검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 13

        1.
        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
        2.
        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
        3.
        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
        4.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Molybdenum disulfide ( MoS2) has been one of the most promising members of transition-metal dichalcogenides materials. Attributed to the excellent electrical performance and special physical properties, MoS2 has been broadly applied in semiconductor devices, such as field effect transistors (FETs). At present, the exploration of further improving the performance of MoS2- based FETs (such as increasing the carrier mobility and scaling) has encountered a bottleneck, and the application of high-κ gate dielectrics has become an effective approach to change this situation. Atomic layer deposition (ALD) enables high-quality integration of MoS2 and high-κ gate dielectrics at the atomic level. In this review, we summarize recent advances in the fabrication of two-dimensional MoS2 FETs using ALD high-κ materials as gate dielectrics. We first briefly discuss the research background of MoS2 FETs. Second, we expound the electrical and other essential properties of high-κ gate dielectrics, which are essential to the performance of MoS2 FETs. Finally, we focus on the advances in fabricating MoS2 FETs with ALD high-κ gate dielectrics on MoS2, as well as the optimized ALD processes. In addition, we also look forward to the development prospect of this field.
        5,200원
        5.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The hybridization of graphene with magnetic nanoparticles has endowed graphene with increasing interest as the adsorbent for wastewater treatment. However, its fabrication often involves a multi-stepped chemical synthesis process. In this work, we demonstrate a facile, one-step, and solvent-free approach to fabricate Fe3O4 nanoparticle-anchored Laser-Induced Graphene ( Fe3O4@LIG) as an efficient adsorbent by direct laser irradiation on a ferric acetylacetonate containing polybenzoxazine film. Raman and X-ray diffraction analysis confirm the graphene component in the adsorbent, and the morphology characterizations show that Fe3O4 nanoparticles are distributed uniformly on LIG with hierarchical meso- and macro-porous structures. Adsorption experiments indicate that Fe3O4@ LIG can adsorb methylene blue (MB) from aqueous solutions in a fast and effective manner, with a maximum adsorption capacity up to 350.9 mg/g. The adsorption kinetics and isotherms are also investigated, which are well-described by the pseudo-second-order model and Langmuir model, respectively. Additionally, Fe3O4@ LIG is also demonstrated with the efficient removal of a variety of organic solvents from water. The favorable adsorption behavior of Fe3O4@ LIG is attributed to its unique porous structure and the molecular interactions with adsorbates. On the other hand, Fe3O4@ LIG has high magnetic property, and therefore, it could be easily recovered from water and well regenerated for repeated use. With the efficient adsorption of organic pollutants, magnetic separability, and good
        5,200원
        6.
        2022.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A porous-carbon material UiO-66-C was prepared from metal–organic frameworks UiO-66 by carbonization in inert gas atmosphere. Physicochemical properties of UiO-66-C materials were well characterized by Powder X-ray diffraction (PXRD), Scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FT-IR), Raman spectrometer, N2 adsorption/ desorption isotherms (BET), and the adsorption properties of the products were studied UiO-66-C has a high specific surface area up to 1974.17 m2/ g. Besides, the adsorption capacity of tetracycline could reach 678.19 mg/g, the adsorption processes agreed well with the pseudo-second-order kinetic model and Langmuir isotherm model.
        4,000원
        8.
        2020.11 구독 인증기관 무료, 개인회원 유료
        Product labels are one way for advertisers to provide information to purchasers on product quality (Atkinson & Rosenthal, 2014). Label policies have been issued to promote information disclosure on food products in some developed countries. Recent years have also seen increasing attempts to promote healthy eating in emerging markets. In China, nutrition labels became mandatory under the nutrition labeling acts. The laws require nutrition information to be presented at the point of purchase as well as in establishments where food is prepared or consumed. Additionally, similar actions were taken by India (India Ministry of Health and Family Welfare, 2011), Mercosur members and in South Africa (Brazilian Ministry of Health, 2012; Institute of Food Technologists [IFT], 2011).
        3,000원
        9.
