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        검색결과 88

        1.
        2024.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chlorine is a crucial radionuclide that must be removed in irradiated nuclear graphite. Understanding the interaction between chlorine and graphene-based materials is essential for studying the removal process of 36Cl from irradiated nuclear graphite. In this study, first-principle density functional theory (DFT) was utilized to investigate the adsorption characteristic of chlorine on the original and reconstructed edges of graphene-based materials. Based on the calculation of adsorption energy of the structures after each step of adsorption, the most energetically favorable adsorption routes at four types of edge were determined: Along the armchair edge and reconstructed zigzag edge, the following adatoms would be adsorbed to compensate the distortion induced by the previously adsorbed atom. Meanwhile at the original zigzag edge, chlorine atoms would be adsorbed alternatively along the edge to minimize the repulsion between two adjacent chlorine atoms. The chemical nature of the bonds formed as a result of adsorption was elucidated through an examination of the density of states (DOS) for the two adsorbed chlorine atoms and the carbon atoms attached. Furthermore, to assess the relative stability of the adsorption structures, formation energy of all energetically favorable structures following adsorption was computed. Consequently, the predominant adsorption structure was identified as the reconstructed armchair edge with two chlorine atoms adsorbed. The desorption process of 36Cl2 from the predominant structure following adsorption was simulated, revealing an energy barrier of 1.14 V for desorption. Comparison with experimental results suggests that the chlorine removed from reconstructed armchair edges significantly contributes to the low-temperature removal stage of 36Cl from irradiated nuclear graphite.
        4,000원
        2.
        2024.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, the formation and characterization of Pt2, Pt3 as well as Pt4 atomic clusters in cup-stacked carbon nanotubes (CSCNTs) are evaluated by DFT to examine the adsorption capacity under the clusters. The results show that the Pt clusters move toward the bottom edge or form rings in the optimized stable structure. Pt far from the carbon substrate possesses more active electrons and adsorption advantages. The three clusters can adsorb up to 17, 18, and 16 hydrogen molecules. Loading metal clusters at the bottom edge maintains a relatively good adsorption property despite the low binding energy through comparative studies. The adsorption capacity does not increase with the number of Pt for metal aggregation reducing the hydrogen adsorption area thus impacting the hydrogen storage ability and the aggregation phenomenon limiting the action of Pt metal. During adsorption, chemisorption occurs only in the Pt2 cluster, while multiple hydrogen molecules achieve physiochemical adsorption in the Pt3 and Pt4 clusters. Compared with the atomic loading of the dispersion system in equal quantities, the dispersion system features higher molecular stability and can significantly reduce the energy of the carbon substrates, providing more sites for hydrogen adsorption in space.
        4,900원
        4.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A phenylboric acid functionalized carbon dot (2-FPBA-CD) for rapid fluorescent sensing of glucose in blood was synthesized by simply mixing N, S-doped carbon dots (CDs) with phenylboric acid at room temperature. At pH 7.4, the response of 2-FPBA-CD to glucose could reach equilibrium in a very short time (10 min), with a wide responsive linear range of 19.70 μM to 2.54 mM, which can be applied to the detection of glucose in serum. The mechanism studies showed that the layered carbon film of 2-FPBA-CD aggregated after adding glucose, thereby leading to the fluorescence quenching of 2-FPBA-CD.
        4,300원
        5.
        2024.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This scholarly investigation delves into the legal complexities arising from the People’s Republic of China’s high-altitude balloons entering US airspace. By analyzing landmark cases, such as the Lockerbie incident, this study emphasizes the urgent need for clear liability norms in international airspace. The 2023 Montana Incursion served to clarify the self-defense and proportionality principles under international law. This study examines the nature of these balloons to determine whether they fall under international accords such as the Chicago Convention. It also explores military classifications and legal ambiguities surrounding non-combatant operators in armed conflicts. This paper identifies gaps in the principles of privacy and ethics concerning intelligence gathering within sovereign boundaries. It advocates for new multilateral treaties with geofencing standards to regulate high-altitude unmanned aerial vehicles. This author aims to fortify legal frameworks based on technological advances.
        6,100원
        6.
