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Microstructure recognition of steels by machine learning based on visual attention mechanism

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Journal of Iron and Steel Research International 2024年第4期31卷 909-923页

作者： xing-yu Chen Lin Cheng Cheng-yang Hu Yu-peng Zhang Kai-ming wu The State Key Laboratory of Refractories and Metallurgy Hubei Province Key Laboratory of Systems Science on Metallurgical ProcessingInternational Research Institute for Steel TechnologyCollaborative Center on Advanced SteelsWuhan University of Science and TechnologyWuhan 430081HubeiChina Metals Valley and Band(Foshan)Metallic Composite Materials Co. Ltd.Foshan 528000GuangdongChina

U-Net has achieved good performance with the small-scale datasets through skip connections to merge the features of the low-level layers and high-level layers and has been widely utilized in biomedical image segmentation as well as recent microstructure image segregation of the *** representative visual attention mechanism modules,named as squeeze-and-excitation networks,convolutional block attention module,and extended calibration algorithm,were intro-duced into the traditional U-Net architecture to further improve the prediction *** is found that compared with the original U-Net architecture,the evaluation index of the improved U-Net architecture has been significantly improved for the microstructure segmentation of the steels with the ferrite/martensite composite microstructure and pearlite/ferrite composite microstructure and the complex martensite/austenite island/bainite microstructure,which demonstrates the advantages of the utilization of the visual attention mechanism in the microstructure *** reasons for the accuracy improvement were discussed based on the feature maps analysis.

关键词： Microstructure recognition-Steel Machine learning Visual attention mechanism Visualization

New approach to measuring topological phase transitions utilizing Floquet technology

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Chinese Physics B 2024年第9期33卷 282-288页

作者： Xue-Ying Yang Wei wu Ping-xing Chen College of Sciences National University of Defense TechnologyChangsha 410073China

The Floquet technique provides a novel anomalous topological phase for non-equilibrium phase *** on the high symmetry of the quantum anomalous Hall model,the findings suggest a one-to-one correspondence between the average spin texture and the Floquet quasi-energy spectrum.A new approach is proposed to directly measure the quasienergy spectrum,replacing previous measurements of the average spin ***,we proposed a reliable experimental scheme based on ion trap *** scheme markedly reduces the measurement workload,improves the measurement fidelity,and is applicable to multiple platforms such as cold atoms and nuclear magnetic resonance.

关键词： topological phase transition Floquet technique ion trap

Manipulating guest-responsive spin transition to achieve switchable fluorescence in a Hofmann-type framework

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Science China Chemistry 2024年第10期67卷 3339-3346页

作者： Xue-Ru wu Shu-Qi wu Zhi-Kun Liu Ming-xing Chen Jun Tao Osamu Sato Hui-Zhong Kou Engineering Research Center of Advanced Rare Earth Materials(Ministry of Education) Department of ChemistryTsinghua UniversityBeijing 100084China Institute for Materials Chemistry and Engineering&IRCCS Kyushu University744 MotookaNishi-kuFukuoka 819-0395Japan Key Laboratory of Cluster Science of Ministry of Education School of Chemistry and Chemical EngineeringLiangxiang CampusBeijing Institute of TechnologyBeijing 102488China Analytical Instrumentation Center College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

The change of fluorescence emission manipulated by spin state transition attracts considerable attention owing to its potential applications in magneto-optical switching ***,we report two two-dimensional(2D)Hofmann-type spin crossover(SCO)metal-organic frameworks(MOFs)[Fe^(Ⅱ)(PNI)_(2){Ag^(Ⅰ)(CN)_(2)}_(2)]·CHCl_(3)(3Ag·CHCl_(3))and[FeⅡ(PNI)_(2){AuⅠ(CN)_(2)}_(2)]·CHCl_(3)(3Au·CHCl_(3))based on the fluorescent ligand N-(4-pyridylmethyl)-1,8-naphthalimide(PNI).Both complexes exhibit interesting SCO behaviors switched by guest solvent molecules,namely three-step transitions for the solvated complexes and complete onestep hysteretic SCO for the desolvated ones,verified by temperature-dependent magnetic susceptibility measurements,Mossbauer spectra,structural analyses,and differential scanning calorimetry ***,temperature-dependent fluorescence spectra exhibit double peaks(monomer and excimer emission)with both emission peaks change consistent with the change in SCO properties during the solvent molecule *** this study,we integrated guest-responsive SCO behavior into MOFs to manipulate the multistability of spin state and fluorescence switching,providing a rational strategy for the development of stimuli-responsive multifunctional materials.

