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Chinese Physics B 2021年第11期30卷 481-487页

作者： Zhe Wang wenguang zhu Department of Physics University of Science and Technology of ChinaHefei 230026China International Center for Quantum Design of Functional Materials(ICQD) Hefei National Laboratory for Physical Sciences at the Microscaleand Synergetic Innovation Center of Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaHefei 230026China Key Laboratory of Strongly-Coupled Quantum Matter Physics Chinese Academy of SciencesSchool of Physical SciencesUniversity of Science and Technology of ChinaHefei 230026China

Monolayer transition metal dichalcogenides can normally exist in several structural polymorphs with distinct electrical,optical,and catalytic *** control of the relative stability and transformation of different phases in these materials is thus of critical importance for *** density functional theory calculations,we investigate the effects of low-work-function metal substrates including Ti,Zr,and Hf on the structural,electronic,and catalytic properties of monolayer MoS_(2) and WS_(2).The results indicate that such substrates not only convert the energetically stable structure from the 1H phase to the 1T'/1T phase,but also significantly reduce the kinetic barriers of the phase ***,our calculations also indicate that the 1T' phase of MoS_(2) with Zr or Hf substrate is a potential catalyst for the hydrogen evolution reaction.

关键词： transition metal dichalcogenides phase transformation hydrogen evolution reaction density functional theory

Giant Rashba-like spin-orbit splitting with distinct spin texture in two-dimensional heterostructures

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Chinese Physics B 2021年第8期30卷 485-491页

作者： Jianbao zhu Wei Qin wenguang zhu Department of Physics University of Science and Technology of Chinaand Key Laboratory of Strongly-Coupled Quantum Matter PhysicsChinese Academy of SciencesHefei 230026China International Center for Quantum Design of Functional Materials(ICQD) Hefei National Laboratory for Physical Sciences at the Microscaleand Synergetic Innovation Center of Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaHefei 230026China

Based on first-principles density functional theory calculation,we discover a novel form of spin-orbit(SO)splitting in two-dimensional(2D)heterostructures composed of a single Bi(111)bilayer stacking with a 2D semiconducting In_(2)Se_(2) or a 2D ferroelectricα-In_(2)Se_(3) *** SO splitting has a Rashba-like but distinct spin texture in the valence band around the maximum,where the chirality of the spin texture reverses within the upper spin-split branch,in contrast to the conventional Rashba systems where the upper branch and lower branch have opposite chirality solely in the region below the band crossing *** ferroelectric nature ofα-In_(2)Se_(3) further enables the tuning of the spin texture upon the reversal of the electric polarization with the application of an external electric *** analysis based on a tight-binding model reveals that such SO splitting texture results from the interplay of complex orbital characters and substrate *** finding enriches the diversity of SO splitting systems and is also expected to promise for spintronic applications.

关键词： spin-orbit splitting two-dimensional heterostructure first-principles calculation

Machine learning potential aided structure search for low-lying candidates of Au clusters

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Chinese Physics B 2022年第7期31卷 613-619页

作者： Tonghe Ying Jianbao zhu wenguang zhu Department of Physics University of Science and Technology of Chinaand Key Laboratory of Strongly-Coupled Quantum Matter PhysicsChinese Academy of SciencesHefei 230026China International Center for Quantum Design of Functional Materials(ICQD) Hefei National Laboratory for Physical Sciences at the Microscaleand Synergetic Innovation Center of Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaHefei 230026China

A machine learning(ML)potential for Au clusters is developed through training on a dataset including several different sized *** ML potential accurately covers the whole configuration space of Au clusters in a broad size range,thus expressing a good performance in search of their global minimum energy *** on our potential,the low-lying structures of 17 different sized Au clusters are identified,which shows that small sized Au clusters tend to form planar structures while large ones are more likely to be stereo,revealing the critical size for the two-dimensional(2D)to three-dimensional(3D)structural *** calculations demonstrate that ML is indeed powerful in describing the interaction of Au atoms and provides a new paradigm on accelerating the search of structures.

