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Sparse-view neutron CT 3D image reconstruction algorithm based on split Bregman method

Nuclear science and Techniques 2024年第9期35卷 41-55页

作者： Teng-Fei Zhu Yang Liu Zhi Luo Xiao-Ping Ouyang School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Xi’an 710024China

As a complement to X-ray computed tomography(CT),neutron tomography has been extensively used in nuclear engineer-ing,materials science,cultural heritage,and industrial *** of the attenuation matrix for neutron tomography with a traditional analytical algorithm requires hundreds of projection views in the range of 0°to 180°and typically takes several hours to *** a low time-resolved resolution degrades the quality of neutron *** the number of projection acquisitions is an important approach to improve the time resolution of images;however,this requires efficient reconstruction ***,sparse-view reconstruction algorithms in neutron tomography need to be *** this study,we investigated the three-dimensional reconstruction algorithm for sparse-view neu-tron CT *** enhance the reconstructed image quality of neutron CT,we propose an algorithm that uses OS-SART to reconstruct images and a split Bregman to solve for the total variation(SBTV).A comparative analysis of the performances of each reconstruction algorithm was performed using simulated and actual experimental *** to the analyzed results,OS-SART-SBTV is superior to the other algorithms in terms of denoising,suppressing artifacts,and preserving detailed structural information of images.

关键词： Neutron CT OS-SART Sparse-view 3D reconstruction Split Bregman Total variation

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Inhibiting liquid permeation into silicone rubber by superhydrophobic coating for prolonged service life

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High Voltage 2023年第5期8卷 986-996页

作者： Shuming Liu Ying Zhou Zhou Zuo Shuqi Liu Qian Wang Zhong Chen Xidong Liang State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical EngineeringTsinghua UniversityBeijingChina School of Material Science and Engineering Nanyang Technological UniversitySingaporeSingapore

Liquid permeation into silicone rubber(SR)may lead to the degradation or complete failure of the composite *** to inhibit liquid permeation,two kinds of superhydrophobic coatings are applied to the SR *** liquid permeation properties of SR with different types of liquids are investigated,and the Langmuir diffusion model is applied to analyse the experimental *** results show that the composite superhydrophobic coating can effectively inhibit liquid permeation by reducing the contact area between the surface and liquid,and the stable structure of the composite coating can maintain the performance after the liquid permeation and ***,the nano‐particle coating without the polymer binder experiences severe performance degradation during the immersion test,and it cannot restrain the liquid permeation anymore after it loses the *** a validation of the effective protection,the insulation resistivity change was *** resistivity decreases sharply for the pristine SR after water permeation;however,the decrease is much smaller for the coated *** current study not only provides new insight into the liquid permeation properties of SR with different surface wettability but also suggests an effective measure to prevent liquid permeation into SR.

关键词： coating permeation liquid

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Machine learning driven rational design of dual atom catalysts on graphene for carbon dioxide electroreduction

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Nano Research 2025年第1期18卷 186-194页

作者： Dongxu Jiao Xinyi Li Mingzi Sun Lin Liu Jinchang Fan Jingxiang Zhao Bolong Huang Xiaoqiang Cui State Key Laboratory of Automotive Simulation and Control School of Materials Science and Engineeringand Key Laboratory of Automobile Materials of MOEJilin UniversityChangchun 130012China Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina College of Chemistry and Chemical Engineering and Key Laboratory of Photonic and Electronic Bandgap MaterialsMinistry of EducationHarbin Normal UniversityHarbin 150025China

The development of high-performance atomiccatalysts for the carbon dioxide reduction reaction(CO_(2)RR)is atime-consuming process due to the complexity of the reactionmechanism and the uncertainty of the active ***,wehave proposed combining density functional theory(DFT)andmachine learning(ML)to investigate the potential of topologicalgraphene-based dual-atom catalysts(DACs)as CO_(2)*** analyzing the ML results,we identify thenumber of d-orbital electrons in the active site as a key factorinfluencing the CO_(2)RR catalytic ***,wepropose a simple descriptor to measure the CO_(2)RR activity ofthese *** findings provide plausible explanations for thesynergistic interactions between bimetallic atoms in CO_(2)RR andallow us to screen the homogeneous Ni-Ni pair as the mostpromising dual-atom *** work offers a fast MLapproach based on limited DFT calculations to predict the mostelectroactive and stable DACs on carbon support for CO_(2)RR,facilitating rapid screening of high-performance dual-atomcatalysts.

