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        검색결과 576

        83.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, nitric acid oxidation with varied treatment temperature and time was conducted on the surfaces of polyacrylonitrile- based ultrahigh modulus carbon fibers. Scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and surface tension/dynamic contact angle instruments were used to investigate changes in surface topography and chemical functionality before and after surface treatment. Results showed that the nitric acid oxidation of ultrahigh modulus carbon fibers resulted in decreases in the values of the crystallite thickness Lc and graphitization degree. Meanwhile, increased treating temperature and time made the decreases more obviously. The surfaces of ultrahigh modulus carbon fibers became much more activity and functionality after surface oxidation, e.g., the total surface energy of oxidized samples at 80 °C for 1 h increased by 27.7% compared with untreated fibers. Effects of surface nitric acid oxidation on the mechanical properties of ultrahigh modulus carbon fibers and its reinforced epoxy composites were also researched. Significant decreases happened to the tensile modulus of fibers due to decreased Lc value after the nitric acid oxidation. However, surface treatment had little effect on the tensile strength even as the treating temperature and processing time increased. The highest interfacial shear strength of ultrahigh modulus carbon fibers/epoxy composites increased by 25.7% after the nitric acid oxidation. In the final, surface oxidative mechanism of ultrahigh modulus carbon fibers in the nitric acid oxidation was studied. Different trends of the tensile strength and tensile modulus of fibers in the nitric acid oxidation resulted from the typical skin–core structure.
        4,500원
        84.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        복장은 한 사람의 성격을 반영하고 개인의 심미적 수준 및 내재적 수양을 직관적으로 체현한다. 한 민족에게 이는 민족의 문화와 풍속 더 나아가 한 민족의 사상과 심미를 체현한다. 이는 일종 특수한 언어이고 매 역사 시기의 경제적 발전, 생활 환경, 종교적 신앙을 체현하기도 한다. 우리나라의 각 민족의 복장 특징에는 각 민족의 문화 형태가 들어있다. 중국 복장은 5,000년의 발전 역사를 지니고 있고 그 중 만족 복장 중의 치파오는 중국 복장 발전 역사 중 독특한 매력을 지니고 있을 뿐더러 그 속에 숨겨진 의미도 있다. 치파오의 정신에는 민족의 지혜가 숨겨져 있다. 민족의 신앙은 치파오가 수수께끼가 가득한 매력을 지니게 하였다. 어떠한 사회 혹은 민족이든 시시각각 변화하고 있는데 이는 문화 자체 혹은 기타 문화와 서로 접촉하여 생긴 문화적 융합과 변화이다. 치파오는 샤먼 복장 문화의 영향을 받아 한족 문화를 경험하고 또 치파오의 시대까지 오게 되었다. 복장 제도의 제한이든 민족 문화의 영향이든 치파오의 색채와 도안은 사람들이 아름다운 생활 형태에 대한 동경을 표현하였다. 치파오는 중국 전통적인 복장 문화의 중요한 조성 부분으로서 치파오 중의 요소는 역사적 문명을 계승하였을 뿐만 아니라 자신의 민족 특색 또한 보류하였고 참고, 전통, 재창조를 통하여 더욱 잘 융합시켰다. 치파오의 발전과 변화는 민족 복장 사이의 상호 반응에 유력한 작용을 하였다. 치파오의 요소는 이미 세계 복장 문화 속에서 풍부한 시대와 문화적 특징을 체현하였고 현대 복장 디자이너들에게 수많은 영감과 창작 원천을 제공하였다. 이후 치파오는 중국에서만 입는 것이 아니라 세계 적으로도 사랑을 받게 되었으며 현대에 수많은 예복의 양식 또 한 중국 치파오의 스타일 및 꽃무늬 도안을 참고한 것이다. 이러한 전통적인 복장은 현대 디자이너의 눈에는 기타 용도가 있을 것이고 그들의 창작 중 전통적인 ‘중국식 요소’는 새로운 빛을 발하게 될 것이다 — 이는 중국 전통적인 민족 복장이 세상에 가져다 준 서프라이즈와 마찬가지이다.
