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Thermodynamic model for deoxidation of liquid steel considering strong metal-oxygen interaction in the quasichemical model framework

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 988-1002页

作者： y.ng-Min Cho youn-Bae kang Graduate Institute of Ferrous and Eco Materials Technology Pohang University of Science and TechnologyPohangKyungbuk37673Rep.of Korea n.EX.T Hub POSCO HoldingsPohangKyungbuk37673Rep.of Korea Department of Materials Science and Engineering Pohang University of Science and TechnologyPohangKyungbuk37673Rep.of Korea

Herein,a thermodynamic model aimed at describing deoxidation equilibria in liquid steel was *** model provides explicit forms of the activity coefficient of solutes in liquid steel,eliminating the need for the minimization of internal Gibbs energy preliminarily when solving deoxidation *** elimination of internal Gibbs energy minimization is particularly advantageous during the coupling of deoxidation equilibrium calculations with computationally intensive approaches,such as computational fluid *** model enables efficient calculations through direct embedment of the explicit forms of activity coefficient in the computing *** proposed thermodynamic model was developed using a quasichemical approach with two key approximations:random mixing of metallic elements(Fe and oxidizing metal) and strong nonrandom pairing of metal and oxygen as nearest *** these approximations,the quasichemical approach yielded the activity coefficients of solutes as explicit functions of composition and temperature without requiring the minimization of internal Gibbs energy or the coupling of separate *** model was successfully applied in the calculation of deoxidation equilibria of various elements(Al,B,C,Ca,Ce,Cr,La,Mg,Mn,nb,Si,Ti,V,and Zr).The limitations of the model arising from these assumptions were also discussed.

关键词： deoxidation equilibria thermodynamics quasichemical approach computational fluid dynamics

Bioinspired nanocomposites with self-adaptive mechanical properties

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nano Research 2024年第2期17卷 633-648页

作者： Grant Kitchen Bohan Sun Sung Hoon kang 13400 n Charles St Department of Materials Science and EngineeringJohns Hopkins UniversityBaltimore 21218USA 23400 n Charles St Department of Mechanical EngineeringJohns Hopkins UniversityBaltimore 21218USA 33400 n Charles St Hopkins Extreme Materials InstituteJohns Hopkins UniversityBaltimore 21218USA

Conventional synthetic materials have fixed mechanical properties and suffer defects,damage,and degradation over *** makes them unable to adapt to changing environments and leads to limited ***,self-adaptive materials inspired by.natural materials have emerged as a solution to address these *** the ability to change their mechanical properties based on changing mechanical environments,repairing defects,and maintaining their mechanical properties,these materials can lead to improved performance while decreasing *** this review,we explore self-adaptive phenomena found in nature that have inspired the development of synthetic self-adaptive materials,and the mechanisms that have been employed to create the next generation of *** potential applications of these materials,the challenges that existing approaches face,and future research opportunities are also discussed.

关键词： nanocomposites self-adaptive materials bioinspired materials force-activated resilience

An Experimental Study on Response and Control of a Flapping-Wing Aerial Robot Under Wind Gusts

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Journal of Bionic Engineering 2024年第1期21卷 209-223页

作者： Kazuki Shimura Hikaru Aono Chang-kwon kang Graduate School of Science and Technology Shinshu University3-15-1 TokidaUedaNagano 3868567Japan Department of Mechanical Engineering and Robotics 3-15-1 TokidaUedaNagano 3868567Japan Department of Mechanical and Aerospace Engineering University of Alabama in HuntsvilleTechnology Hall N266HuntsvilleAL35899USA

Bioinspired flapping-wing micro-air-vehicles(FWMAVs)have the potential to be useful aerial tools for gathering information in various *** recent advancements in manufacturing technologies and better understanding of aerodynamic mechanisms behind of the flapping flight,outdoor flights have become a ***,to fully realize the potential of FWMAVs,further improvements are necessary,particularly in terms of stability and robustness under gusty *** this study,the response and control of a tailless two-winged FWMAV under the wind gusts are *** experiments are conducted with a one-degree-of-freedom gimbal to focus on effects of wind gusts on the rotational motion of the ***-derivative and sliding-mode controls are adopted for the attitude *** present that the body angles changed in time and reached approximately 50°at the maximum due to the wing *** sliding-mode controller can more effectively control the rotational angle in the presence of disturbances and both the wing speed and changes in wind speed have an impact on the effectiveness of attitude *** results contribute to the development of of tailless two-winged,single-motor driven FWMAVs in terms of the design of attitude controller and testing apparatus.