关键词： CO_(2)reaction reduction dual-atom catalysts density functional theory machine learning

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A theoretical and experimental study of deformation mechanism dictated by disclination-dislocation coupling in Mg alloys at different temperatures

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材料科学技术（英文版） 2025年第5期208卷 176-188页

作者： Chunfeng Du Yipeng Gao Yizhen Li Quan Li Min Zha Cheng Wang Hailong Jia Hui-Yuan Wang Key Laboratory of Automobile Materials of Ministry of Education&School of Materials Science and Engineering Nanling CampusJilin UniversityChangchun 130025China Key Laboratory of Automobile Materials of Ministry of Education&School of Materials Science and Engineering Nanling CampusJilin UniversityChangchun 130025China International Center of Future Science Jilin UniversityChangchun 130012China International Center of Future Science Jilin UniversityChangchun 130012China State Key Lab of Superhard Materials and Key Laboratory of Material Simulation Methods&Software of Ministry of Education College of PhysicsJilin UniversityChangchun 130012China Key Laboratory of Automobile Materials of Ministry of Education&School of Materials Science and Engineering Nanling CampusJilin UniversityChangchun 130025China International Center of Future Science Jilin UniversityChangchun 130012China State Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Material Science and EngineeringHebei University of TechnologyTianjin 300130China

Dislocations and disclinations are fundamental topological defects within crystals,which determine the mechanical properties of metals and *** their important roles in multiple physical mecha-nisms,e.g.,dynamic recovery and grain boundary mediated plasticity,the intrinsic coupling and corre-lation between disclinations and dislocations,and their impacts on the deformation behavior of metallic materials still remain obscure,partially due to the lack of a theoretical tool to capture the rotational na-ture of *** using a Lie-algebra-based theoretical framework,we obtain a general equation to quantify the intrinsic coupling of disclinations and *** quasi in-situ electron backscat-ter diffraction characterizations and disclination/dislocation density analyses in Mg alloys,the generation,coevolution and reactions of disclinations and dislocations during dynamic recovery and superplastic de-formation have been quantitatively *** has been demonstrated that the obtained governing equa-tion can capture multiple physical processes associated with mechanical deformation of metals,e.g.,grain rotation and grain boundary migration,at both room temperature and high *** establishing the disclination-dislocation coupling equation within a Lie algebra description,our work provides new insights for exploring the coevolution and reaction of disclinations/dislocations,with profound implica-tions for elucidating the microstructure-property relationship and underlying deformation mechanisms in metallic materials.

关键词： Magnesium alloys Dislocations Grain boundaries Plastic deformation Grain rotation Disclination-dislocation coupling

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Meta-GPS++: Enhancing Graph Meta-Learning with Contrastive Learning and Self-Training

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ACM Transactions on Knowledge Discovery from Data 2024年第9期18卷 1-30页

作者： Liu, Yonghao Li, Mengyu Li, Ximing Huang, Lan Giunchiglia, Fausto Liang, Yanchun Feng, Xiaoyue Guan, Renchu Key Laboratory of Symbolic Computation and Knowledge Engineering of the Ministry of Education College of Computer Science and Technology Jilin University Changchun China University of Trento Trento Italy Zhuhai Lab. of the Key Lab. of Symbolic Computation and Knowledge Eng. of the Ministry of Education Zhuhai College of Science and Technology Zhuhai China

Node classification is an essential problem in graph learning. However, many models typically obtain unsatisfactory performance when applied to few-shot scenarios. Some studies have attempted to combine meta-learning with graph neural networks to solve few-shot node classification on graphs. Despite their promising performance, some limitations remain. First, they employ the node encoding mechanism of homophilic graphs to learn node embeddings, even in heterophilic graphs. Second, existing models based on meta-learning ignore the interference of randomness in the learning process. Third, they are trained using only limited labeled nodes within the specific task, without explicitly utilizing numerous unlabeled nodes. Finally, they treat almost all sampled tasks equally without customizing them for their uniqueness. To address these issues, we propose a novel framework for few-shot node classification called Meta-GPS. Specifically, we first adopt an efficient method to learn discriminative node representations on homophilic and heterophilic graphs. Then, we leverage a prototype-based approach to initialize parameters and contrastive learning for regularizing the distribution of node embeddings. Moreover, we apply self-Training to extract valuable information from unlabeled nodes. Additionally, we adopt S (scaling and shifting) transformation to learn transferable knowledge from diverse tasks. The results on real-world datasets show the superiority of Meta-GPS. Our code is available here. © 2024 Copyright held by the owner/author(s).

