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Chinese Physics B 2024年第8期33卷 526-543页

作者：徐兆文白雪马健万壮壮王超群 Laser Institute Qilu University of Technology(Shandong Academy of Sciences)Jinan 250104China

Quantitative relationship between nanosecond pulsed laser parameters and the characteristics of laser-generated ultrasonic waves in polycrystalline materials was *** high energy of the pulsed laser with a large irradiation spot simultaneously generated ultrasonic longitudinal and shear waves at the epicenter under the slight ablation *** optimized denoising technique based on wavelet thresholding and variational mode decomposition was applied to reduce noise in shear waves with a low signal-to-noise *** approach for characterizing grain size was proposed using spectral central frequency ratio(SCFR)based on time-frequency *** results demonstrate that the generation regime of ultrasonic waves is not solely determined by the laser power density;even at high power densities,a high energy with a large spot can generate an ultrasonic waveform dominated by the thermoelastic *** is ascribed to the intensification of the thermoelastic effect with the proportional increase in laser irradiation spot area for a given laser power ***,both longitudinal and shear wave SCFRs are linearly related to grain size in polycrystalline materials;however,the shear wave SCFR is more sensitive to finer-grained *** study holds great significance for evaluating metal material properties using laser ultrasound.

关键词： laser-ultrasonics polycrystalline materials ultrasonic time-frequency characteristics grain size

Decade Milestone Advancement of Defect-Engineered g-C_(3)N_(4) for Solar Catalytic Applications

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Nano-Micro Letters 2024年第4期16卷 153-218页

作者： Shaoqi Hou Xiaochun Gao Xingyue Lv Yilin Zhao Xitao Yin Ying Liu Juan Fang Xingxing Yu Xiaoguang Ma Tianyi Ma Dawei Su School of Mathematical and Physical Sciences Faculty of ScienceUniversity of Technology Sydney(UTS)SydneyNSW 2007Australia Laboratory of Plasma and Energy Conversion School of Physics and Optoelectronic EngineeringLudong University186 Middle Hongqi RoadYantai 264025People’s Republic of China School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083People’s Republic of China department of Chemistry The University of Tokyo7‑3‑1 HogoBunkyoTokyoJapan School of Science STEM CollegeRMIT UniversityMelbourneVIC 3000Australia

Over the past decade, graphitic carbon nitride(g-C_(3)N_(4)) has emerged as a universal photocatalyst toward various sustainable carbo-neutral technologies. Despite solar applications discrepancy, g-C_(3)N_(4) is still confronted with a general fatal issue of insufficient supply of thermodynamically active photocarriers due to its inferior solar harvesting ability and sluggish charge transfer dynamics. Fortunately, this could be significantly alleviated by the “all-in-one” defect engineering strategy, which enables a simultaneous amelioration of both textural uniqueness and intrinsic electronic band structures. To this end, we have summarized an unprecedently comprehensive discussion on defect controls including the vacancy/non-metallic dopant creation with optimized electronic band structure and electronic density, metallic doping with ultraactive coordinated environment(M–N_(x), M–C_(2)N_(2), M–O bonding), functional group grafting with optimized band structure, and promoted crystallinity with extended conjugation π system with weakened interlayered van der Waals interaction. Among them, the defect states induced by various defect types such as N vacancy, P/S/halogen dopants, and cyano group in boosting solar harvesting and accelerating photocarrier transfer have also been emphasized. More importantly, the shallow defect traps identified by femtosecond transient absorption spectra(fs-TAS) have also been highlighted. It is believed that this review would pave the way for future readers with a unique insight into a more precise defective g-C_(3)N_(4) “customization”, motivating more profound thinking and flourishing research outputs on g-C_(3)N_(4)-based photocatalysis.

关键词： Defect engineering g-C_(3)N_(4) Electronic band structures Photocarrier transfer kinetics Defect states

Physics-embedded machine learning search for Sm-doped PMN-PT piezoelectric ceramics with high performance

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Chinese Physics B 2024年第8期33卷 81-88页

作者：辛睿王亚祺房泽郑凤基高雯付大石史国庆刘建一张永成 College of Physics Center for Marine Observation and CommunicationsNational Demonstration Center for Experimental Applied Physics EducationQingdao UniversityQingdao 266071China Centre for Theoretical and Computational Physics College of PhysicsQingdao UniversityQingdao 266071China

