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Journal of Rare Earths 2016年第1期34卷 45-54页

作者： Younes HANIFEHPOUR Nazanin HAMNABARD Bamin KHOMAMI Sang Woo JOO Bong-Ki MIN jae hak jung School of Mechanical Engineering Yeungnam University Department of Chemical and Biomolecular Engineering University of Tennessee Center for Research Facilities Yeungnam University School of Chemical Engineering Yeungnam University

Novel high-efficiency visible-light-sensitive Nd-doped CdTe nanoparticles were prepared with various doping concentra- tions of neodymium ion by a facile hydrothermal method. The reaction products were analyzed via X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, photoelectron spectroscopy （XPS）, and UV-Vis diffuse re- flectance spectroscopy techniques. Red shift was seen in the absorption band edge peak in the UV-Vis absorbance specmun with in- creasing Nd content. The XRD and XPS results confirmed that Nd ions successfully replaced Cd atoms and were incorporated into the crystal lattice of CdTe. SEM and TEM images indicated spherical structure and high crystallinity. Even at a very low Nd/CdTe molar ratio of 2 mol.%, Nd doping could greatly enhance the photocatalytic activity of CdTe. The photocatalytic activity of Nd-doped CdTe nanoparticles was evaluated by monitoring the decolorization of RRed 43 in aqueous solution under visible-light irradiation. The color removal efficiency of Nd0.08Cd0.9eYe and pure CdTe were 83.14% and 14.32% after 100 min of treatment, respectively. Among different amounts of the doping agent, 8 tool.% Nd indicated the highest decolorization. The presence of radical scavengers such as CF, CO3-, SO4〉, and huthanol was found to reduce the decolorization efficiency.

关键词： neodymium cadmium telluride hydrothermal photocatalyst rare earths

Ni, Co-double hydroxide wire structures with controllable voids for electrodes of energy-storage devices

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Journal of Materials Science & Technology 2020年第20期52卷 126-135页

作者： Jin Kyu Kim Chang Soo Lee jae Hun Lee jung Tae Park Jong hak Kim Department of Chemical and Biomolecular Engineering Yonsei University50 Yonsei-roSeodaemun-guSeoul 03722Republic of Korea Department of Chemical Engineering Konkuk University120 Neungdong-roGwangjin-guSeoul 05029Republic of Korea

We re port the facile synthesis of Ni,Co-double hydroxide wire(NCHW)-based electrodes directly grown on a conductive substrate via a hydrothermal *** NCHW nanostructures were grown on Ni foam,and the growth was controlled using different compositions of solvents(ethanol and water).With increasing volume ratio of ethanol to water,the density of the wires decreased,and the spatial voids between the wires *** formation of large empty spaces improved the electrochemical performance because the exposure of a large surface area of the structure to the electrolyte resulted in a large number of active sites and facile electrolyte penetration into the *** different NCHW structures were ascribed to the pivotal role of the solvent in the urea hydrolysis;the solvent triggered the formation of hydroxides during the hydrothermal *** electrochemical performance of the NCHW electrodes was investigated via galvanostatic charge/discha rge tests,cyclic voltammetry,and electrochemical impedance *** highest specific capacitance was 1694.7 m F/cm^2 at 2 mA/cm^2,with excellent capacitance retention of 81.5% after 5000 *** superior electrochemical performance of the NCHW electrodes is attributed to the large number of active sites and facile electrolyte diffusion into the structure,due to the well-organized structure with an optimized density of nanowires and large voids between the wires.

关键词： Ni,Co-double hydroxide Nanowire Electrode Energy-storage device Supercapacitor

The optimal timing of post-prostate biopsy magnetic resonance imaging to guide nerve-sparing surgery

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Asian Journal of Andrology 2014年第2期16卷 280-284,I0010页

作者： Young Hwii Ko Phil Hyun Song Ki hak Moon Hee Chang jung Jun Cheon Deuk jae Sung Department of Urology Yeuflgnam University School of Medicine Daegu Korea Department of Urology Korea University School of Medicine Seoul Korea Department of Radiology Korea University School of Medicine Seoul Korea

