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Journal of Energy Chemistry 2024年第7期94卷 430-440页

作者： Jaewon Baek Sunha kim hee-Tak kim Oc hee Han Department of Chemical&Biomolecular Engineering KAISTDaejeon 34141Republic of Korea Metropolitan Seoul Center Korea Basic Science InstituteSeoul 03759Republic of Korea Graduate School of Analytical Science&Technology Chungnam National UniversityDaejeon 34134Republic of Korea

Despite the proficiency of lithium(Li)-7 NMR spectroscopy in delineating the physical and chemical states of Li metal electrodes,challenges in specimen preparation and interpretation impede its *** this study,we conducted a comprehensive postmortem analysis utilizing ^(7)Li NMR,employing a stan-dard magic angle spinning probe to examine protective-layer coated Li metal electrodes and LiAg alloy electrodes against bare Li metal electrodes within Li metal batteries(LMBs).Our investigation explores the effects of sample burrs,alignment with the magnetic field,the existence of liquid electrolytes,and precycling on the ^(7)Li NMR *** contrasting NMR spectra before and after cycling,we identi-fied alterations in Li^(0) and Li^(+) signals attributable to the degradation of the Li metal *** NMR analyses decisively demonstrate the efficacy of the protective layer in mitigating dendrite and solid elec-trolyte interphase ***,we noted that Li*ions near the Li metal surface exhibit magnetic susceptibility anisotropy,revealing a novel approach to studying diamagnetic species on Li metal elec-trodes in *** study provides valuable insights and practical guidelines for characterizing distinct lithium states within LMBs.

关键词： NMR spectroscopy Lithium-7 Lithium metal battery Electrolyte Electrode-protective layer Solid electrolyte interface Magnetic susceptibility anisotropy Lithium-metal NMR signal Diamagnetic^(7)Li NMR signal

Insights into the changes in the surface properties of goethite with Ni in the lattice in the presence of salicylhydroxamic acid:Experimental and density functional theory studies

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 665-677页

作者： Levie Mweene Gilsang Hong hee-Eun Jeong hee-won Kang Hyunjung kim Department of Earth Resources and Environmental Engineering Hanyang University222 Wangsimni-roSeongdong-guSeoul 04763Republic of Korea

Comparative experiments and theoretical analysis of the surface chemistry changes of goethite(GT)and goethite containing Ni(GTN)in the lattice in the presence of salicylhydroxamic acid(SA)were *** was revealed that in the presence of 100 g·t^(-1)of SA,the flotation recovery of GTN and GT increased with increasing pH,achieving a maximum recovery of 98.9%for both minerals at p H 8.3 and decreasing beyond that pH,with GTN having a slightly higher recovery than GT,except at pH *** was further confirmed by the higher complexation energies of GTN···SA(-883.87 kJ·mol^(-1))compared with GT···SA(-604.23 kJ·mol^(-1))resulting from covalent,closed-shell,and conventional hydrogen *** higher adsorption of SA onto GTN relative to GT was due to the formation of aπ-hole in GTN,thereby promoting a higher interaction of the collector with the ***,the presence of Ni in the GT lattice improves and decreases the adsorption and desorption of SA onto and from the mineral,respectively,compared with those onto and from GT.

关键词： nickel goethite adsorption salicylhydroxamic acid recovery

Development and application of a multi-step porcine in vitro system to evaluate feedstuffs and feed additives for their efficacy in nutrient digestion, digesta characteristics, and intestinal immune responses

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Animal Nutrition 2024年第2期17卷 265-282页

作者： hee Yeon kim Jun-Ok Moon Sung Woo kim Application Center CJ Blossom Park Department of Animal Science North Carolina State University

