检索结果-南通市图书馆

Chemical and mechanical properties of stainless, environment-friendly, and nonflammable Mg alloys (SEN alloys): A review

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第3期12卷 841-872页

作者： Jong Un Lee Hyun Ji Kim Sang-Cheol Jin Ye Jin Kim Young Min Kim bong Sun You jun Ho Bae Sung Hyuk Park Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea Department of Materials Science and Metallurgical Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Missile Research Institute Agency for Defense DevelopmentDaejeon 34060Republic of Korea

This review article provides overall understanding of stainless,environment-friendly,and nonflammable Mg alloys(SEN alloys)recently developed at the Korea Institute of Materials *** alloys are produced by adding small amounts of Ca and Y(each<1 wt%)into commercial Mg–Al based alloys,resulting in exceptional ignition and corrosion resistances and impressive mechanical *** main advantages of SEN alloys are as follows.(1)A dense multi-oxide layer of SEN alloys comprising MgO,CaO,and Y_(2)O_(3) impedes the outward dispersion of Mg vapor and the inward penetration of O_(2) during oxidation,thereby enhancing the oxidation and ignition resistances.(2)The presence of Ca-and Y-based second-phase particles in SEN alloys can enhance their corrosion resistance because Ca-containing particles prevent the spread of corrosion,and the replacement of Al-containing particles with less noble ones containing Y(e.g.,Al–Mn–Y or Al–Y particles)retards corrosion.(3)The addition of minor amounts of Ca and Y renders excellent mechanical properties due to improved strengthening *** enhanced properties are attributed to more pronounced dynamic recrystallization and grain refining behaviors caused by the second-phase particles during extrusion.(4)Despite the presence of various types of second-phase particles,the fatigue properties of SEN9 alloys are similar to those of commercial AZ91 alloys.(5)Simultaneous introduction of Ca and Y suppresses the formation of Mg17Al12 discontinuous precipitates during aging,leading to the enhanced elongation of aged SEN alloys.(6)Adding mischmetal into the SEN9 alloy leads to a six-fold enhancement in ***,the studies conducted on SEN alloys demonstrate their excellent ignition and corrosion resistances and mechanical properties,which broaden the industrial applications of Mg alloys by addressing their inherent weaknesses.

关键词： SEN magnesium alloy Corrosion resistance Ignition resistance Mechanical properties Extrudability.

Machine Learning-Assisted Fabrication of PCBM-Perovskite Solar Cells with Nanopatterned TiO2 Layer

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第4期7卷 223-230页

作者： Siti Norhasanah Sanimu Hwa-Young Yang Jeevan Kandel Ye-Chong Moon Gangasagar Sharma Gaudel Seung-Ju Yu Yong Ju Kim Sejung Kim bong-Hyun jun Won-Yeop Rho Graduate School of Integrated Energy-AI Jeonbuk National University School of Energy and Chemical Engineering Ulsan National Institute of Science and Technology (UNIST) Department of Herbal Medicine Resources College of Environmental and Bioresource Sciences Jeonbuk National University School of Chemical Engineering Jeonbuk National University Department of Bioscience and Biotechnology Konkuk University School of International Engineering and Science Jeonbuk National University

To unlock the full potential of PSCs,machine learning （ML） was implemented in this research to predict the optimal combination of mesoporous-titanium dioxide （mp-TiO2） and weight percentage （wt%） of phenyl-C61-butyric acid methyl ester （PCBM）,along with the current density(Jsc),open-circuit voltage (Voc),fill factor （ff）,and energy conversion efficiency （ECE）.

