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Journal of Energy Chemistry 2023年第8期83卷 229-238,I0007页

作者： Dung Tien Tuan Vu Jinsol Im Jae-Hee Kim Jisoo Han gyeong jun chung Giang Thi Huong Nguyen junhyeok Seo Minjae Kim Eui-Hyung Hwang Young-Gil Kwon Jae Wook Shin Kuk Young Cho Seung-Wan Song Department of Chemical Engineering&Applied Chemistry Chungnam National UniversityDaejeon 34134Republic of Korea Department of Materials Science&Chemical Engineering Hanyang UniversityAnsan 15588Republic of Korea Fine Chem Co.Ltd. Daejeon 34365Republic of Korea d CSIM Co.Ltd. Yesan 32400Republic of Korea Dongwha Electrolyte Nonsan 32925Republic of Korea

Elevating the charge cut-off voltage beyond traditional 4.2 V is a commonly accepted technology to increase the energy density of Li-ion batteries(LIBs) but the risk of Li-dendrites and fire hazard increases as well. The use of ambi-functional additive, which forms stable solid electrolyte interphase(SEI) simultaneously at both cathode and anode, is a key to enabling a dendrites-free and well-working high-voltage LIB. Herein, a novel ambi-functional additive, pentaerythritol disulfate(PEDS), at 1 wt% without any other additive is demonstrated. We show the feasibility and high impacts of PEDS in forming lithium sulfateincorporated robust SEI layers at NCM523 cathode and graphite anode in 1 Ah-level pouch cell under4.4 V, 25 °C and 0.1 C rate, which mitigates the high-voltage instability, metal-dissolution and cracks on NCM523 particles, and prevents Li-dendrites at graphite anode. Improved capacity retention of 83%after 300 cycles is thereby achieved, with respect to 69% with base electrolyte, offering a promising path toward the design of practical high-energy LIBs.

关键词： Lithium-ion pouch cell Lithium plating-free High-voltage Ambi-functional additive SEI layer

Historical Changes and Characteristics of Rehabilitation,Management and Utilization of Forest Resources in South Korea

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Journal of Mountain Science 2005年第2期2卷 164-172页

作者： Eui-gyeong KIM Dong-jun KIM Division of Forest Science Gyeongsang National UniversityChinju 660-701KoreaSchool of Forest ResourcesChungbuk National UniversityCheongju 361-763Korea

This study analyzed the causes of forest devastation,the characteristics of forest rehabilitation process,and the success factors of reforestation. And it reviewed the management of rehabilitated forest resources and identified the income sources of mountain villages in South Korea. The devastation of forest starting from the early twentieth century was continued to the 1950’s. The main causes of deforestation were the illegal cutting of trees for fuel and the slash-and-burning agriculture in forest. The success factors of reforestation were the decrease in the dependence on forest of fuel source,strict administration system and national participation. Sustainable forest management could be made possible through the practical use of social issues like public work project for prevention of landslide damages caused by the thinned logs left in the forest. Also it could be possible by making people realize that the public benefit was obtained from forest and the income sources of mountain villages were supplemented by non-timber forest products and tourism. Food and Agriculture Organization indicated Korea as the country that forestation was succeeded in a very short period. Korea seems to be not ordinary because economic growth was accomplished with rehabilitating natural environment. Korean forestation can become a good prototype of combining environmental rehabilitation and economic development.

关键词： Forestation forest management forest utilization South Korea

Homogenization with the Quasistatic Tresca Friction Law:Qualitative and Quantitative Results

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Chinese Annals of Mathematics,Series B 2023年第5期44卷 781-802页

作者： Changqing YE Eric T.chung jun-zhi CUI Department of Mathematics the Chinese University of Hong KongShatinHong Kong SARChina LSEC Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

Modeling of frictional contacts is crucial for investigating mechanical performances of composite materials under varying service *** paper considers a linear elasticity system with strongly heterogeneous coefficients and quasistatic Tresca friction law,and studies the homogenization theories under the frameworks of H-convergence and small ε-*** qualitative result is based on H-convergence,which shows the original oscillating solutions will converge weakly to the homogenized solution,while the author’s quantitative result provides an estimate of asymptotic errors in H^(1)-norm for the periodic *** paper also designs several numerical experiments to validate the convergence rates in the quantitative analysis.