关键词： Contrastive Learning

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Multiscale Modeling with Online Correction for Darcy–Forchheimer Flow

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Lobachevskii Journal of Mathematics 2024年第11期45卷 5424-5436页

作者： Spiridonov, D.A. Huang, J. Laboratory of Computational Technologies and Artificial Intelligence North-Eastern Federal University Yakutsk 677000 Russian Federation School of Mathematics and Computational Science Xiangtan University National Center for Applied Mathematics in Hunan and Hunan Key Laboratory for Computation and Simulation in Science and Engineering Hunan Xiangtan 411105 China

Abstract: In this research, we present an algorithm of the Online generalized multiscale finite element method (Online GMsFEM) for Darcy–Forchheimer model in fractured media. The mathematical model describes a nonlinear Darcy flow with a high inertial effect and flow speed. The fine grid approximation is carried out by the finite element method (FEM) and to approximate lower dimensional fractures we use a discrete fracture model (DFM). We use a model reduction approach called Online GMsFEM, that is based on local residuals of coarse neighborhoods. The online multiscale basis functions are constructed in each local domain based on residuals. Such online multiscale basis functions make it possible take into account the effects of nonlinear coefficients in the Darcy–Forchheimer equation. We present numerical results in two-dimensional heterogeneous fractured domain. We investigate the accuracy of the method, depending on the influence of nonlinearity. The numerical experiments show that the Online GMsFEM has high accuracy for such nonlinear problems. The accuracy weakly depends on the magnitude of the nonlinear part of the equation. © Pleiades Publishing, Ltd. 2024.

关键词： Darcy–Forchheimer model discrete fracture model finite element method fractured domain multiscale model reduction nonlinear flow problem Online generalized multiscale finite element method

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An Algebraic Multigrid-Based Physical Factorization Preconditioner for the Multi-Group Radiation Diffusion Equations in Three Dimensions

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Numerical Mathematics(Theory,Methods and Applications) 2023年第2期16卷 410-432页

作者： Xiaoqiang Yue Zekai Zhang Xiaowen Xu Shuying Zhai Shi Shu National Center for Applied Mathematics in Hunan Key Laboratory of Intelligent Computing&Information Processing of Ministry of EducationHunan Key Laboratory for Computation and Simulation in Science and EngineeringXiangtan UniversityXiangtan 411105China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100094China School of Mathematical Sciences Huaqiao UniversityQuanzhou 362021China.

The paper investigates the robustness and parallel scaling properties of a novel physical factorization preconditioner with algebraic multigrid subsolves in the iterative solution of a cell-centered finite volume discretization of the threedimensional multi-group radiation diffusion *** key idea is to take advantage of a particular kind of block factorization of the resulting system matrix and approximate the left-hand block matrix selectively spurred by parallel processing *** spectral property of the preconditioned matrix is then *** practical strategy is considered sequentially and in ***,numerical results illustrate the numerical robustness,computational efficiency and parallel strong and weak scalabilities over the real-world structured and unstructured coupled problems,showing its competitiveness with many existing block preconditioners.

关键词： Radiation diffusion equations physical factorization preconditioning algebraic multigrid parallel and distributed computing

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Evolution hydrothermal aging resistance mechanism study of zirconium and manganese doped CeO_(2)catalysts in soot catalytic combustion based on low Miller indices crystal surface effect

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Journal of Rare Earths 2024年第7期42卷 1272-1281,I0003页

作者： Zonglin Li Pan Wang Hong Ni Chengcheng Ao Lidong Zhang Hefeng Zhang Kai Li School of Automotive and Traffic Engineering Jiangsu UniversityZhenjiang212013China State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation Chinese Research Academy of Environmental ScienceBeijing100012China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei230026China

The thermogravimetric analysis(TGA)experiments were carried out to reveal the mechanism of Zr and Mn doping on catalytic activity of CeO_(2)catalyst both fresh and after hydrothermal aging,and the lattice morphology and valence changes were characterized by means of Brunauer-Emmett-Teller(BET)method,X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and H_(2)-temperature programmed reduction(H_(2)-TPR).Density functional theory(DFT)and molecular thermodynamics calculations were applied to investigate the change in catalytic activity,crystal surface energy and crystal morphology caused by hydrothermal *** maximum reaction rate temperature of fresh Mn/CeO_(2)(389℃)is similar to that of CeO_(2)(371℃)and lower than that of Zr/CeO_(2)(447℃),but the catalytic performance of CeO_(2)decreases more severely after hydrothermal *** catalyst crystals show different degrees of crystal surface migration after hydrothermal aging,which leads to the reduction of Ce^(3+)/Ce^(4+) ratio and the active sites *** calculations indicate that the doping of Zr and Mn reduces the surface energy of the low Miller indices surface and increases the oxygen vacancy formation energy,leading to better thermal stability and lower catalytic *** Zr and Mn doping also changes the adsorption energy and Gibbs free energy of H_(2)O,which dominates the migration of(111)to(110)and(100)in the vapor *** crystal surface migration mechanism of CeO_(2)catalysts doped with Zr and Mn induced by H_(2)O molecules at high temperature obtained in this study can provide a valuable addition to the regeneration of CeO_(2)catalysts in the after-treatment systems of diesel engines.

