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Properties of radiation defects and threshold energy of displacement in zirconium hydride obtained by new deep-learning potential

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Chinese Physics B 2024年第7期33卷 456-465页

作者：王玺唐孟蒋明璇陈阳春刘智骁邓辉球 School of Physics and electronics Hunan UniversityChangsha 410082China college of materials Science and engineering Hunan UniversityChangsha 410082China

Zirconium hydride(ZrH_(2)) is an ideal neutron moderator material. However, radiation effect significantly changes its properties, which affect its behavior and the lifespan of the reactor. The threshold energy of displacement is an important quantity of the number of radiation defects produced, which helps us to predict the evolution of radiation defects in ZrH_(2).Molecular dynamics(MD) and ab initio molecular dynamics(AIMD) are two main methods of calculating the threshold energy of displacement. The MD simulations with empirical potentials often cannot accurately depict the transitional states that lattice atoms must surpass to reach an interstitial state. Additionally, the AIMD method is unable to perform largescale calculation, which poses a computational challenge beyond the simulation range of density functional theory. Machine learning potentials are renowned for their high accuracy and efficiency, making them an increasingly preferred choice for molecular dynamics simulations. In this work, we develop an accurate potential energy model for the ZrH_(2) system by using the deep-potential(DP) method. The DP model has a high degree of agreement with first-principles calculations for the typical defect energy and mechanical properties of the ZrH_(2) system, including the basic bulk properties, formation energy of point defects, as well as diffusion behavior of hydrogen and zirconium. By integrating the DP model with Ziegler–Biersack–Littmark(ZBL) potential, we can predict the threshold energy of displacement of zirconium and hydrogen in ε-ZrH_(2).

关键词： zirconium hydride deep learning potential radiation defects molecular dynamics threshold energy of displacement

Crystalline-amorphous M@MN_x(M=Co,Fe,Ni)encapsulated in nitrogen-doped carbon for enhanced efficient and durable hydrogen evolution reaction

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Rare Metals 2024年第4期43卷 1547-1556页

作者： Yang Yang Xiao-Chuan Duan Shao-Hui Guo Xian-Ming Zhang college of materials Science and engineering College of ChemistryKey Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of TechnologyYuci030600China

Developing earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is important for the sustainable energy ***,efficient and stable heterocatalysts consisting of crystalline-amorphous M@MN_(x)(M=Co,Fe,Ni)encapsulated in N-doped carbon layers supported with N-doped graphene sheets(denoted as M@MN_(x)@NC-NG)are synthesized by facile hydrothermal reaction and nitridation *** the nitriding process,metal ions in M(tzbc)_2(H_(2)O)_4(tzbc=4-(1H-1,2,4-triazol-1-yl)benzoic acid)complexes are reduced to crystalline M cores,accompanied by the formation of amorphous MN_(x)shells;the tzbc ligands are insitu carbonized to form outermost N-doped carbon(NC)layers that connect with inner MN_(x)via M-N-C motifs inherited from the complex precursors and inhibit the transition of MN_(x)from amorphous to crystalline *** Co@CoN_(x)@NC-NG catalyst exhibits excellent HER activity with small overpotentials of 45 and 64 mV at a cathode current density of 10 mA·cm^(-2)and low Tafel slopes of 40 and 85 mV·dec^(-1)in 0.5 mol·L^(-1)H_(2)SO_4 and1.0 mol·L^(-1)KOH electrolytes,*** Co@CoN_(x)@NC-NG retains 97%of the initial overpotential after 100,000 s in both acidic and alkaline *** outstanding HER performance originates from the crystalline-amorphous Co@CoN_(x)that redistributes electrons around the heterointerfaces,facilitating the conversion process of H^(+)/H_(2)O to hydrogen and thereby promoting HER *** outermost NC layers serve as the armor of Co@CoN_(x),and graphene nanosheets act as carriers of egg-like Co@CoN_(x)@NC and conduction paths for electron shuttles,ensuring stable and continuous electrocatalytic hydrogen production.

关键词： Hydrogen evolution reaction Electrocatalysts Iron group metals Heterojunction Crystalline-amorphous structure

Prediction of liquid circulation flow rate in RH degasser:improvement of decarburization at low atmospheric pressure

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Journal of Iron and Steel Research(International) 2024年第7期31卷 1661-1667页

作者： Gu-jun Chen Sheng-ping He college of materials Science and engineering Yangtze Normal UniversityChongqing 400044China college of materials Science and engineering Chongqing UniversityChongqing 400044China

The two-fluid model coupled with population balance model was used for simulating the gas-liquid flow in the Ruhrstahl-Heraeus(RH)*** predicted circulation flow rate was compared with that measured from a water model experiment to validate the mathematical ***,influence of snorkel immersion depth on liquid circulation flow rate was numerically investigated under an atmospheric pressure of 101 and 84 kPa,*** result indicates that the circulation flow rate of the RH degasser in the high-altitude area was severely reduced because of the decrease in atmospheric ***,increasing the snorkel immersion depth from 0.5 to 0.7 m can compensate for the decrease in atmospheric *** test result indicates that decarburization rate is significantly enhanced by increasing the snorkel immersion *** optimization,the percentage of heats with a final carbon content less than 0.002 wt.%is significantly increased from 22.0%to 96.4%.