关键词： Homogenization Frictional contact mechanics Quasistatic Tresca frictionlaw

Sustainable Furfural Biomass Feedstocks Electrooxidation toward Value-Added Furoic Acid with Energy-Saving H_(2) Fuel Production Using Pt-Decorated Co_(3)O_(4) Nanospheres

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Energy & Environmental Materials 2024年第2期7卷 350-358页

作者： Talshyn Begildayeνa Jayaraman Theerthagiri Seung jun Lee Ahreum Min gyeong-Ah Kim Siνakumar Manickam Myong Yong Choi Department of Chemistry(BK21 FOUR) Core-Facility Center for Photochemistry&NanomaterialsResearch Institute of Natural SciencesGyeongsang National UniversityJinju 52828South Korea Petroleum and Chemical Engineering Faculty of EngineeringUniversiti Teknologi BruneiJalan Tungku Link GadongBandar Seri Begawan BE1410Brunei Darussalam

Here,furfural oxidation was performed to replace the kinetically sluggish O_(2)evolution reaction(OER).Pt-Co_(3)O_(4)nanospheres were developed via pulsed laser ablation in liquid(PLAL)in a single step for the paired electrocatalysis of an H_(2)evolution reaction(HER)and furfural oxidation reaction(FOR).The FOR afforded a high furfural conversion(44.2%)with a major product of 2-furoic acid after a 2-h electrolysis at 1.55 V versus reversible hydrogen electrode in a 1.0-M KOH/50-mM furfural *** Pt-Co_(3)O_(4)electrode exhibited a small overpotential of 290 mV at 10 mA cm^(-2).As an anode and cathode in an electrolyzer system,the Pt-Co_(3)O_(4)electrocatalyst required only a small applied cell voltage of~1.83 V to deliver 10 mA cm^(-2),compared with that of the pure water electrolyzer(OER||HER,~1.99 V).This study simultaneously realized the integrated production of energy-saving H_(2)fuel at the cathode and 2-furoic acid at the anode.

关键词： biomass conversion electrochemical furfural oxidation overall water splitting Pt-Co_(3)O_(4)electrocatalyst pulsed laser ablation in liquid

Analytic Feynman Integrals of Functionals in a Banach Algebra Involving the First Variation

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Chinese Annals of Mathematics,Series B 2016年第2期37卷 281-290页

作者： Hyun Soo chung Vu Kim TUAN Seung jun CHANG Department of Mathematics Dankook University Department of Mathematics University of West Georgia

This paper deals with the analytic Feynman integral of functionals on a Wiener space. First the authors establish the existence of the analytic Feynman integrals of functionals in a Banach algebra S_α. The authors then obtain a formula for the first variation of integrals. Finally, various analytic Feynman integration formulas involving the first variation are established.

关键词： Analytic Feynman integral Banach algebra First variation Cameron-Storvick theorem Wiener space

Rapid Synthesis of Piezoelectric ZnO-Nanostructures for Micro Power-Generators

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Journal of Materials Science & Technology 2013年第10期29卷 893-897页

作者： Nai-Feng Hsu Tien-Kan chung Ming Chang Hong-jun Chen Department of General Education Army Academy Department of Mechanical Engineering National Chiao Tung University Department of Mechanical Engineering Chung Yuan Christian University State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology

