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        검색결과 8

        1.
        2024.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this paper, iron ore tailings (IOT) were separated from the tailings field and used to prepare cement stabilized macadam (CSM) with porous basalt aggregate. First, the basic properties of the raw materials were studied. Porous basalt was replaced by IOT at ratios of 0, 20 %, 40 %, 60 %, 80 %, and 100 % as fine aggregate to prepare CSM, and the effects of different cement dosage (4 %, 5 %, 6 %) on CSM performance were also investigated. CSM’s durability and mechanical performance with ages of 7 d, 28 d, and 90 d were studied with the unconfined compression strength test, splitting tensile strength test, compressive modulus test and freeze-thaw test, respectively. The changes in Ca2+ content in CSM of different ages and different IOT ratios were analyzed by the ethylene diamine tetraacetic acid (EDTA) titration method, and the micro-morphology of CSM with different ages and different IOT replaced ratio were observed by scanning electron microscopy (SEM). It was found that with the same cement dosage, the strengths of the IOT-replaced CSM were weaker than that of the porous basalt aggregate at early stage, and the strength was highest at the replaced ratio of 60 %. With a cement dosage of 4 %, the unconfined compressive strength of CSM without IOT was increased by 6.78 % at ages from 28 d to 90 d, while the splitting tensile strength increased by 7.89 %. However, once the IOT replaced ratio reached 100 %, the values increased by about 76.24 % and 17.78 %, which was better than 0 % IOT. The CSM-IOT performed better than the porous basalt CSM at 90 d age. This means IOT can replace porous basalt fine aggregate as a pavement base.
        4,300원
        2.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon nanotubes (CNTs) were added into the self-healing polyurethane materials as conductive filler, the mass fraction of carbon nanotubes was adjusted, and 1% polyaniline was doped. The conductive self-healing polyurethane composites with different carbon nanotubes content (PU)-1/3/5/8/10 were prepared, and analyzed and tested. The result shows that the permeability threshold value of the composite material is 8wt%, and the comprehensive performance of the composite material PU-8 is the best; the resistance of PU-8 is 1278Ω, PU-8P has a resistance of 1400Ω; using an infrared camera, it can be seen that the material can reach 143.3 °C under the DC current of 0.1A, reaching the temperature condition when the material is repaired; the swelling test shows that the PU-8P equilibrium swelling rate is 177%, the gel content is 52.67%, and there is no dissolution in dimethyl sulfoxide. Solvent stability is better than PU-8;DSC test shows that the glass transition temperature of the soft segment of PU-8P is 43 °C, and the glass transition temperature of the hard segment is − 55 °C, which is not much different from that of PU-8; TG test shows that the epitaxial starting temperature of PU-8P is 365 °C; the observation photo is magnified by a stereo microscope at ten times and the PU-8P sample is cut of in the middle at room temperature, applying a constant voltage of 30 V, the cracks disappeared. The material cracks realized self-healing with electricity, and the repair efficiency reached 20.5%.
        4,300원
        3.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The oxygen-rich activated carbon (AC) was facilely developed using petroleum coke as a raw material by KOH activation under the rapid heating rate. The porosity and surface chemistry of ACs prepared under different heating rates were characterized and their adsorption properties for methylene blue (MB) were investigated. The results showed that the AC5 prepared under the heating rate of 5 °C min−1 had the highest surface area compared with the AC10, AC15 or AC20, while the AC20 prepared under the heating rate of 20 °C min−1 consisted of the highest oxygen content and most –OH functional group compares with the other ACs. These indicated that rapid heating rate was against the formation of more developed porosity, however, it was beneficial to producing more oxygen functional groups. As to MB adsorption, AC15 exhibited the maximum adsorption capacity for MB of 884 mg g−1 due to high surface area of 2803 m2 g−1 and high oxygen content of 23.27%. Moreover, despite the fact that AC20 had much lower surface area than the AC5, the AC20 showed higher MB adsorption capacity than the AC5. This was because the AC20 has the highest content of –OH, which was a positive impetus for MB adsorption. Therefore, rapid heating rate was an effective and simple approach to preparing the oxygen-rich ACs for improving the adsorption capacity of MB.
        4,000원
        4.
