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SmartMat 2023年第2期4卷 78-87页

作者： Yunchao Xu Gengming Zhang Wanrong Liu Chenxing Jin Yiling Nie Jia Sun Junliang Yang hunan key laboratory for super microstructure and ultrafast process School of Physics and ElectronicsCentral South UniversityChangshaChina hunan key laboratory of Nanophotonics and Devices School of Physics and ElectronicsCentral South UniversityChangshaChina

A significant step toward constructing high‐efficiency neuromorphic systems is the electronic emulation of advanced synaptic functions of the human *** previous studies have focused on mimicking the basic functions of synapses using single‐gate transistors,multigate transistors offer an opportunity to simulate more complex and advanced memory‐forming behaviors in biological *** this study,a simple and general method is used to assemble rubber semiconductors into suspended two‐phase composite films that are transferred to the surface of the ion‐conducting membrane to fabricate flexible multiterminal photoelectronic *** suspended ion conductive film is used as the gate dielectrics and supporting *** prepared devices exhibit excellent electrical stability and mechanical flexibility after being *** photoelectronic synaptic behavior and pulse‐dependent plasticity are ***,the device realizes the spatiotemporally integrated electrical and optical stimuli to mimic spatiotemporal information *** study provides a promising direction for constructing more complex spiking neural networks and more powerful neuromorphic systems with brain‐like dynamic spatiotemporal processing functions.

关键词： ion‐conducting membrane multiterminal neuromorphic devices optoelectronic neurotransistors self‐assembly semiconductor spatiotemporal information processing

Electronic effects on radiation damage inα-iron:A molecular dynamics study

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Chinese Physics B 2024年第3期33卷 521-529页

作者：江林李敏付宝勤崔节超侯氢 key laboratory for Radiation Physics and Technology Institute of Nuclear Science and TechnologySichuan UniversityChengdu 610064China

Iron(Fe)-based alloys,which have been widely used as structural materials in nuclear reactors,can significantly change their microstructure properties and macroscopic properties under high flux neutron irradiation during operation,thus,the problems associated with the safe operation of nuclear reactors have been put forward *** this work,a molecular dynamics simulation approach combined with electronic effects is developed for investigating the primary radiation damage process inα-***,the influence of electronic effects on the collision cascade in Fe is systematically evaluated based on two commonly used interatomic potentials for *** simulation results reveal that both electronic stopping(ES)and electron-phonon coupling(EPC)can contribute to the decrease of the number of defects in the thermal spike *** application of ES reduces the number of residual defects after the cascade evolution,whereas EPC has a reverse *** introduction of electronic effects promotes the formation of the dispersive subcascade:ES significantly changes the geometry of the damaged region in the thermal spike phase,whereas EPC mainly reduces the extent of the damaged ***,the incorporation of electronic effects effectively mitigates discrepancies in simulation outcomes when using different interatomic potentials.

关键词： radiation damage electronic effects molecular dynamics simulation α-iron

Passivation with crosslinkable diamine yields 0.1 V non-radiative Vloss in inverted perovskite solar cells

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Science Bulletin 2021年第5期66卷 417-420,M0003页

作者： Fang Wan Lili Ke Yongbo Yuan Liming Ding hunan key laboratory of super microstructure and ultrafast process School of Physics and ElectronicsCentral South UniversityChangsha 410083China Center for Excellence in Nanoscience(CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)National Center for Nanoscience and TechnologyBeijing 100190China

Organic-inorganic hybrid perovskite solar cells(PSCs)have attracted continually increasing attention in recent years due to its outstanding photoelectric properties and bright commercial prospect[1–6].So far,the certified power conversion efficiency(PCE)record of PSCs increased up to be 25.2%[7].However,the efficiency for PSCs with inverted structure was generally lower(~22.3%)[8].A major reason for the relatively lower PCE in inverted solar cells was that the achieved open-circuit voltage(V_(oc))was generally lower than that of conventional PSCs based on the same photoactive layers[9–11].