关键词： RH degasser Two-fluid model Population balance model-Circulation flow rate Decarburization Snorkel immersion depth

Stacking MoS_(2) flower-like microspheres on pomelo peels-derived porous carbon nanosheets for high-efficient X-band electromagnetic wave absorption

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Nano Research 2024年第3期17卷 1607-1615页

作者： Jia Zhao Zhe Gu Qingguo Zhang college of Chemistry and materials engineering Bohai UniversityJinzhou 121013China

The key to solve increasingly severe electromagnetic(EM)pollution is to explore sustainable,easily prepared,and cost-effective EM wave absorption materials with exceptional absorption ***,instead of anchoring on carbon materials in single layer,MoS_(2) flower-like microspheres were stacked on the surface of pomelo peels-derived porous carbon nanosheets(C)to fabricate MoS_(2)@C nanocomposites by a facile solvothermal *** wave absorption performances of MoS_(2)@C nanocomposites in X-band were systematically investigated,indicating the minimum reflection loss(RLmin)of-62.3 dB(thickness of 2.88 mm)and effective absorption bandwidth(EAB)almost covering the whole X-band(thickness of 2.63 mm)with the filler loading of only 20 wt.%.Superior EM wave absorption performances of MoS_(2)@C nanocomposites could be attributed to the excellent impedance matching characteristic and dielectric loss capacity(conduction loss and polarization loss).This study revealed that the as-prepared MoS_(2)@C nanocomposites would be a novel prospective candidate for the sustainable EM absorbents with superior EM wave absorption performances.

关键词： pomelo peels-derived porous carbon nanosheets(C) MoS_(2)@C nanocomposites stacked structure electromagnetic(EM)wave absorption

Recent advances in electrochemical performance of Mg-based electrochemical energy storage materials in supercapacitors:Enhancement and mechanism

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Journal of Magnesium and Alloys 2024年第1期12卷 35-58页

作者： Yuntao Xiao Xinfang Zhang Can Wang Jinsong Rao Yuxin Zhang college of materials Science and engineering Chongqing UniversityChongqing 400044China

The application of Mg-based electrochemical energy storage materials in high performance supercapacitors is an essential step to promote the exploitation and utilization of magnesium resources in the field of energy ***,the inherent chemical properties of magnesium lead to poor cycling stability and electrochemical reactivity,which seriously limit the application of Mg-based materials in ***,in this review,more than 70 research papers published in recent 10 years were collected and *** representative research works were selected,and the results of various regulative strategies to improve the electrochemical performance of Mg-based materials were *** effects of various regulative strategies(such as constructing nanostructures,synthesizing composites,defect engineering,and binder-free synthesis,etc.)on the electrochemical performance and their mechanism are demonstrated using spinelstructured MgX_(2)O_(4) and layered structured Mg-X-LDHs as *** addition,the application of magnesium oxide and magnesium hydroxide in electrode materials,MXene's solid spacers and hard templates are ***,the challenges and outlooks of Mg-based electrochemical energy storage materials in high performance supercapacitors are also discussed.

关键词： Supercapacitor Electrochemical energy storage Mg-based materials

Mechanism of microarc oxidation on AZ91D Mg alloy induced byβ-Mg_(17)Al_(12) phase

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International Journal of Minerals,Metallurgy and materials 2024年第4期31卷 712-724页

作者： Dajun Zhai Xiaoping Li Jun Shen college of materials Science and engineering Chongqing UniversityChongqing 400044China

This work proposed a strategy of indirectly inducing uniform microarc discharge by controlling the content and distribution ofβ-Mg_(17)Al_(12)phase in AZ91D Mg *** kinds of nano-particles(ZrO_(2)and TiO_(2))were designed to be added into the substrate of Mg alloy by friction stir processing(FSP).Then,Mg alloy sample designed with different precipitated morphology ofβ-Mg_(17)Al_(12)phase was treated by microarc oxidation(MAO)in Na_(3)PO_(4)/*** characteristics and performance of the MAO coating was analyzed using scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),contact angle meter,and potentiodynamic *** was found that the coarseα-Mg grains in extruded AZ91D Mg alloy were refined by FSP,and theβ-Mg_(17)Al_(12)phase with reticular structure was broken and *** nano-ZrO_(2)particles were pinned at the grain boundary by FSP,which refined theα-Mg grain and promoted the precipitation ofβ-Mg_(17)Al_(12)phase in *** effectively inhibited the“cascade”phenomenon of microarcs,which induced the uniform distribution of discharge *** MAO coating on Zr-FSP sample had good wettability and corrosion ***,TiO_(2)particles were hardly detected in the coating on TiFSP sample.