        2024.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Heavy metal ions pollution has become of worldwide critical concern, thus, it is particularly important to monitor it in the environment and food for ensuring human health. In this study, p-phenylenediamine and 2-mercaptothiazoline were used to prepare nitrogen (N) and sulfur (S) co-doped carbon dots (N/SCDs) for fluorescent and colorimetric detection of Cu2+. The fabricated N/SCDs with bright green fluorescence showed excellent optical characteristics and favorable water solubility. In an aqueous system, a significant fluorescence quenching of N/SCDs at 512 nm is obtained in the presence of Cu2+. It also caused a significant colorimetric response with the color of prepared N/SCDs solution changed from colorless to yellow. Under optimal conditions, the analytical results showed that the linear range spanning from 5 to 400 μM, with a detection limit of 0.215 μM in fluorescence and 0.225 μM in colorimetric detection. In addition, N/SCDs displayed high selectivity toward Cu2+. No obvious interference was observed over other metal ions. Furthermore, we have also used N/SCDs to monitor Cu2+ in tap and lake water. The recovery of Cu2+ ranged between 89.6% and 113.1%. Exhibiting remarkable sensitivity and selectivity, the designed sensor offers a promising detection method for Cu2+ detection in the real sample.
        4,000원
        8.
        2024.04 구독 인증기관·개인회원 무료
        Bacillus thuringiensis (Bt) is widely used as an environmentally friendly insecticide compared to chemical insecticides. However, challenges such as difficulty in direct practical application, limited efficacy duration, and stability have been identified. To solve these issues, formulation-based research is being extensively conducted. In this study, the high insecticidal activity strain Bt IMBL-B9, identified in previous research, was subjected to large-scale cultivation using a fermentor. Subsequently, various formulations were developed through formulation processes. and characteristics such as their wettability, suspensibility and particle size were assessed to select the optimized formulation.
        9.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sulforaphane is a naturally occurring active substance found in vegetables that is known for its potential in preventing and treating cancer. This compound has demonstrated promising effects in inhibiting the growth of various types of cancer, including esophageal, lung, colon, breast, and liver cancer. However, its instability towards pH and heat limits its application in the medical and food industries. To address this challenge, novel drug delivery systems have been developed to improve the stability and efficacy of sulforaphane, making it a more suitable candidate for clinical use in cancer research. In this study, nanocomposite materials were prepared using multi-walled carbon nanotubes (MWCNTs) and chitosan (CS) as base materials, with polydopamine (PDA) acting as a bridge material. The synthesized composite materials were used as drug carriers for the release of sulforaphane. The results of the study showed that the drug loading increased with an increase in the concentration of sulforaphane, indicating that the nanocomposite materials were effective in delivering and releasing the drug. Moreover, a positive correlation was observed between the drug loading and the thickness of the PDA layer. These findings suggest that the use of MWCNTs, CS, and PDA in the development of drug delivery systems can enhance the stability and efficacy of sulforaphane, potentially leading to improved cancer treatment outcomes.
        4,000원
        10.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        N-doping content and configurations have a significant effect on the electrochemical performance of carbon anodes. Herein, we proposed a simple method to synthesize highly N self-doped chitosan-derived carbon with controllable N-doping types by introducing 2ZnCO3 ·3Zn(OH)2 into the precursor. The as-synthesized NC-CS/2ZnCO3·3Zn(OH)2 electrode exhibited more than twice the reversible capacity (518 mAh g− 1 after 100 cycles at 200 mA g− 1) compared to the NC-CS electrode, superior rate performance and outstanding cycling stability. The remarkable improvement should be mainly attributed to the increase of N-doping content (particularly the pyrrolic-N content), which provided more active sites and favored Li+ diffusion kinetics. This study develops a cost-effective and facile synthesis route to fabricate high-performance N self-doped carbon with tunable doping sites for rechargeable battery applications.
        4,000원
        11.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fe3O4/g-C3N4/TiO2 catalyst has been fabricated using a simple ultrasonic method with high photocatalytic activity. The morphology, structure and optical properties of Fe3O4/ g-C3N4/TiO2 were systematically investigated by a variety of characterization techniques. The optimum degradation conditions were investigated by degrading tetracycline (TC) under visible light irradiation. The results showed that the degradation efficiency was the highest when the initial TC concentration was 5.0 mg/L, the pH value was 11 and the catalyst dosage was 1.0 g/L. After 100 min of visible light irradiation, the degradation efficiency of TC achieved at 73.61%, which was 1.64 and 1.19 times that of g-C3N4 and Fe3O4/ g-C3N4, respectively. Moreover, Fe3O4/ g-C3N4/TiO2 had good stability and recyclability. The results of capture experiments showed that ‧O2 − and ‧OH were the main active species during the photocatalytic process, and a possible photocatalytic reaction mechanism of Fe3O4/ g-C3N4/TiO2 catalyst was proposed. This study provides a new way to improve the photocatalytic performance of g-C3N4, which has great potential in degrading pollutants such as antibiotics in wastewater.