关键词： machine learning nanopatterning PCBM perovskite solar cells prediction

Trifunctional robust electrocatalysts based on 3D Fe/N-doped carbon nanocubes encapsulating Co4N nanoparticles for efficient battery-powered water electrolyzers

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Carbon Energy 2024年第6期6卷 124-139页

作者： Hyung Wook Choi Hongdae Lee jun Lu Seok Bin Kwon Dong In Jeong Beum Jin Park Jiwon Kim bong Kyun Kang Gun Jang Dae Ho Yoon Ho Seok Park SKKU Advanced Institute of Nano Technology(SAINT) Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea School of Chemical Engineering Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea School of Advanced Materials Science and Engineering Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea Department of Electronic Materials Devicesand Equipment EngineeringSoonchunhyang UniversityAsan CityChungnamRepublic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwon-siGyeonggi-doRepublic of Korea Department of Health Sciences and Technology Samsung Advanced Institute for Health Sciences and Technology(SAIHST)Sungkyunkwan UniversitySuwonRepublic of Korea

Herein,we have designed a highly active and robust trifunctional electrocatalyst derived from Prussian blue analogs,where Co_(4)N nanoparticles are encapsulated by Fe embedded in N-doped carbon nanocubes to synthesize hierarchically structured Co_(4)N@Fe/N-C for rechargeable zinc-air batteries and overall water-splitting *** confirmed by theoretical and experimental results,the high intrinsic oxygen reduction reaction,oxygen evolution reaction,and hydrogen evolution reaction activities of Co_(4)N@Fe/N-C were attributed to the formation of the heterointerface and the modulated local electronic ***,Co_(4)N@Fe/N-C induced improvement in these trifunctional electrocatalytic activities owing to the hierarchical hollow nanocube structure,uniform distribution of Co_(4)N,and conductive encapsulation by Fe/***,the rechargeable zinc-air battery with Co_(4)N@Fe/N-C delivers a high specific capacity of 789.9 mAh g^(-1) and stable voltage profiles over 500 ***,the overall water electrolyzer with Co_(4)N@Fe/N-C achieved better durability and rate performance than that with the Pt/C and IrO2 catalysts,delivering a high Faradaic efficiency of 96.4%.Along with the great potential of the integrated water electrolyzer powered by a zinc-air battery for practical applications,therefore,the mechanistic understanding and active site identification provide valuable insights into the rational design of advanced multifunctional electrocatalysts for energy storage and conversion.

关键词： battery-powered electrolyzers hierarchical structure Prussian blue analog trifunctional electrocatalyst zinc-air battery

Design, Implementation and Verification of Topology Network Architecture of Smart Home Tree

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第8期68卷 2399-2411页

作者： Youbang Guan bong jun Choi Department of Advanced Research and Development QingdaoChina Department of Engineering University of LeicesterLeicesterEngland School of Computer Science and Engineering Soongsil UniversitySeoulKorea

Smart home technology provides consumers with network connectivity,automation or enhanced services for home *** the Internet of Things era,a vast data flow makes business platforms have to own the same computing power to match their business *** achieves computing power through implementing big data algorithms deployed in the cloud data ***,because of the far long geographical distance between the client and the data center or the massive data capacity gap,potentially high latency and high packet loss will reduce the usability of smart home systems if service providers deploy all services in the cloud data *** computing and fog computing can significantly improve the utilization of network resources and reconstruct the network architecture for the user’s *** article enables a fog resource-based resource allocation management *** provides a method that can more reasonably allocate network resources through a virtualized middle-tier method to ensure low response time and configure Quality of Service to ensure the use of delay-sensitive critical applications to improve the reliability of smart home communication ***,the proposed method has is tested and verified by adjusting the variables of the network *** realize the optimization of resource allocation of client network without changing the hardware of client.

关键词： Topology network smart home tree resource allocation internet of things

Nonlinear Electrical Impedance Tomography Method Using a Complete Electrode Model for the Characterization of Heterogeneous Domains

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2023年第3期134卷 1707-1735页

作者： Jeongwoo Park bong-Gu jung jun Won Kang Department of Civil and Environmental Engineering Hongik UniversitySeoul04066Korea