关键词： Flapping-wing micro-air vehicles Sliding-mode control Pitch and roll angle-Wind gus

Boosted Lithium-Ion Transport Kinetics in n-Type Siloxene Anodes Enabled by Selective nucleophilic Substitution of Phosphorus

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nano-Micro Letters 2024年第10期16卷 618-637页

作者： Se In Kim Woong-Ju Kim Jin Gu kang Dong-Wan Kim School of Civil Environmental and Architectural EngineeringKorea University02841 SeoulSouth Korea nanophotonics Research Center Korea Institute of Science and Technology02792 SeoulSouth Korea

Doped two-dimensional(2D)materials hold significant promise for advancing many technologies,such as microelectronics,optoelectronics,and energy ***,n-type 2D oxidized Si nanosheets,namely.n-type siloxene(n-SX),are employed as Li-ion battery *** thermal evaporation of sodium hypophosphite at 275℃,P atoms are effectively incorporated into siloxene(SX)without compromising its 2D layered morphology and unique Kautsky-type crystal ***,selective nucleophilic substitution occurs,with only Si atoms being replaced by P atoms in the O_(3)≡Si-H *** resulting n-SX possesses two delocalized electrons arising from the presence of two electron donor types:(i)P atoms residing in Si sites and(ii)H *** doping concentrations are varied by controlling the amount of precursors or their mean free *** at 2000 mA g^(-1),the n-SX electrode with the optimized doping concentration(6.7×10^(19) atoms cm^(-3))delivers a capacity of 594 mAh g^(-1) with a 73%capacity retention after 500 *** improvements originate from the enhanced kinetics of charge transport processes,including electronic conduction,charge transfer,and solid-state *** approach proposed herein offers an unprecedented route for engineering SX anodes to boost Li-ion storage.

关键词： Li-ion battery Two-dimensional n-type siloxene Doping mechanism Kinetics

Spatiotemporal variations in glacier area and surface velocity of the northern Antarctic Peninsula during 2018-2022

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Advances in Climate Change Research 2024年第2期15卷 297-311页

作者： yu-Long kang Shi-Chang kang Wan-Qin GUO Tao CHE Zong-Li JIAnG Zhen-Feng WAnG Qiang-Qiang XU Cheng-De y.nG State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100083China Key Laboratory of Remote Sensing of Gansu Province Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China School of Earth Sciences and Spatial Information Engineering Hunan University of Science and TechnologyXiangtan 411201China

Ice sheet serves as a crucial indicator for assessing climate *** loss in recent remote sensing-based studies indicated that the Antarctic Peninsula has rapid rates of glacier retreat and speed up of surface ***,observations of seasonal variability of ice speed are limited,and glacier-area changes require multi-temporal *** study investigated the changes in area and surface velocities of∼375 glaciers on the northern Antarctic Peninsula(nAP)utilizing satellite images acquired by the Sentinel 1&2 satellites during *** results indicate that the glacier area reduced by approximately 166.1±44.2 km^(2)(-0.2%±0.1%per year)during the study period,with an acceleration after 2020(-0.4%±0.3%per year),and the most dramatic reduction happened on the eastern *** maximum annual ice speeds on the nAP generally exceeded 3500 m per year,while the ice speeds in 2021 were the highest(exceeded 4210 m per year).The ice speed variability in austral autumn was higher than in other seasons,meanwhile the summer ice speeds showed an increasing *** glacier G012158E47018n,Mcneile Glacier,glacier G299637E64094S and Drygalski Glacier showed the most remarkable ice speed variations represented by high daily velocities and strong fluctuations on their *** results demonstrated that the variations in glacier area and seasonal ice speed on the nAP were responsive to the ice-ocean-atmosphere ***,seasonal velocity and area variations should be considered when conducting accurate mass balance calculations,model validations and change mechanism analyses under climate warming scenarios.