关键词： Soot CeO_(2)-based catalyst CDPF Rare earth metal oxides DFT calculations

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Microdynamic modulation through Pt–O–Ni proton and electron“superhighway”for pH-universal hydrogen evolution

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Journal of Energy Chemistry 2025年第2期101卷 808-815,I0018页

作者： Dewen Wang Yuting Chen Bohan Yao Tian Meng Yanchao Xu Dongxu Jiao Zhicai Xing Xiurong Yang State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina University of Science and Technology of China Hefei 230026AnhuiChina Department of Chemistry Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Energy Materials for Electric PowerSouthern University of Science and TechnologyShenzhen 518055GuangdongChina State Key Laboratory of Automotive Simulation and Control School of Materials Science and EngineeringJilin UniversityChangchun 130012jilinChina

Optimizing the microdynamics in alkaline and neutral conditions is a significant but challenging task in developing pH-universal hydrogen evolution(HER)***,a unique Pt-O-Ni bridge has been constructed to alter the coordination and electronic environment between Pt nanoparticles(Pt_n)and nickel metaphosphate(NPO)substrate(Pt-NPO).Sufficient electron transfer from NPO to Pt_n to maintain an electron-rich environment and a low valence state of Pt_***,H*is produced from the H_(2)O dissociation on Ni site and then spillover toward Pt sites to bind into H_(2),which makes up for the insufficient H_(2)O dissociation ability of Pt in Volmer ***-NPO exhibits long-term stability and only need the overpotentials of 22.3,33.0 and 30.5 mV to attain 10 mA cm^(-2)in alkaline,neutral and acidic media,*** anion-exchange membrane(AEM)water electrolyzer catalyzed by Pt-NPO shows high water electrolysis performance that a cell voltage of 1.73 V is needed to obtain the current density of500 mA cm^(-2)in 1 M KOH at 80℃,at the same time maintains good stability for 350 *** regulation strategy proposed in this work is helpful for the design and synthesis of highly efficient pH-universal HER electrocatalysts.

关键词： Hydrogen evolution reactions pH-universal HER electrocatalysts Metal-support interactions Microdynamics Atomic and electronic regulation

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Occurrence and health risk assessment of organic amine pesticides in drinking water of the Yangtze River delta urban agglomeration

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Journal of Environmental sciences 2025年第6期152卷 99-110页

作者： Zao Yang Shengwei Zhang Feng Wang Bin Dong Minghong Cai School of Environmental Science and Engineering Tongji UniversityShanghai 200092China Ministry of Natural Resources Key Laboratory for Polar Science Polar Research Institute of ChinaShanghai 200136China State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200030China

Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ***,there is a lack of data on the occurrence of OAPs in drinking water and their potential human health *** this study,tapwater(TW)and bottledwater(BW)sampleswere collected from eight cities in the Yangtze River Delta urban agglomeration in China,and their OAP levelswere analyzed using high-throughput organic analysis testing coupled with high-volume solid-phase extraction(Hi-throat/Hi-volume SPE techniques).This study is the first to systematically characterize the trace levels of OAPs in drinking water in *** findings indicated that the total concentration of OAPs(OAPs)in TW(average 11.06±4.99 ng/L)was 29.4%higher than in BW(average 8.55±3.98 ng/L)and fewer kinds(7)of OAPs were detected in ***,the long-term intake of TW in some areas was linked to carcinogenic risks even at an acceptable OAP range,particularly in males,with molinate being the major contributor(61.3%)to OAP *** analysis revealed that the occurrence and health risks of OAPs in drinking water were mainly influenced by the quality of water sources and the technologies adopted in drinking water treatment plants(DWTPs).Furthermore,our findings demonstrated that advanced treatment technologies such as nanofiltration could more effectively remove OAPs in raw water(up to 87.5%).Therefore,our findings highlighted the importance of selecting appropriate advanced treatment technologies in DWTPs.

关键词： Drinking water safety Organic amine pesticides Yangtze River Delta urban Agglomeration Health risk

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