关键词：钙钛矿太阳电池开路电压能量转换效率非辐射复合载流子复合倒置结构 EDA 钝化

Unveiling strain-enhanced moiréexciton localization in twisted van der Waals homostructures

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Nano Research 2024年第4期17卷 3245-3252页

作者： Henry Rui He Haihong Zheng Biao Wu Shaofei Li Junnan Ding Zongwen Liu Jian-Tao Wang Anlian Pan Yanping Liu Institute of Quantum Physics School of PhysicsCentral South UniversityChangsha 410083China State key laboratory of Precision Manufacturing for Extreme Service Performance Central South UniversityChangsha 410083China School of Chemical and Biomolecular Engineering The University of SydneyNSW 2006Australia Beijing National laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China College of Materials Science and Engineering Hunan UniversityChangsha 410082China State key laboratory of High-Performance Complex Manufacturing Central South UniversityChangsha 410083China Shenzhen Research Institute of Central South University Shenzhen 51800China

Moirésuperlattices,arising from the controlled twisting of van der Waals homostructures at specific angles,have emerged as a promising platform for quantum emission ***,the manipulation of strain provides a versatile strategy to finely adjust electronic band structures,enhance exciton luminescence efficiency,and establish a robust foundation for two-dimensional quantum light ***,the intricate interplay between strain and moirépotential remains partially ***,we introduce a meticulously designed fusion of strain engineering and the twisted 2L-WSe_(2)/2L-WSe_(2) homobilayers,resulting in the precise localization of moiré*** low-temperature photoluminescence spectroscopy,we unveil the emergence of highly localized moiré-enhanced emission,characterized by the presence of multiple distinct emission ***,our investigation demonstrates the effective regulation of moirépotential depths through strain engineering,with the potential depths of strained and unstrained regions differing by 91%.By combining both experimental and theoretical approaches,our study elucidates the complex relationship between strain and moirépotential,thereby opening avenues for generating strain-induced moiréexciton single-photon sources.

关键词： moirésuperlattices strain engineering moiréexcitons moirépotential

An experimental study on effects of temperature gradient on microstructure of a 308L stainless steel manufactured by directed energy deposition

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Journal of Iron and Steel Research International 2024年第8期31卷 2031-2040页

作者： Ting Dai De-yu Gu Yu-wen Qiu Wei Guo Hui Ding Yi-wei Sun School of Materials Science and Engineering Jiangsu Key Laboratory of Advanced Metallic MaterialsSoutheast UniversityNanjing 211189JiangsuChina

The effect of spatial temperature gradient on the microstructural evolution of a 308L stainless steel during the directed energy deposition(DED)process was experimentally investigated.A novel cooling system was designed and incorporated to a DED system in order to control the temperature gradient along the deposition direction during *** deposition,the workpiece was placed on a lifting platform,and as the deposition process proceeded,the platform and workpiece were gradually lowered into cooling water so that the temperature gradient along the deposition direction could be controlled and maintained stable during the deposition *** microstructure characterization results indicated that a deposition strategy with higher G and G/R values(where G is temperature gradient and R is solidification rate)produced finer cellular grains that were better aligned with the deposition direction,while a deposition strategy with lower G and G/R values produced columnar grains with larger primary arm spacing and less aligned with the deposition direction.

关键词： Additive manufacturing Directed energy deposition Stainless steel microstructure Temperature gradient

Protection of entanglement between two V-atoms in a multi-cavity coupling system

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Chinese Physics B 2022年第1期31卷 124-129页

作者： Wen-Jin Huang Mao-Fa Fang Xiong Xu Synergetic Innovation Center for Quantum Effects and Applications Key Laboratory of Low-dimensional Quantum Structures and Quantum Control of Ministry of EducationSchool of Physics and ElectronicsHunan Normal UniversityChangsha 410081China School of Physics and Electronics Hunan Key Laboratory of Super Microstructure and Ultrafast ProcessState Key Laboratory of Powder MetallurgyCentral South UniversityChangsha 410083China