The goal of our study was to evaluate the impact of the interval between prostate biopsy and magnetic resonance imaging （MRI） on the accuracy of simple tumor localization, which is essential information that enables nerve-sparing surgery. We also sought to determine the optimal timing of a post-biopsy MRI, A total of 184 patients who had undergone MRI before radical prostatectomy at an institution without a predetermined schedule for MRI after a prostate biopsy were enrolled. The mean interval from the biopsy to the MRI was 30.8 ± 18.6days. The accuracy of the MRI for simplified tumor location （right, left, bilateral and none） was 44.6%. In the group with discordant pathologic and MRI findings, the most common reason recorded was ＇MRI predicted a unilateral lesion, but pathology revealed bilateral lesions＇（58.3%）, followed by ＇MRI predicted no lesion, but pathology revealed the presence of a lesion＇（32.0%）. Multivariable analysis showed that the discordant group had a shorter interval （25.0 ± 14.3 vs 38.1 ± 20.6days, P 〈 0.01） preceding the MRI and a higher rate of hemorrhage as observed by MRI （80.4% vs 54.8%, P 〈 0.01） in comparison with the accordant group. In receiver operating characteristics analysis, the area under the curve of the MRI interval in accurate prediction of the tumor location was 0.707 （P 〈 0.001）. At the MRI interval＇s cutoff of 28.5days, the sensitivity was 73.2% and the specificity was 63.7%. When the MRI was performed within 28days, the accumulated accuracy was only 26.1% （23/88）; however, when it was performed after 28days, the reversely accumulated accuracy was 61.5% （59/96）. These data support a waiting period of at least 4weeks after a biopsy before performing an MRI for the purposes of surgical refinement.

关键词： magnetic resonance imaging nerve preservation prostate biopsy radical prostatectomy

Text-mining analysis using national R&D project data of South Korea to investigate innovation in graphene environment technology

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International Journal of Innovation Studies 2023年第1期7卷 87-99页

作者： Ji Yeon Lee jung Woo Choi jae-hak Choi Byeong-Hee Lee NTIS Center Korea Institute of Science and Technology InformationDaejeon34141South Korea Department of Science and Technology Management Policy University of Science and TechnologyDaejeon34113South Korea Department of Polymer Science and Engineering Chungnam National UniversityDaejeon34134South Korea

This study investigates the possibilities offered by the development of graphene environment technology that can contribute to new and effective approaches for the transition to an ecologically benign *** analyze the research and development progress in graphene environment technology,graphene environment technology research trends of South Korea for the years 2009e2020 are investigated by acquiring information pertaining to national research and development projects related to graphene environment technology from the National Science and Technology Information *** structured and unstructured data are analyzed using diverse text-mining methods,such as keyword frequency analysis,association rule mining,and topic *** results indicate that graphene research in South Korea is focused primarily on graphene use in batteries and energy-storage devices,such as solar cells,fuel cells,and secondary *** study can help understand the manner by which the South Korean government has been investing in the research and development of graphene environment technology;additionally,it discusses the future applications and prospects of graphene for the next decade.

关键词： Graphene technology Environmental transition National R&D project information Text mining Trend analysis

Prediction of Nitrogen Diffusivity in α-ferrite Based on Thermodynamics

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Journal of Iron and Steel Research International 2015年第8期22卷 743-745页

作者： jae-gil jung Seok-jae LEE Light Metal Division Korea Institute of Materials Science Division of Advanced Materials Engineering Research Center for Advanced Materials Development Chonbuk National University

A thermodynamic based equation to predict the diffusivity of nitrogen in α-ferrite was investigated in consideration of the equilibrium nitrogen concentration. The temperature-dependent jump distance calculated from the lattice parameter of ferrite was used to derive the frequency factor as a function of temperature. The calculation accuracy for nitrogen diffusivity using the proposed thermodynamic based equation was improved by comparing the calculation results using previous empirical equations based on Arrhenius type relationship with measured diffusivity of nitrogen for α-ferrite at different temperatures.