In this paper, we report a rapid synthesis of piezoelectric ZnO-nanostructures and fabrication of the nanostructures- based power-generators demonstrating an energy conversion from an environmental mechanical/ultrasonic energy to an electrical energy. The ZnO nanostructures are grown on a silicon wafer by a modified chemical solution method （CSD, chemical-solution-deposition） with a two-step thermal-oxidation approach. The synthesis process can be completed within 1 h. By varying the mixture-ratio of Zn micro-particles in an oxalic acid solution with 0.75 mol/l concentration in the CSD process, the growth mechanism is well-controlled to synthesize three different types of ZnO-nanostructures （i.e., dandelion-like nanostructures, columnar nanostructures, and nanowires）. Furthermore, through oxidizing at different temperatures in the thermal-oxidation process, the featured geometry of the nanostructures （e.g., the length and diameter of a nanowire） is modified. The geometry, size, morphology, crystallization, and material phase of the modified nanostructures are characterized by scanning electron microscopy and X-ray diffraction. Finally, the nanostructures are used to fabricate several micro power-generators. Through the piezoelectric effect, a maximum current density output of 0.28 μA cm-2 generated by a power-generator under an ultrasonic wave is observed.

关键词： Piezoelectric ZnO nanostructures Chemical solution method Thermal-oxidation Power-generator

UV-assisted flash light welding process to fabricate silver nanowire/graphene on a PET substrate for transparent electrodes

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Nano Research 2018年第4期11卷 2190-2203页

作者： Wan-Ho chung Sung-Hyeon Park Sung-jun Joo Hak-Sung Kim Department of Mechanical Engineering Hanyang University 17 Haendang-Dong Seongdong-Gu Seoul 133-791 Republic of Korea Institute of Nano Science and Technology Hanyang University Seou1133-791 Republic of Korea

Graphene oxide and silver nanowires were bar coated onto polyethylene terephthalate （PET） substrates and then welded using an ultraviolet （UV）-assisted flash light irradiation process to achieve both high electrical conductivity and low haze. The irradiation process connected adjacent silver nanowires by welding, while simultaneously reducing the graphene oxide to graphene. This process was performed using a custom W-assisted flash light welding system at room temperature under ambient conditions and was extremely rapid, with processing time of several milliseconds. The effects of varying the weight fractions of the silver nanowires and graphene oxide and of varying the W-assisted flash light welding conditions （light energy and pulse duration） were investigated. The surface morphologies of the welded silver nanowire/graphene films were analyzed using scanning electron microscopy. Optical characterizations, including transmittance and haze measurements, were also conducted using a spectrophotometer. To test their resistance to oxidation, the welded silver nanowire/graphene films were subjected to high temperature in a furnace （100 ℃）, and their sheet resistances were measured every hour. The flash light welding process was found to yield silver nanowire/graphene films with high oxidation resistance, high conductivity （14.35 Ω·sq-1）, high transmittance （93.46%）, and low haze （0.9%）. This material showed uniform temperature distribution when applied as a resistive heating film.

关键词： silver nanowires graphene oxide transparent electrode flash light welding printed electronics

Manifolding active sites and in situ/operando electrochemical-Raman spectroscopic studies of single-metal nanoparticle-decorated CuO nanorods in furfural biomass valorization to H_(2) and 2-furoic acid

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Journal of Energy Chemistry 2023年第9期84卷 50-61页

作者： Jiwon Kim Talshyn Begildayeva Jayaraman Theerthagiri Cheol Joo Moon Ahreum Min Seung jun Lee gyeong-Ah Kim Myong Yong Choi Department of Chemistry(BK21 FOUR) Research Institute of Natural SciencesGyeongsang National UniversityJinju 52828Republic of Korea Core-Facility Center for Photochemistry&Nanomaterials Gyeongsang National UniversityJinju 52828Republic of Korea Department of IT-Energy Convergence(BK21 FOUR) Korea National University of TransportationChungju 27469Republic of Korea

