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鐵 觸媒上의 벤젠 水素添加 반응의 反應機構에 대한 考察
尹奇俊 成均館大學校 科學技術硏究所 1984 論文集 Vol.35 No.2
The experimental data reported in the literature on the benzene hydrogenation over an iron catalyst were re-analyzed and a reaction mechanism, in which the rate-determining step is the surface reaction of a chemisorbed partially-hydrogenated benzene with a chemisorbed hydrogen atom, was discussed. The derived rate equation of the following form, r = (k'K_EK_BK_H^5/2P_BP_H2^5/2) / (1 + K_BP_B)^2 provided a satisfactory fit of the data below 453 K, and the kinetic parameter values obtained were more reasonable than those in the original paper. The decrease of the reaction rate above 453 K could be explained by the marked decrease of the amount of the chemisorbed hydrogen or of the chemisorbed benzene.
Cu/Kieselguhr 觸媒에 依한 Acrylonitrile의 水和反應에 關한 硏究
尹奇俊,姜喆象 成均館大學校 科學技術硏究所 1990 論文集 Vol.41 No.2
Catalytic hydration of acrylonitrle over Cu/kieselguhr catalysts was studied at 343K. The catalysts with varying Cu loadings were prepared by the precipitation method using NaOH and K_2CO_3 solutions as the precipitants. The active surface areas were measured by O_2 chemisorption at 77K in order to determine the areal reaction rate constants. Some effects of the precipitant and the Cu loading were investigated. The results were as follows : (1) Only acrylamide was produced over the catalysts prepared using NaOH, whereas ethylene cyanohydrin was also produced over the catalyst prepared using K_2CO_3. (2) The reaction rate for the production of acrylamide was first order with respect to the concentration of acrylonitrile. (3) The areal reaction rate constant. for the catalysts prepared using NaOH decreased significantly with decreasing Cu loading. The constant at 343K for the catalyst having 50% Cu loading was 2.83 x 10 wxp(-6)l/㎡. min.
SILICA 및 ALUMINA 擔持 鐵觸媒의 H_2 및 CO 化學吸着 特性
尹奇俊,金寅泰,崔祉勳 成均館大學校 科學技術硏究所 1990 論文集 Vol.41 No.2
H_2 and CO chemisorption experiments were performed on silica-and alumina-supported iron catalysts and the chemisorption characteristics of H_2 and CO were compared. Effects of the supports on the chemisorption characteristics, dispersion, and reducibility of the catalysts were also compared. In addition, effects of the metal loading and the methods of catalyst preparation were investigated. The catalysts were prepared by the incipient wetness method with varying preparation conditions and Fe loadings. The adsorption experiments were carried out at various temperatures from 195K to 473K. Oxidation of the catalysts were performed in order to determine the degree of reduction of Fe. The results were as follows : (1) The amount of CO chemisorbed on the silica-supported catalysts decreased with temperature. That on the alumina-supported catalysts decreased with temperature up to 373K, but it became larger at 473K. (2) The amount of chemisorbed H_2 increased with temperature up to 473K for all the catalysts. The amount of chemisorbed H_2 was much lower than that of CO chemisobed at 195K. (3) The percentage reduction of the silica-supported catalysts was higher than that of the alumina-suppoted catalysts. The dispersion of the silica-supported catalysts was lower than that of the alumina-supported catalysts. (4) The catalysts perpared by different methods did not show different chemisorption characteristics, but exhibited different dispersion or percentage reduction.
파이로인산나트륨과 염화나트륨으로 촉진된 지르코니아 촉매에 의한 메탄의 Oxidative Coupling
윤기준,이정복 成均館大學校 科學技術硏究所 1997 論文集 Vol.48 No.1
Sodium-salt-promoted zirconia(ZrO_2) catalysts were prepared by using zirconium hydroxide as the precursor of ZrO_2 and each or both of sodium pyrophosphate and sodium chloride as the promoter(s). While ZrO_2 by itself exhibited no activity of oxidative coupling of methane (OCM) but high activity of combustion, Na_4P_2O_7-promoted zirconia exhibited appreciable activity of 0CM and significantly reduced activity of combustion. As the content of Na_4P_2O_7 increased, within the range investigated, the C_2 selectivity became higher but the C_2 yield remained nearly constant. While the Na_4P_2O_7-promoted catalysts showed relatively stable performance, the NaCl-promoted catalysts deactivated rapidly due to the loss of NaCl. For the catalysts which were simutaneously promoted by the two sodium salts, the action of each promoter was shown independently without any synergistic effect.