Pb(Mg_(1/3)Nb_(2/3))O_(3)–PbTiO_(3)(PMN-PT)piezoelectric ceramics have excellent piezoelectric properties and are used in a wide range of *** the solid solution ratios of PMN/PT and different concentrations of elemental doping are the main methods to modulate their piezoelectric *** combination of these controllable conditions leads to an exponential increase of possible compositions in ceramics,which makes it not easy to extend the sample data by additional experimental or theoretical *** this paper,a physics-embedded machine learning method is proposed to overcome the difficulties in obtaining piezoelectric coefficients and Curie temperatures of Sm-doped PMN-PT ceramics with different *** contrast to all-data-driven model,physics-embedded machine learning is able to learn nonlinear variation rules based on small datasets through potential correlation between ferroelectric *** on the model outputs,the positions of morphotropic phase boundary(MPB)with different Sm doping amounts are *** also find the components with the best piezoelectric property and comprehensive ***,we set up a database according to the obtained results,through which we can quickly find the optimal components of Sm-doped PMN-PT ceramics according to our specific needs.

关键词： Pb(Mg_(1/3)Nb_(2/3))O_(3)–PbTiO_(3)(PMN-PT)ceramic physics-embedded machine learning piezoelectric coefficient Curie temperature

Photometric Analysis for Asteroid(81)Terpsichore using Convex Inversion and Phase Function Fitting Methods

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Research in Astronomy and Astrophysics 2024年第6期24卷 201-208页

作者： Ao Wang Xiaobin Wang Xiaoyun Xu Longhua Qin Quangui Gao Huaizhen Li Yong Xiao Hairu Zhao department of Physics Yuxi Normal UniversityYuxi 653100China Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China

The shapes and rotation states(periods and pole orientations)of main-belt asteroids are important for understanding their formation and *** order to obtain sufficient photometric data covering different apparitions for asteroid(81)Terpsichore,ground-based photometric observations in 2020 and 2021 were carried *** combining published and newly obtained photometric data,we calculated the shape and spin parameters for(81)Terpsichore using the convex inversion *** this method,we have derived a best fitted pole orientation—(22.2±_(3.1)^(3.3°),17.5±_(5.5)^(10.8°))with a spin period of 10.94±_(0.01)^(0.01)*** on the derived convex shape of(81)Terpsichore,we have fitted the H,G+1,G_(2)phase function using the calibrated TESS data and Gaia data after accounting for the lightcurve amplitude *** a result,we have derived its absolute magnitude H=8.68±_(0.19)^(0.22)mag with corresponding phase function parameters G_(1)=0.82±_(0.10)^(0.09)and G_(2)=0.02±_(0.02)^(0.03).

关键词： asteroids:general minor planets asteroids:individual(Terpsichore) techniques:photometric

A review on electrocatalytic CO_(2) conversion via C-C and C-N coupling

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Carbon Energy 2024年第2期6卷 167-194页

作者： Zhuangzhi Zhang Sijun Li Zheng Zhang Zhou Chen Hua Wang Xianguang Meng Wenquan Cui Xiwei Qi Jiacheng Wang Hebei Provincial Laboratory of Inorganic Nonmetallic Materials College of Materials Science and EngineeringNorth China University of Science and TechnologyTangshanChina Key Laboratory of Luminescence Analysis and Molecular Sensing Ministry of EducationCollege of Chemistry and Chemical EngineeringSouthwest UniversityChongqingChina State Key Laboratory of New Textile Materials and Advanced Processing Technologies Hubei Key Laboratory of Biomass Fibers and Eco-Dyeing and FinishingCollege of Chemistry and Chemical EngineeringWuhan Textile UniversityWuhanChina College of Materials Xiamen UniversityXiamenChina Hebei Iron and Steel Laboratory TangshanChina Hebei Key Laboratory for Environment Photocatalytic and Electrocatalytic Materials College of Chemical EngineeringNorth China University of Science and TechnologyTangshanChina College of Metallurgy and Energy North China University of Science and TechnologyTangshanChina State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghaiChina Institute of Electrochemistry School of Materials Science and EngineeringTaizhou UniversityTaizhouChina

Electrochemical C-C and C-N coupling reactions with the conversion of abundant and inexpensive small molecules,such as CO_(2) and nitrogencontaining species,are considered a promising route for increasing the value of CO_(2) reduction *** development of high-performance catalysts is the key to the both electrocatalytic *** this review,we present a systematic summary of the reaction systems for electrocatalytic CO_(2) reduction,along with the coupling mechanisms of C-C and C-N bonds over outstanding electrocatalytic materials recently *** key intermediate species and reaction pathways related to the coupling as well as the catalyst-structure relationship will be also discussed,aiming to provide insights and guidance for designing efficient CO_(2) reduction systems.

