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Important step towards an understanding of the exotic Zc（3900）

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Science china(Physics,Mechanics & Astronomy) 2024年第9期Mechanics & Astronomy) .卷 203-204页

作者： c.Hanhart Institute for Advanced Simulation Forschungszentrum Jülich

The Standard Model of particle physics, which contains the field theories for the electro-weak interaction(QED) and the strong interaction(QcD), is an extremely successful theory describing a huge variety of phenomena at the atomic and subatomic level with incredible accuracy. However, the inner workings of the strong interaction for systems characterised by small momentum transfers(of the order of ΛQcDor smaller) are still not fully understood.

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Spatial distributions of soil nutrients affected by land use,topography and their interactions,in the Loess Plateau of china

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International Soil and Water conservation Research 2024年第1期12卷 227-239页

作者： Wenxin Zhou changjia Li Wenwu Zhao Lindsay c.Stringer Bojie Fu State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijingChina Institute of Land Surface System and Sustainable Development Faculty of Geographical ScienceBeijing Normal UniversityBeijingChina Department of Environment and Geography University of YorkYorkUK York Environmental Sustainability Institute University of YorkYorkUK

Soil nutrient availability and their spatial distributions are strongly related to land use and landscape *** study aims to address the knowledge gap regarding the interaction between these factors and the underlying *** selected five land uses(grassland with Artemisia gmelinii,woodland with Robinia pseudoacacia,shrubland with caragana korshinskii and Hippophae rhamnoides,and apple orchard with Malus pumila)and nine slope positions across hillslopes in the Loess Plateau,china,to investigate their combined effects on the contents and stocks of soil organic carbon(SOc),total nitrogen(TN)and total phosphorus(TP).Parametric and non-parametric statistical tests were conducted to determine the significant differences in the means or the medians of the soil nutrient *** showed that the SOc and TN contents of shrubland with caragana korshinskii were statistically significantly greater than those of the grassland(pc and TN contents generally decreased from the upper slope to the middle slope,and to the foot slope for the grassland,woodland and shrublands,and on the contrary,an increasing trend from the upper slope,to the middle slope,and to the foot slope was identified for the apple *** study highlights that land use,slope position and their interaction have significant effects on the spatial distributions of soil *** provides essential empirical evidence for the identification of the optimal vegetation type and slope positions in land management and vegetation restoration activities.

关键词： Soil organic carbon Total nitrogen Total phosphorus Slope position Vegetation restoration

Optimization of a photovoltaic-battery system using deep reinforcement learning and load forecasting

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Energy and AI 2024年第2期16卷 168-183页

作者： António corte Real G.Pontes Luz J.M.c.Sousa M.c.Brito S.M.Vieira IDMEc Instituto Superior TécnicoUniversidade de LisboaLisboa1049-001Portugal Instituto Dom Luiz Faculdade de CiênciasUniversidade de LisboaCampo Grande1749-016LisboaPortugal

Home Energy Management Systems(HEMS)are increasingly relevant for demand-side management at the residential level by collecting data(energy,weather,electricity prices)and controlling home appliances or storage *** control can be performed with classical models that find optimal solutions,with high real-time computational cost,or data-driven approaches,like Reinforcement Learning,that find good and flexible solutions,but depend on the availability of load and generation data and demand high computational resources for *** this work,a novel HEMS is proposed for the optimization of an electric battery operation in a real,online and data-driven environment that integrates state-of-the-art load forecasting combining cNN and LSTM neural networks to increase the robustness of *** Reinforcement Learning agents are trained with different algorithms(Double DQN,Dueling DQN,Rainbow and Proximal Policy Optimization)in order to minimize the cost of electricity purchase and to maximize photovoltaic self-consumption for a PV-Battery residential *** show that the best Reinforcement Learning agent achieves a 35%reduction in total cost when compared with an optimization-based agent.

关键词： Energy management system Deep reinforcement learning Demand-side management Load forecasting Deep learning Energy storage systems

Assessment of nano-to-micro-scale geomechanical properties and their time-dependent behavior: current status and progressive perspectives

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Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第1期3卷 1-15页

作者： Mary c.Ngoma Oladoyin Kolawole John A.Reif Jr.Department of Civil and Environmental EngineeringNew Jersey Institute of TechnologyNewarkNJ07102USA

Rocks can deform at varying scales(nano-,micro-and macro-scale)under different temperatures,pressures,stresses,and time ***-core scale(nano-to micro-scale)changes in rock properties can influence local(fine-scale)and bulk scale(macro-scale)rock ***,there is a lack of comprehensive knowledge on how rock deformation at sub-core scale(i.e.,nano-to micro-scale)is assessed and its potential to accurately predicte and estimate the macro-scale mechanical behavior of *** study presents a comprehensive and forward-leaning review of the assessment of nano-scale and micro-scale rock mechanical parameters,their timedependent behavior,and potential applications in rock ***,we highlighted the key findings based on experimental and numerical methods for evaluating rock mechanical parameters,and presented the limitations of these ***,we discussed the reliability of sub-core scale mechanical assessments in predicting macromechanical(larger-scale)properties and the behavior of rocks in ***,we offer recommendations to advance investigations focused on rock mechanical assessments at these smaller scales and provide a more accurate characterization at the sub-core scale.