This paper presents an electrical impedance tomography(EIT)method using a partial-differential-equationconstrained optimization *** forward problem in the inversion framework is described by a complete electrodemodel(CEM),which seeks the electric potential within the domain and at surface electrodes considering the contact impedance between *** finite element solution of the electric potential has been validated using a commercial *** inverse medium problem for reconstructing the unknown electrical conductivity profile is formulated as an optimization problem constrained by the *** method seeks the optimal solution of the domain’s electrical conductivity to minimize a Lagrangian functional consisting of a least-squares objective functional and a regularization *** the stationarity of the Lagrangian leads to state,adjoint,and control problems,which constitute the Karush-Kuhn-Tucker(KKT)first-order optimality ***,the electrical conductivity profile of the domain is iteratively updated by solving the KKT conditions in the reduced space of the control *** results show that the relative error of the measured and calculated electric potentials after the inversion is less than 1%,demonstrating the successful reconstruction of heterogeneous electrical conductivity profiles using the proposed EIT *** method thus represents an application framework for nondestructive evaluation of structures and geotechnical site characterization.

关键词： Electrical impedance tomography complete electrode model inverse medium problem Karush-Kuhn-Tucker(KKT)optimality conditions nondestructive evaluation of structures

A new strengthening mechanism driven by disruptive shear and solute segregation during warm rolling in 1.4 GPa class 12.5 wt% Al added-FeMnC ultra-lightweight steel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第26期157卷 174-188页

作者： Chiwon Kim Hyun-Uk Hong Joonoh Moon bong Ho Lee Seong-jun Park Chang-Hoon Lee Department of Materials Convergence and System Engineering Changwon National University 20 Changwondaehak-roChangwonGyeongnam 51140Republic of Korea Advanced Analysis Team Daegu Gyeongbuk Institute of Science and Technology 333 Technojungang-daeroDaegu42988Republic of Korea Ferrous Alloy Department Korea Institute of Materials Science 797 ChangwondaeroChangwonGyeongnam 51508Republic of Korea

Novel strengthening of Fe-29.1Mn-12.5Al-1.35C-4.95Cr steel achieved by warm rolling was *** solution-treated steel consisted of aγ-matrix containing nano-sizedκ-carbide((Fe,Mn)_(3) AlC)and elongated prior ferrite,which was transformed into FeAl-type B2 and Fe_(3) Al-type D0_(3) *** solution-treated steel exhibited poor strain hardening owing to glide softening associated withκ-carbide shearing by ***,after warm rolling with a reduction ratio of 30%at 300℃,the yield and tensile strengths significantly increased from 917 to 1300 MPa and 1025 to 1419 MPa,*** tensile test conducted at 300℃to simulate warm rolling exhibited serrated flows,indicating dy-namic strain aging(DSA).Atom probe tomography exhibited that the C atoms inκ-carbide were swept away along the slip direction by disruptive shear during rolling at 300℃.The swept C atoms along the slip direction interacted strongly with dislocations at 300℃,with repeated pinning and breakaway of dislocations from the C *** contributed to significant strengthening owing to the formation of a solute-rich atmosphere after warm *** results of the tensile tests at 300℃indicated that the de-gree of strengthening was proportional to the pre-strain *** strength of 1.4 GPa can be achieved with good ductility(17%elongation)by warm *** novel warm-rolling strengthening method ex-pedites the potential application of Fe-29.1Mn-12.5Al-1.35C-4.95Cr as a 1.4 GPa class ultra-lightweight steel.

关键词： FeMnAlC Cr addition κ-carbide Dynamic strain aging Strengthening

Formation of carbon and oxygen rich surface layer on high purity magnesium by atmospheric carbon dioxide plasma

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第1期11卷 88-99页

作者： Gyoung G.Jang Sinchul yeom Jong K.Keum Mina Yoon Harry III Meyer Yi-Feng Su Jiheon jun Manufacturing Science Division Oak Ridge National Laboratory(ORNL)One Bethel Valley RoadPO Box 2008MS6054Oak RidgeTN 37831United States Material Science and Technologies Division Oak Ridge National Laboratory(ORNL)One Bethel Valley RoadOak RidgeTN 37831United States Neutron Scattering Division&Center for Nanophase Materials Sciences ORNLOne Bethel Valley RoadOak RidgeTN 37831United States Chemical Sciences Division ORNLOne Bethel Valley RoadOak RidgeTN 37831United States

