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Microstructure and mechanical properties of a recycled aluminum alloy fabricated by consolidation of small pieces

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Heat Treatment and Surface engineering 2024年第1期6卷

作者： Liu, Feifei Zhang, Deliang School of Materials Science and Engineering Northeastern University Shenyang China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern University Shenyang China Key Laboratory of Data Analytics and Optimization for Smart Industry (Ministry of Education) Northeastern University Shenyang China

The microstructure and mechanical properties of recycled AA6063 aluminum alloy rods fabricated by hot extrusion of forging compacts formed by upsetting compacts of small AA6063 aluminum alloy pieces with different Fe contents before and after T6 heat treatment were studied. In the as-extruded state and with the higher extrusion ratio of 25:1, the microstructure consists of fully recrystallized grains, but the high iron content regions exhibit clearly finer equiaxed grains due to the stronger grain boundary pinning and nucleation effects of a higher number density of Fe-rich phase particles. Increasing the extrusion ratio increases both the strength and ductility of the as-extruded material. The reason is that increasing extrusion ratio enhances the bonding strength of the prior boundaries between the strips formed by deformation of the small pieces. In the T6 heat-treated state, increasing the extrusion ratio from 9:1 to 25:1 clearly increases the fraction of fine and equiaxed grains. The enhancement of the bonding strength and the refinement of the microstructure with the increase of extrusion ratio cause the yield strength and ultimate tensile strength to increase from 174 and 221 MPa to 213 and 237 MPa, respectively, and the elongation to fracture to decrease from 22.1 to 15.4%. Solid-state recycled samples all exhibit a ductile fracture behavior despite formation of microcracks at the prior boundaries. © 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.

关键词： Aluminum alloy hot extrusion mechanical properties microstructure solid state recycling

High Sensitive Butanone Gas Sensor Based on Co3o4 Modified Sno2 Hollow Spheres with Ppb-Level Detection Limit

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SSRN

SSRN 2022年

作者： Yang, Liu Ji, Hanyang Yuan, Zhenyu Meng, Fanli College of Information Science and Engineering Northeastern University Shenyang110819 China Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology Qinhuangdao066004 China Key Laboratory of Data Analytics and Optimization for Smart Industry Northeastern University Ministry of Education Shenyang110819 China

Butanone is a precursor chemical and detrimental to human body, as a consequence, it is significant for social stability to accurately detect trace butanone. In this paper, Co3O4/SnO2 is prepared by modifying Co3O4 nanoparticles on the surface of SnO2 hollow spheres, demonstrating outstanding sensitivity to butanone. SEM, TEM, HRTEM, EDS, XRD, XPS, EPR and BET characterize the morphology, composition, and properties of Co3O4/SnO2. The response of 0.5 at% Co3O4/SnO2 to 100 ppm butanone is 3900 at 210 °C, moreover, the detection limit can reach ppb level (response is 7.2 to 1 ppb), with excellent repeatability and stability. Since Cox+ can replace Sn2+, the content of oxygen vacancy on the surface is adjusted by modifying Co3O4 with different content to improve the gas sensitivity. Of course, the specific surface area and pore size change correspondingly. The role of p-n heterojunction, as well as the synergistic sensitization principle of catalytic and small size effect, are also analyzed in detail. The gas sensing results show that 0.5 at% Co3O4/SnO2 is an excellent gas sensing material. © 2022, The Authors. All rights reserved.

关键词： Oxygen vacancies

Recent research progress on the direct carbon capture of steel slag to prepare building materials

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Green and smart Mining engineering 2024年第4期1卷 387-395页

作者： Zihe Gao Qing Zhao Mengjie Tao Zengrui Wang Chengjun Liu Henrik Saxén Ron Zevenhoven Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819China School of Metallurgy Northeastern UniversityShenyang 110819China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education) Northeastern UniversityShenyang 110819China Process and Systems Engineering Laboratory Åbo Akademi UniversityTurku 20500Finland

Driven by the“dual carbon”and“green metallurgy”targets,the steel industry feels the pressure of carbon emission reduction and steel slag resource *** the year 2000,accelerated carbonation technology using basic oxides in steel slag to store CO_(2)has been widely investigated *** this study,the chemical and mineral compositions and the main physical properties of different steel slags are summarized to achieve the dual purpose of CO_(2)mineralization and steel slag *** paper also summarizes the latest advancements in the direct carbonation of steel *** the carbonation process,residual free calcium oxide and magnesium oxide can be further carbonated to aid in the preparation of building *** direct carbonation method improves the use of steel slag as an aggregate and in cementitious applications,exhibiting effective performance in steel-slag-based *** the limited extent of steel slag carbonation and the modest utilization of available products,this paper explores the current research on carbonated steel slag for building material fabrication and discusses the variety of green building materials.