关键词： spin crossover fluorescence multifunctional materials metal-organic frameworks Hofmann-type

基于单根TaON纳米带的光晶体管与紫外到近红外响应（英文）

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无机材料学报 2019年第9期34卷 1004-1010页

作者：陶友荣陈晋强吴兴才南京大学化学化工学院教育部介观材料重点实验室配位化学国家重点实验室

用Ta2O5纳米带模板转化法控制合成TaON纳米带,典型的纳米带长约0.5 cm,横截面积40 nm×200 nm^400 nm×5600 nm。在SiO2/Si基片上加工出TaON单根纳米带的场效应晶体管;该晶体管的电子迁移率和开关比分别为9.53×10^–4cm^2/(V·s)和3.4,... 详细信息

用Ta2O5纳米带模板转化法控制合成TaON纳米带,典型的纳米带长约0.5 cm,横截面积40 nm×200 nm^400 nm×5600 nm。在SiO2/Si基片上加工出TaON单根纳米带的场效应晶体管;该晶体管的电子迁移率和开关比分别为9.53×10^–4cm^2/(V·s)和3.4,在254~850 nm范围内显示良好的光响应。在405 nm (42 mW/cm2)的光照下,外加5.0 V的偏压时,光响应为249 mA/W,光开关比为11。因此,该器件具有良好的光探测性, TaON纳米带可作为光电子器件的候选材料。另外,实验还控制合成出Ta2O5@TaON纳米带,并加工成单根纳米带的场效应晶体管,虽然相同光照条件下的光响应弱于TaON纳米带,但仍算是一种好的光电材料。

关键词： TaON纳米带模板合成场效应晶体管光探测器

On-chip source-device-independent quantum random number generator

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Photonics Research 2024年第7期12卷 1379-1394页

作者： LANG LI MINGLU cai TAO WANG ZICONG TAN PENG HUANG KAN wu GUIHUA ZENG State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong UniversityShanghai 200240China Institute of Quantum Sensing and Information Processing School of Sensing Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Research Center for Quantum Sciences Hefei National LaboratoryShanghai 201315China Shanghai Xun Tai Quantech Co. Ltd.Shanghai 200241China

Quantum resources offer intrinsic randomness that is valuable for applications such as cryptography, scientific simulation, and computing. Silicon-based photonics chips present an excellent platform for the cost-effective deployment of next-generation quantum systems on a large scale, even at room temperature. Nevertheless,the potential susceptibility of these chips to hacker control poses a challenge in ensuring security for on-chip quantum random number generation, which is crucial for enabling extensive utilization of quantum resources.

关键词： temperature quantum random

Topological Structure-Modulated Collagen Carbon as Two-in-One Energy Storage Configuration toward Ultrahigh Power and Energy Density

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Energy & Environmental Materials 2024年第2期7卷 18-29页

作者： Li Yuan Wenlong cai Yunhong Wei Yiran Pu Can Liu Yun Zhang Hao wu College of Materials Science and Engineering Sichuan UniversityChengdu 610065China Department of Applied Chemistry University of Science and Technology of ChinaHefei 230026China

Efficient energy storage devices with suitable electrode materials,that integrate high power and high energy,are the crucial requisites of the renewable power source,which have unwrapped new possibilities in the sustainable development of energy and the ***,a facile collagen microstructure modulation strategy is proposed to construct a nitrogen/oxygen dual-doped hierarchically porous carbon fiber with ultrahigh specific surface area(2788 m^(2)g^(-1))and large pore volume(4.56 cm^(3)g^(-1))via local microfibrous breakage/disassembly of natural structured *** operando spectroscopy and density functional theory unveil that the dual-heteroatom doping could effectively regulate the electronic structure of carbon atom framework with enhanced electric conductivity and electronegativity as well as decreased diffusion resistance in favor of rapid pseudocapacitive-dominated Li^(+)-storage(353 mAh g^(-1)at 10 A g^(-1)).Theoretical calculations reveal that the tailored micro-/mesoporous structures favor the rapid charge transfer and ion storage,synergistically realizing high capacity and superior rate performance for NPCF-H cathode(75.0 mAh g^(-1)at 30 A g^(-1)).The assembled device with NPCF-H as both anode and cathode achieves extremely high energy density(200 Wh kg^(-1))with maximum power density(42600 W kg^(-1))and ultralong lifespan(80%capacity retention over 10000 cycles).