In vitro model provides alternatives to the use of live animals in research. In pig nutrition, there has been a tremendous increase in in vivo research over the decades. Proper utilization of in vitro models could provide a screening tool to reduce the needs of in vivo studies, research duration, cost, and the use of animals and feeds. This study aimed to develop a multi-step porcine in vitro system to simulate nutrient digestion and intestinal epithelial immune responses affected by feedstuffs and feed additives. Seven feedstuffs(corn, corn distillers dried grains with solubles [corn DDGS], barley, wheat, soybean meal, soy protein concentrates, and Corynebacterium glutamicum cell mass [CGCM]), feed enzymes(xylanase and phytase), and supplemental amino acids(arginine, methionine, and tryptophan), were used in this in vitro evaluation for their efficacy on digestibility, digesta characteristics, and intestinal health compared with the results from previously published in vivo studies. All in vitro evaluations were triplicated. Data were analyzed using Mixed procedure of SAS9.4. Evaluations included(1) nutrient digestibility of feedstuffs,(2) the effects of feed enzymes, xylanase and phytase, on digestibility of feedstuffs and specific substrates, and(3) the effects of amino acids, arginine, tryptophan, and methionine, on anti-inflammatory, anti-oxidative, and anti-heat stress statuses showing their effects(P < 0.05) on the measured items. Differences in dry matter and crude protein digestibility among the feedstuffs as well as effects of xylanase and phytase were detected(P < 0.05), including xylo-oligosaccharide profiles and phosphorus release from phytate. Supplementation of arginine, tryptophan, and methionine modulated(P < 0.05) cellular inflammatory and oxidative stress responses. The use of this in vitro model allowed the use of 3 experimental replications providing sufficient statistical power at P < 0.05. This indicates in vitro models can have increased prec

关键词： Digestion Feed additive Feedstuff In vitro Intestine Pig

Fabrication of heteroatom-doped cobalt oxide yolk–shell microsphere using recycled solution from waste materials and their excellent electrochemical properties as an anode material for lithium-ion batteries

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Rare Metals 2024年第10期43卷 4934-4947页

作者： Yeong Beom kim Chanho kim Seung-Hyun kim Yun Chan Kang Dongju Lee Gi dae Park Department of Advanced Materials Engineering Chungbuk National University Department of Materials Science and Engineering Korea University Research Institute YKSintering Co.Ltd.

Heteroatom-doped transition metal oxides have attracted great attention as advanced anode materials for lithium-ion batteries due to their high theoretical capacity and superior ***,the limited resource availability has led to a substantial rise in prices for valuable metals such as Ni and Co,posing a significant challenge for their *** address this issue,recycling of these metals from waste materials have gained prominence,and particularly the recovery of Co has been mostly focused on its economic ***,we introduced a novel recycling strategy for fabrication of heteroatomdoped CoOx（comprising mainly Co3O4with a minor CoO phase） anode with a yolk–shell structure for lithium-ion batteries,by separating Co from cemented tungsten carbide *** employing a simple leaching process and subsequent spray pyrolysis,the yolk–shell structured microsphere comprising CoOxwas successfully ***,the presence of other waste metals in the leachate facilitated multi-heteroatom doping during ***,the introduction of various dopants into CoOxinduced oxygen vacancy formation,thereby enhancing the electrochemical properties of the *** a result,compared with the phase-pure （undoped） CoOxyolk–shell,the heteroatom-doped CoOxyolk–shell exhibited robust cycling stability (602 mAh·g-1for 200 cycles at 1 A·g-1) and excellent rate capability(210 mAh·g-1at 10 A·g-1).

关键词： Anode Cobalt oxide Heteroatom doping Lithium-ion batteries Recycling

Ag-GST/HfO_(x)-based unidirectional threshold switching selector with low leakage current and threshold voltage distribution for high-density cross-point arrays

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Rare Metals 2024年第1期43卷 280-288页

作者： Kyoung-Joung Yoo dae-Yun Kang Nahyun kim Ho-Jin Lee Ta-Hyeong kim Taeho kim Tae Geun kim School of Electrical Engineering Korea UniversitySeoul 02841Republic of Korea

The use of electrochemical-metallization-based volatile threshold switching selectors in cross-point arrays has been widely explored owing to their high on-off ratios and simple ***,these devices are unsuitable for cross-point architectures because of the difficulty in controlling the random filament formation that results in large fluctuations in the threshold voltage during *** this study,we investigated the unidirectional threshold transition characteristics associated with an Ag/GST/HfO_(x)/Pt-based bilayer selector and demonstrated the occurrence of a low leakage current(<1×10^(-11) A) and low distribution of the threshold voltage(Δ0.11 V).The bilayer structure could control the filament formation in the intermediate state through the insertion of an HfO_(x) tunneling *** stacking a bilayer selector with NiO_(x)based resistive random-access memory,the leakage and programming currents of the device could be significantly *** the crossbar array configuration,we performed equivalent circuit analysis of a one-selector oneresistor(1S1R) devices and estimated the optimal array size to demonstrate the applicability of the proposed *** maximum acceptable crossbar array size of the 1S1R device with the Ag/GST/HfO_(x)/Pt/Ti/NiO_(x)/Pt structure was 5.29×10^(14)(N^(2),N=2.3×10^(7)).