关键词： Dual carbon Green metallurgy Steel slag Carbonation Building materials

Prospects for searching for sterile neutrinos with gravitational wave and γ-ray burst joint observations

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arXiv 2024年

作者： Feng, Lu Han, Tao Zhang, Jing-Fei Zhang, Xin College of Physical Science and Technology Shenyang Normal University Shenyang110034 China Liaoning Key Laboratory of Cosmology and Astrophysics College of Sciences Northeastern University Shenyang110819 China MOE Key Laboratory of Data Analytics and Optimization for Smart Industry Northeastern University Shenyang110819 China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern University Shenyang110819 China

Sterile neutrinos can influence the evolution of the universe, and thus cosmological observations can be used to detect them. Future gravitational-wave (GW) observations can precisely measure absolute cosmological distances, helping to break parameter degeneracies generated by traditional cosmological observations. This advancement can lead to much tighter constraints on sterile neutrino parameters. This work provides a preliminary forecast for detecting sterile neutrinos using third-generation GW detectors in combination with future short γ-ray burst observations from a THESEUS-like telescope, an approach not previously explored in the literature. Both massless and massive sterile neutrinos are considered within the ΛCDM cosmology. We find that using GW data can greatly enhance the detection capability for massless sterile neutrinos, reaching 3σ level. For massive sterile neutrinos, GW data can also greatly assist in improving the parameter constraints, but it seems that effective detection is still not feasible. Copyright © 2024, The Authors. All rights reserved.

关键词： Cosmology

Exploring the Key Features of Repeating Fast Radio Bursts with Machine Learning

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arXiv 2024年

作者： Sun, Wan-Peng Zhang, Ji-Guo Li, Yichao Hou, Wan-Ting Zhang, Fu-Wen Zhang, Jing-Fei Zhang, Xin Liaoning Key Laboratory of Cosmology and Astrophysics College of Sciences Northeastern University Shenyang110819 China College of Mathematics and Statistics Liaoning University Shenyang110036 China College of Science Guilin University of Technology Guilin541004 China MOE Key Laboratory of Data Analytics and Optimization for Smart Industry Northeastern University Shenyang110819 China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern University Shenyang110819 China

Fast radio bursts (FRBs) are enigmatic high-energy events with unknown origins, which are observationally divided into two categories, i.e., repeaters and non-repeaters. However, there are potentially a number of non-repeaters that may be misclassified, as repeating bursts are missed due to the limited sensitivity and observation periods, thus misleading the investigation of their physical properties. In this work, we propose a repeater identification method based on the t-distributed Stochastic Neighbor Embedding algorithm and apply the classification to the first Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) catalog. We find that the spectral morphology parameters, specifically spectral running (r), represent the key features for identifying repeaters from the non-repeaters. Also, the results suggest that repeaters are more biased toward narrowband emission, whereas non-repeaters are inclined toward broadband emission. We provide a list of 163 repeater candidates, five of which are confirmed with an updated repeater catalog from CHIME/FRB. Our findings improve our understanding of the various properties underlying repeaters and non-repeaters, as well as guidelines for future FRB detection and categorization. Copyright © 2024, The Authors. All rights reserved.

关键词： Radio

Aspiration dynamics generate robust predictions in structured populations

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arXiv 2018年

作者： Zhou, Lei Wu, Bin Du, Jinming Wang, Long Center for Systems and Control College of Engineering Peking University Beijing100871 China School of Sciences Beijing University of Posts and Telecommunications Beijing100876 China Liaoning Engineering Laboratory of Operations Analytics and Optimization for Smart Industry Northeastern University Shenyang110819 China Institute of Industrial and Systems Engineering Northeastern University Shenyang110819 China

Evolutionary game dynamics in structured populations are strongly affected by updating rules. Previous studies usually focus on imitation-based rules, which rely on payoff information of social peers. Recent behavioral experiments suggest that whether individuals use such social information for strategy updating may be crucial to the outcomes of social interactions. This hints at the importance of considering updating rules without dependence on social peers' payoff information, which, however, is rarely investigated. Here, we study aspiration-based self-evaluation rules, with which individuals self-assess the performance of strategies by comparing own payoffs with an imaginary value they aspire, called the aspiration level. We explore the fate of strategies on population structures represented by graphs or networks. Under weak selection, we analytically derive the condition for strategy dominance, which is found to coincide with the classical condition of risk-dominance. This condition holds for all networks and all distributions of aspiration levels, and for individualized ways of self-evaluation. Our condition can be intuitively interpreted: one strategy prevails over the other if the strategy brings more satisfaction to individuals than the other does. Our work thus sheds light on the intrinsic difference between evolutionary dynamics induced by aspiration-based and imitation-based rules. Copyright © 2018, The Authors. All rights reserved.