Here,CuO nanorods fabricated via pulsed laser ablation in liquids were decorated with Ir,Pd,and Ru NPs(loading~7 wt%) through pulsed laser irradiation in the liquids *** resulting NPs-decorated CuO nanorods were characterized spectroscopically and employed as multifunctional electrocatalysts in OER,HER,and the furfural oxidation reactions(FOR).Ir-CuO nanorods afford the lowest overpotential of~345 mV(HER) and 414 mV(OER) at 10 mA cm^(-2),provide the highest 2-furoic acid yield(~10.85 mM) with 64.9% selectivity,and the best Faradaic efficiency~72.7% in 2 h of FOR at 1.58 V(***).In situ electrochemical-Raman analysis of the Ir-CuO detects the formation of the crucial intermediates,such as Cu(Ⅲ)-oxide,Cu(OH)_(2),and Ir_x(OH)_y,on the electrode-electrolyte surface,which act as a promoter for HER and *** Ir-CuO ‖ Ir-CuO in a coupled HER and FOR-electrolyzer operates at~200 mV lower voltage,compared with the conventional electrolyzer and embodies the dual advantage of energy-saving H_(2) and 2-furoic acid production.

关键词： Single-metal nanoparticle-decorated CuO nanorods Pulsed laser ablation and irradiation in liquids Furfural oxidation reaction Hydrogen evolution reaction Energy-saving H_(2)production 2-Furoic acid

Observational constraints on running vacuum model

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Chinese Physics C 2019年第2期43卷 132-137页

作者： Jin-jun Zhang chung-Chi Lee Chao-Qiang Geng School of Physics and Information Engineering Shanxi Normal University DAMTP Centre for Mathematical Sciences University of Cambridge Department of Physics National Tsing Hua University National Center for Theoretical Sciences

We investigate the power spectra of the CMB temperature and matter density in the running vacuum model(RVM) with the time-dependent cosmological constant of A=3 vH^2+ Λ_0, where H is the Hubble parameter. In this model, dark energy decreases in time and decays to both matter and radiation. By using the Markov chain Monte Carlo method, we constrain the model parameter v as well as the cosmological observables. Explicitly, we obtain v ≤1.54× 10^(-4)(68% confidence level) in the RVM with the best-fit χ_(RVM)~2 =13968.8, which is slightly smaller thanχ_(ΛCDM)~2= 13969.8 in the ΛCDM model of v = 0.

关键词： matter power spectrum running vacuum model CMB temperature spectrum cosmological constant

Clinical applications of next-generation sequencing in colorectal cancers

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World Journal of Gastroenterology 2013年第40期19卷 6784-6793页

作者： Tae-Min Kim Sug-Hyung Lee Yeun-jun chung MRC Cancer Evolution Research Center College of MedicineThe Catholic University of KoreaSeoul 137-701South Korea Integrated Research Center for Genome Polymorphism Department of MicrobiologyCollege of MedicineThe Catholic University of KoreaSeoul 137-701South Korea Department of Pathology College of MedicineThe Catholic University of KoreaSeoul 137-701South Korea

Like other solid tumors,colorectal cancer(CRC) is a genomic disorder in which various types of genomic alterations,such as point mutations,genomic rearrangements,gene fusions,or chromosomal copy number alterations,can contribute to the initiation and progression of the disease. The advent of a new DNA sequencing technology known as next-generation sequencing(NGS) has revolutionized the speed and throughput of cataloguing such cancer-related genomic alterations. Now the challenge is how to exploit this advanced technology to better understand the underlying molecular mechanism of colorectal carcinogenesis and to identify clinically relevant genetic biomarkers for diagnosis and personalized therapeutics. In this review,we will introduce NGS-based cancer genomics studies focusing on those of CRC,including a recent large-scale report from the Cancer Genome Atlas. We will mainly discuss how NGS-based exome-,whole genome- and methylome-sequencing have extended our understanding of colorectal carcinogenesis. We will also introduce the unique genomic features of CRC discovered by NGS technologies,such as the relationship with bacterial pathogens and the massive genomic rearrangements of chromothripsis. Finally,we will discuss the necessary steps prior to development of a clinical application of NGS-related findings for the advanced management of patients with CRC.

关键词： Next-generation sequencing Cancer genomics Colorectal cancers Personalized medicine The cancer genome atlas