关键词： machine learning potential gold cluster first-principles calculation

Slip behavior of Bi-modal structure in a metastable β titanium alloy during tensile deformation

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Journal of Materials Science & Technology 2020年第22期54卷 188-196页

作者： wenguang zhu Changsheng Tan Ruoyu Xiao Qiaoyan Sun Jun Sun State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong UniversityXi'an.710049China School of Materials Science&Engineering Xi'an University of TechnologyXi'an710048China

β titanium alloys with bi-modal structure which exhibit improved strength-ductility combination and fatigue property are widely used in aviation and aerospace ***,owing to the small size of primary α(αp) and nano-scaled multi variant distribution of secondary α platelets(αs),investigating the deformation behavior is really a challenging *** this work,by applying transmission electron microscopy(TEM),the slip behavior in αp and transformed β matrix with different tensile strain was *** α/β solution treatment,the initial dislocation slips on {110} plane with direction in β *** furtherdeformation,(110),(101) and(1 1 2) multi slip is generated which shows a long straight cro s sing *** cell is exhibited in β matrix at tensile strain above 20 %.Diffe rent from the solid solution treated sample,high density wavy dislocations are generated in transformedβ *** fraction fine as hinders dislocation motion in β matrix effectively which in turn dominates the strength of the *** primary α phase(αp),a core-shell structure is formed during *** pyramidal a+c slip and prismatic/basal a slip are generated in the shell *** core region,plastic deformation is governed by prismatic/basal a *** of the core-shell structure is the physical origin of the improved *** one hand,the work hardening layer(shell) improves the strength of αp,which could deform compatibly with the hard transformed β ***,the center area(core) deforms homogeneously which will sustain plastic strain effectively and increase the *** paper studies the slip behavior and reveals the origin of the improved strength-ductility combination in Bi-modal structure on a microscopic way,which will give theoretical advises for developing the next generation high strength β titanium alloys.

关键词： βTitanium alloy Plastic deformation Slip behavior Bi-modal structure Core-shell structure

Prediction of quantum anomalous Hall effect in CrI_(3)/ScCl_(2)bilayer heterostructure

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Chinese Physics B 2022年第10期31卷 507-513页

作者： Yuan Gao Huiping Li wenguang zhu International Center for Quantum Design of Functional Materials(ICQD) Hefei National Laboratory for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefei 230026China Department of Physics University of Science and Technology of ChinaHefei 230026China

Based on first-principles calculations,a two-dimensional(2D)van der Waals(vd W)bilayer heterostructure consisting of two topologically trivial ferromagnetic(FM)monolayers CrI_(3)and ScCl_(2)is proposed to realize the quantum anomalous Hall effect(QAHE)with a sizable topologically nontrivial band gap of 4.5 me *** topological nature is attributed to an interlayer band inversion between the monolayers and critically depends on the symmetry of the stacking *** further demonstrate that the topologically nontrivial band gap can be increased nearly linearly by the application of a perpendicular external pressure and reaches 8.1 me V at 2.7 GPa,and the application of an external out-of-plane electric field can also modulate the band gap and convert the system back to topologically trivial via eliminating the band *** effective model is developed to describe the topological phase evolution in this bilayer *** work provides a new candidate system based on 2D vd W materials for realization of potential high-temperature QAHE with considerable controllability.

关键词： quantum anomalous Hall effect two-dimensional heterostructure

Strain transfer behavior and crystallographic mechanism of crack initiation during cyclic deformation in zirconium

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Journal of Materials Science & Technology 2023年第31期162卷 234-246页

作者： Xiangkang Zeng Conghui Zhang wenguang zhu Mingliang zhu Tongguang Zhai Chi Ma Tingchuang Shu KangKai Song School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Key Laboratory of Pressure Systems and Safety Ministry of EducationSchool of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai 200237China School of Materials Science and Engineering Shandong Jianzhu UniversityJinan 250101China