关键词： Dynamics

Multi-AUV Cooperative Underwater Multi-Target Tracking Based on Dynamic-Switching-enabled Multi-Agent Reinforcement Learning

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arXiv 2024年

作者： Wang, Shengbo Lin, Chuan Han, Guangjie Zhu, Shengchao Li, Zhixian Wang, Zhenyu Ma, Yunpeng Software College Northeastern University Shenyang China Key Laboratory of Data Analytics and Optimization for Smart Industry Northeastern University Ministry of Education China Department of Internet of Things Engineering Hohai University Changzhou213022 China Jiangsu Key Laboratory of Power Transmission and Distribution Equipment Technology Hohai University China

In recent years, autonomous underwater vehicle (AUV) swarms are gradually becoming popular and have been widely promoted in ocean exploration or underwater tracking, etc. In this paper, we propose a multi-AUV cooperative underwater multi-target tracking algorithm especially when the real underwater factors are taken into account. We first give normally modelling approach for the underwater sonar-based detection and the ocean current interference on the target tracking process. Then, based on software-defined networking (SDN), we regard the AUV swarm as a underwater ad-hoc network and propose a hierarchical software-defined multi-AUV reinforcement learning (HSARL) architecture. Based on the proposed HSARL architecture, we propose the"Dynamic-Switching" mechanism, it includes"Dynamic-Switching Attention" and"Dynamic-Switching Resampling" mechanisms which accelerate the HSARL algorithm’s convergence speed and effectively prevents it from getting stuck in a local optimum state. Additionally, we introduce the reward reshaping mechanism for further accelerating the convergence speed of the proposed HSARL algorithm in early phase. Finally, based on a proposed AUV classification method, we propose a cooperative tracking algorithm called Dynamic-Switching-Based MARL (DSBM)driven tracking algorithm. Evaluation results demonstrate that our proposed DSBM tracking algorithm can perform precise underwater multi-target tracking, comparing with many of recent research products in terms of various important metrics. Copyright © 2024, The Authors. All rights reserved.

关键词： Reinforcement learning

A learning-based solution method for practical slab allocation problem in multiple hot rolling lines

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A I I E Transactions

A I I E Transactions 2024年第9期56卷

作者： Ying Meng Qingxin Guo Qingyang Wang Haichao Wang a National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern University Shenyang Chinab Key Laboratory of Data Analytics and Optimization for Smart Industry (Northeastern University) Ministry of Education China b Key Laboratory of Data Analytics and Optimization for Smart Industry (Northeastern University) Ministry of Education Chinac Liaoning Engineering Laboratory of Data Analytics and Optimization for Smart Industry Northeastern University Shenyang China b Key Laboratory of Data Analytics and Optimization for Smart Industry (Northeastern University) Ministry of Education Chinad Liaoning Key Laboratory of Manufacturing System and Logistics Optimization Northeastern University Shenyang China

Steel slabs are key in-process products in the steel production process. The slab allocation problem is to allocate slabs to suitable orders by considering complicated technical restrictions and multiple management requirements. In practice, thousands of slabs in multiple production lines should be allocated to orders. Due to the complexity and large scale of the problem, it takes planners a long time to make decisions, and the obtained allocation schemes are usually ineffective because of the myopic nature of the rule-based methods. In this article, we present a learning-based solution method for solving a practical slab allocation problem in multiple hot rolling lines. We formulate the problem as an integer programming model, then a data-based method is adopted to evaluate the mismatching cost between slabs and orders. To effectively solve the large-sized problem, a learning-based decomposition strategy is proposed to decompose the original problem into several small-sized subproblems. Then, a branch-and-price algorithm is proposed to optimally solve the subproblems. To further speed up the solution process, a primal heuristics based on column generation is designed to solve the large-sized subproblems. The solution methods have been implemented in a steel company and effectively increased slab utilization and reduced production cost.

关键词： Slab allocation combinatorial optimization branch-and-price learning

Prospects for probing the interaction between dark energy and dark matter using gravitational-wave dark sirens with neutron star tidal deformation

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arXiv 2023年

作者： Li, Tian-Nuo Jin, Shang-Jie Li, Hai-Li Zhang, Jing-Fei Zhang, Xin College of Sciences Northeastern University Shenyang110819 China Basic Teaching Department Shenyang Institude of Engineering Shenyang110136 China Key Laboratory of Data Analytics and Optimization for Smart Industry Ministry of Education Northeastern University Shenyang110819 China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern University Shenyang110819 China

Gravitational wave (GW) standard siren observations provide a rather useful tool to explore the evolution of the universe. In this work, we wish to investigate whether the dark sirens with neutron star (NS) deformation from third-generation (3G) GW detectors could help probe the interaction between dark energy and dark matter. We simulate the GW dark sirens of four detection strategies based on the three-year observation and consider four phenomenological interacting dark energy models to perform cosmological analysis. We find that GW dark sirens could provide tight constraints on Ωm and H0 in the four IDE models, but perform not well in constraining the dimensionless coupling parameter β with the interaction proportional to the energy density of cold dark matter. Nevertheless, the parameter degeneracy orientations of CMB and GW are almost orthogonal, and thus the combination of them could effectively break cosmological parameter degeneracies, with the constraint errors of β being 0.00068-0.018. In addition, we choose three typical equation of states (EoSs) of NS, i.e., SLy, MPA1, and MS1, to investigate the effect of NS’s EoS in cosmological analysis. The stiffer EoS could give tighter constraints than the softer EoS. Nonetheless, the combination of CMB and GW dark sirens (using different EoSs of NS) shows basically the same constraint results of cosmological parameters. We conclude that the dark sirens from 3G GW detectors would play a crucial role in helping probe the interaction between dark energy and dark matter, and the CMB+GW results are basically not affected by the EoS of NS. Copyright © 2023, The Authors. All rights reserved.

关键词： Sirens