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Structural Durability & Health Monitoring 2025年第1期19卷 55-75页

作者： zhenyu zhang Quan Jin Haitao zhang Zhao Liu Yuyang Wu Longfei zhang Renzhang Yan CCCC Third Highway Engineering Co. Ltd.Beijing101300China School of Civil Engineering Chongqing Jiaotong UniversityChongqing400074China

When the upper chord beam of the beam-string structure(BSS)is made of concrete-filled steel tube(CFST),its overall stiffness will change greatly with the construction of concrete placement,which will have an impact on the design of the tensioning plans and selection of control measures for the *** order to accurately obtain the bending stiffness of CFST beam and clarify its impact on the mechanical properties of composite BSS during construction,the influence of some factors such as height-width ratio,wall thickness of steel tube,elasticity modulus of concrete,and friction coefficient on the bending stiffness are analyzed parametrically by the numerical simulation technology based on an actual *** calculation formula of the equivalent bending stiffness of CFST is also established through mathematical statistical ***,the equivalent bending stiffness is introduced into the construction and use stages of the composite BSS,respectively,and the mechanical properties such as prestress-tensioning control value,structural deformation,and internal force of key members are comparatively analyzed when adopting two different construction ***,the optimal construction plan of concrete placement first and then prestress-tensioning is proposed.

关键词： Concrete panels freeze-thaw damage compression-shear crack tension-shear crack

Riding on bifurcating Berry curvatures into reentrant quantum anomalous Hall states

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Science China(Physics,Mechanics & Astronomy) 2022年第4期65卷 125-126页

作者： zhenyu zhang International Center for Quantum Design of Functional Materials(ICQD) Hefei National Laboratory for Physical Sciences at MicroscaleUniversity of Science and Technology of ChinaHefei 230026China

When a sufficiently strong magnetic field is applied to a twodimensional electron gas,it will drive the electrons into quantized states,known as the Landau *** transport properties of such a system are best manifested by the emergence of the(integer)quantum Hall effect(QHE)[1],characterizing the system as a quantum Hall insulator,a close and proceeding analog of the quantum spin Hall insulator.

关键词： quantum system states

A promising new route toward materialization of high-temperature topological superconductors

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Science Bulletin 2017年第10期62卷 671-672页

作者： zhenyu zhang International Center for Quantum Design of Functional Materials (ICQD) Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Centerof Quantum Information and Quantum Physics University of Science and Technology of China Hefei 230026 China

Topologically non-trivial superconductivity,or more succinctly known as chiral superconductivity,is a new property of quantum matter actively chased after by today’s condensed matter *** motivations for such research efforts are mainly *** one,it is naturally intriguing to integrate superconductivity and topology,respectively among the most fundamental and stimulating concepts in physics and *** the other,prop-

关键词：超导体拓扑学凝聚态物质物化高温量子计算超导性物理学

Optical waveguide in curved and welded perovskite nanowires

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Science China(Technological Sciences) 2023年第5期66卷 1471-1479页

作者： zhang zhenyu zhang YuPeng HONG BinBin WANG GuoPing College of Electronics and Information Engineering Shenzhen UniversityShenzhen 518060China

Single-crystalline lead halide perovskite nanowires are emerging as promising one-dimensional blocks for nanoscience and nanotechnology,and extensive studies of nano-lasers and nano-photodetectors have been ***,as perfect confined structures,their optical waveguide performances have not been widely paid attention to up to ***,we report on the such issue on single-crystalline CsPbBr3nanowires and quantify it by near-field optical response *** waveguide is verified as total internal reflection mode at the visible band(532 nm),and its far-field end-facet coupling efficiency of 89.6%and propagation loss as low as 5.9 dB/mm are measured from the nanowire with cross-sectional geometry of~600 nm×300 *** evident bending loss exists in naturally curved nanowires,while it usually emerges in artificial-bended ones due to the wrinkled *** welded nanowire networks show significant advantages in integrated waveguides over the artificial assembled ones,due to the coupled photons at the space-confined end-facet *** surface reasoned by lattice degradation is detrimental to propagation loss,but it provides leaked channels for waveguide coupling on nanowire *** work studies the optical waveguide performance of perovskite nanowires with different geometries and goes a step further for integrated nanophotonics.