关键词： Glacier area Seasonal ice speed Sentinel 1&2 northern Antarctic Peninsula Ice-ocean-atmosphere processes

Erosion Characteristics of Oil-immersed On-load Tap Changer Contacts Under Vary.ng Contact Speeds and Pressures

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Chinese Journal of Electrical Engineering 2024年第1期10卷 21-34页

作者： Zongy.ng Li Shuaibing Li y.ngqiang kang Zheng Li Hongwei Li School of new Energy and Power Engineering Lanzhou Jiaotong UniversityLanzhou 730070China School of Electrical Engineering Southwest Jiaotong UniversityChengdu 611756China School of Automation and Electrical Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

With the growing demand for precise voltage adjustment and reactive regulation,the frequent operation of on-load tap changers(OLTCs)in oil-immersed systems has led to increased erosion of switch contacts by arcs during the switching *** erosion causes significant wear on the contacts,thereby reducing their ***,the present study aims to investigate the behavior and mechanism of arc erosion on contact surfaces in oil-immersed *** achieve this,a self-designed friction and wear test device for OLTC contacts was utilized to conduct experiments at various sliding speeds and contact ***,finite element analysis was employed to validate the experimental results regarding the influence of sliding speed on arc *** surface morphology of the contacts was observed using an optical *** findings revealed that as the sliding speed increased,the arc energy,arc initiation rate,and contact resistance initially exhibited an upward trend,then decreased,and eventually increased *** minimum values were observed at a sliding speed of 90 mm/***,the arc energy,arc initiation rate,and contact resistance decreased gradually as the contact pressure *** reaching a contact pressure of 1.5 n,the variation in the arc energy *** lower contact pressures,arc erosion dominated the wear on the contact ***,at higher contact pressures,the wear transitioned from predominantly arc erosion to a combination of mechanical wear and arc *** summary,experimental and analytical investigations provided insights into the effects of sliding speed and contact pressure on the behavior of arc erosion,contact resistance,and surface damage of OLTC contacts in oil-immersed systems.

关键词： Oil-immersed on-load tap changer arc energy contact resistance friction and wear arc erosion

Diamond-based electron emission: Structure, properties and mechanisms

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CHInESE PHySICS B 2024年第9期33卷 165-177页

作者： Gu, Liang-Xue y.ng, Kai Teng, y.n Zhao, Wei-kang Zhao, Geng-you Fan, kang-kang Feng, Bo Zhang, Rong Zheng, you-Dou ye, Jian-Dong Zhu, Shun-Ming Tang, Kun Gu, Shu-Lin nanjing Univ Sch Elect Sci & Engn Nanjing 210046 Peoples R China

Diamond has an ultrawide bandgap with excellent physical properties, such as high critical electric field, excellent thermal conductivity, high carrier mobility, etc. Diamond with a hydrogen-terminated (H-terminated) surface has a negative electron affinity (nEA) and can easily produce surface electrons from valence or trapped electrons via optical absorption, thermal heating energy or carrier transport in a Pn junction. The nEA of the H-terminated surface enables surface electrons to emit with high efficiency into the vacuum without encountering additional barriers and promotes further development and application of diamond-based emitting devices. This article reviews the electron emission properties of H-terminated diamond surfaces exhibiting nEA characteristics. The electron emission is induced by different physical mechanisms. Recent advancements in electron-emitting devices based on diamond are also summarized. Finally, the current challenges and future development opportunities are discussed to further develop the relevant applications of diamond-based electron-emitting devices.