The protection of the entanglement between two V-atoms(EBTVA)in a multi-cavity coupling system is *** whole system consists of two *** two V-atoms are initially in the maximum entangled state and interacts locally with its own dissipative cavity which is coupled to the external cavities with high quality factor(ECWHQF).The results show that,when there is no ECWHQF,the EBTVA can be protected effectively in the case where the V-atom and the dissipative cavity are weak coupled in large detuning,while when there are different numbers n of ECWHQF coupled to two dissipative cavities,by adjusting the parameters of the number n of ECWHQF and the coupling strength k between cavities,the EBTVA can be protected perfectly and *** result provides an effective method for protecting entanglement resources of three-level system.

关键词： V-atom multi-cavity coupling system entanglement negativity

Effects of heat treatment on microstructures and properties of a heterostructured alloy with dissimilar components fabricated by WAAM

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Rare Metals 2024年第9期43卷 4441-4461页

作者： Ming-Cai Pan Jun-Qiang Xu Yong Peng Ning-Ning Liang Si Lan Qi Zhou Ke-Hong Wang School of Materials Science and Engineering Nanjing University of Science and Technology key laboratory of Controlled Arc Intelligent Additive Manufacturing Technology

Heat treatment significantly influences homogeneous material microstructures and mechanical properties, which can be improved by an optimal heat treatment process. However, heat treatment application to heterogeneous materials presents significant challenges due to compositional and microstructural heterogeneities. Herein,a laminated heterostructured alloy comprising alternating316L stainless steel（SS） and 18Ni300 maraging steel（MS）layers fabricated using wire and arc additive manufacturing was investigated. A solution treatment was applied at900 °C for 0.5 h. Subsequently, the solution-treated and asfabricated（AF） samples were aged at 500 °C for 4 h; these samples were denoted SA and AT, respectively. The AT phase compositions and orientations were similar to those of AF. The SA 316L SS layer resembled that of AF, but the SA 18Ni300 MS layers exhibited a reduced austenite phase fraction and refined grain size, attributable to solid-state transformation. In the AT sample, aging induced the formation of nanoscale acicular ω phase and ellipsoidal Ni3Ti,Fe2Mo, and X precipitates in the 18Ni300 MS ***, the SA precipitates contained acicular Fe Ni2and ellipsoidal ω, Ni3Ti, and X precipitates, and their fractions were lower than those in AT precipitates. The18Ni300 MS layer microhardness in the heat-treated samples increased due to nanoprecipitation, but the 316L SS layer microhardness resembled that of AF. The AT and SA ultimate tensile strengths increased to（1360 ± 50） and（1473 ± 41） MPa, respectively, attributable to precipitation strengthening. The SA 316L SS layer exhibited a high stress-induced martensite fraction, enhancing the ductility of heated samples.

关键词： Heat treatment Laminated heterostructured alloy Mechanical property microstructure Wire and arc additive manufacturing

Modulated thermal transport for flexural and in-plane phonons in double-stub graphene nanoribbons

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Chinese Physics B 2018年第8期27卷 566-571页

作者： Chang-Ning Pan Meng-Qiu Long JuJa He hunan key laboratory of super Micro-structure and ultrafast process School of Physics and Electronics Central South UniversityChangsha 410083China School of Science Hunan University of TechnologyZhuzhou 412008China

Thermal transport properties are investigated for out-of-plane phonon modes （FPMs） and it-plane phonon modes （IPMs） in double-stub graphene nanoribbons （GNRs）. The results show that the quantized thermal conductance plateau of FPMs is narrower and more easily broken by the double-stub structure. In the straight GNRs, the thermal conductance of FPMs is higher in the low temperature region due to there being less cut-off frequency and more low-frequency excited modes. In contrast, the thermal conductance of IPMs is higher in the high temperature region becau~,＇.e of the wider phonon energy spectrum. Furthermore, the thermal transport of two types of phonon modes can be modulated by the double-stub GNRs, the thermal conductance of FPMs is less than that of IPMs in the low temperatures, but it dominates the contribution to the total thermal conductance in the high temperatures. The modulated thermal conclu~＇tanc：e can provide a guideline for designing high-performance thermal or thermoelectric nanodevices based on graphene.