关键词： nitrogen diffusivity ct-ferrite thermodynamics prediction

Reduced interface energy loss in non-fullerene organic solar cells using room temperature-synthesized SnO2 quantum dots

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Journal of Materials Science & Technology 2020年第17期52卷 12-19页

作者： In Su Jin Minwoo Park jae Woong jung Department of Advanced Materials Engineering for Information&Electronics Kyung Hee University1732 Deogyeong-daeroGiheung-guYongin-siGyeonggi-do 446-701Republic of Korea Department of Chemical and Biological Engineering Sookmyung Women's UniversitySeoul 04310Republic of Korea

We herein report the room temperature synthesis of colloidal SnO2 quantum dots and their application in non-fullerene organic solar cells as an excellent electron transport *** thiourea-assisted hydrolysis at room temperature affords the nanocrystalline SnO2 quantum dots with a diameter of 3-4 *** utilization of the SnO2 quantum dots as an electron transporting layer effectively reduces the interfacial trap density and charge recombination in the solar cell devices,leading to not only the reduced energy loss but also excellent photocurrent *** optimized organic solar cells employing SnO2 quantum dots with polyethylenimine ethoxylated achieves power conversion efficiencies up to 12.023%with a VOC,a JSC,and a FF of 0.89 V,18.89 mA cm^–2,and *** work suggest that the SnO2 quantum dot is a promising electron transporting material to construct efficient organic solar cells for practical *** work also demonstrates the key strategy for thiourea-assisted hydrolysis to synthesize fine and nanocrystalline SnO2 quantum dots.

关键词： Energy loss Organic solar cells Interface SnO2 Quantum dots

Simultaneously enhanced efficiency and ambient stability of inorganic perovskite solar cells by employing tetramethylammonium chloride additive in CsPbI2Br

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Journal of Materials Science & Technology 2022年第7期102卷 224-231页

作者： In Su Jin Bhaskar Parida jae Woong jung Department of Advanced Materials Engineering for Information and Electronics Kyung Hee University1732 Deogyeong-daeroGiheung-guYongin-siGyeonggi-do 446-701Republic of Korea Integrated Education Institute for Frontier Materials(BK21 Four) Kyung Hee University1732 Deogyeong-daeroGiheung-guYongin-siGyeonggi-do 446-701Republic of Korea

Although all-inorganic perovskites possess suitable bandgap and thermal stability for photovoltaic ap-plications,the unstable film morphologies,and poor moisture stabilities lag behind the organic-inorganic hybrid ***,we demonstrate that high qualityα-CsPbI_(2 ) Br films with improved phase sta-bility,high crystallinity,and pinhole-free film morphology was achieved by employing tetramethylammo-nium chloride(TMACl)as an *** a result,the TMACl-added CsPbI_(2) Br films exhibited high power conversion efficiency of 14.12%with an open-circuit voltage of 1.19 V,a short-circuit current density of 15.08 mA/cm^(2),and a fill factor of *** importantly,the TMACl addition imparts hydrophobicity to the film surface of CsPbI_(2) Br,which delivered excellent stability up to 30 days in the ambient condition and thermal stability at 85℃ for 156 h,***,the TMACl-added device also exhibited excellent PCE of 27.16%under indoor light source(1000 lux),which presents a promising approach for designing stable but high performance all-inorganic perovskite solar cells.

关键词： Inorganic perovskite solar cells CsPbI2Br Additive Tetramethylammonium chloride Efficiency

Early experience of the compression anastomosis ring (CAR^(TM) 27) in left-sided colon resection

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World Journal of Gastroenterology 2011年第43期17卷 4787-4792页

作者： jung-Yeon Lee Jin-Hee Woo Hong-Jo Choi Ki-jae Park Young-Hoon Roh Ki-Han Kim hak-Yoon Lee Department of Surgery Dong-A University Medical Center

AIM:To evaluate clinical validity of the compression anastomosis ring(CARTM27) anastomosis in left-sided colonic resection. METHODS:A non-randomized prospective data collection was performed for patients undergoing an elective left-sided colon resection,followed by an anastomosis using the CARTM27 between November 2009 and January *** criteria of the use of the CARTM27 were anastomoses between the colon and at or above the intraperitoneal *** primary short-term clinical endpoint,rate of anastomotic leakage,and other clinical outcomes,including intraand postoperative complications,length of operation time and hospital stay,and the ring elimination time were evaluated. RESULTS:A total of 79 patients(male,43;median age,64 years) underwent an elective left-sided colon resection,followed by an anastomosis using *** was performed laparoscopically in 70 patients,in whom two patients converted to open procedure(2.9%) .There was no surgical *** an intraoperative complication,total disruption of the anastomosis occurred by premature enforced tension on the proximal segment of the anastomosis in one *** ring was removed and another new CARTM27 anastomosis was *** patient with sigmoid colon cancer showed postoperative anastomotic leakage after 6 d postoperatively and temporary diverting ileostomy was *** date of expulsion of the ring could not be recorded because most patients were not aware that the ring had been *** patients manifested clinical symptoms of anastomotic stricture. CONCLUSION:Short-term evaluation of the CARTM27 anastomosis in elective left colectomy suggested it to be a safe and efficacious alternative to the standard hand-sewn or stapling technique.