        6,600원
        85.
        2021.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, the electrochemical behavior of Sm on the binary liquid Al-Ga cathode in the LiCl-KCl molten salt system is investigated. First, the co-reduction process of Sm(III)-Al(III), Sm(III)-Ga(III), and Sm(III)-Ga(III)-Al(III) on the W electrode (inert) were studied using cyclic voltammetry (CV), square-wave voltammetry (SWV) and open circuit potential (OCP) methods, respectively. It was identified that Sm(III) can be co-reduced with Al(III) or Ga(III) to form AlzSmy or GaxSmy intermetallic compounds. Subsequently, the under-potential deposition of Sm(III) at the Al, Ga, and Al-Ga active cathode was performed to confirm the formation of Sm-based intermetallic compounds. The X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analyses indicated that Ga3Sm and Ga6Sm intermetallic compounds were formed on the Mo grid electrode (inert) during the potentiostatic electrolysis in LiCl-KCl-SmCl3-AlCl3- GaCl3 melt, while only Ga6Sm intermetallic compound was generated on the Al-Ga alloy electrode during the galvanostatic electrolysis in LiCl-KCl-SmCl3 melt. The electrolysis results revealed that the interaction between Sm and Ga was predominant in the Al-Ga alloy electrode, with Al only acting as an additive to lower the melting point.
        4,900원
        86.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With the development of the economy and the continuous improvement of people’s living standards, consumers’ increasing demand for safe food has become an inevitable trend of social development. On the one hand, food safety is an urgent social problem needed to be solved in China. On the other hand, the food safety guarantee method based on a traceability system is popular. This paper systematically studies the influencing factors of consumers’ willingness to pay for the extra price of traceable pork in the Yanbian area through empirical analysis. The result showed that consumers’ attitude and subjective norms, and perceived behavior control, have significantly positively affect consumers’ willingness to pay the extra price. Meanwhile, consumers’ perceived risk of traceable pork significantly moderates the effect on consumers’ attitude and willingness to pay an extra price. The results can provide the corresponding reference for government agencies to formulate policies and provide valuable suggestions for enterprises to develop a pork traceability market to realize the development of a pork traceability system in the Yanbian area to ensure consumers’ food safety.
        4,000원
        87.
        2021.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        On October 29, 2020, the Fifth Plenary Session of the 19th Central Committee of the Communist Party of China (CPC) pointed out that traditional and non-traditional security should be coordinated, and security development should be integrated into all areas and processes of national development. Terrorism as an escalating threat factor in non-traditional security issues, anti-terrorism has become an important component of maintaining social security and stability, safeguarding people's lives and implementing national security strategy. Focusing on the "14th five-year plan" and the overall national security concept, through analyzing the overall environment of China's current counter-terrorism intelligence, and using the PEST-SWOT model to probe into the strengths and weaknesses of China's counter -terrorism intelligence information security. A scientific and reasonable international coordination and Cooperation Mechanism of counter-terrorism intelligence is put forward to provide an important guarantee for the modernization of counter-terrorism intelligence system and adherence to the overall national security concept.