关键词： graphene nanoribbon flexural phonons in-plane phonons thermoelectric properties

Simulation of Fracture process of Lightweight Aggregate Concrete Based on Digital Image processing Technology

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Computers, Materials & Continua 2024年第6期79卷 4169-4195页

作者： Safwan Al-sayed Xi Wang Yijiang Peng key laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing100124China

The mechanical properties and failure mechanism of lightweight aggregate concrete(LWAC)is a hot topic in the engineering field,and the relationship between its microstructure and macroscopic mechanical properties is also a frontier research topic in the academic *** this study,the image processing technology is used to establish a micro-structure model of lightweight aggregate *** the information extraction and processing of the section image of actual light aggregate concrete specimens,the mesostructural model of light aggregate concrete with real aggregate characteristics is *** numerical simulation of uniaxial tensile test,uniaxial compression test and three-point bending test of lightweight aggregate concrete are carried out using a new finite element method-the base force element method ***,the image processing technology is used to produce beam specimens,uniaxial compression specimens and uniaxial tensile specimens of light aggregate concrete,which can better simulate the aggregate shape and random distribution of real light aggregate ***,the three-point bending test is numerically ***,the uniaxial compression specimen generated by image processing technology is numerically ***,the uniaxial tensile specimen generated by image processing technology is numerically *** mechanical behavior and damage mode of the specimen during loading were *** results of numerical simulation are compared and analyzed with those of relevant *** feasibility and correctness of the micromodel established in this study for analyzing the micromechanics of lightweight aggregate concrete materials are *** processing technology has a broad application prospect in the field of concrete mesoscopic damage analysis.

关键词： Digital image processing lightweight aggregate concrete mesoscopic model numerical simulation fracture analysis bending beams

Coupling Stacking Orders with Interlayer Magnetism in Bilayer H-VSe2

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Chinese Physics Letters 2020年第10期37卷 61-67页

作者： Aolin Li Wenzhe Zhou Jiangling Pan Qinglin Xia Mengqiu Long Fangping Ouyang State key laboratory of Powder Metallurgy and Powder Metallurgy Research InstituteCentral South UniversityChangsha 410083China School of Physics and Electronics and Hunan Key Laboratory for Super-Microstructure and Ultrafast ProcessCentral South UniversityChangsha 410083China School of Physics and Technology Xinjiang UniversityUrumqi 830046China

Stacking-dependent magnetism in van der Waals materials has caught intense *** on the first principle calculations,we investigate the coupling between stacking orders and interlayer magnetic orders in bilayer H-VSe *** is found that there are two stable stacking orders in bilayer H-VSe 2,named AB-stacking and A′*** standard DFT framework,the A′B-stacking prefers the interlayer AFM order and is semiconductive,whereas the AB-stacking prefers the FM order and is ***,under the DFT+U framework both the stacking orders prefer the interlayer AFM order and are *** detailedly analyzing this difference,we find that the interlayer magnetism originates from the competition between antiferromagnetic interlayer super-superexchange and ferromagnetic interlayer double exchange,in which both the interlayer Se-4 p z orbitals play a crucial *** the DFT+U calculations,the double exchange is suppressed due to the opened bandgap,such that the interlayer magnetic orders are decoupled with the stacking *** on this competition mechanism,we propose that a moderate hole doping can significantly enhance the interlayer double exchange,and can be used to switch the interlayer magnetic orders in bilayer VSe *** method is also applicable to a wide range of semiconductive van der Waals magnets.

关键词： stacking interlayer orders