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Plasma Science and Technology 2024年第5期26卷 91-99页

作者：韦金红李嵩陈红曾凡正贾成林付泽斌葛行军钱宝良 college of advanced interdisciplinary Studies National University of Defense TechnologyChangsha 410073People’s Republic of China

To guide the illuminating design to improve the on-state performances of gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS),the effect of spot size on the operation mode of GaAsPCSS based on a semi-insulating wafer with a thickness of 1 mm,triggered by a 1064-nm extrinsic laser beam with the rectangular spot,has been investigated *** is found that the variation of the spot size in length and width can act on the different parts of the output waveform integrating the characteristics of the linear and nonlinear modes,and then significantly boosts the PCSS toward different operation *** this basis,a two-channel model containing the active and passive parts is introduced to interpret the relevant influencing *** indicate that the increased spot length can peak the amplitude of static domains in the active part to enhance the development of the nonlinear switching,while the extended spot width can change the distribution of photogenerated carriers on both parts to facilitate the linear switching and weaken the nonlinear switching,which have been proved by comparing the domain evolutions under different spot sizes.

关键词： GaAs PCSS operation mode spot size on-state performances two-channel model domain evolution

Cascade electrolysis and thermocatalysis: a reliable system for upgrading C1 to C4 hydrocarbons

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Rare Metals 2024年第1期43卷 410-412页

作者： Chao-Yue Sun Wen Li Hai-Qing Wang Institute for advanced interdisciplinary Research(iAIR) College of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022China

The carbon cycle is important for maintaining a stable climate and carbon balance on Earth. Renewable-electricitydriven upcycling of carbon dioxide (CO_(2)) into value-added multi-carbon molecules is a potentially sus... 详细信息

关键词： cycling hydrocarbons enable

Recent progress of parameter-adjustable high-power photonic microwave generation based on wide-bandgap photoconductive semiconductors

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Chinese Optics Letters 2024年第1期22卷 113-122页

作者：荀涛牛昕玥王朗宁张斌姚金妹易木俣杨汉武侯静刘金亮张建徳 college of advanced interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Nanhu Laser Laboratory National University of Defense TechnologyChangsha 410073China

Radio frequency/microwave-directed energy sources using wide bandgap SiC photoconductive semiconductors have attracted much attention due to their unique advantages of high-power output and multi-parameter adjustable *** the past several years,benefitting from the sustainable innovations in laser technology and the significant progress in materials technology,megawatt-class output power electrical pulses with a flexible frequency in the P and L microwave wavebands have been achieved by photoconductive semiconductor ***,we mainly summarize and review the recent progress of the high-power photonic microwave generation based on the SiC photoconductive semiconductor devices in the linear modulation mode,including the mechanism,system architecture,critical technology,and experimental demonstration of the proposed high-power photonic microwave *** outlooks and challenges for the future of multi-channel power synthesis development of higher power photonic microwave using wide bandgap photoconductors are also discussed.

关键词： high-power photonic microwave wide bandgap photoconductive semiconductor devices linear modulation multi-parameter adjustable microwave generation multi-channel power synthesis

Bioinspired sensing-memory-computing integrated vision systems: biomimetic mechanisms, design principles, and applications

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Science China(Information Sciences) 2024年第5期67卷 5-27页

作者： Yujie HUANG Yinlong TAN Yan KANG Yabo CHEN Yuhua TANG Tian JIANG Institute for Quantum Information and State Key Laboratory of High Performance Computing College of Computer National University of Defense Technology college of advanced interdisciplinary Studies National University of Defense Technology Institute for Quantum Science and Technology College of ScienceNational University of Defense Technology

With the explosion of sensory data in the Internet of Things(Io T) era, conventional machine vision systems are becoming increasingly difficult to meet the requirements of high efficiency, low energy consumption, and low latency due to their inherent shortcomings of separate sensing, memory, and computing units. Inspired by the retina and neuromorphic computing, the sensing-memory-computing integrated vision system(SMCVS) that features low power consumption, low latency, and high parallelism has been considered a promising technology to surpass the von Neumann architecture and realize strong artificial ***, novel materials like two-dimensional semiconductors and quantum dots with novel optoelectronic performance provide hardware carriers for implementing integrated sensing-memory-computing architectures,attracting considerable attention. This paper reviews the recent research progress in bioinspired vision systems in terms of biomimetic mechanisms, design principles, computational architectures, and ***, the biomimetic mechanisms are illustrated to guide the design of high-performance artificial visual perception systems. Then the research progress of optoelectronic-synapse-based bioinspired vision systems in the device principles and applications including image filtering, color recognition, visual adaptation, and motion detection are summarized. Finally, the challenges and future developing directions of the SMCVS are provided regarding bionic application, architecture design, and device fabrication.