        6,700원
        88.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 종방향과 횡방향에서 규칙파가 외란으로 입사하는 선박의 종동요 및 횡동요를 억제하는 문제를 다룬다. 선박의 안전 운항을 위해서 파랑 중 선박의 종동요 및 횡동요를 안정화시키는 것은 필수적인 과제로 여겨진다. 종동요 및 횡동요 거동에서 중요한 특징 중에 하나는 공진인데, 이 현상은 특정한 조건에서 예상치 못한 큰 응답을 초래한다. 종동요와 횡동요는 두 운동이 상호 결합되어 있고 복원항이 강한 비선형을 갖고 있음으로 계의 파라미터에 따라 다양한 동적 거동을 보이는 것이 중요한 특징인데, 특히 종동요에서 이 특성이 두드러지게 나타난다. 무엇보다, 선박의 조종성능 및 안전을 위해 선박의 종동요 가속도 응답을 완전히 억제하는 것은 상당히 도전적인 과제이다. 이 연구에서는 준 슬라이딩 모드 제어 기법을 이용하여 종동요와 횡동요를 줄임으로 파랑 중의 선박을 안정적인 직립 상태로 유지시키고, 아울러 채터링을 감소시키는 목적을 달성하였다. 리아프노프 이론으로 준 슬라이딩 모드 제어의 안정성을 판명하였고, 수치 시뮬레이션으로 제어 방식의 유효성을 증명하였다. 제시한 기법으로 종동요 및 횡동요 응답의 수렴 및 채터링 감소라는 두 가지 목표가 효과적으로 달성되었다.
        4,000원
        90.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 중국 길림성 연변 주 지역의 ‘연변황우’ 소비자 대상으로 설문조사를 실시하였음. 먼저 국내외 브랜드 인지 및 구매 의사에 관한 이론을 검토하고 소비자의 브랜드 인식 등의 이론을 바탕으로 연구 가설을 제시하였음. ‘연변황우’에 대한 소비자 구매 의사에 영향을 미치는 요인을 구축하여 분석을 실시하였음. 연구 결과 1. ‘연변황우’ 브랜드 이미지는 소비자의 구매 의사에 긍정적인 영향을 미치며 소비자의 ‘품질 감지’ 요인에 정(+)의 영향을 미침. 2. ‘위험 감지’ 요인에는 부(-)의 영향을 미침. ‘품질 감지’ 요인은 ‘연변황우’ 구매 의사에 긍정적인 영향을 미침. 3. ‘연변황우’의 브랜드 이미지 관리를 강화해야하며 이는 브랜드의 연구관련에 새로운 분야 탐색에 중요한 의의가 있음.
        4,000원
        91.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The porous carbons with high specific surface area and excellent electrochemical properties were prepared using three types of green needle coke as raw materials. Electrochemical performances of the porous carbons derived from different microstructure green needle coke were investigated. The XRD and Raman spectra demonstrated that the content of the ordered carbon microcrystals were decreased and the content of amorphous and cross-linked structure were increased in the porous carbons with comparison to the raw materials. The results of N2 adsorption–desorption analysis verified that the content of ordered microcrystalline structure in the raw materials evidently influence the specific surface area and pore size distribution of the porous carbons. The porous carbon with 1665 m2 g−1 specific surface area and 2.89 nm average pore size has shown that the specific capacitance was 288 F g−1 at the current density 1 A g−1. Furthermore, the capacity retention was 94.93% and the Coulombic efficiency was 92.87% after 5000 charge/discharge cycles.
        4,000원
        92.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to improve the thermal shock and ablation resistance of high thermal conductivity carbon/carbon composites, carbon nanotubes (CNTs) were introduced by electrophoretic deposition. After modification, the flexural strength of the composites increases by 53.0% due to the greatly strengthened interfaces. During thermal shock between 1100 °C and room temperature for 30 times, the strength continues to increase, attributed to the weakened interfaces in favor of fiber and CNT pull-out. By introducing CNTs at interfaces, thermal conductivity of the composites along the fiber axial direction decreases and that along the fiber radial direction increases. As the thermal shock process prolongs, since the carbon structure integrity of CNT and matrix in the modified composites is improved, the conductivity increases whatever the orientation is, until the thermal stress causes too many defects. As for the anti-ablation performance, the mass ablation rates of the CNT-modified composites with fibers parallel to and vertical to the flame decrease by 69.6% and 43.9% respectively, and the difference in the mass ablation rate related with fiber orientations becomes much less. Such performance improvement could be ascribed to the reduced oxidative damage and the enhanced interfaces.