        4,000원
        12.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        β-Resin was extracted by solvent separation of refined coal tar pitch. Several analytical methods revealed that β-resin had a better aromatic plane packing structure and a higher number of carbon residues, making it ideal for mesophase transformation. The mesophase transformation process of β-resin (the formation of liquid-crystalline spheres, the growth of mesophase spheres, and the coalescence and disintegration of mesophase spheres) was observed in situ using a polarizing microscope with a hot stage. Moreover, the mesophase transformation mechanism of β-resin was investigated at each transformation stage. The mesophase content and mesophase transformation kinetics were analyzed based on the area method and quinoline insoluble (QI) substitution method. Both methods revealed changes in the mesophase content of β-resin. However, the test results of the two methods were slightly different at the initial stage of mesophase transformation and tended to be consistent during the later stage.
        4,500원
        13.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As a promising anode for sodium-ion batteries (SIBs), cobalt sulfide ( CoS2) has attracted extensive attention due to its high theoretical capacity, easy preparation, and superior electrochemical activity. However, its intrinsic low conductivity and large volume expansion result in poor cycling ability. Herein, nitrogen-doped carbon-coated CoS2 nanoparticles (N–C@ CoS2) were prepared by a C3N4 soft-template-assisted method. Carbon coating improves the conductivity and prevents the aggregation of CoS2 nanoparticles. In addition, the C3N4 template provides a porous graphene-like structure as a conductive framework, affording a fast and constant transport path for electrons and void space for buffering the volume change of CoS2 nanoparticles. Benefitting from the superiorities, the Na-storage properties of the N–C@CoS2 electrode are remarkably boosted. The advanced anode delivers a long-term capacity of 376.27 mAh g− 1 at 0.1 A g− 1 after 500 cycles. This method can also apply to preparing other metal sulfide materials for SIBs and provides the relevant experimental basis for the further development of energy storage materials.
        4,000원
        14.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the demand for flexible wearable electronic devices increases, the development of light, thin and flexible high-performance energy-storage devices to power them is a research priority. This review highlights the latest research advances in flexible wearable supercapacitors, covering functional classifications such as stretchability, permeability, self-healing and shapememory capabilities, as well as practical studies on energy harvesting capabilities.
        6,000원
        15.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Phytohormones (plant hormones) are a class of small-molecule organic compounds synthesized de novo in plants. Although phytohormones are present in trace amounts, they play a key role in regulating plant growth and development, and in response to external stresses. Therefore, the analysis and monitoring of phytohormones have become an important research topic in precision agriculture. Among the various detection methods, electrochemical analysis is favored because of its simplicity, rapidity, high sensitivity, and in-situ monitoring. Graphene and graphene-like carbon materials have abundant sources, exhibiting large specific surface area, and excellent physicochemical properties. Thus, they have been widely used in the preparation of electrochemical biosensors for phytohormone detection. In this paper, the research advances of electrochemical sensors based on graphene and graphene-like carbon materials for phytohormone detection have been reviewed. The properties of graphene and graphene-like carbon materials are first introduced. Then, the research advances of electrochemical biosensors (including conventional electrochemical sensors, photoelectrochemical sensors, and electrochemiluminescence sensors) based on graphene and graphene-like carbon materials for phytohormone detection is summarized, with emphasis on their sensing strategies and the roles of graphene and graphene-like carbon materials in them. Finally, the development of electrochemical sensors based on graphene and graphene-like carbon materials for phytohormone detection is prospected.
        4,900원
        16.
        2023.07 구독 인증기관·개인회원 무료
        The present study choose to conduct consumer behavioral research in Metaverse situation, explores factors that influence consumer shopping enjoyment and purchase intention from product, service and technology perceptive. The research team gathered the primary data through questionnaire subjecting to Chinese consumers (n=300) who know about TaoBao future city which themes on virtual buying in Metaverse. In addition, structural equation modeling is employed to examine the hypothesized relationship among the variables. The result shows that all the driving factors positive effects consumer shopping enjoyment and then influence purchase intention positively. The finding is significantly fundamental to establish theoretical framework future about virtual shopping in Metaverse, and help marketers realize how to set virtual stores in Metaverse to enhance consumer shopping experience so that they could improve consumer purchase intention in the context.