关键词： AZ91D Mg alloy microarc oxidation friction stir processing ZrO_(2) TiO_(2) β-Mg_(17)Al_(12)

Improvement of Microstructure and Mechanical Properties of Rapid Cooling Friction Stir-welded A1050 Pure Aluminum

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Journal of Wuhan University of Technology(materials Science) 2024年第1期39卷 134-141页

作者：许楠 LIU Lutao SONG Qining ZHAO Jianhua BAO Yefeng college of materials Science and engineering Hohai UniversityChangzhou 213200China

Two-mm thick A1050 pure aluminum plates were successfully joined by conventional and rapid cooling friction stir welding(FSW), respectively. The microstructure and mechanical properties of the welded joints were investigated by electron backscatter diffraction characterization, Vickers hardness measurements, and tensile testing. The results showed that liquid CO_(2) coolant significantly reduced the peak temperature and increased the cooling rate, so the rapidly cooled FSW joint exhibited fine grains with a large number of dislocations. The grain refinement mechanism of the FSW A1050 pure aluminum joint was primarily attributed to the combined effects of continuous dynamic recrystallization, grain subdivision, and geometric dynamic recrystallization. Compared with conventional FSW, the yield strength, ultimate tensile strength, and fracture elongation of rapidly cooled FSW joint were significantly enhanced, and the welding efficiency was increased from 80% to 93%. The enhanced mechanical properties and improved synergy of strength and ductility were obtained due to the increased dislocation density and remarkable grain refinement. The wear of the tool can produce several WC particles retained in the joint, and the contribution of second phase strengthening to the enhanced strength should not be ignored.

关键词： aluminum alloy friction stir welding recrystallization microstructure mechanical properties

Cost-effective fabrication of liquid metals via a laser induced graphene stamp for highly-stretchable integrated optoelectronics

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Nano Research 2024年第8期17卷 7603-7613页

作者： Weiqi Sun Li Xiang Zebang Luo Hui Wang Dong Li Anlian Pan college of materials Science and engineering Hunan UniversityChangsha 410082China

Stretchable electronics have found widespread applications in various fields such as wearable electronics,soft robots,and *** an important promising alternative of traditional rigid conductors,liquid metals have demonstrated immense potential to provide high conductivity and stretchability for the stretchable electronic ***,limited by their fluidity and high surface tension,challenges remain in achieving liquid metal patterns with low-cost,high-precision,large-scale,and complex ***,a fabrication technique was proposed based on laser-induced graphene(LIG)stamps to enable liquid metal self-selectively adhere to *** metal patterns could thus be achieved in different designed geometries and could be transferred onto stretchable *** liquid metal patterns exhibit exceptional electrical conductivity(3.24×10^(6)S/m even under 1000%strain),high stretchability(1000%strain,maximum of 2500%),small resistance changes under significant deformations(with a quality factor of 62.5 under 1000%strain),and high resolution(down to 50μm).Utilizing the patterned liquid metals,a stretchable integrated multifunctional optoelectronic system was demonstrated,encompassing a stretchable display matrix,a pressure sensor array,a wireless powering coil,and cardiovascular sensors,which further highlight the remarkable application potential of liquid metals in optoelectronic user-interaction and advanced physiological monitoring.

关键词： liquid metal wettability selective adhesion transfer printing stretchable electronics

Interfacial Reaction of Ti6Al4V Lattice Structure-Reinforced VW92 Alloy Matrix Composites

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 570-576页

作者： Haijun Wang Renju Cheng Xianhua Chen Mingbo Yang Daiyi Deng Lirui Liu Yongfeng Zhou Yanlong Ma Kaihong Zheng Fusheng Pan college of materials Science and engineering Chongqing University of TechnologyChongqing 400054China college of materials Science and engineering Chongqing UniversityChongqing 400044China Institute of New materials Guangdong Academy of SciencesGuangzhou 510650China

A novel melting infiltration by ultrasonic vibration was investigated and applied to fabricate Ti6Al4V(TC4)lattice structure-reinforced Mg-10Gd-2Y-1Zn-xZr(refer to VW92 hereafter,x=0,0.5 wt%)alloy matrix *** edge-to-edge matching model indicates that the well-matching and possible orientation relationships(ORs)between theα-Mg andα-Ti,[10-10]_(α-Mg)//[11-23]_(α-Ti) in(0002)_(α-Mg)//(10-10)_(α-Ti) possesses the smallest misfit of 0.4%(f_(r)),and thus theα-Mg grains can nucleate on the TC4 lattice *** reaction occurred in the TC4/VW92+0.5 wt%Zr composites,and the reaction product was confirmed to be Al_(2)Zr_(3),AlZr_(2) andα-Ti(Zr)particles formed by continuous solution of *** the interfacial products,the AlZr_(2) phase is a brittle phase with high-volume fraction,which is not conducive to the load *** generally speaking,theα-Ti(Zr)and theα-Mg tend to form a coherent interface,which is beneficial for improving the interfacial bonding strength of composites.

关键词： TC4 VW92 composites TC4 lattice structure Interfacial reaction Mismatch