关键词： collagen carbon energy storage device theoretical calculations topological structure modulation ultrahigh power and energy density

Molding simulation of airfoil foam sandwich structure and interference optimization of foam-core

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Chinese Journal of Aeronautics 2024年第10期37卷 325-338页

作者： Qianying CEN Zeyang xing Qingyou WANG Lili LI Zhigang WANG Zhanjun wu Ling LIU School of Aerospace Engineering&Applied Mechanics Tongji UniversityShanghai 200092China AVIC Harbin Aircraft Industry Group Co.Ltd Harbin 150066China School of Aeronautics and Astronautics Dalian University of TechnologyDalian 116024China

During the Co-Cure Molding(CCM)of airfoil foam sandwich structure,it is challenging to avoid collapse of foam core at the trailing ***,an Equal Proportional Thickening(EPT)method is proposed to optimize the interference of polymethacrylimide(PMI)foam core during the CCM ***,based on some basic parameters of composite skin and foam core obtained by experiments or multi-scale simulations,a thermal-curing-mechanical coupling analysis for the CCM of foam sandwich structure is performed and the results show that the maximum stress within foam core occurs at the completion of mold-closing,which tends to decrease during the subsequent CCM ***,the foam core is thickened by traditional equidistant-thickening method,and the simulation reveals that the foam core at the trailing edge tends to collapse because of stress ***,if the foam core is thickened by the proposed EPT method,the mold-closing caused collapse at the trailing edge can be effectively avoided,and a thickening ratio range of 0.6%–2.0%is obtained,which is further proved by practical ***,the interference design scheme proposed can ensure the molding quality and effectively reduce the scrap of molded products.

关键词： Airfoil foam sandwich structure Polymethacrylimide(PMI)foam Interference Co-curing Molding simulation

Nitrogen–sulfur co-doped porous carbon derived from asphalt as efficient catalyst for oxygen reduction

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Rare Metals 2024年第1期43卷 380-388页

作者： Jing-Sheng Ma Ming-Zai wu Ling Chen Li-xing Zhang Ying Xiong Key Laboratory of Structure and Functional Regulation of Hybrid Materials Ministry of EducationInstitute of EnergyHefei Comprehensive National Science CenterAnhui UniversityHefei 230601China

As an environment-friendly and low-cost petrochemical by-product, asphalt has great potential in the preparation of metal-free oxygen reduction electrocatalysts with excellent performance and outstanding stability. In this paper, we converted asphalt into porous carbon nanosheets by a simple activation method, using potassium citrate as the swelling agent.

关键词： stability porous catalyst

Granger causal representation learning for groups of time series

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Science China(Information Sciences) 2024年第5期67卷 56-68页

作者： Ruichu cai Yunjin wu Xiaokai HUANG Wei CHEN Tom Z.J.FU Zhifeng HAO School of Computer Science Guangdong University of Technology Peng Cheng Laboratory College of Science Shantou University

Discovering causality from multivariate time series is an important but challenging *** existing methods focus on estimating the Granger causal structures among multivariate time series,while ignoring the prior knowledge of these time series, e.g., the group of the time series. Focusing on discovering the Granger causal structures among groups of time series, we propose a Granger causal representation learning method to solve this problem. First, we use the multiset canonical correlation analysis method to learn the Granger causal representation of each group of time series. Then, we model the Granger causal relationships among the learned Granger causal representations using a recurrent neural network with temporal information. Finally, we formulate the above two stages into one unified optimization problem, which is efficiently solved using the augmented Lagrangian method. We conduct extensive experiments on synthetic and real-world datasets to validate the correctness and effectiveness of the proposed method.

关键词： Granger causal discovery Granger causal representation learning time series data recurrent neural network multiset canonical correlation analysis