关键词： sensing-memory-computing architecture neuromorphic computing retinomorphic device image recognition visual system

Efficient single‑pixel imaging based on a compact fiber laser array and untrained neural network

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Frontiers of Optoelectronics 2024年第1期17卷 85-93页

作者： Wenchang Lai Guozhong Lei Qi Meng Yan Wang Yanxing Ma Hao Liu Wenda Cui Kai Han college of advanced interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Nanhu Laser Laboratory National University of Defense TechnologyChangsha 410073China

This paper presents an efficient scheme for single-pixel imaging(SPI)utilizing a phase-controlled fiber laser array and an untrained deep neural *** fiber lasers are arranged in a compact hexagonal structure and coherently combined to generate illuminating light *** the utilization of high-speed electro-optic modulators in each individual fiber laser module,the randomly modulated fiber laser array enables rapid speckle projection onto the object of ***,the untrained deep neural network is incorporated into the image reconstructing process to enhance the quality of the reconstructed *** simulations and experiments,we validate the feasibility of the proposed method and successfully achieve high-quality SPI utilizing the coherent fiber laser array at a sampling ratio of 1.6%.Given its potential for high emitting power and rapid modulation,the SPI scheme based on the fiber laser array holds promise for broad applications in remote sensing and other applicable fields.

关键词： Single-pixel imaging Fiber laser array Deep learning Remote sensing

Twistronics and moiréexcitonic physics in van der Waals heterostructures

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Frontiers of physics 2024年第4期19卷 147-185页

作者：李思维韦可刘祺瑞唐宇翔江天 college of advanced interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Institute for Quantum Science and Technology National University of Defense TechnologyChangsha 410073China

Heterostructures composed of two-dimensional van der Waals(vdW)materials allow highly controllable stacking,where interlayer twist angles introduce a continuous degree of freedom to alter the electronic band structures and excitonic *** by the discovery of Mott insulating states and superconductivity in magic-angle bilayer graphene,the emerging research fields of“twistronics”and moiréphysics have aroused great academic interests in the engineering of optoelectronic properties and the exploration of new quantum phenomena,in which moirésuperlattice provides a pathway for the realization of artificial excitonic *** we systematically summarize the current achievements in twistronics and moiréexcitonic physics,with emphasis on the roles of lattice rotational mismatches and atomic ***,we review the effects of the interlayer twist on electronic and photonic physics,particularly on exciton properties such as dipole moment and spin-valley polarization,through interlayer interactions and electronic band *** also discuss the exciton dynamics in vdW heterostructures with different twist angles,like formation,transport and relaxation processes,whose mechanisms are complicated and still need further ***,we review the theoretical analysis and experimental observations of moirésuperlattice and moirémodulated *** exotic moiréeffects are also shown,including periodic potential,moiréminiband,and varying wave function symmetry,which result in exciton localization,emergent exciton peaks and spatially alternating optical selection *** further introduce the expanded properties of moirésystems with external modulation factors such as electric field,doping and strain,showing that moirélattice is a promising platform with high tunability for optoelectronic applications and in-depth study on frontier ***,we focus on the rapidly developing field of correlated electron physics based on the moiré

关键词： moirésuperlattice twistronics van der Waals heterostructure moiréexciton correlated electronic state

A head-mounted photoacoustic fiberscope for hemodynamic imaging in mobile mice

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Light(Science & Applications) 2024年第6期13卷 1012-1014页

作者： Xiaoyan Zheng Shuai Na National Biomedical Imaging Center College of Future TechnologyPeking UniversityBeijing100871China Academy for advanced interdisciplinary Studies Peking UniversityBeijing100871China

A miniaturized photoacoustic fiberscope has been developed, featuring a lateral resolution of 9 microns and a lightweight design at 4.5 grams. Engineered to capture hemodynamic processes at single-blood-vessel resolution at a rate of 0.2 Hz, this device represents an advancement in head-mounted tools for exploring intricate brain activities in mobile animals.

关键词： fiber mobile Engine

Phase field modeling of ferroelastic variant switching in yttria-stabilized t'zirconia with strain gradient elasticity and interface tension

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Science China(Technological Sciences) 2024年第5期67卷 1443-1457页

作者： ZHOU QianQian WEI YueGuang ZHOU YiChun YANG Li college of Engineering BIC-ESATPeking UniversityBeijing100871China School of advanced Materials and Nanotechnology Xidian UniversityXi’an710126China Frontier Research Center of Thin Films and Coatings for Device Applications Academy of Advanced Interdisciplinary ResearchXidian UniversityXi’an710126China