关键词： optical waveguide perovskite nanowires SNOM curved nanowire welded networks

Selective flattening of magnon bands in kagome-lattice ferromagnets with Dzyaloshinskii-Moriya interaction

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Science China(Physics,Mechanics & Astronomy) 2020年第10期63卷 98-104页

作者： YuHeng Xing FuSheng Ma LiFa zhang zhenyu zhang NNU-SULI Thermal Energy Research Center(NSTER)Center for Quantum Transport and Thermal Energy Science(CQTES) School of Physics and TechnologyNanjing Normal UniversityNanjing 210023China International Center for Quantum Design of Functional Materials(ICQD) Hefei National Laboratory for Physical Sciences at Microscaleand Synergetic Innovation Center of Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaHefei 230026China

There is growing interest in revealing exotic properties of collective spin excitations in kagome-lattice ferromagnets such as magnon Hall effects,topological magnon insulators,and flat magnon *** the well-established nearest-neighbor Heisenberg ferromagnet model with Dzyaloshinskii-Moriya interaction(DMI),in this study we uncover intriguing new aspects in the selectivity and topology of flat magnon *** the three magnon bands(except for the top one,which is flat in the absence of DMI),we observe that each of the three bands can be selectively flattened at the critical DMI of D=±√3 J/3 and D=±√3 *** a general DMI,the magnon bands become non-flat;however,there are nested lines that create a David star pattern for all three magnon bands whose flatness is robust during changing exchange coupling or *** to prevailing belief,we show that each of the three flat bands is actually topologically trivial at critical ***,we show that while the middle band remains topologically trivial,for the other two bands,D=0 corresponds to the topological phase transition where their Chern numbers get interchanged;when D=±√3 J,the system undergoes a phase transition to the nonferromagnetic *** central findings increase our understanding of spin excitations for future magnonics applications.

关键词： flat magnon bands kagome lattice ferromagnet Dzyaloshinskii-Moriya interaction

Boron based hypergolic ionic liquids:A review

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Green Energy & Environment 2021年第6期6卷 794-822页

作者： zhenyu zhang Zirui Zhao Binshen Wang Jiaheng zhang State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyShenzhen518055China Research Centre of Printed Flexible Electronics School of Materials Science and EngineeringHarbin Institute of TechnologyShenzhen518055China

The advance of space technology is deeply affected by the breakthrough of high-performance *** ionic liquids(HILs)are one of the most potential fuels for bipropellant ***,high viscosity value and low specific impulse of traditional N-based HILs limit their ***,boron-based HILs with low viscosity become the new candidates,and their derivatives are also found to promote the hypergolicity as additives in ***,the synthesis,physical chemical properties and thermal performance of boron-based HILs and HILadditive system are reviewed.

关键词： Ionic liquids Hypergolic fuels Boron-based compounds

Topological and superconducting properties of monolayered CoN and CoP:A first-principles comparative study

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 98-108页

作者： Jiaqing Gao zhenyu zhang Ping Cui International Center for Quantum Design of Functional Materials(ICQD) Hefei National Research Center for Physical Sciences at Microscale(HFNL)University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Two-dimensional systems that simultaneously harbor superconductivity and nontrivial band topology may serve as appealing platforms for realizing topological superconductivity with promising applications in fault-tolerant quantum ***,based on first-principles calculations,we show that monolayered Co N and Co P with the isovalent Fe Se-like structure are stable in freestanding form,even though their known bulk phases have no resemblance to *** two systems are further revealed to display intrinsic band inversions due to crystal field splitting,and such orderings are preserved with the inclusion of spin-orbit coupling(SOC),which otherwise is able to open a curved band gap,yielding a non-zero Z2 topological invariant in each *** a mechanism of topologicalization is distinctly contrasted with that identified recently for the closely related monolayers of CoX(X=As,Sb,Bi),where the SOC plays an indispensable role in causing a nontrivial band ***,we demonstrate that,by applying equi-biaxial tensile strain,the electron-phonon coupling strength in monolayered CoN can be significantly enhanced,yielding a superconducting transition temperature(Tc)up to 7-12 K for the Coulomb pseudopotential ofμ*=0.2-0.1,while the CoP monolayer shows very low Tc even under pronounced *** different superconducting behaviors can be attributed to different variations in lattice softening and electronic density of states around the Fermi level upon *** central findings enrich the understanding of different mechanisms of band inversions and topologicalization and offer platforms for achieving the coexistence of superconductivity and nontrivial band topology based on two-dimensional systems.

