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A dislocation-based model for cyclic plastic response of lath martensitic steels

Acta Mechanica Sinica 2022年第2期38卷 110-118,I0004页

作者： Long Yu Wenbin Liu Haonan Sui Ying Liu Huiling Duan State Key Laboratory for Turbulence and Complex System Department of Mechanics ami Engineering ScienceBeijing Innovation Center for Engineering Science and Advanced Technology(BIC-ESAT)College of EngineeringPeking UniversityBeijing 100871China Key Laboratory of High Energy Density Physics Simulation(HEDPS) Center for Applied Physics and Technology(CAPT)and IFSACollaborative Innovation Center of MoEPeking UniversityBeijing 100871China

Softening behavior of lath martensitic steels is related to the coarsening of laths and dislocation evolution during cyclic *** the physical mechanism,we developed a dislocation-based model to study the cyclic plastic response for lath martensitic *** a block,we proposed an interfacial dislocation evolution model to physically present the interaction between mobile dislocations in the block and interfacial dislocations by considering the coarsening mechanism of the ***,the evolution behavior of backstress caused by dislocation pile up at the block boundary has been ***,a hierarchical model based on the elastic-viscoplastic self-consistent(EVPSC)theory is developed,which can realize the scale transition among representative volume element(RVE),prior austenite grains(PAGs)and *** to the proposed model,the effective mechanical responses including the cyclic hysteretic loop and peak stress at different cycles for lath martensitic steel have been theoretically predicted and investigated.

关键词： Lath martensitic steel Cyclic softening Hierarchical microstructure Lath coarsening Crystal plasticity

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What have we known so far for fluorescence staining and quantification of microplastics:A tutorial review

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Frontiers of Environmental science & Engineering 2022年第1期16卷 37-50页

作者： Shengdong Liu Enxiang Shang Jingnan Liu Yining Wang Nanthi Bolan MBKirkham Yang Li Key Laboratory of Water and Sediment Sciences of Ministry of Education State Key Laboratory of Water Environment SimulationSchool of EnvironmentBeijing Normal UniversityBeijing 100875China College of Science and Technology Hebei Agricultural UniversityHuanghua 061100China School of Agriculture and Environment The University of Western AustraliaPerthWA 6001Australia The UWA Institute of Agriculture The University of Western AustraliaPerthWA 6001Australia Global Innovative Centre for Advanced Nanomaterials College of EngineeringScience and EnvironmentUniversity of NewcastleCallaghanNSW 2308Australia Department of Agronomy Throckmorton Plant Sciences CenterKansas State UniversityManhattanKS 66506USA

Understanding the fate and toxicity of microplastics(MPs,<5 mm plastic particles)is limited by quantification *** paper summarizes the methods in use and presents new ***,sampling and pretreatment processes ofMPs,including sample collection,digestion,density separation,and quality control are *** the promising and convenient staining procedures and quantification methods for MPs using fluorescence dyes are *** factors that influence the staining of MPs,including their physicochemical properties,are summarized to provide an optimal operation *** general,the digestion step is crucial to eliminate natural organic matter(NOM)to avoid interference in *** was reported to be the most appropriate solvent,and 10–20μg/mL are recommended as optimal dye *** addition,a heating and cooling procedure is recommended to maintain the fluorescence intensity of MPs for two *** staining,a fluorescence microscope is usually used to characterize the morphology,mass,or number of MPs,but compositional analysis cannot be determined with *** fluorescence staining methods have been implemented to study MP abundance,transport,and toxicity and have been combined with other chemical characterization techniques,such as Fourier transform infrared spectroscopy and Raman *** studies are needed to focus on the synthesis of novel dyes to avoid NOM’s *** need to be combined with other spectroscopic techniques to characterize plastic composition and to develop image-analysis *** stability of stained MPs needs to be improved.

关键词： Plastic particles Fluorescence dyes Identification Concentration quantification

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Space–Time Conservation Element and Solution Element Method 1

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丛书名： Engineering Applications of Computational Methods

1000年

作者： Chih-Yung Wen Lisong Shi Yazhong Jiang

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Augmenting photoluminescence of monolayer MoS_(2) using high order modes in a metal dimer-on-film nanocavity

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Photonics Research 2021年第4期9卷 501-506页