Fully-reversed cyclic deformation of a pure Zr(a thickness of 17 mm)was conducted at two different strain amplitudes(0.4%and 0.8%)to investigate the deformation and crack initiation behaviors based on slip trace *** was found that prismaticaslip with a higher Schmid Factor(m>0.4)was the dominant deformation *** grains containing persistent slip bands(PSBs)tended to go towards[1210]pole and the Schmid Factor had a critical value of 0.4 above which prismatic and pyramidal slip were *** cracks were mainly initiated at PSBs and grain boundaries(GBs).It showed that 61.1%of the cracks were PSB cracks under a strain amplitude of 0.4%,while it decreased to 53.5%at a strain amplitude of 0.8%.PSB cracks were mainly parallel to prismaticaslip with higher Schmid Factor while some cracks tended to be initiated at GBs with higher misorientation *** interaction of PSBs with GBs would result in strain transferring to the neighboring *** transfer was more likely to occur at the condition of the higher geometrical compatibility factor m,and lower residual Burgers vectorb,which could reduce strain localization.

关键词： Fatigue crack initiation Crystallographic orientation PSBs GBs Strain transfer

Performance Evaluation for Medium Voltage MIMO-OFDM Power Line Communication System

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China Communications 2020年第1期17卷 151-162页

作者： Yingxue Li Min Zhang wenguang zhu Mengyuan Cheng Cheng Zhou Yongpeng Wu Jiangxi Economic Research Institutestate STATE GRIDNanchang 330000China Department of Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Power line communication(PLC)provides intelligent electrical functions such as power quality measurement,fault surveys,and remote control of electrical *** of research works have been done in low voltage(LV)scenario due to the fast development of in-home *** aim of this paper is to evaluate the link-level performance of a medium voltage(MV)MIMO-OFDM communication system based on transmission link under underground power line *** MIMO channel is modeled as a modified multipath model in the presence of impulsive noise and background *** first perform a measurement on the practical MV MIMO channel parameters for a section of buried cable of 1 km long in Ganzhou city,Jiangxi province,*** on the measured channel,we design the frame structure based on an IEEE standard for broadband over power line networks[1]to support MV MIMO-OFDM *** to designed frame structure,we design an encoder and a decoder for a dual binary tail-biting turbo code and optimize some key decoder parameters for low bit error rate ***,the link-level performance for both spatial multiplexing and spatial diversity are *** results show that MV MIMO-OFDM is a promising approach to provide both high data rate and link reliability for PLC.

关键词： power line communication(PLC) MIMO-OFDM multi-conductor medium voltage underground cables turbo code

Surface-adsorbed ions on TiO2 nanosheets for selective photocatalytic CO2 reduction

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Nano Research 2018年第6期11卷 3362-3370页

作者： Xiaogang Li Wentuan Bi Zhe Wang wenguang zhu Wangsheng Chu Changzheng Wu Yi Xie Hefei National Laboratory for Physical Sciences at the Microscale iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) and CAS Key Laboratory of Mechanical Behavior and Design of Materials University of Science and Technology of China Hefei 230026 China International Center for Quantum Design of Functional Materials (ICQD) Hefei National Laboratory for Physical Sciences at the Microscale (HFNL) Synergetic Innovation Center of Quantum Information and Quantum Physics Department of Physics and Key Laboratory of Strongly-Coupled Quantum Matter Physics Chinese Academy of Sciences School of Physical Sciences University of Science and Technology of China Hefei 230026 China National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei230026 China

A method based on the adsorption of ions on the surface of two-dimensional （2D） nanosheets has been developed for photocatalytic COz reduction. Isolated Bi ions, confined on the surface of TiO2 nanosheets using a simple ionic adsorption method facilitate the formation of a built-in electric field that effectively promotes charge carrier separation. This leads to an improved performance of the photocatalytic COa reduction process with the preferred conversion to CH4. The proposed surface ion-adsorption method is expected to provide an effective approach for the design of highly efficient photocatalytic systems. These findings could be very valuable in photocatalytic CO2 reduction applications.

