient operation of a Bunsen reaction section, we investigated the phase separation characteristics of $H_2SO_4-HI-H_2O-I_2$ system into two liquid phases($H_2SO_4$-rich phase and $HI_x$-rich phase) in the high temperature ranges, mainly from 353 to 393 K, and in the $H_2SO_4/HI/H_2O/I_2$ molar ratio of $1/2/14{\sim}30/0.3{\sim}13.50$. The desired results for the minimization of impurities in each phase were obtained in conditions with the higher temperature and the higher $I_2$ molar composition. On the basis of the distribution of $H_2O$ to each phase, it is appeared that the affinity between $HI_x$ and $H_2O$ was more superior to that between $H_2SO_4$ and $H_2O$.