关键词： topological yielding otherwise

Two-dimensional superconductors with intrinsic p-wave pairing or nontrivial band topology

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Science China(Physics,Mechanics & Astronomy) 2023年第6期66卷 53-73页

作者： Wei Qin Jiaqing Gao Ping Cui zhenyu zhang International Center for Quantum Design of Functional Materials(ICQD) Hefei National Research Center for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefei 230026China Department of Physics The University of Texas at AustinAustin 78712USA

Over the past fifteen years,tremendous efforts have been devoted to realizing topological superconductivity in realistic materials and systems,predominately propelled by their promising application potentials in fault-tolerant quantum information *** this article,we attempt to give an overview on some of the main developments in this field,focusing in particular on two-dimensional crystalline superconductors that possess either intrinsic p-wave pairing or nontrivial band *** first classify the three different conceptual schemes to achieve topological superconductor(TSC),enabled by real-space superconducting proximity effect,reciprocal-space superconducting proximity effect,and intrinsic *** the first scheme has so far been most extensively explored,the subtle difference between the other two remains to be fully *** then move on to candidate intrinsic or p-wave superconductors,including Sr2Ru O4,UTe2,Pb3Bi,and graphene-based *** TSC systems that rely on proximity effects,the emphases are mainly on the coexistence of superconductivity and nontrivial band topology,as exemplified by transition metal dichalcogenides,cobalt pnictides,and stanene,all in monolayer or few-layer *** review completes with discussions on the three dominant tuning schemes of strain,gating,and ferroelectricity in acquiring one or both essential ingredients of the TSC,and optimizations of such tuning capabilities may prove to be decisive in our drive towards braiding of Majorana zero modes and demonstration of topological qubits.

关键词： topological superconductivity p-wave pairing proximity effects two-dimensional crystalline superconductors

Spray Characteristics of Air-Assisted Injector Under Different Ambient Pressures

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Journal of Beijing Institute of Technology 2020年第3期29卷 317-325页

作者： Hao Wu Fujun zhang zhenyu zhang School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Shenzhen Research Institute Beijing Institute of TechnologyShenzhen 518057China

Spray atomization of liquid fuel plays an important role in droplet evaporation,combustible mixture formation and subsequent combustion ***-atomized liquid spray contributes to high fuel efficiency and low pollutant *** direct injection(GDI)has been recognized as one of the most effective ways to improve fuel *** a special direct injection method,the air-assisted direct injection utilizes high-speed flow of high-pressure air at the injector exit to assist liquid fuel injection and promote spray atomization at a low injection *** injection method has excellent application potential and advantages for high performance and lightweight *** this study,the hollow cone spray emerging from an air-assisted injector was studied in a constant volume chamber with the ambient pressures ranging from 5 kPa to 300 *** macro characteristics of spray were obtained using high speed backlit *** Doppler particle analyzer(PDPA)was utilized to study the microcosmic spray *** results show that under the flash boiling condition,the spray will generate a strong flash boiling point which causes the cone shape spray to expand both inwards and *** axisymmetric inward expansion would converge together and form a lathy aggregation area below the nozzle and the axisymmetric outward expansion greatly increases the spray *** sauter mean diameter(SMD)of flash boiling condition can be reduced to 5μm compared to the level close to 10μm in the non-flash boiling condition.

关键词： ambient pressure air-assisted injector spray characteristics flash boiling phase Doppler particle analyzer(PDPA)

Resource Allocation for Cognitive Network Slicing in PD-SCMA System Based on Two-Way Deep Reinforcement Learning

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China Communications 2024年第6期21卷 53-68页

作者： zhang zhenyu zhang Yong Yuan Siyu Cheng Zhenjie School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Beijing Key Laboratory of Work Safety Intelligent Monitoring(Beijing University of Posts and Telecommunications) Beijing 100876China

In this paper,we propose the Two-way Deep Reinforcement Learning(DRL)-Based resource allocation algorithm,which solves the problem of resource allocation in the cognitive downlink network based on the underlay *** users(SUs)in the cognitive network are multiplexed by a new Power Domain Sparse Code Multiple Access(PD-SCMA)scheme,and the physical resources of the cognitive base station are virtualized into two types of slices:enhanced mobile broadband(eMBB)slice and ultrareliable low latency communication(URLLC)*** design the Double Deep Q Network(DDQN)network output the optimal codebook assignment scheme and simultaneously use the Deep Deterministic Policy Gradient(DDPG)network output the optimal power allocation *** objective is to jointly optimize the spectral efficiency of the system and the Quality of Service(QoS)of *** results show that the proposed algorithm outperforms the CNDDQN algorithm and modified JEERA algorithm in terms of spectral efficiency and QoS ***,compared with the Power Domain Non-orthogonal Multiple Access(PD-NOMA)slices and the Sparse Code Multiple Access(SCMA)slices,the PD-SCMA slices can dramatically enhance spectral efficiency and increase the number of accessible users.

关键词： cognitive radio deep reinforcement learning network slicing power-domain non-orthogonal multiple access resource allocation