关键词： Rock mechanics Rock deformation Nanomechanics Rock creep Rock engineering

Progress on the antiferromagnetic topological insulator MnBi2Te4

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National Science Review 2024年第2期11卷 33-49页

作者： Shuai Li Tianyu Liu chang Liu Yayu Wang Hai-Zhou Lu X.c.Xie Department of Physics Harbin Institute of Technology Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology(SUSTech) Quantum Science center of Guangdong-Hong Kong-Macao Greater Bay Area(Guangdong) Shenzhen Key Laboratory of Quantum Science and Engineering International Quantum Academy Beijing Academy of Quantum Information Sciences Beijing Key Laboratory of Optoelectronic Functional Materials&Micro-Nano Devices Department of Physics Renmin University of China State Key Laboratory of Low Dimensional Quantum Physics Department of PhysicsTsinghua University Frontier Science center for Quantum Information Hefei National Laboratory International center for Quantum Materials School of Physics Peking University Institute for Nanoelectronic Devices and Quantum computing Fudan University

Topological materials, which feature robust surface and/or edge states, have now been a research focus in condensed maTher physics. They represent a new class of materials exhibiting nontrivial topological phases,and provide a platform for exploring exotic transport phenomena, such as the quantum anomalous Hall effect and the quantum spin Hall effect. Recently, magnetic topological materials have attracted considerable interests due to the possibility to study the interplay between topological and magnetic *** particular, the quantum anomalous Hall and axion insulator phases can be realized in topological insulators with magnetic order. MnBi2Te4, as the first intrinsic antiferromagnetic topological insulator discovered, allows the examination of existing theoretical predictions; it has been extensively studied, and many new discoveries have been made. Here we review the progress made on MnBi2Te4from both experimental and theoretical aspects. The bulk crystal and magnetic structures are surveyed first, followed by a review of theoretical calculations and experimental probes on the band structure and surface states, and a discussion of various exotic phases that can be realized in MnBi2Te4. The properties of MnBi2Te4thin films and the corresponding transport studies are then reviewed, with an emphasis on the edge state transport. Possible future research directions in this field are also discussed.

关键词： MnBi2Te4 magnetic topological insulator antiferromagnetic quantum anomalous Hall effect axion insulator

Predicting grain size-dependent superplastic properties in friction stir processed ZK30 magnesium alloy with machine learning methods

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Journal of Magnesium and Alloys 2024年第5期12卷 1931-1943页

作者： Farid Bahari-Sambran Fernando carreno c.M.cepeda-Jiménez Alberto Orozco-caballero Physical Metallurgy Department CENIM-CSICAv.Gregorio del Amo 828040 MadridSpain Department of Mechanical Engineering Chemistry and Industrial DesignPolytechnic University of MadridRonda de Valencia 328012MadridSpain

The aim of this work is to predict,for the first time,the high temperature flow stress dependency with the grain size and the underlaid deformation mechanism using two machine learning models,random forest(RF)and artificial neural network(ANN).With that purpose,a ZK30 magnesium alloy was friction stir processed(FSP)using three different severe conditions to obtain fine grain microstructures(with average grain sizes between 2 and 3μm)prone to extensive superplastic *** three friction stir processed samples clearly deformed by grain boundary sliding(GBS)deformation mechanism at high *** maximum elongations to failure,well over 400% at high strain rate of 10^(-2)s^(-1),were reached at 400℃ in the material with coarsest grain size of 2.8μm,and at 300℃ for the finest grain size of 2μ***,the superplastic response decreased at 350℃ and 400℃ due to thermal instabilities and grain coarsening,which makes it difficult to assess the operative deformation mechanism at such *** work highlights that the machine learning models considered,especially the ANN model with higher accuracy in predicting flow stress values,allow determining adequately the superplastic creep behavior including other possible grain size scenarios.