关键词： C-C coupling C-N coupling CO_(2) conversion electrocatalysis urea synthesis

Simultaneously achieving high energy density and responsivity in submicron BaTiO_(3) film capacitors integrated on Si

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Journal of Advanced Ceramics 2024年第2期13卷 198-206页

作者： Jun Ouyang Yinxiu Xue Chuanqi Song Meiling Yuan Kun Wang Yuyao Zhao Hongbo Cheng Hanfei Zhu Chao Liu Institute of Advanced Energy Materials and Chemistry School of Chemistry and Chemical EngineeringQilu University of Technology(Shandong Academy of Sciences)Jinan 250353China Key Laboratory of Key Film Materials&Application for Equipment School of Material Sciences and EngineeringXiangtan UniversityXiangtan 411105China School of Materials Science and Engineering Shandong UniversityJinan 250061China Academic Affairs Office Civil Aviation University of ChinaTianjin 300300China China Tobacco shandong Industrial Co. Ltd.Jinan 250014China

In the research field of energy storage dielectrics,the“responsivity”parameter,defined as the recyclable/recoverable energy density per unit electric field,has become critically important for a comprehensive evaluation of the energy storage capability of a *** this work,high recyclable energy density and responsivity,i.e.,W_(rec)=161.1 J·cm^(-3) and ξ=373.8 J·(kV·m^(2))^(-1),have been simultaneously achieved in a prototype perovskite dielectric,BaTiO_(3),which is integrated on Si at 500℃ in the form of a submicron thick *** ferroelectric film features a multi-scale polar structure consisting of ferroelectric grains with different orientations and inner-grain ferroelastic domains.A LaNiO_(3) buffer layer is used to induce a{001}textured,columnar nanograin microstructure,while an elevated deposition temperature promotes lateral growth of the nanograins(in-plane diameter increases from~10-20 nm at lower temperatures to~30 nm).These preferably oriented and periodically regulated nanograins have resulted in a small remnant polarization and a delayed polarization saturation in the film’s P-E behavior,leading to a high recyclable energy ***,an improved polarizability/dielectric constant of the BaTiO_(3) film has produced a much larger maximum polarization than those deposited at lower temperatures at the same electric field,leading to a record-breaking responsivity for this simple perovskite.

关键词： energy storage energy density responsivity BaTiO_(3) dielectric capacitor Si

Controllable selective anchoring of subnanometric Ru clusters or single-atoms/clusters on tungsten nitride for the hydrogen oxidation

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Science China Chemistry 2024年第11期67卷 3749-3756页

作者： Qijiao Sun Chuanqiang Wu Yiqiang Sun Yuan Shen Lei Zhao Xiaodong Yang Li Yang Yunxiang Lin Keke Mao Kun Xu School of Chemistry and Chemical Engineering Key Laboratory of Functional Inorganic Material Chemistry of Anhui Province Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education Anhui University Information Materials and Intelligent Sensing Laboratory of Anhui province Institutes of Physical Science and Information TechnologyAnhui University School of Chemistry and Chemical Engineering University of Jinan School of Energy and Environment Anhui University of Technology

The impregnation method in the preparation of metal cluster catalysts typically inadvertently introduces single atoms（SAs） into the substrate. However, the question of whether the introduction of SAs will further improve the catalytic activity of cluster systems for specific reactions such as the hydrogen oxidation reaction（HOR） remains unraveled. Herein, we demonstrate Ru clusters anchored on WN nanowires（RuC/WN） show a higher alkaline HOR catalytic activity in comparison with Ru SAs and nanoclusters（NCs）-coupled catalyst anchored on WN nanowires system（RuC,S/WN）. Notably, the RuC/WN exhibits superb intrinsic catalytic activity with a mass-normalized exchange current density of 890 m A mg-1PGM, which is among the top level of well developed Ru-based HOR catalysts. Both theoretical simulation and experimental investigation suggest that RuC/WN owns an optimized H*and OH*reaction intermediates for the alkaline HOR, therefore resulting in the excellent intrinsic HOR catalytic performance.