关键词： diamond negative electron affinity (nEA) Pn junction electron emission 81.15.Gh 81.05.ug 07.30.Bx 07.30.Kf EnHAnCED THERMIOnIC EMISSIOn FIELD-EMISSIOn DOPED DIAMOnD CVD-DIAMOnD n-TyPE SURFACE FUnCTIOnALIZATIOn PHOTOELECTROn EMISSIOn SOLVATED ELECTROnS GRAIn-BOUnDARIES FILMS

Tailoring high-refractive-index nanocomposites for manufacturing of ultraviolet metasurfaces

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Microsystems & nanoengineering 2024年第2期10卷 303-310页

作者： Hy.njung kang Dongkyo Oh nara Jeon Joohoon Kim Hongyoon Kim Trevon Badloe Junsuk Rho Department of Mechanical Engineering Pohang University of Science and Technology(POSTECH)PohangRepublic of Korea Graduate School of Artificial Intelligence Pohang University of Science and Technology(POSTECH)PohangRepublic of Korea Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)PohangRepublic of Korea Department of Electrical Engineering Pohang University of Science and Technology(POSTECH)PohangRepublic of Korea POSCO-POSTECH-RIST Convergence Research Center for Flat Optics and Metaphotonics PohangRepublic of Korea national Institute of nanomaterials Technology.nInT) PohangRepublic of Korea

nanoimprint lithography.nIL)has been utilized to address the manufacturing challenges of high cost and low throughput for optical *** overcome the limitations inherent in conventional imprint resins characterized by a low refractive index(n),high-n nanocomposites have been introduced to directly serve as ***,comprehensive research on these nanocomposites is notably *** this study,we focus on the composition of high-n zirconium dioxide(ZrO_(2))nanoparticle(nP)concentration and solvents used to produce ultraviolet(UV)metaholograms and quantify the transfer fidelity by the measured conversion *** utilization of 80 wt%ZrO_(2)nPs in MIBK,MEK,and acetone results in conversion efficiencies of 62.3%,51.4%,and 61.5%,respectively,at a wavelength of 325 *** analysis of the solvent composition and nP concentration can further enhance the manufacturing capabilities of high-n nanocomposites in nIL,enabling potential practical use of optical metasurfaces.

关键词： ultraviolet refractive nanocomposites

Anti-obesity effects of fucoidan from Sargassum thunbergii in adipocytes and high fat diet induced obese mice through inhibiting adipogenic specific transcription factor

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Food Science and Human Wellness 2024年第3期13卷 1608-1616页

作者： Hyo-Geun Lee H.H.A.C.K.Jayawardhana Fengqi y.ng D.P.nagahawaththa n.M.Liy.nage Ky.ng-Mo Song y.n-Sang Choi Seung-Hong Lee you-Jin Jeon Min-Cheol kang Department of Marine Life Sciences Jeju National UniversityJeju 63243Republic of Korea Marine Science Institute Jeju National UniversityJeju 63333Republic of Korea Research Group of Food Processing Korea Food Research InstituteWanju 55365Republic of Korea Department of Pharmoceutical Engineering Soonchunhyang UniversityAsan 31538Republic of Korea

The prevalence of obesity has increased and is a health concern *** to the concerns regarding synthetic anti-obesity treatments,nowadays natural products become a *** studies proved that there is a potential to use marine algae as anti-obesity ***,in this study,the lipid inhibitory effect of crude polysaccharide of amyloglucosidase-assisted hydrolysate from Sargassum thunbergii(STAC)and its fucoidan fractions(STAFs)on 3T3-L1 cells and high-fat diet(HFD)-induced obese mice were *** to the results,the STAF3,showed the highest xylose content and exhibited significant inhibitory effects on lipid accumulation by downregulating adipogenic and lipogenic proteins in 3T3-L1 ***,oral supplementation with STAC significantly declined gain in body weight and fat weight,and serum lipid contents in an HFD-induced obesity mouse *** and chemical characterizations demonstrated that puritied STAF3 has consistent surface morphology and small particle size,with similar structural characteristics as commercial ***,these results indicate that STAC and purified STAF3 from Sargassum thunbergia is a potent source to develop as ananti-obesity agents or functional food products to counter obesity.

关键词： Sargassum thunbergii Fucoidan Anti-obesity Anti-steatosis