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        검색결과 9,512

        1748.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nanostructured ZnO materials have been studied extensively because of their functional properties. This paper presents a composite material of zinc oxide quantum dots (ZnO QDs) and porous carbon using a one-step carbonization process. The direct carbonization of a metal–organic complex generates mesostructured porous carbon with a homogeneous distribution of ZnO QDs. The structural and morphological properties are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The resulting ZnO QDs@porous carbon composite delivers a high specific capacity of 990 mAh g−1 at 100 mA g−1, 357 mAh g−1 at 2 A g−1, and high reversibility when evaluated as an anode for lithium ion batteries.
        4,000원
        1749.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to classify the types of decoration techniques used in women’s Chima and Jeogori in traditional Hanbok catalogs from 2010 to 2020, and to analyze the frequency of each type. The method of this study is as follows. This study first investigated the transition of modern Hanbok and decorative techniques by analyzing and classifying such work in previous studies. Based on this, the technique of decorating the Jeogori and Chima that appeared in the traditional Hanbok catalog of the study period was analyzed. The results of the study are as follows. In the case of Jeogori, in the first half of 2010, the decorative technique of a relatively large size was used, and the decorativeness tended to be strong. However, in the late 2010s, the number of decorative techniques used in Jeogori has decreased, and the size of the decorative technique has become smaller and more concise, leading to a tendency to understated decoration. In the case of Chima, techniques to express natural texture by processing threads or fabrics themselves were mainly used rather than techniques to add decoration to the surface, and techniques to express various surface texture tended to develop toward the late 2010s. The change in the decoration technique of Jeogori and Chima appears to be a combination of social, cultural, and economic factors such as a change in consumption culture and a reduction in the wedding market.
        5,100원
        1750.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        호프스태터와 예이츠는 인생의 신비함은 결코 틀리지 않으며, 신비하고, 매혹적이라는 점에 동의하는 것 같아 서로 연관성이 있어보여서 서로 비교하면서 읽게 되었다. 인생의 신비로움을 파헤치는 그들의 노력은 환상적이다. 그러나 읽으면 읽을수록 더 혼란스러워지는 것도 사실인 듯하다. 그러나 거의 따라가는 듯도 하며 책을 다 읽은 지금도 신비의 여운이 감돈다.
        4,000원
        1751.
        2021.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Here, Zn ferrite is synthesized along with reduced graphene oxide (rGO) by a facile one-step hydrothermal method. The difference between the synthesized nanocomposites with those in other reported work is that the reaction conditions in this work are 160 oC for 12 h. The synthesized products are characterized by field-emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and attenuated total reflection. Further, the adsorption property of rGO–Zn ferrite (rGZF) nanocomposite is studied after confirming its successful synthesis. The adsorption capacity of rGZFs toward rhodamine B (RB) is ˃ 9.3 mg/g, whereas that of bare ZF nanoparticles is 1.8 mg/g in aqueous media. The efficiencies of rGZF and bare ZF to remove RB are 99 % and 20 %, respectively. Employing rGZF, 60 % of RB is decomposed within 5 min. The kinetic study reveals that the adsorption process of removing RB by bare Zn ferrite follows pseudo-firstorder kinetics. However, after zinc ferrite is incorporated with rGO, the kinetics changes to pseudo-second-order. Furthermore, the Langmuir isotherm is accomplished by the adsorption process employing rGZF, indicating that a monolayer adsorption process occurs. The thermodynamic parameters of the process are also calculated.
        4,000원
        1752.
        2021.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We confirm whether Zr powders can restrain a rapid nitrification reaction and offer a stable oxidation reaction according to temperatures in nitrogen gas purification. A pellet-type, porous Zr getter is prepared (diameter: 10 and thickness: 3 mm) using Zr powder with an average particle size of 45 μm. While maintaining the whole system, the Zr getter reaction is confirmed with an increase in temperature from 150 to 550 oC at increments of 100 oC under 99.999 % purity nitrogen atmosphere comprising of 10 ppm of impurity. Surface color, pore size, stabilized layer, and phase change are confirmed with optical microscopy, SEM-EDS, Micro-Raman, and X-ray diffraction (XRD) according to the Zr getter temperature. The surface color of the Zr getter changes from metallic silver to dark gray as temperature increases. In the EDS results, the nitrogen component is not observed, and oxygen content increases from each surface at elevated temperatures. The Raman and XRD results show the oxidation layer as a result of 350 oC annealing. Therefore, the Zr getter can be applied as a nitrogen getter under 5-nine purity nitrogen atmosphere after appropriate oxidized pre-stabilization process to prevent rapid nitrification reaction.
        4,000원
        1753.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The morning ritual was a rite whereby a morning audience with the emperor was held for feudal lords sovereigns and subjects living in the precincts, monarchs or foreign envoys of the outskirts of the capital, and other ethnic group. Distinction between the main and subordinate rituals, changes in the ceremony according to the times, and the position or rank of those participating in the rite, were factors that directly affected the costumes worn for ritual. Accordingly, in this paper, the costumes worn by members of the Ming dynasty (emperor, prince imperial, prince) were examined in terms of the period and detailed ceremonies with a focus on the morning ritual and costume systems presented in the official historical records. Through this study, only Mian-fu (冕服) and Pi-bian-fu (皮弁服) were defined by the costume system ase costumes worn in the morning ritual. However, through comparative analysis with the morning ritual system, it was confirmed that Tongtian-guan-fu (通天 冠服), Yishan-guan-fu (翼善冠服), and Bianfu (便服: slightly casual wear) were also worn. It is worth noting that the color of Gunlong-pao (袞龍袍) was differentiated according to status; the Emperor wore yellow, the Prince Imperial and lower levels wore red, which was the traditional perception of academia. However, following confirmation of the custom costume for the morning ritual, it was confirmed that the color of this differentiation appeared during the 3rd year of Emperor Yongle of Ming (1305). Previously five traditional colors (blue, red, yellow, white, and black) were used for the season.
        5,200원
        1754.
        2021.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To solve the common problems of concrete preparation in low-temperature environments, calcium formate (C2H2O4Ca), anhydrous sodium sulfate (Na2SO4), triethanolamine (C6H15O3N), calcium bromide (CaBr2), and triisopropanolamine (C9H21NO3) are selected as early strength agents and mixed with C40 concrete in different dosages under low-temperature environments of 5 oC and 10 oC to develop a high-efficiency low-temperature compound early strength agent based on the effect of single-doped early strength agents. The effects of the compound early strength agent on the early strength of the concrete, the cement paste setting time, and cement fluidity at 5 oC and 10 oC are investigated, and the corresponding reaction mechanism is discussed from the perspective of micro-products. The best compound early strength agent ratio is found to be 2% of calcium formate + 0.08 % of TEA (C6H15O3N). The compound early strength agent effectively promotes the formation of hydration products, such as Ca(OH)2 and C-S-H gel. In comparison with the control group, the strength of the concrete cured for 18 h, 1 d, 3 d, and 7 d under simulated natural conditions at 5 oC increases by 700%, 540%, 11.4 % and 10 %, respectively, whereas at 10 oC, the corresponding values are 991%, 400%, 19.6 % and 11 %, respectively. The strength of the concrete at each age is close to the normal temperature standard of the curing strength. The addition of the compound early strength agent causes a reduction in cement fluidity and initial and final setting times, and also yields a good effect on the porosity of the early concrete.
        4,600원