关键词： Selector device Tunneling barrier Threshold switching Sputtering 1S1R Cross-point array

Effect of Silane Coupling Agent on the Flexural Property of Glass Fiber Reinforced Composite Film

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Journal of Materials Science and Chemical Engineering 2014年第10期2卷 38-42页

作者： Hye-Hyun kim Si-Young kim dae-hee kim Chae-Young Oh Nam-Ju Jo Department of Polymer Science & Engineering Pusan National University Busan Korea

Transparent glass fiber reinforced composites films ware fabricated by UV light induced chemical crosslinking of composite materials consisting of glass fiber and UV curable resin in film state. In order to apply film to flexible device, excellent flexural property is required, then the delamination should not occurred between glass fiber and UV curable resin when film is bent. To minimize delamination and improve the interfacial adhesion at interface between glass fiber and UV curable resin, the γ-aminopropyl triethoxy silane and γ-glycid oxypropyl trimethoxy silane were applied for the surface treatment of glass fibers. Silanization of glass fiber surface was checked by scanning electron microscopy and the degree of delamination of composite film was confirmed through the bending test, ASTEM290-96a, used by haze meter.

关键词： Glass Fiber Silane UV Curable Resin Composite Flexural Property Haze

Flexible thermocouple using a thermoelectric graphene fiber with a seamless junction

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Journal of Materials Science & Technology 2024年第5期172卷 15-22页

作者： Seungwon kim Soomook Lim Myeong hee Jeong Wonjoon kim Seunghyun Baik Ji Won Suk School of Mechanical Engineering Sungkyunkwan UniversitySuwonGyeonggi-do 16419Republic of Korea Department of Smart Fab.Technology Sungkyunkwan UniversitySuwonGyeonggi-do 16419Republic of Korea SKKU Advanced Institute of Nanotechnology(SAINT) Sungkyunkwan UniversitySuwonGyeonggi-do 16419Republic of Korea

Temperature is an important physical variable that indicates the condition of the human body and artificial *** wearable applications require the development of temperature sensors with different form *** this study,a fiber-shaped thermoelectric temperature sensor is fabricated using a continuous graphene fiber whose two halves possess different reduction states.A seamless junction is formed by partially reducing a wet-spun graphene oxide fiber with hydroiodic acid(HI)solutions of different ***-half of the fiber is mildly reduced with 0.97 wt%HI,while the other half is highly reduced with 30.6 wt%*** different reduction states of the graphene composite fiber result in different Seebeck coefficients,allowing for the fabrication of a fiber-shaped graphene thermocou-ple without any laborious *** flexible graphene thermocouple exhibits high sensitivity with a thermopower of 12.5μV K^(-1)in the temperature range of room temperature to∼70℃.Furthermore,it exhibits high linearity with a correlation coefficient exceeding 0.995 and fast response with a time constant of 0.24 *** to its mechanical robustness and flexibility,the stand-alone graphene ther-mocouple can be knitted into a cotton fabric glove,which presents a fast response to environmental changes without any external power *** work offers a unique fabrication method for producing a high-performance,flexible thermocouple that features a seamless and clear junction without the use of additional *** alternative method eliminates the complicated assembly processes typically required for conventional thermocouples.

关键词： Graphene fiber Thermocouple Reduced graphene oxide Flexible temperature sensor Seebeck coefficient

Dual in-situ observation of tribochemical and morphological evolution of single-layer WS_(2)and multi-layer WS_(2)/C coatings

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Friction 2024年第7期12卷 1580-1598页

作者： Yuzhen LIU Jae-Ho HAN Shusheng XU Young Chan JUNG dae-Eun kim State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Department of Mechanical Engineering Yonsei UniversitySeoul03722Republic of Korea Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai Yantai 264000China Yantai Zhongke Research Institute of Advanced Materials and Green Chemical Engineering Yantai 264000China