关键词： Compression anastomosis Colon Anastomotic leakage CARTM27

Porous Microspheres Comprising CoSe2 Nanorods Coated with N-Doped Graphitic C and Polydopamine-Derived C as Anodes for Long-Lived Na-Ion Batteries

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Nano-Micro Letters 2022年第7期14卷 118-139页

作者： jae Seob Lee Rakesh Saroha jung Sang Cho Department of Engineering Chemistry Chungbuk National UniversityCheongjuChungbuk 361-763Republic of Korea

Metal–organic framework-templated nitrogen-doped graphitic carbon(NGC)and polydopaminederived carbon(PDA-derived C)-double coated one-dimensional CoSe_(2) nanorods supported highly porous threedimensional microspheres are introduced as anodes for excellent Na-ion batteries,particularly with long-lived cycle under carbonate-based electrolyte *** microspheres uniformly composed of ZIF-67 polyhedrons and polystyrene nanobeads(φ=40 nm)are synthesized using the facile spray pyrolysis technique,followed by the selenization process(P-CoSe_(2)@NGC NR).Further,the PDA-derived C-coated microspheres are obtained using a solution-based coating approach and the subsequent carbonization process(P-CoSe_(2)@PDA-C NR).The rational synthesis approach benefited from the synergistic effects of dual carbon coating,resulting in a highly conductive and porous nanostructure that could facilitate rapid diffusion of charge species along with efficient electrolyte infiltration and effectively channelize the volume ***,the prepared nanostructure exhibits extraordinary electrochemical performance,particularly the ultra-long cycle life *** instance,the advanced anode has a discharge capacity of 291(1000th cycle,average capacity decay of 0.017%)and 142 mAh g^(-1)(5000th cycle,average capacity decay of 0.011%)at a current density of 0.5 and 2.0 A g^(-1),respectively.

关键词： Spray pyrolysis Sodium-ion batteries Cobalt selenide nanorods Porous microspheres Dual carbon coating

Effects of homogenization temperature on microstructure and mechanical properties of high-speed-extruded Mg–5Bi–3Al alloy

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Journal of Magnesium and Alloys 2022年第10期10卷 2833-2846页

作者： jae Won Cha Sang-Cheol Jin jae-Gil jung Sung Hyuk Park School of Materials Science and Engineering Kyungpook National University80 DaehakroDaegu 41566Republic of Korea Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

This study investigates the effects of billet homogenization temperature on the dynamic recrystallization behavior during high-speed extrusion and resultant microstructure and tensile properties of the Mg–5Bi–3Al(BA53,wt%)*** billets homogenized at 350 and450℃(350H and 450H billets)are extruded at a high speed of 69 m/*** 350H billet has a relatively smaller grain size and a higher abundance of fine Mg3Bi2particles compared to the 450H *** extrusion of the 350H billet,enhanced dynamic recrystallization occurs as a result of its finer grains and abundance of particles,while the growth of recrystallized grains is suppressed by the grain-boundary pinning effect of ***,the extruded 350H material is characterized by smaller grains,relatively greater number of Mg3Bi2particles,and a higher internal strain energy than the extruded 450H *** tensile strength of the extruded 350H material is higher than that of the extruded 450H material owing to stronger grain-boundary hardening,particle hardening,and strain hardening *** extruded 350H material also exhibits a higher tensile elongation as its smaller grains inhibit the formation of crack-inducing undesirable twins during *** results from this study demonstrate that a decrease in the homogenization temperature from 450 to 350℃leads to improved strength and ductility in the high-speed-extruded BA53 material.

关键词： Mg–Bi–Al alloy High-speed extrusion Homogenization Dynamic recrystallization Tensile properties