作者： Shiyin Cao Liping Hou Qifa Wang Chenyang Li Weixing Yu Xuetao Gan Kaihui Liu Malin Premaratne Fajun Xiao Jianlin Zhao MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information TechnologySchool of Physical Science and TechnologyNorthwestern Polytechnical UniversityXi’an 710129China Key Laboratory of Spectral Imaging Technology of Chinese Academy of Sciences Xi’an 710119China State Key Laboratory for Mesoscopic Physics Collaborative Innovation Centre of Quantum MatterSchool of PhysicsPeking UniversityBeijing 100871China Advanced Computing and Simulation Laboratory(AχL) Department of Electrical and Computer Systems EngineeringMonash UniversityClaytonVIC 3800Australia

Plasmonic particle-on-film nanocavities,supporting gap modes with ultra-small volume,provide a great solution to boost light–matter interactions at the *** this work,we report on the photoluminescence(PL)enhancement of monolayer MoS_(2) using high order modes of an Au nanosphere dimer-on-film nanocavity(DoFN).The high order plasmon modes,consisting of two bonding quadrupoles in the dimer and their images in the Au film,are revealed by combining the polarization-resolved scattering spectra with the numerical *** integrating the monolayer MoS_(2) into the DoFN,these high order modes are used to enhance PL intensity through simultaneously boosting the absorption and emission processes,producing a 1350-fold enhancement *** opens an avenue to enhance the light–matter interaction with high order plasmon modes and may find applications in future optoelectronics and nanophotonics devices.

关键词： cavity high integrating

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Porous SiC/melamine-derived carbon foam frameworks with excellent electromagnetic wave absorbing capacity

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Journal of advanced Ceramics 2019年第4期8卷 479-488页

作者： Xinli YE Zhaofeng CHEN Sufen AI Bin HOU Junxiong ZHANG Xiaohui LIANG Qianbo ZHOU Hezhou LIU Sheng CUI International Laboratory for Insulation and Energy Efficiency Materials College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 211106China Suzhou Superlong Aviation Heat Resistance Material Technology Co. Ltd.Suzhou 215400China Beijing Spacecrafts China Academy of Space TechnologyBeijing 100080China Department of Reactor Engineering China Institute of Atomic EnergyBeijing 102413China The State Key Lab of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing Tech UniversityNanjing 211800China

Porous three-dimensional Si C/melamine-derived carbon foam(3 D-Si C/MDCF)composite with an original open pore structure was fabricated by the heat treatment of the commercial melamine foam(MF),carbonization of the stable MF,and chemical vapor deposition of the ultra-thin Si C *** electron microscopy(SEM)and X-ray diffraction(XRD)were employed to detect the microstructure and morphology of the as-prepared *** results indicated that the 3 D-Si C/MDCF composites with the coating structure were prepared *** obtained minimum reflection loss was–29.50 d B when the frequency and absorption thickness were 11.36 GHz and 1.75 mm,***,a novel strategy was put forward to state that the best microwave absorption property with a thin thickness of 1.65 mm was gained,where the minimum reflection loss was–24.51 d B and the frequency bandwidth was 3.08 *** excellent electromagnetic wave absorption ability resulted from the specific cladding structure,which could change the raw dielectric property to acquire excellent impedance *** present work had a certain extend reference meaning for the potential applications of the lightweight wave absorption materials with target functionalities.

关键词： three-dimensional SiC/melamine-derived carbon foam(3D-SiC/MDCF) chemical vapor deposition coating structure electromagnetic wave absorption characteristic minimum reflection loss

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Accelerating ab initio real-space electronic structure calculations for low-dimensional materials using an atom-sphere grid truncation method

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Physical Review B 2024年第15期110卷 155157页

作者： Lantian Xue Qiang Xu Cheng Ma Wenhui Mi Yanchao Wang Yu Xie Yanming Ma Key Laboratory of Material Simulation Methods & Software of Ministry of Education College of Physics State Key Lab of Superhard Materials College of Physics International Center of Future Science Key Laboratory of Physics and Technology for Advanced Batteries of Ministry of Education College of Physics

In recent decades, the real-space finite-difference implementations of Kohn–Sham density functional theory have exhibited substantial improvements in computational efficiency for large-scale systems. However, the substantial memory consumption arising from the numerous grid points has begun to limit the widespread adoption of this method. In this study, a general method is presented—applicable to both periodic and Dirichlet boundary conditions—to reduce the number of real-space grids. This approach introduces a truncation of the real-space grids based on atomic positions, which reduces memory requirements and enables a more efficient real-space scheme tailored for simulating low-dimensional and porous materials with uneven spatial distributions. By testing the method on zero-dimensional clusters, one-dimensional tubes, two-dimensional clusters adsorbed on graphene, and three-dimensional metal-organic framework materials, a 30–73% reduction in grid points and a 36–71% reduction in computational time per step are observed for simulations with a 2 meV/atom energy difference.

