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Local quantum Fisher information and quantum correlation in the mixed-spin Heisenberg XXZ chain

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Frontiers of physics 2024年第2期19卷 235-245页

作者： Peng-Fei Wei Qi Luo Huang-Qiu-Chen Wang Shao-Jie Xiong Bo Liu Zhe Sun School of Physics Hangzhou Normal UniversityHangzhou 310036China zhejiang Institute of Modern Physics and School of Physics Zhejiang UniversityHangzhou 310027China School of information and Electrical Engineering Hangzhou City UniversityHangzhou 310015China zhejiang provincial key laboratory of Urban Wetlands and Regional Change Hangzhou 311121China

We study the local quantum Fisher information(LQFI)in the mixed-spin Heisenberg XXZ *** the maximal and minimal LQFI are studied and the former is essential to determine the accuracy of the quantum parameter estimation,the latter can be well used to characterize the discord-type quantum *** investigate the effects of the temperature and the anisotropy parameter on the maximal LQFI and thus on the accuracy of the parameter *** we make use of the minimal LQFI to study the discord-type correlations of different site *** dimensions of the subsystems cause different values of the minimal LQFI which reflects the asymmetry of the discord-type *** addition,the site pairs at different positions of the spin chains have different minimal LQFI,which reveals the influence of the surrounding spins on the bipartite quantum *** results show that the LQFI obtained through a simple calculation process provides a convenient way to investigate the discord-type correlation in high-dimensional systems.

关键词： local quantum Fisher information quantum correlation mixed-spin Heisenberg XXZ chain

Tunable quantum anomalous Hall effects in ferromagnetic van der Waals heterostructures

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National science Review 2024年第3期11卷 100-107页

作者： Feng Xue Yusheng Hou Zhe Wang Zhiming Xu Ke He Ruqian Wu Yong Xu Wenhui Duan Beijing Academy of Quantum information sciences State key laboratory of Low Dimensional Quantum Physics Department of Physics Tsinghua University Guangdong provincial key laboratory of Magnetoelectric Physics and Devices Center for Neutron Science and Technology School of Physics Sun Yat-sen University State key laboratory of Surface Physics Key Laboratory of Computational Physical Sciences and Department of PhysicsFudan University Frontier science Center for Quantum information Department of Physics and Astronomy University of California-Irvine Tencent Quantum laboratory Tencent Technology(Shenzhen)Co.Ltd RIKEN Center for Emergent Matter science(CEMS) Institute for Advanced Study Tsinghua University

The quantum anomalous Hall effect（QAHE） has unique advantages in topotronic applications, but it is still challenging to realize the QAHE with tunable magnetic and topological properties for building functional devices. Through systematic first-principles calculations, we predict that the in-plane magnetization induced QAHE with Chern numbers C = ±1 and the out-of-plane magnetization induced QAHE with high Chern numbers C = ±3 can be realized in a single material candidate, which is composed of van der Waals（vdW）coupled Bi and MnBi2Te4monolayers. The switching between different phases of QAHE can be controlled in multiple ways, such as applying strain or（weak） magnetic field or twisting the vdW materials. The prediction of an experimentally available material system hosting robust, highly tunable QAHE will stimulate great research interest in the field. Our work opens a new avenue for the realization of tunable QAHE and provides a practical material platform for the development of topological electronics.

关键词： quantum anomalous Hall effect topological quantum phase transition van der Waals heterostructures tunable Chern number high Chern number

Underwater Image Classification Based on EfficientnetB0 and Two-Hidden-Layer Random Vector Functional Link

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Journal of Ocean University of China 2024年第2期23卷 392-404页

作者： ZHOU Zhiyu LIU Mingxuan JI Haodong WANG Yaming ZHU Zefei School of information science and Technology Zhejiang Sci-Tech UniversityHangzhou 310018China zhejiang key laboratory of DDIMCCP Lishui UniversityLishui 323000China School of Mechanical Engineering Hangzhou Dianzi UniversityHangzhou 310018China

The ocean plays an important role in maintaining the equilibrium of Earth’s ecology and providing humans access to a wealth of *** obtain a high-precision underwater image classification model,we propose a classification model that combines an EfficientnetB0 neural network and a two-hidden-layer random vector functional link network(EfficientnetB0-TRVFL).The features of underwater images were extracted using the EfficientnetB0 neural network pretrained via ImageNet,and a new fully connected layer was trained on the underwater image dataset using the transfer learning *** learning ensures the initial performance of the network and helps in the development of a high-precision classification ***,a TRVFL was proposed to improve the classification property of the *** construction of the two hidden layers exhibited a high accuracy when the same hidden layer nodes were *** parameters of the second hidden layer were obtained using a novel calculation method,which reduced the outcome error to improve the performance instability caused by the random generation of parameters of ***,the TRVFL classifier was used to classify features and obtain classification *** proposed EfficientnetB0-TRVFL classification model achieved 87.28%,74.06%,and 99.59%accuracy on the MLC2008,MLC2009,and Fish-gres datasets,*** best convolutional neural networks and existing methods were stacked up through box plots and Kolmogorov-Smirnov tests,*** increases imply improved systematization properties in underwater image classification *** image classification model offers important performance advantages and better stability compared with existing methods.