Carbon and oxygen-rich corrosion barrier layer formed on Mg by a simple and scalable CO_(2) atmospheric plasma(CO_(2)-AP)*** reactive CO_(2)-AP interacts with the Mg surface and forms a unique layered structure with the top MgCO_(3)/MgO-intermixed particulates pillars and the bottom dense *** surface features were simultaneously formed on the nano-/micro-structured MgO layer by carbonate molecules,plasma-active CO_(2) molecules,and/or other volatile organic compounds on the nano-/micro-structured MgO particle *** resulting surfaces after CO_(2)-AP were either hydrophobic or hydrophilic and exhibited lower anodic current or high resistance for Mg *** the hydrophobic surfaces of CO_(2)-AP treated Mg,molecular dynamic simulations were performed to understand the origin of hydrophobicity and identified that the amorphous carbon layers formed on the Mg surface are the *** environmentally benign abundant-gas-based process enables the cost reduction associated with waste treatment,generation of by-product,and supply of raw material.

关键词： Atmospheric plasma Magnesium Corrosion protection Surface modification

In?uence of Carbon Equivalent Value on the Weld Bead Bending Properties of High-Strength Low-Alloy Steel Plates

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2017年第4期33卷 321-329页

作者： Ki Hyuk Kim In jun Moon Ki Won Kim Ki bong Kang Byung Gyu Park Kwang Seok Lee R&D Center of Dongkuk Steel Mill Co. Ltd Pohang 790-729 South Korea Korea Institute of Materials Science Implementation Research Division Materials Deformation Department 797 Changwondaero Changwon Gyeongnarn642-831 South Korea

The contribution of chemical compositions in terms of carbon equivalent value（CEV） on impending crack propagation during weld bead bend tests（WBBTs） was studied with five different high-strength lowalloy steel plates that underwent different rolling processes. The test showed that cracks developed at the weld joint, easily passed through the coarse-grain heat-affected zone（CGHAZ）, and finally were arrested within the heat-affected zone（HAZ）. An apparent decrease in the average crack length, which consequently indicated improvement in crack arrestability, was found with decreasing CEV. In addition,the relatively fine microstructure in the HAZ of low-CEV steel plates helped in preventing the crack from further propagation. Special emphasis was placed on the empirical expectation of critical CEV above which WBBT might fail.

关键词： Mechanical characterization Steel Welding Fracture Crack arrestability against bending

Optimal Resource Allocation for NOMA Wireless Networks

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第2期74卷 3249-3261页

作者： Fahad R.Albogamy M.A.Aiyashi Fazirul Hisyam Hashim Imran Khan bong jun Choi Turabah University College Computer Sciences ProgramTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of Mathematics Jazan UniversityJazanP.O.Box 218Saudi Arabia Department of Computer and Communication Systems Engineering Faculty of EngineeringUniversiti Putra Malaysia(UPM)43400SerdangMalaysia Department of Electrical Engineering University of Engineering and Technology PeshawarP.O.Box 814Pakistan School of Computer Science and Engineering Soongsil UniversitySeoulKorea

The non-orthogonal multiple access(NOMA)method is a novel multiple access technique that aims to increase spectral efficiency(SE)and accommodate enormous user ***-user signals are superimposed and transmitted in the power domain at the transmitting end by actively implementing controllable interference information,and multi-user detection algorithms,such as successive interference cancellation(SIC),are performed at the receiving end to demodulate the necessary user *** its basic signal waveform,like LTE baseline,could be based on orthogonal frequency division multiple access(OFDMA)or discrete Fourier transform(DFT)-spread OFDM,NOMA superimposes numerous users in the power *** contrast to the orthogonal transmission method,the nonorthogonal method can achieve higher spectrum ***,it will increase the complexity of its *** power allocation techniques will have a direct impact on the system’s *** a result,in order to boost the system capacity,an efficient power allocation mechanism must be *** research developed an efficient technique based on conjugate gradient to solve the problem of downlink power *** major goal is to maximize the users’maximum weighted sum *** suggested algorithm’s most notable feature is that it converges to the global optimal *** compared to existing methods,simulation results reveal that the suggested technique has a better power allocation capability.

关键词： Non-orthogonalmultiple access wireless networks power domain 5G networks