• 영어어문교육
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• 제15권3호
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• pp.199-222
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• 2009

As great attention is given to a high quality of English education in Korea, more and more in-service and pre-service English teachers are looking for an opportunity to study in an English speaking country to become better qualified teachers. However, after receiving a degree in an English speaking country, many teachers fail to apply what they have learned to their own teaching due to their tensions of identity, beliefs, knowledge, and professionalism within the changes of sociocultural settings. By using sociocultural theory as a theoretical framework, this paper explores how formal training and Ph.D. studies in the U.S. have influenced a Korean teacher educator in applying theory to practice in relation to her identity, beliefs, knowledge, and professionalism during 30 years of her teaching experience. Rather than facing tensions, the teacher educator has been willing to change her roles, broaden and deepen her beliefs in teaching and knowledge about theory of teaching and learning, and continue her professional development. Limitations and implications of the study are provided.

• 대한화학회지
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• 제39권10호
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• pp.783-788
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• 1995

Silyltriflate는 phenyl기가 포함된 규소화합물을 $CF/_3/SO/_3/H$와 반응시켜 얻어진다. Silyltriflate와 allylmagnesium bromide와의 반응에서는 allyl기가 포함된 실란 유도체 $R/_2/SiHCH/_2/CH\;=\;CH/_2/(R\;=\;Me,Ph)$이 형성되었다. 이 화합물은 백금 촉매하에서 polycarbosilane을 형성하였으며 polycarbosilane의 Si-Ph 결합은 다시 트리플산에 의해 polycarbosilane의 triflat 유도체를 형성하였다.

• 한국세라믹학회지
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• 제28권7호
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• pp.517-524
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• 1991

The CVD process of BPSG (BoroPhosphoSilicate Glass) and its thin film properties were studied. B2H6, PH3, SiH4 and O2 gases were reacted in a AP (Atmospheric Pressure) CVD system in the temperature range of 300℃ and 460℃. The interaction of B2H6 and PH3 was studied from the deposition rate and dopant incorporation change point of view. The dependency of BPSG step coverage on the temperature was changed with different O2/(B2H6+PH3+SiH4) ratio. Finally, the boundary which distinguishes the stable BPSG's from the ones that react with Di (Deionized) water or cleaning chemicals such as H2SO4, HCl, H2O2, NH4OH etc could be defined.

• Journal of applied mathematics & informatics
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• 제30권5_6호
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• pp.749-757
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• 2012

We consider the M/PH,G/1 queue with two classes of customers in which class-1 customers have deterministic impatience time and have preemptive priority over class-2 customers who are assumed to be infinitely patient. The service times of class-1 and class-2 customers have a phase-type distribution and a general distribution, respectively. We obtain performance measures of class-2 customers such as the queue length distribution, the waiting time distribution and the sojourn time distribution, by analyzing the busy period of class-1 customers. We also compute the moments of the queue length and the waiting and sojourn times.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.736-739
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• 2002

We report on white light emission from a light emitting diode(LED) prepared by blending a red emitting copolymer, m-SiPh PPV-co-MEH PPV, and a blue emitting polyvinylcarbazole (PVK). White light emission was realized when the weight ratio of the m-SiPh PPV-co-MEH PPV : PVK equals to 1 : 30, in which the commission Internationale de L'Eclairage coordinates were x=0.3266 and y=0.3438.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.41-42
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• 2001

The chemopreventive effect of tea against 2-amino-l-methyl-6-phenylimidazo［4, 5-b ］pyridine (PhIP)-DNA adduct formation and its mechanism were studied. Rats were exposed to freshly prepared aqueous extracts of green tea (3% w/v) as the sole source of drinking water for 10 days prior to administration with a single dose of PhIP (10 mg/kg body wt) by oral gavage. PhIP-DNA adducts in the liver, colon, heart, and lung were measured using the $^{32}$ P-postlabelling technique.(omitted)

• 분석과학
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• 제8권4호
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• pp.643-648
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• 1995

Cyclic voltammetric method is used to survey microscopic environments which take place at the surfactant-modified carbon electrode when the hydrophobic and hydrophilic environments of $Ru(ph){_3}^{2+}$(tris 1,10-phenanthroline ruthenium(II) chloride) is created by the addition of anionic surfactant, sodium dodecyl sulfate(SDS). Critical micelle concentration(CMC) of SDS in $Ru(ph){_3}^{2+}$ measured by cyclic voltammetry(CV) is in aggrement with that by surface tensiometry. Influence of the concentration of supporting electrolyte at surfactant-modified carbon electrode is investigated.

• 한국결정학회지
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• 제11권2호
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• pp.80-83
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• 2000

Compound [Ni(P(OEt)3)4] (1) reacted with bis(diphenylphosphino)ethane (Ph2PCH2CH2Ph2, dppe) to give bis(bis(diphenylphosphine)ethane)nickel(0), [Ni(dppe)2] (2). Compound 2 was characterized by spectroscopy (1H-and 31P{1H}-NMR) and X-ray crystallography. Crystallographic data for 2: monoclinic space group P21/n, a=9.826(1)Å, b=21.167(2)Å, c=21.425(2)Å, β=91.957(9)°, Z=4, R(wR2)=0.0377(0.0882).

• 대한화학회지
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• 제13권1호
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• pp.37-40
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• 1969

The separation and species of $MoO_4^{--}$ and $WO_4^{--}$ at the various PH value have been studied by the method of cation exchange chromatography. Elution curves of $MoO_4^{--}$ and $WO_4^{--}$ have been made with a 5 cm column of the resin, $Dowe{\times}50W{\times}12$(100-200 mesh), using solutions of various PH value as eluent. Complete separation of $MoO_4^{--}$ and $WO_4^{--}$ was obtained in each PH of 10% EtOH. According to the evaluation of peak position and number of peaks of elution curves, it is likely to exist cationic species of $MoO_4^{--}$.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.378-382
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• 2009

Rates of solvolyses of benzhydryl chloride ($Ph_2$CHCl, 1) and benzhydryl bromide ($Ph_2$CHBr, 2) in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, 2,2,2-trifluoroethanol (TFE) and acetone are reported. Solvolyses were also carried out in TFE-ethanol mixtures. Application of the extended Grunwald-Winstein equation led to l value of 1.19 (1), 1.29 (2) and m value of 1.00 (1), 0.77 (2), correlation coefficient of 0.965 (1) and 0.970 (2). Sensitivities (l = 1.19 (1), 1.29 (2) and m = 1.00 (1), 0.77 (2)) were similar to those obtained for several previously studied solvolyses, in which an $S_N$2 pathway is proposed for the solvolyses of benzhydryl halides ($Ph_2$CHX, X = Cl or Br).