尹奇俊,金聲根 成均館大學校 科學技術硏究所 1992 論文集 Vol.43 No.1
Decomposition of methanol over a Cu/Si0_2 catalyst under total pressure of 1 atm was investigated in a temperature range between 563 and 643K using a tubular flow reactor. Besides CO and H_2 as the decomposition products large amounts of HCHO and CO_2 were observed. Deactivation rate of the catalyst was considerably fast. It was concluded that CO_2 was formed mainly from CO by the Boudouard reaction and that accompanying carbon deposition was the cause of the deactivation. Overall conversion of methanol increased with increasing temperature up to 603K and then decreased with further increase of temperature ; the rate of CO formation varied in a similar trend. This is considered due to that at higher temperatures carbon deposition occurs more rapidly, resulting in blocking of a singificant portion of the catalyst surface within a few minutes. With increasing temperature the selectivity to CO_2 decreased and the selectivity to HCHO increased. This indicates that formation of CO_2 is a structure-sensitive reaction whereas formation of HCHO is a less structure-sensitive one.
尹奇俊 成均館大學校 科學技術硏究所 1985 論文集 Vol.36 No.1
CO chemisorption rate data on highly-dispersed iron particles in a temperature range of 300-473。K were analyzed in terms of chemical reactors occurring on the surface for elucidation of chemisorption mechanism and structures of final chemisorbed species. The final structure varied depending on temperature and the chemisorption was interpreted to proceed via initial rapid formation of linear-type CO to a final structure. The final structures suggested were a subcarbonyl type at 300˚K, laying-down CO at 373˚K, and dissociated CO at 473˚K.
윤기준,서지영 국민체육진흥공단 한국스포츠정책과학원 2020 체육과학연구 Vol.31 No.4
[Purpose] The purpose of this study was to explore the concept of physical education redesign. [Methods] Studies on curriculum redesign, physical education curriculum redesign and the revised 2015 physical education curriculum were collected and analysed. [Results] First, three different types of curriculum redesign were discussed. Second, there was no clear concept of physical education redesign. Third, both ‘learning content area’ and ‘standard achievement’ were related to the physical education curriculum redesign. [Conclusions] Two different aspects of physical education curriculum redesign emerged. Establishing the clear concept of physical education curriculum redesign and presenting the concept in the next national physical education curriculum were suggested. [목적] 본 연구의 목적은 체육과 교육과정 재구성의 개념을 탐색하고 이를 바탕으로 체육교사의 교육과정 재구성 이해 및 실천을 지원하는 교육과정 문서 개선 방안을 제시하는 데 있다. [방법] 교육과정 재구성 담론 관련 선행연구, 체육과 교육과정 재구성 관련 선행연구, 2015 개정 체육과 교육과정에서 제시하는 재구성의 의미를 분석하였다. [결과] 첫째, 교육과정 재구성을 원형 강조, 새로운 원형 구성, 원형과 재구성의 역할 구분의 세 가지로 구분하였다. 둘째, 선행연구 및 2015 개정 체육과 교육과정에서는 체육과 교육과정 재구성의 의미를 분명하게 제시하지 않고 있다. 셋째, 2015 개정 체육과 교육과정에서는 내용체계 및 성취기준 항에서 재구성이 가능하다. [결론] 체육과 교육과정 재구성은 소극적인 의미와 적극적인 의미의 재구성으로 실천될 수 있으며, 향후 체육과 교육과정 문서에서는 재구성의 의미와 허용 범위를 분명하게 제시할 것을 제안하였다.
윤기준,정동렬,조자영,문종하,김진혁 대한금속·재료학회 2008 ELECTRONIC MATERIALS LETTERS Vol.4 No.1
The effects of annealing atmosphere on the Si-O, Si-N, Si-H, and N-H bonding characteristics in SiON films and their structural and optical properties were investigated. X-ray diffractions showed no evidence of crystals in any of the SiON films. The deposition rate increased as the N2O/SiH4 flow ratio increased and the SiH4 flow rate increased. It was possible to obtain SiON films with a surface roughness of about 1 nm and a high deposition rate of about 4 μm/h when the processing parameters were optimized at rf power of 200 W, a N2O/SiH4 flow ratio of 3, and a SiH4 flow rate of 100 sccm. The intensity of Si-O peaks increased in the samples annealed in an oxygen atmosphere, but it decreased in the samples annealed in nitrogen atmosphere. The intensity of the Si-N peak decreased in the samples annealed in an oxygen atmosphere, but it increased in the samples annealed in a nitrogen atmosphere. The position of Si-O peaks shifted from 1030 nm to 1140 nm in the samples annealed both in oxygen and in nitrogen atmospheres. We also observed that the intensities of the Si-H (~2250cm-1) and N-H (~3550cm-1) peaks decreased noticeably as the annealing temperature increased in all annealed samples.