        2018.07 구독 인증기관 무료, 개인회원 유료
        Product labels are one way for advertisers to provide information to purchasers on product quality (Atkinson & Rosenthal, 2014). Label policies have been issued to promote information disclosure on food products in some developed countries. Recent years have also seen increasing attempts to promote healthy eating in emerging markets. In China, nutrition labels became mandatory under the nutrition labeling acts. The laws require nutrition information to be presented at the point of purchase as well as in establishments where food is prepared or consumed. Additionally, similar actions were taken by India (India Ministry of Health and Family Welfare, 2011), Mercosur members and in South Africa (Brazilian Ministry of Health, 2012; Institute of Food Technologists [IFT], 2011). While nutritional labeling has received a lot of attention both in academia and from the press, some key gaps remain in the nutrition labeling literature. First, a great deal of marketing research has focused on consumer responses (e.g., Balasubramanian & Cole, 2002; Hieke & Taylor, 2012; Ippolito & Mathios, 1995; Parker & Lehmann, 2014; Shah, Bettman, Ubel, Keller, & Edell, 2014) and firm responses (e.g., Moorman 1998; Moorman, Du, & Mela, 2005; Moorman, Ferraro, & Huber, 2012) to nutrition labeling laws. Although stock market investors express greater interest in information about nutrition issues that can be integrated into financial analyses (Global Access to Nutrition Index [ATNI] Investor Statement, 2013), the issue of how standardized information requirements affect investors’ responses in financial markets has been understudied. As used here, standardized product-information disclosure refers to a requirement to present facts about firms’ offerings in a common format using uniform metrics (Moorman et al. 2012). Understanding the extent to which investors consider product information-disclosure polices when they make investment decisions is important because a company’s financial health is not only the ultimate measure for the success or failure of any strategic initiative (Luo & Bhattacharya, 2009), but also one of the most important measures of public policy effectiveness (Joshi & Hanssens, 2010; Srinivasan & Hanssens, 2009; Schwert, 1981). Moreover, urgent concerns have spilled over from the product market to the financial market (Chen, Ganesan, & Liu, 2009) due to the enormous economic costs and damage to firms’ reputations in product-harm crises (e. g., melamine contamination in several Chinese brands of infant milk powder) (Ngo, 2014). Another gap in the literature is how nutritional-labeling requirements affect emerging markets. In contrast to the situation in long-developed countries, emerging markets are subject to different pressures for food marketers and thus a distinctive environment surrounds the regulation of food product labeling. In China, food safety and quality is considered an urgent concern, and the issue has forced regulators and companies to take action (Yan, 2008). Unlike mature stock markets, the majority of investors in China are individuals (Chen, Li, & Shi, 2010). The Chinese markets are under-regulated and deficient in gathering and disseminating information to private or public organizations, and it is difficult for listed firms with insufficient records to form reputations (Singh et al., 2005). As a result, information asymmetry is accentuated and imperfect signals released from firms highly impact investor decisions. Thus, examining the effectiveness of labeling requirements in developing economies is important as is comparing these results to those found in more developed countries. Despite the importance of the issue in emerging markets, empirical work for investigating investor response to the public policy of nutrition labeling (Ghani, & Childs, 1999) or firms’ nutrition claim strategies (Cao & Yan, 2016) has been restricted in developed markets (e.g., the U.S.). Little is understood the changes in corporate financial performance because of regulations requiring product information disclosure in emerging markets. As a result of the pressures for consumer protection and regulation, it is increasingly important for policy makers to be able to understand the financial consequences of such regulation because of information disclosure policies (Moorman et al., 2005). Thus, an additional contribution of this study is to help better inform the policy debate in emerging markets. To fill these research gaps, we investigated the influence of the influx of standardized product information on the stock market. Specifically, we conducted an event study to examine the effect on firms’ stock values from the issuance of the food nutrition label acts (FNLAs) in China, a fast-growing emerging market. The acts require food manufacturers to provide standardized nutritional information on pre-packaged food labels. This study contributes to the marketing literature on the financial impact of regulation in emerging markets. In China, on the day the FNLA was issued, they were associated with positive abnormal stock returns of related firms. This result is contrary to the study by Ghani and Childs (1999) that reported that the NLEA passage showed a negative impact on firms’ stock prices. Second, the financial value from the issuance of regulations was strengthened by three marketing leverages—advertising, donations, and R&D. Finally, although Moorman et al. argued that the NLEA increased the number of small-share firms exiting the U.S. market (Moorman et al., 2005), we found that in the short term, large firms benefited less than small firms from product information disclosure in China’s stock market. These findings provide empirical evidence that regulatory controls create changes in shareholder wealth and provide an assessment of the financial market’s perceptions regarding the role of mandatory product- information disclosure in future corporate growth. In addition, evidence of the effects of regulatory changes on wealth is of significant value to policymakers and market participants as they evaluate the benefits and costs of information disclosure in emerging markets.