关键词： underwater image classification EfficientnetB0 random vector functional link convolutional neural network

Understanding and improving Yangtze River Basin summer precipitation prediction using an optimal multi-Physics ensemble

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Frontiers of Earth science 2024年第1期18卷 256-277页

作者： Yang ZHAO Fengxue QIAO Xin-Zhong LIANG Jinhua YU Climate Environment and Sustainability CenterNanjing University of Information Science and TechnologyNanjing 210044China key laboratory of geographic information science(Ministry of Education) East China Normal UniversityShanghai 200241China School of geographic sciences East China Normal UniversityShanghai 200241China Department of Atmospheric and Oceanic science University of MarylandCollege Park MD 20740USA Earth System science Interdisciplinary Center University of MarylandCollege Park MD 20740USA key laboratory of Meteorological Disaster(KLME)(Ministry of Education)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science and TechnologyNanjing 210044China

This study employs the regional Climate-Weather Research and Forecasting model(CWRF)to first investigate the primary physical mechanisms causing biases in simulating summer precipitation over the Yangtze River Basin(YRB),and then enhance its predictive ability through an optimal multi-physics ensemble *** CWRF 30-km simulations in China are compared among 28 combinations of varying physics parameterizations during 1980−***-term average summer biases in YRB precipitation are remotely correlated with those of large-scale *** teleconnections of biases are highly consistent with the observed correlation patterns between interannual variations of precipitation and circulations,despite minor shifts in their primary action *** YRB precipitation aligns with a southward shifted East Asian westerly jet,an intensified low-level southerly flow south of YRB,and a south-eastward shifted South Asian high,alongside higher moisture availability over ***,decreased YRB precipitation corresponds to an opposite circulation *** CWRF control configuration using the ensemble cumulus parameterization(ECP),compared to other cumulus schemes,best captures the observed YRB precipitation characteristics and associated circulation *** ECP with the Morrison or Morrison-aerosol microphysics and the CCCMA or CAML radiation schemes enhances the overall CWRF *** to the control CWRF,the ensemble average of these skill-enhanced physics configurations more accurately reproduces YRB summer precipitation’s spatial distributions,interannual anomalies,and associated circulation *** Bayesian Joint Probability calibration to these configurations improves the ensemble’s spatial distributions but compromises its interannual anomalies and teleconnection *** findings highlight substantial potential for refining the representation of climate system physics to improve YRB precipitation *** is notabl

关键词： physics parameterization regional climate model downscaling skill enhancement multi-physics ensemble teleconnection bias reduction

Deep learning-assisted common temperature measurement based on visible light imaging

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Chinese Physics B 2024年第8期33卷 230-236页

作者：朱佳仪何志民黄成曾峻林惠川陈福昌余超群李燕张永涛陈焕庭蒲继雄 College of Physics and information Engineering Minnan Normal UniversityZhangzhou 363000China Fujian provincial key laboratory of Light Propagation and Transformation College of Information Science&EngineeringHuaqiao UniversityXiamen 361021China

Real-time,contact-free temperature monitoring of low to medium range(30℃-150℃)has been extensively used in industry and agriculture,which is usually realized by costly infrared temperature detection *** paper proposes an alternative approach of extracting temperature information in real time from the visible light images of the monitoring target using a convolutional neural network(CNN).A mean-square error ofinformation from the images which were collected under different illuminance and were not used for *** to the conventional machine learning algorithms mentioned in the recent literatures,this real-time,contact-free temperature measurement approach that does not require any further image processing operations facilitates temperature monitoring applications in the industrial and civil fields.

关键词： convolutional neural network visible light image temperature measurement low-to-medium-range temperatures

Erosion-induced recovery CO_(2) sink offset the horizontal soil organic carbon removal at the basin scale

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science China Earth sciences 2024年第6期67卷 2019-2033页

作者： Lingxia WANG Xiaodong NIE Jiaqi LI Yaojun LIU Hui WANG Yazhe LI Zhongwu LI School of geographic science Hunan Normal UniversityChangsha 410081China Institute of Interdisciplinary Studies Hunan Normal University and Hunan Provincial Key Laboratory for Eco-environmental Changes and Carbon Sequestration of the Dongting Lake BasinChangsha 410081China College of Environmental science and Engineering Hunan University and Key Laboratory of Environmental Biology and Pollution Control(Hunan University)Ministry of EducationChangsha 410082China