        2018.07 구독 인증기관·개인회원 무료
        Similar to traditional advertising, product placement plays important roles in consumer purchasing behaviors through the AIDA model (e.g., Ghirvu,2013) of which attention is the very first stage. While there is an established literature on brand recall and recognition as methods of product placement evaluation, the role of attention, which is an important topic in traditional advertising research, has been sparsely studied in the context of product placement. This paper proposes that attention is a psychological state which affects information selection and processing. Captured attention reflects audience’s selective attention to editorial content including placements, while sustained attention (or processing) requires allocated attentional capacity to process information captured from the placement. When available attentional capacity is insufficient, product placements cannot be adequately processed to form accurate memory (Lee & Faber, 2007). Accordingly, this paper aims to investigate the pathway of ‘placement characteristics –audience attention – audience memory’ in order to reinterpret the relationship between placement characteristics and audience memory through the lens of attention. We do this by answering two pertinent questions: 1) how placement characteristics (e.g., exposure duration, frequency, location and size) influence captured attention; and, 2) how captured attention and sustained attention affect audience memory. To do so, we draw on psychology literature, especially the feature integration theory (Treisman & Gelade, 1980), in establishing the theoretical connections between placement features, captured attention, sustained attention and memory. By a theatre methodology, we found sustained attention mediated between captured attention and audience memory, while more prominent placement characteristics had stronger relationships with captured attention. Furthermore, audience’s levels of involvement in the media content and familiarity with the placed brand moderated the relationship between sustained attention and audience memory.
        5.
        2018.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        At present, an important research area is the search for materials that are compatible with CMOS technology and achieve a satisfactory response rate and modulation efficiency. A strong local field of graphene surface plasmon polariton (SPP) can increase the interaction between light and graphene, reduce device size, and facilitate the integration of materials with CMOS. In this study, we design a new modulator of SPP-based cycle branch graphene waveguide. The structure comprises a primary waveguide of graphene–LiNbO3–graphene, and a secondary cycle branch waveguide is etched on the surface of LiNbO3. Part of the incident light in the primary waveguide enters the secondary waveguide, thus leading to a phase difference with the primary waveguide as reflected at the end of the branch and interaction coupling to enhance output light intensity. Through feature analysis, we discover that the area of the secondary waveguide shows significant localized fields and SPPs. Moreover, the cycle branch graphene waveguide can realize gain compensation, reduce transmission loss, and increase transmission distance. Numerical simulations show that the minimum effective mode field area is about 0.0130l2, the gain coefficient is about 700 cm–1, and the quality factor can reach 150. The structure can realize the mode field limits of deep subwavelength and achieve a good comprehensive performance.
        4,000원
        6.
        2012.10 구독 인증기관 무료, 개인회원 유료
        With escalating economic growth during the last three decades, flower industry of China, especially cut flower is sharply developed. In this paper a brief review of the cut flower current situation of globe and current status of flower industry of China especially of cut flower in the world is presented. The acreage, yield, potential of cut flower in China along with distribution of major cut flower products and constraint of cut flower also was indicated in this paper was also presented.
        4,000원
        7.
        2005.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Using 13.7 m telescope of Qinghai station of NAO, PMO at Delin Ha, 43 IRAS sources were mapped with 13CO J=1-0 C18O J=1-0 and CO J=1-0. Each source has one or more cores. The distances of these cores range from 1 pc to several pc, and the masses from 102M⊙ to 105M⊙. High velocity outflows were detected. The mass, momentum and energy of these massive cores are larger than those of the low mass ones. With radio, IRAS, MSX data, stellar source distribution were investigated, and sourceless cores that deviate from infrared sources were identified. They are potential high mass star formation sites.
        3,000원
        8.
        2019.08 서비스 종료(열람 제한)
        The Sogdian Merchants were the undertakers of international trade on the Land Silk Road in the Middle Ages, and their business footprints spread all over Eurasia. The ancient trading currency of Sogdian Merchants is a key to study the trading history of the region and the entire Silk Road. Although the economic strength of Sogdiana was strong, the country was very weak and had been controlled by the powerful forces around it. Sogdian Merchants wanted to use large amounts of currency for exchanging activities in countries along the Silk Road, they must imitate the currency of the powerful countries that controlled the Silk Road or even use their currencies directly to meet the needs of long-distance transshipment trade. Most scholars agreed that the Persian Sassanian silver coins used to be the currency of circulation along the Silk Road. Whether the main purpose of the unearthed Byzantine gold coins was to act as circulating currencies on the Silk Road at that time, there is still a great controversy.