关键词： hydrogen oxidation reaction Ru cluster catalyst Ru single atoms and nanoclusters coupled catalyst tungsten nitride substrate

Footprints of axion-like particle in pulsar timing array data and James Webb Space Telescope observations

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 55-62页

作者： Shu-Yuan Guo Maxim Khlopov Xuewen Liu Lei Wu Yongcheng Wu Bin Zhu department of Physics Yantai UniversityYantai 264005 China Institute of Physics Southern Federal UniversityRostov on Don 344090 Russia National Research Nuclear University MEPhI(Moscow Engineering Physics Institute) Moscow 115409 Russia Virtual Institute of Astroparticle Physics Paris 75018 France department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023 China

Several pulsar timing array(PTA) collaborations have recently reported the evidence for a stochastic gravitational-wave background(SGWB), which can unveil the formation of primordial seeds of inhomogeneities in the early universe. With the SGWB parameters inferred from PTAs data, we can make a prediction of the seeds for early galaxy formation from the domain walls in the axion-like particles(ALPs) field distribution. This also naturally provides a solution to the observation of high redshifts by the James Webb Space Telescope. The predicted photon coupling of the ALP is within the reach of future experimental searches.

关键词： stochastic gravitational-wave background pulsar timing array axion-like particle JWST

Cotton leaf disease detection method based on improved SSD

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International Journal of Agricultural and Biological Engineering 2024年第2期17卷 211-220页

作者： Wenjuan Guo Shuo Feng Quan Feng Xiangzhou Li Xueze Gao College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China School of Cyber Security Gansu University of Political Science and LawLanzhou 730070China College of Mechanical and Electrical Engineering Sichuan Agricultural UniversityYa’an 625014China

In response to the problems of numerous model parameters and low detection accuracy in SSD-based cotton leaf disease detection methods,a cotton leaf disease detection method based on improved SSD was proposed by combining the characteristics of cotton leaf ***,the lightweight network MobileNetV2 was introduced to improve the backbone feature extraction network,which provides more abundant semantic information and details while significantly reducing the amount of model parameters and computing complexity,and accelerates the detection speed to achieve real-time ***,the SE attention mechanism,ECA attention mechanism,and CBAM attention mechanism were fused to filter out disease target features and effectively suppress the feature information of jamming targets,generating feature maps with strong semantics and precise location *** test results on the self-built cotton leaf disease dataset show that the parameter quantity of the SSD_MobileNetV2 model with backbone network of MobileNetV2 was 50.9%of the SSD_VGG model taking VGG as the *** with SSD_VGG model,the P,R,F1 values,and mAP of the MobileNetV2 model increased by 4.37%,3.3%,3.8%,and 8.79%respectively,while FPS increased by 22.5 frames/*** SE,ECA,and CBAM attention mechanisms were introduced into the SSD_VGG model and SSD_MobileNetV2 *** gradient weighted class activation mapping algorithm to explain the model detection process and visually compare the detection results of each *** results indicate that the P,R,F1 values,mAP and FPS of the SSD_MobileNetV2+ECA model were higher than other models that introduced the attention ***,this model has less parameter with faster running speed,and is more suitable for detecting cotton diseases in complex environments,showing the best detection ***,the improved SSD_MobileNetV2+ECA model significantly enhanced the semantic information of the shallow feature map of the model,and has a goo

关键词： cotton disease detection SSD MobileNetV2 attention mechanism

Layered(C_(5)H_(6)ON)_(2)[Sb_(2)O(C_(2)O_(4))_(3)]with a large birefringence derived from the uniform arrangement of π-conjugated units

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Chinese Journal of Structural Chemistry 2024年第6期43卷 50-55页

作者： Dong-Xue Jiao Hui-Li Zhang Chao He Si-Yu Chen Ke Wang Xiao-Han Zhang Li Wei Qi Wei College of Chemistry and Chemical Engineering Qingdao UniversityShandong266071PR China College of Science Hebei University of Science and TechnologyShijiazhuangHebei050018PR China

An organic-inorganic hybrid antimony(Ⅲ)oxalate(C_(5)H_(6)ON)_(2)[Sb_(2)O(C_(2)O_(4))_(3)]has been successfully obtained by simultaneous combination of a-conjugated 4-hydroxypyridine and(C_(2)O_(4))^(2-)group with stereochemical active Sb(Ⅲ)*** compound features a layered structure,and the equatorial planes of SbO6 units,π-conjugated(C_(2)O_(4))^(2-)and(C5H6ON)+groups are closer to a planar arrangement,representing strong structural anisotropy that favors a large *** expected,(C_(5)H_(6)ON)_(2)[Sb_(2)O(C_(2)O_(4))_(3)]exhibits a large birefringence of 0.279 at 546 *** and theoretical analyses indicate that the combination of multipleπ-conjugated units is a feasible approach for designing and exploring new superior birefringent materials.

关键词： Organicπ-conjugated unit Birefringence Stereochemically active lone pair Layered structure