To improve soil carbon sequestration capacity,the full soil carbon cycle process needs to be understood and *** is essential to evaluate whether water erosion acts as a net source or sink of atmospheric CO_(2)at the basin scale,which encompasses the entire hydrological *** study introduced an approach that combined a spatially distributed sediment delivery model and biogeochemical model to estimate the lateral and vertical carbon fluxes by water erosion at the basin *** this coupling model to the Dongting Lake Basin,the results showed that the annual average amount of soil erosion during 1980-2020 was 1.33×10^(8)t,displaying a decreasing trend followed by a slight *** 12% of the soil organic carbon displacement was ultimately lost in the riverine systems,and the rest was deposited downhill within the *** average lateral soil organic carbon loss induced by erosion was 8.86×10^(11)g C in 1980 and 1.50×10^(11)g C in 2020,with a decline rate of 83%.A net land sink for atmospheric CO_(2)of 5.54×1011g C a^(-1)occurred during erosion,primarily through sediment burial and dynamic ***,ecological restoration projects and tillage practice policies are still significant in reducing erosion,which could improve the capacity of the carbon sink for recovery beyond the rate of horizontal carbon ***,our model enables the spatial explicit simulation of erosion-induced carbon fluxes using costeffective and easily accessible input data across large spatial scales and long ***,it offers a valuable tool for predicting the interactions between carbon dynamics,land use changes,and future climate.

关键词： Water erosion Sediment transfer Lateral soil carbon loss Land-atmosphere CO_(2) flux Dongting Lake Basin

Multimodal Cross-Attention Mechanism-Based Algorithm for Elderly Behavior Monitoring and Recognition

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Chinese Journal of Electronics 2024年

作者： Hao LIU Zhiquan FENG Qingbei GUO School of information science and Engineering University of Jinan Shandong provincial key laboratory of Network Based Intelligent Computing

In contrast to the general population, behavior recognition among the elderly poses increased specificity and difficulty, rendering the reliability and usability aspects of safety monitoring systems for the elderly more challenging. Hence, this study proposes a multi-modal perception-based solution for an elderly safety monitoring recognition system. The proposed approach introduces a recognition algorithm based on multi-modal cross-attention mechanism, innovatively incorporating complex information such as scene context and voice to achieve more accurate behavior recognition. By fusing four modalities, namely image, skeleton, sensor data, and audio, we further enhance the accuracy of recognition. Additionally, we introduce a novel human-robot interaction mode, where the system associates directly recognized intentions with robotic actions without explicit commands, delivering a more natural and efficient elderly assistance paradigm. This mode not only elevates the level of safety monitoring for the elderly but also facilitates a more natural and efficient caregiving approach. Experimental results demonstrate significant improvement in recognition accuracy for 11 typical elderly behaviors compared to existing methods.

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Two-layer Lagrange-based relay network topology and trajectory design for solar system explorations

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science China(information sciences) 2024年第6期67卷 342-358页

作者： Jun CAO Jian JIAO Hao LIU Rongxing LU Qinyu ZHANG Guangdong provincial key laboratory of Aerospace Communication and Networking Technology Harbin Institute of Technology (Shenzhen) Faculty of Computer science (FCS) University of New Brunswick

Exploration targeting outer planets and even the edge of the solar system is an emerging direction for the deep-space exploration in the next decades. To address this challenge, a novel two-layer Lagrangebased relay network topology is proposed in this study. Specifically, we utilize the Sun-Mars and Sun-Saturn Lagrange points(LPs) L4 and L5 to build a two-layer backbone relay network, which ensures continuous and high-efficiency communication capability for the exploration of the solar system. Furthermore, we utilize the planetary gravity assist and design the transfer trajectory of backbone relays with the help of planetary celestial body motion equations and Kepler's laws. Moreover, we conduct link budget analysis for multihop relay transmission under Gamma-Gamma distribution, shadowed Rician fading, and additive white Gaussian noise channels in several typical exploration scenarios and validate that the LP relays can effectively support future deep-space exploration missions.

关键词： deep-space communication Lagrangian points backbone relay network transfer trajectory relay selection

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Monitoring Surface Water Change in Northeast China in 1999–2020:Evidence from Satellite Observation and Refined Classification

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Chinese geographical science 2024年第1期34卷 106-117页

作者： LIU Kai ZHANG Dapeng CHEN Tan CUI Peipei FAN Chenyu SONG Chunqiao key laboratory of Watershed geographic sciences Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing210008China University of Chinese Academy of sciences Nanjing(UCASNJ)Nanjing211135China geographic information and Tourism College Chuzhou UniversityChuzhou239000China

As a typical region with high water demand for agricultural production,understanding the spatiotemporal surface water changes in Northeast China is critical for water resources management and sustainable ***,the long-term variation characteristics of surface water of different water body types in Northeast China remain rarely *** study investigated how surface water bodies of different types(e.g.,lake,reservoir,river,coastal aquaculture,marsh wetland,ephemeral water) changed during1999–2020 in Northeast China based on various remote sensing-based *** results showed that surface water in Northeast China grew dramatically in the past two decades,with an equivalent area increasing from 24 394 km^(2) in 1999 to 34 595 km^(2) in *** surge of ephemeral water is the primary driver of surface water expansion,which could ascribe to shifted precipitation *** wetlands,rivers,and reservoirs experienced a similar trend,with an approximate 20% increase at the interdecadal *** contrast,coastal aquacultures and natural lakes remain relatively *** study is expected to provide a more comprehensive investigation of the surface water variability in Northeast China and has important practical significance for the scientific management of different types of surface water.

关键词： surface water spatiotemporal variation water body classification remote sensing Northeast China