The outstanding tribological performance of transition metal dichalcogenides(TMDs)is attributed to their unique sandwich microstructure and low interlayer shear *** advantageous structure allows TMDs to demonstrate exceptional friction reduction ***,the incorporation of TMDs and amorphous carbon(a-C)in multi-layer structures shows excellent potential for further enhancing tribological and anti-oxidation *** carbon,known for its high ductility,chemical inertness,and excellent wear resistance,significantly contributes to the overall performance of these multi-layer *** gain an in-depth understanding of the tribological mechanism and evolution of TMDs’multi-layer coatings,a dual in-situ analysis was carried out using a tribometer equipped with a 3D laser microscope and a Raman *** innovative approach allowed for a comprehensive evolution of the tribological,topographical,and tribochemical characteristics of both single-layer WS_(2)and multi-layer WS_(2)/C coatings in real *** findings from the dual in-situ tribotest revealed distinct failure characteristics between the single-layer WS_(2)coating and the multi-layer WS_(2)/C *** single-layer WS_(2)coating predominantly experienced failure due to mechanical removal,whereas a combination of mechanical removal and tribochemistry primarily influenced the failure of the multi-layer WS_(2)/C *** tribological evolution process of these two coatings can be classified into four stages on the basis of their tribological behavior:the running-in stage,stable friction stage,re-deposition stage,and lubrication failure *** stage represents a distinct phase in the tribological behavior of the coatings and contributes to our understanding of their behavior during sliding.

关键词： In-situ analysis multi-layer coating tribology tribochemistry

N,P co-doped 3D porous carbon with self-assembled morphological control via template-free method for potassiumion battery anodes

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Rare Metals 2024年第9期43卷 4243-4252页

作者： Jeehoon Yu dae Kyom kim Hong Geun Oh Seung-Keun Park Youngjae Yoo Department of Advanced Materials Engineering Chung-Ang UniversityAnseong-si 17546Republic of Korea

The larger ionic radius of potassium ions than that of lithium ions significantly limits the accomplishment of rapid diffusion kinetics in graphite electrodes for potassium-ion batteries(PIBs),resulting in comparatively poor rate performance and cycle ***,we report a high-rate performance and cycling stability amorphous carbon electrode achieved through nitrogen and phosphorous *** as-prepared N,P co-doped carbon electrodes have distinct 3D structures with large surface areas,hierarchical pore architectures,and increased interlayer spaces resulting from the direct pyrolysis of supramolecular self-assembled aggregates without *** obtained electrode N3P1 exhibits a reversible specific capacity of 258 m Ah·g^(-1)at a current density of 0.1A·g^(-1)and a good long-term cycle performance(96.1%capacity retention after 800 cycles at 0.5 A·g^(-1)).Kinetic investigations show that the N3P1 electrode with the welldeveloped porous structure and large number of surface defects exhibits capacitive-driven behavior at all scan rates,which may be attributed by N and P ***-situ transmission electron microscopy analyses in the fully discharged and charged states demonstrate structural stability and reversibility owing to the expanded interlayer *** suggested synthesis approach is simple and effective for producing heteroatom-doped carbon materials for PIBs and other advanced electrochemical energy storage materials.

关键词： Amorphous carbons 3D porous structures Nitrogen and phosphorous co-doping Potassium-ion batteries

Is it now possible to transition from laparoscopic liver resection to robotic liver resection?

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Hepatobiliary Surgery and Nutrition 2024年第3期13卷 557-559页

作者： Kyeong Sik kim dae Won Jun Department of General Surgery College of MedicineHanyang UniversitySeoulKorea Department of Internal Medicine College of MedicineHanyang UniversitySeoulKorea Hanyang Institute of Bioscience and Biotechnology Hanyang UniversitySeoulKorea

Minimally invasive surgery(MIS)has significantly progressed and emerged as the preferred approach for various gastrointestinal procedures,including gastrectomy,cholecystectomy,and various colorectal surgeries(1).However,the widespread acceptance of robotic surgery in liver resection has encountered obstacles,attributed to factors such as the lack of appropriate surgical instruments,the intricate learning curve,and safety ***,the utilization of MIS in liver resection is linked to decreased blood loss,reduced post-operative pain,shorter hospital stays,and lower morbidity rates compared to both open and laparoscopic liver resection procedures(2).

关键词： Laparoscopic liver resection robotic liver resection minimally invasive surgery(MIS)