关键词： Electronic structure Density functional theory development First-principles calculations Numerical techniques

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Influence of Nanoceramic Particle Size on the Wear Resistance of Micro-Arc Oxidation Coatings for 2a12 Aluminum Alloy

SSRN

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SSRN 2024年

作者： Li, Wen Cheng, Ming Zhang, Xiaochen Wei, Guoke Aviation Key Laboratory of Science and Technology on Advanced Surface Engineering AVIC Manufacturing Technology Institute Beijing100024 China Science and Technology on Power Beam Processes Laboratory AVIC Manufacturing Technology Institute Beijing100024 China

The 2A12 aluminum alloy, renowned for its exceptional mechanical properties, faces significant limitations in applications involving abrasive environments or frequent contact with other surfaces due to its inadequate wear resistance. This shortcoming substantially reduces the service life of components and escalate maintenance costs, highlighting the urgent need for advanced surface modification techniques. This study meticulously investigates the influence of nanoceramic particle size on the wear resistance of micro-arc oxidation (MAO) coatings, a surface modification method known for forming dense, adherent ceramic layers on aluminum alloys. The systematic experimentation revealed that the incorporation of 150 nm α-Al2O3 nanoparticles into the MAO matrix achieves an optimal dispersion, leading to a substantial enhancement in wear resistance. The sample with 5g/L of 150 nm α-Al2O3 nanoparticles doping in the MAO electrolyte demonstrated the lowest mass loss, underscoring its superior wear resistance. The improved microstructure, enriched with hard ceramic phases such as α-Al2O3 and mullite, plays a pivotal role in withstanding wear. Moreover, this study identified that an optimal balance of surface roughness and coating thickness is essential for achieving enhanced wear resistance. The findings of this research provide a compelling strategy for the design of wear-resistant coatings tailored for high-performance applications across aerospace, automotive, and general engineering industries. By optimizing the particle size and concentration in MAO coatings, this study paves the way for the development of durable materials capable of thriving in demanding environments, thereby extending the service life and reducing maintenance requirements of components. © 2024, The Authors. All rights reserved.

关键词： Wear resistance

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Effect of two-dimensional nanomaterials with different addition amounts on organic fluorosilicone resin antifouling coatings

Effect of two-dimensional nanomaterials with different addit...

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第十二届全国腐蚀与防护大会

作者： Ming Cheng Wen Li Guoke Wei Aviation Key Laboratory of Science and Technology on Advanced Surface Engineering AVIC Manufacturing Technology Institute Science and Technology on Power Beam Processes Laboratory AVIC Manufacturing Technology Institute School of Mechanical Engineering and Automation Beihang University

Nowadays, biofouling, the process of continuous enrichment of large and small organisms in the ocean on man-made surfaces, is a worldwide problem. It has a ring-breaking effect on all sea-related weapons and equipment, increasing sea-related aircraft drag, reducing speed and affecting combat effectiveness. The solution to biofouling has always relied on the poisoning effect of heavy metal ions, which has also caused serious pollution of the marine environment. In recent years, with the in-depth research on nanomaterials, it provides a new solution for the prevention and removal of biofouling. Silicone and fluorine antifouling coatings are widely used as antifouling coatings. But they both have advantages and disadvantages, so making the silicone chain is the main chain, introducing a certain amount of-CF3 group in the side chain, and using the ultra-low surface energy property of this group tends to be oriented to the surface, while the whole macromolecule maintains the high elasticity property of linear polysiloxane, so that it has the characteristics of both silicone and fluorine antifouling coatings. In addition to the copolymerization of silicone and fluorine, studies have shown that the physical blending of inert low relative molecular mass organic fluorine compounds(perfluoropolyethers, fluorinated acrylate copolymers, etc.) in silicone could improve the antifouling properties of the coating. These materials have great potential in antifouling research field. The two-dimensional nanomaterials have a unique role in the antifouling performance enhancement of organic fluorosilicone coatings. In this study, through the covalent hybridization and functionalized modification of various two-dimensional nanomaterials(e.g., bismuth tungstate, bismuth chloride oxide, bismuth bromide oxide, bismuth iodide oxide, tungsten oxide), two-dimensional nanohybrid materials with a sheet-sheet nanostructure were built, which led to a significant improvement of the overall mechanic

关键词： organic fluorosilicone resin two-dimensional nanomaterials antifouling performance

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Continuous and comprehensive atmospheric observations in Beijing:a station to understand the complex urban atmospheric environment

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Big Earth Data 2020年第3期4卷 295-321页