The 6–8 wt%yttria-stabilized zirconia with a tetragonal structure(t’-YSZ)is extensively employed in thermal barrier *** exceptional fracture toughness of t’-YSZ can be attributed to its distinctive ferroelastic toughening *** and interface tension play a critical role in ferroelastic variant switching at the micro-and *** paper presents an original thermodynamically consistent phase field(PF)theory for analyzing ferroelastic variant switching at the micro-and nano-scale of t’-*** theory incorporates strain gradient elasticity using higher-order elastic energy and interface tension tensor via geometric nonlinearity to represent biaxial tension resulting from interface ***,a mixed-type formulation is employed to implement the higher-order theory through the finite element *** an interface in equilibrium,the effects of strain gradient elasticity result in a more uniform distribution of stresses,whereas the presence of interface tension tensor significantly amplifies the stress magnitude at the *** introduction of an interface tension tensor increases the maximum value of stress at the interface by a factor of 4 to *** nucleation and evolution of variants at a pre-existing crack tip in a mono-phase t’-YSZ have also been *** strain gradient elasticity is capable of capturing the size effect of ferroelastic variant switching associated with microstructures in ***,when the grain size approaches that of the specimen,the critical load required for variant switching at the crack tip increases,resulting in greater dissipation of elastic energy during ferroelastic variant ***,the interface tension accelerates the evolution of *** presented framework exhibits significant potential in modeling ferroelastic variant switching at the micro-and nano-scale.

关键词： thermodynamics strain gradient elasticity interface tension phase field method ferroelastic variant switching

Quantitative analysis and prediction of the sound field convergence zone in mesoscale eddy environment based on data mining methods

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Acta Oceanologica Sinica 2024年第5期43卷 110-120页

作者： Ming Li Yuhang Liu Yiyuan Sun Kefeng Liu college of advanced interdisciplinary Studies National University of Defense TechnologyNanjing 211101China Jiangsu Ocean University Lianyungang 222061China college of Horticulture Forestry Sciences Huazhong Agricultural UniversityWuhan 430070China

The mesoscale eddy(ME)has a significant influence on the convergence effect in deep-sea acoustic *** paper use statistical approaches to express quantitative relationships between the ME conditions and convergence zone(CZ)*** on the Gaussian vortex model,we construct various sound propagation scenarios under different eddy conditions,and carry out sound propagation experiments to obtain simulation *** a large number of samples,we first adopt the unified regression to set up analytic relationships between eddy conditions and CZ *** sensitivity of eddy indicators to the CZ is quantitatively ***,we adopt the machine learning(ML)algorithms to establish prediction models of CZ parameters by exploring the nonlinear relationships between multiple ME indicators and CZ *** the research,we can express the influence of ME on the CZ quantitatively,and achieve the rapid prediction of CZ parameters in ocean *** prediction accuracy(R)of the CZ distance(mean R:0.9815)is obviously better than that of the CZ width(mean R:0.8728).Among the three ML algorithms,Gradient Boosting Decision Tree has the best prediction ability(root mean square error(RMSE):0.136),followed by Random Forest(RMSE:0.441)and Extreme Learning Machine(RMSE:0.518).

关键词： convergence zone mesoscale eddy statistic analysis quantitative prediction machine learning

Single-atomic activation on ZnIn_(2)S_(4)basal planes boosts photocatalytic hydrogen evolution

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Nano Research 2024年第7期17卷 5949-5955页

作者： Jianpeng Cui Ying Wang Luxue Lin Xiaotian Yang Xuyu Luo Shiying Guo Xiaoyong Xu college of Physics Science and Technology and Center for Interdisciplinary ResearchYangzhou UniversityYangzhou 225002China

The use of single-atom cocatalysts plays a crucial role in enhancing artificial photocatalysis,where the precise construction of stable and efficient single-atom configuration is essential but remains ***,we report a simple one-step hydrothermal method for preparing single-atomic Mo modified ZnIn_(2)S_(4)(Mo-ZIS)nanosheets as a highly active photocatalytic hydrogen evolution(PHE)*** Mo substituting for portion of In atoms in ZIS nanosheets induces the spatial charge redistribution,which not only promotes the separation of photogenerated charge carriers but also optimizes the Gibbs free energy of adsorbing H*on S atoms at basal *** a result,Mo-ZIS exhibits an impressive PHE rate as high as 6.71 mmol·g^(−1)·h^(−1),over 10 times that of the pristine ZIS,with an apparent quantum efficiency(AQE)up to 38.8%at 420 *** study gains insights into the coordination configuration and electronic modulation resulting from single-atomic decoration,providing mechanistic cognitions for the development of advanced photocatalysts via non-precious metal atomic modification.

关键词： photocatalytic hydrogen evolution ZnIn_(2)S_(4) single-atom activation Gibbs free energy