关键词： two-dimensional nanomaterials surface modification ion adsorption photocatalysis TiO2 nanosheets

Prediction of protected band edge states and dielectric tunable quasiparticle and excitonic properties of monolayer MoSi_(2)N_(4)

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npj Computational Materials 2022年第1期8卷 1216-1222页

作者： Yabei Wu Zhao Tang Weiyi Xia Weiwei Gao Fanhao Jia Yubo Zhang wenguang zhu Wenqing Zhang Peihong Zhang Department of Materials Science and Engineering and Shenzhen Institute for Quantum Science&engineering Southern University of Science and TechnologyShenzhenGuangdong518055China Guangdong Provincial Key Lab for Computational Science and Materials Design and Shenzhen Municipal Key Lab for Advanced Quantum Materials and DevicesSouthern University of Science and TechnologyShenzhenGuangdong518055China ICQD Hefei National Laboratory for Physical Science at the MicroscaleKey Laboratory of Strongly-Coupled Quantum Matter PhysicsChinese Academy of SciencesDepartment of Physicsand Synergetic Innovation Center of Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaHefeiAnhui230026China Department of Physics University at BuffaloState University of New YorkBuffaloNY14260USA Department of Physics Dalian University of TechnologyDalianLiaoning116024China International Centre for Quantum and Molecular Structures Materials Genome InstituteDepartment of PhysicsShanghai University99 Shangda RoadShanghai200444China

The electronic structure of two-dimensional(2D)materials are inherently prone to environmental perturbations,which may pose significant challenges to their applications in electronic or optoelectronic devices.A 2D material couples with its environment through two mechanisms:local chemical coupling and nonlocal dielectric screening *** local chemical coupling is often difficult to predict or control *** dielectric screening,on the other hand,can be tuned by choosing the substrates or layer thickness in a controllable ***,a compelling 2D electronic material should offer band edge states that are robust against local chemical coupling *** it is demonstrated that the recently synthesized MoSi_(2)N_(4)is an ideal 2D semiconductor with robust band edge states protected from capricious environmental chemical coupling *** many-body perturbation theory calculations are carried out to illustrate how the band edge states of MoSi_(2)N_(4)are shielded from the direct chemical coupling effects,but its quasiparticle and excitonic properties can be modulated through the nonlocal dielectric screening *** unique property,together with the moderate band gap and the thermodynamic and mechanical stability of this material,paves the way for a range of applications of MoSi_(2)N_(4)in areas including energy,2D electronics,and optoelectronics.

关键词： dielectric protected quasi

Designing high-strength titanium alloy using pseudo-spinodal mechanism through diffusion multiple experiment and CALPHAD calculation

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Journal of Materials Science & Technology 2021年第15期74卷 78-88页

作者： Di Wu Libin Liu Lijun Zeng wenguang zhu Wanlin Wang Xiaoyong Zhang Junfeng Hou Baoliang Liu Jiafeng Lei Kechao Zhou State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China School of Material Science and Engineering Central South UniversityChangsha 410083China School of Metallurgy and Environment Central South UniversityChangsha 410083China School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055China School of Materials Science&Engineering North Minzu UniversityYinchuan 750021China Xi'an Trianlge Defence Incorporated Company Xi'an710089China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China

This study used the pseudo-spinodal mechanism to obtain the ultrafineαphase for designing highstrength titanium *** multiple experiments were designed to find the composition range of TM-x Mo-y V alloy(TM:Ti-4.5 Al-2 Cr-2.5 Nb-2 Zr-1 Sn)for obtaining ultrafineα*** results confirm that when the alloy composition is located near the intersection of theαandβphase free energy curves,the alloy will undergo pseudo-spinodal transformation and obtain the ultrafineα*** designed TM-6 Mo-3 V alloy has a yield strength of 1411 MPa and an elongation of 6.5%.The strength of the alloy depends on the thickness,fraction of theαphase and the solid solution strengthening effect of the alloying *** deformation mechanism of the alloy is the dislocation slip of theαandβphases and the twin deformation of theα*** large number ofα/βinterfaces produced by the fineαphase is the main reason for limiting the ductility of the *** use of the pseudo-spinodal mechanism combined with diffusion multiple experiments and CALPHAD is an effective method for designing high-strength titanium alloys.

关键词： Pseudo-spinodal mechanism Alloy design CALPHAD Diffusion multiple Strengthening mechanism