作者： Yongchun Liu Chao Yan Zemin Feng Feixue Zheng Xiaolong Fan Yusheng Zhang Chang Li Ying Zhou Zhuohui Lin Yishou Guo Ying Zhang Li Ma Wenshuo Zhou Zhikun Liu Lubna Dada Kaspar Dallenbach Jenni Kontkanen Runlong Cai Tommy Chan Biwu Chu Wei Du Lei Yao Yonghong Wang Jing Cai Juha Kangasluoma Tom Kokkonen Joni Kujansuu Anton Rusanen Chenjuan Deng Yueyun Fu Rujing Yin Xiaoxiao Li Yiqun Lu Yiliang Liu Chaofan Lian Dongsen Yang Weigang Wang Maofa Ge Yuesi Wang Douglas R.Worsnop Heikki Junninen Hong He Veli-Matti Kerminen Jun Zheng Lin Wang Jingkun Jiang Tuukka Petaja Federico Bianchi Markku Kulmala Aerosol and Haze Laboratory Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical TechnologyBeijingChina Institute for Atmospheric and Earth System Research/Physics Faculty of ScienceUniversity of HelsinkiHelsinkiFinland State Key Joint Laboratory of Environment Simulation and Pollution Control State Environmental Protection Key Laboratory of Sources and Control of Air Pollution ComplexSchool of EnvironmentTsinghua UniversityBeijingChina State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijingChina Department of Environmental Science&Engineering Fudan UniversityShanghaiChina State Key Laboratory for Structural Chemistry of Unstable and Stable Species Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijingChina Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Nanjing University of Information Science&TechnologyNanjingChina State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina Aerodyne Research Inc. BillericaMassachusettsUSA Institute of Physics University of TartuTartuEstonia Joint International Research Laboratory of Atmospheric and Earth System Sciences School of Atmospheric SciencesNanjing UniversityNanjingChina

Due to profound impact on climate and human health,air quality has attracted attention from all levels of the civil *** key step in the provision of required tools for the society to tackle the complex air quality problem is to characterize it in a comprehensive manner with a long-term ***,we describe a continuous and comprehensive observation station and its accompanying state-ofthe-art instrumentation that was established to investigate the complex urban atmospheric environment in a rapidly developing Chinese *** station,located in downtown Beijing,aims to study air quality by identifying the major atmospheric pollutants and key processes determining their formation and loss mechanisms.A few hundreds of parameters are continuously measured with the state-of-the-art instruments,including trace gas concentrations,aerosol particle size distributions,and mass concentrations,covering aerosol particle chemical composition from molecules to micrometer-sized aerosol *** produced long-term,comprehensive big data with around 1�10^(11)bytes per *** this paper,we provide an overview on the facilities of the station,the instrumentation used,the workflow of continuous observations and examples of results from 2018 to 2019 and a basis for establishing a modern long-term,comprehensive atmospheric urban observation station in other megacities.

关键词： Continuous and comprehensive atmospheric observation air pollution complex photochemical smog haze new particle formation

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Super-directive Scattering of Optimized Multi-layered Dielectric Cylinder by Differential Evolution Algorithm 4

Super-directive Scattering of Optimized Multi-layered Dielec...

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4th IEEE International Conference on Electronic Information and Communication technology, ICEICT 2021

作者： Zhang, Yongli Chen, Wan Lv, Bo Gao, Lei Zhang, Mingyue China Academy of Civil Aviation Science and Technology Beijing China Space Environment Simulation and Research Infrastructure Harbin Institute of Technology Harbin China Key Laboratory of In-Fiber Integrated Optics of Ministry of Education College of Physics and Optoelectronic Engineering Harbin Engineering University Harbin China Harbin Medical University Harbin China Heilongjiang Xinshan Technology Co. Ltd Harbin China Key Laboratory of In-Fiber Integrated Optics of Ministry of Education College of Physics and Optoelectronic Engineering Harbin Engineering University Harbin China

ISBN: (纸本)9781665432030

Superdirective antenna can realize high channel capacity of multiple-input multiple-output system (MIMO). The optimization of superdirective scattering by a novel weighting optimizing goal and Dirac-Delta function model is proposed. Both main-lobe and side-lobe characteristics of the lobe are optimized. Compared with the traditional optimization method, which only takes the main-lobe characteristic into consideration, the directivity has improved by 50% (from 6.0 to 9.0). Meanwhile, the radius of the scattering object is only 0.1λ0, which indicates this antenna is a super-directive antenna. ©2021 IEEE

关键词： Dielectric devices

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