        3,000원
        10.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The wind field and precipitable water vapor over the Tibetan Plateau are analyzed using the numerical model WRF. The spatial and vertical distributions of the relevant meteorological factors are summarized, providing evidence for selecting and further evaluating an astronomical site. This study serves as a further demonstration towards astro-climate regionalization, and provides us with an essential database for an astronomical site survey over the Tibetan Plateau.
        3,000원
        11.
        2011.05 구독 인증기관·개인회원 무료
        The genomic structure and phylogenetic relationships of HSP88 genes from P. tenuipes Jocheon-1, P. tenuipes, C. militaris and C. pruinosa are described. The HSP88 genomic DNA from P. tenuipes Jocheon-1, P. tenuipes and C. militaris all contain 5 introns and 6 exons with the length of 13, 62, 32, 1438, 306, 288 bp, encoding 713 amino acid residues. C. pruinosa HSP88 genomic DNA contains 4 introns and 5 exons encoding 713 amino acids. The length of each exon of C. pruinosa HSP88 is 13, 62, 32, 1744, 288 bp and the length of exon 4 is identical to the total length of exon 4 and exon 5 of HSP88 of P. tenuipes Jochoen-1, P. tenuipes, and C. militaris. The deduced amino acid sequence of P. tenuipes Jocheon-1 HSP88 showed 99% identity with the P. tenuipes, 97% identity with the Cordyceps militaris, and 98% identity with the C. pruinosa. Phylogenetic analysis confirmed that the P. tenuipes Jocheon-1, P. tenuipes, C. militaris and C. pruinosa HSP88 are placed together within the ascomycetes group of fungal clade.
        12.
        2011.05 구독 인증기관·개인회원 무료
        In this study, a full-length heat shock protein88 complementary DNA (cDNA) of Paecilomyces tenuipes Jocheon-1 was obtained by screening of P. tenuipesJocheon-1 Uni-Zap cDNA library and 5' RACE polymerase chain reaction. The Paecilomyces tenuipes Jocheon-1 heat shock protein88 cDNA contains an open reading frame of 2,139 bp encoding 713 amino acid residues. The deduced amino acid sequence of the P. tenuipes Jocheon-1 HSP88 cDNA showed 77% identity to N. haematococca HSP88 and 45-76% identity to other fungi HSP88. Phylogenetic analysis and BLAST program analysis confirmed that the deduced amino acid sequences of the P. tenuipes Jocheon-1 HSP88 gene belonged to the ascomycetes group within the fungal clade and P. tenuipes Jocheon-1 HSP88 also contains the conserved ATPase domain at the N-terminal. The cDNA encoding P. tenuipes Jocheon-1 HSP88 was expressed as a 88 kDa polypeptide in baculovirus-infected insect Sf9 cells. Under different stress conditions, mRNA expression of P. tenuipes Jocheon-1 HSP88 were quantified by real-time PCR and the result showed that heat shock stress affected the mRNA expression levels of P. tenuipes Jocheon-1 HSP88.
        13.
        2009.08 구독 인증기관·개인회원 무료
        The cultivation of oat in China could be traced back to 2500 B.C. while the Qinghai province, which located in the North-East of the Qinghai-Tibetan Plateau, has been the major region for oat production due to its high quality caused by the unique climate say long sun-shine hours and large temperature discrepancy between days and nights that is beneficial to the accumulation of nutrients in oat plant. Oat has been grown in the Qinghai alpine region on the altitude ranging from 1600m to 3600m and regarded as an ideal forage plant due to its resistance to environment. The role of oat drew more attention in 1980s along with the implementing of so called four-matched policy, which compounds establishment of fenced rangeland, animal bars, fodder production base and settled living place for local herdsmen who used to be nomadic around the region. To make a full use of the oat resource in Qinghai province, a great deal research and extension with respect of oat had been engaged in the region. The author overviewed researches accomplished in Qinghai province on oat germplasm collection, breeding of fine oat variety, cultivate techniques, oat base establishment and production and marketing system establishment as well in terms of projects completed.