关键词： Machine learning Artificial intelligence Magnesium alloys Superplasticity Friction stir processing Grain coarsening

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Doped low-density parity-check codes

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Digital communications and Networks 2024年第1期10卷 217-226页

作者： Yong Li Rui Liu Xianlong Jiao Youqiang Hu Zhen Luo Francis c.M.Lau college of computer Science Chongqing UniversityChongqing400044China School of Automation Chongqing UniversityChongqing400044China college of Electronic and Information Engineering Southwest UniversityChongqing400715China Future Wireless Networks and IoT Focusing Area Department of Electronic and Information EngineeringHong Kong Polytechnic UniversityHong KongChina

In this paper,we propose a doping approach to lower the error floor of Low-Density Parity-check(LDPc)*** doping component is a short block code in which the information bits are selected from the coded bits of the dominant trapping sets of the LDPc ***,an algorithm for selecting the information bits of the short code is proposed,and a specific two-stage decoding algorithm is *** results demonstrate that the proposed doped LDPc code achieves up to 2.0 dB gain compared with the original LDPc code at a frame error rate of 10^(-6)Furthermore,the proposed design can lower the error floor of original LDPc codes.

关键词： LDPc codes Doped LDPc codes Tanner graph Quadratic residue codes Trapping sets

Spatio-temporal variability in microfossil and geochemical records of cenomanian-Turonian oceanic anoxic event-2: a review

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Journal of Palaeogeography 2024年第4期13卷 646-674页

作者： c.P.Sooraj Shweta Gupta Jahnavi Punekar Department of Earth Sciences Indian Institute of Technology Bombay

The cenomanian-Turonian boundary oceanic anoxic event(OAE-2; Bonarelli event; ～94 Ma) is associated with a species turnover in the marine calcareous microfossil record, widespread marine anoxia,black shale deposition and positive δ13c excursions. This study reviews 141 cTBE sites globally, aiming to understand micropaleontological, geochemical, and sedimentological expressions of OAE-2. There is a clear palaeogeographic and palaeobathymetric heterogeneity in the development of OAE-2 marine anoxia. A majority of the documented OAE-2 sites are from deep marine environments. The calcareous nannoplankton and benthic foraminifera record a diversity decline, while planktic foraminifera shows community level shifts and no major mass extinction. The variability of total organic carbon in OAE-2 sediments across sites(10 wt.%) and the δ13c profiles(diachronous) have been attributed to different mechanisms of anoxia *** increased primary “productivity model” gains support from productivity proxies(e.g., Ba, P, cu, Ni),redox-sensitive elements(e.g., Mn, Mo, U, V, As), and eutrophic genera(e.g., benthic foraminifera Gabonita spp., calcareous nannofossils Biscutum spp. and Zeugrhabdotus erectus). The enhanced organic carbon“preservation model” in stratified(semi) restricted basins gains support from sites with lower enrichment of redox-sensitive elements and oligotrophic flora and fauna in the OAE-2 records. Geochronology of the caribbean and the High Atlantic Large Igneous Province events(cLIP and HALIP) mark them as likely triggers of the OAE-2 related global perturbation of marine biogeochemistry. Volcanic triggers may have caused climate warming, altered hydrological cycles, enhanced continental weathering, shifts in ocean circulation, and nutrient flows. Addressing knowledge gaps, further research is urged, utilizing innovative proxies, and exploring underrepresented depositional systems to comprehensively understand OAE-2 onset and biotic crisis.

关键词： Oceanic anoxic Event-2 Global organic carbon distribution Geochemical proxies Marine calcifiers Palaeoceanography

Mechanism of Primary Frequency Regulation for Battery Hybridization in Hydropower Plant

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cSEE Journal of Power and Energy Systems 2024年第5期10卷 2127-2137页

作者： Yiwen Liao Weijia Yang Zhecheng Wang Yifan Huang c.Y.chung State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China Department of Electrical Engineering The Hong Kong Polytechnic UniversityHong KongChina

Battery hybridization in hydropower plants is a hydropower flexibility enhancement technology innovation that can potentially expand hydropower’s contributions to the grid,but its fundamental characteristics and influencing mechanisms are still *** this paper,primary frequency regulation(PFR)performance and the mechanism of this new technology are studied.A battery hybridized hydropower plant(BH-HPP)model,based on a field-measured-data-based hydropower plant(HPP)model and a verified battery simplified model,is *** of system stability and dynamics is undertaken for three different battery control strategies by root locus and participation factor *** to conventional HPPs,analysis results theoretically reveal BH-HPP can not only accelerate system regulation rapidity but also effectively enlarge HPP stability region during PFR *** domain simulation verifies the results and further shows synthetic control has better performance among introduced ***,initial design ranges of control parameters considering battery capacity and a renewable energy source scenario case are also *** work could provide theoretical support for flexibility enhancement solutions for hydropower systems.

关键词： Battery hybridization dynamic response hydropower plant primary frequency regulation stability