        17.
        2023.07 구독 인증기관·개인회원 무료
        Metaverse tourism is blurring the boundaries between the virtual and physical worlds. Among the core technologies in the metaverse world (e.g., Avatar, Virtual reality, Augmented reality, NFTs, etc.), the avatar has the potential power to revolutionise customer experience. Destination management organisation (DMO) can boost customers’ immersion through effective avatar customer journey design (ACJD) in the metaverse world. Yet, there is a lack understanding of how practitioners view an effective ACJD in the metaverse world. This study aims to explore the role of avatars on customer journey design in a metaverse tourism program (e.g., Dunhuang) from practitioners’ perspectives through a qualitative study. This study advances theoretical understanding about metaverse tourism in the tourism literature, and provides important implications for tourism industry on how to design tourist experiences in metaverse tourism.
        18.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        How to effectively deal with the polluted water by the pollutant of organic dyes is the world problem. It is of great significance if the organic dyes in the polluted water can be directly turned into the useful materials through a facile approach. Herein, the water which contains the common organic dye, Reactive red 2 (RR2), has been chosen to be the model to synthesize graphene quantum dots (GQDs) by a facile route. The comprehensive characterizations, including TEM (HRTEM), XPS, Raman, PL and UV–Vis. spectra, have been performed to confirm the structures and explore the properties of the synthesized GQDs. Meanwhile, the excellent PL properties and low biotoxicity of the GQDs confer them with the potential applications in the biological fields. When the GQDs are excited by the wavelength of 360 nm, the maximum emission is achieved at 428 nm. It is well demonstrated that the synthesized GQDs are able to detect the Al3+ which causes multiple diseases, such as Parkinson, Alzheimer, kidney disease, and even cancer. The detection range is from 90 to 800 μM, which is different from the reported kinds of the literature. Therefore, this work not only provides an economical and environmental route on solving the universal problem from organic dyes, but also facilitates to advancing the synthesis and application of GQDs.
        4,000원
        19.
        2022.12 구독 인증기관 무료, 개인회원 유료
        Since the Western Zhou dynasty in China, the word 聖人began to have a special meaning, entered various social fields such as literature and history and medicine, and gradually integrated into Chinese traditional culture. As an important symbol of traditional Chinese medicine culture, 聖人 shows a basic category of the core concept and value system of traditional Chinese medical classics represented by the book of Huangdi Neijing(also named The Inner Canon of Huangdi) in the pre-Qin and Han dynasties. In Huangdi Neijing which is the foundation work of the theoretical system of traditional Chinese medicine, 聖人is not only a man with perfect personality under the traditional Chinese moral and ethical concepts, but also a regimen practitioner and a master of universe laws and the best model of physical and mental health. Based on the traditional Chinese medicine book Huangdi Neijing, this paper uses the knowledge of Chinese philology and traditional Chinese medicine culture to trace the origin meaning of the Chinese word 聖人 from the perspective of genesis, and examines the semantic evolution of 聖人 and its cultural characteristics in the development of the Chinese nation and the Traditional Chinese medicine
        5,700원
        20.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A composite photocatalyst of zinc oxide (ZnO) nanoparticles decorated with different content of reduced graphene oxide (rGO) was prepared via a simple and facile one-step method in this paper. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectra, and UV–Vis diffuse reflection spectroscopy (UV–Vis DRS) were used to characterize the crystal structure, morphology and optical properties of the rGO–ZnO composite photocatalyst. The photocatalytic properties of the composites were investigated using methyl orange (MO), a typical orange compound, as a test pollutant. The results showed that rGO–ZnO composites displayed significantly enhanced photocatalytic activity in MO degradation than pure ZnO, and the pseudo-first-order kinetic constant on the optimal rGO–ZnO composite was 14 times as great as that on pure ZnO. The enhanced photocatalytic ability of the rGO-ZnO composites was mainly benefited from the high specific surface area and high conductivity of rGO, which facilitated efficient charge separation in the rGO-ZnO nanocomposite.
        4,200원
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