        4,500원
        93.
        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
        94.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Direct injection of genome editing tools such as CRISPR/Cas9 system into developing embryos has been widely used to generate genetically engineered pigs. The approach allows us to produce pigs carrying targeted modifications at high efficiency without having to apply somatic cell nuclear transfer. However, the targeted modifications during embryogenesis often result in mosaicism, which causes issues in phenotyping founder animals and establishing a group of pigs carrying intended modifications. This study was aimed to establish a genomic PCR and sequencing system of a single blastomere in the four-cell embryos to detect potential mosaicism. We performed genomic PCR in four individual blastomeres from four-cell embryos. We successfully amplified target genomic region from single blastomeres of 4-cell stage embryo by PCR. Sanger sequencing of the PCR amplicons obtained from the blastomeres suggested that PCR-based genotyping of single blastomere was a feasible method to determine mutation type generated by genome editing technology such as CRISPR/Cas9 in early stage embryos. In conclusion, we successfully genotyped single blastomeres in a single 4-cell stage embryo to detect potential mosaicism in porcine embryos. Our approach offers a simple platform that can be used to screen the prevalence of mosaicism from designed CRISPR/Cas9 systems.
        4,000원
        95.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper is based on field survey data and applies it to the logistic model to analyze consumers' online shopping intention to buy fresh produce. According to the total effect of online shopping intention, it was revealed that consumers' age, educational level, and monthly household income significantly influence willingness to buy fresh produce online. The product quality, price and brand name were the main factors affecting consumers' willingness to buy fresh produce online. The customer service quality, payment security, and logistics quality significantly also affected consumers' willingness to buy fresh produce online. In conclusion, it is important for vitalizing online sales of fresh produce to ensure the quality, use well-known brand name, and improve logistics service and e-commerce platforms.
        4,000원
        96.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, China's agricultural listed companies have developed rapidly. This paper studies the operating efficiency of listed agricultural companies in China. exploring the factors that affect the operating efficiency of listed agricultural companies, and proposes targeted countermeasures for the development of listed agricultural companies. And give some suggestions to Korean agricultural companies and A share investors. This paper uses the DEA model, selects the 40 best-developed Chinese agricultural listed companies in 2018 as a sample, analyzes the operating efficiency of these companies, and added two new input variables: asset impairment losses (AIL) and business tax and surcharge (BTS), which will also have an impact on operating efficiency. This paper can provide reliable suggestions for the development of agricultural listed companies, and thus guide the healthy operation of agricultural companies.
        4,000원
        97.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        극단문화는 전통사회의 중요한 문화매체이다. 극단은 일정한 세속적 사회관계 네트워크 속에서 존재하며, 사람들의 ‘관습’ 의 영향을 받아 일정한 안정성을 가지고 있다. 극장이 의존하 는 ‘필드(field)’는 더 복잡한 요소도 망라한다. 이에 따라 ‘필드 (field)’에 따라 극장의 형태도 달라진다. 슈산 진하극단 발전 역사가 백 년을 넘고, 여기에서는 슈산 진하극단의 ‘필드(field)’ 문화에 대한 연구를 통해 극단의 문화 발전의 일반적인 규율을 탐구하는 것이다.
        4,900원
        98.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the cytotoxic potential of three different commercially available absorbent feminine hygiene products and one transdermal patch using direct contact and extract exposure methods. Two different cell lines were used – mouse fibroblast L929 and normal human skin fibroblast CCD-986sk cell lines. The test samples were extracted using three different methods in accordance to International Organization for Standardization (ISO). Viability of cells was analyzed using MTT assay and morphology of the cells were also observed using phase contrast microscopy. Overall, the direct contact method using L929 cells showed that all the test samples had no toxic effect when exposed to extracts for 1 h. For the exposure method, no toxic effect was observed in both L929 and CCD986sk cells incubated with all the test samples regardless of the extraction methods used.
        4,000원
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