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Sensitivity of topological edge states in a non-Hermitian dimer chain

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Photonics Research 2021年第4期9卷 574-582页

作者： zhiwei guo Tengzhou Zhang Juan Song Haitao Jiang Hong Chen MOE Key Laboratory of Advanced Micro-structured Materials School of Physics Sciences and EngineeringTongji UniversityShanghai 200092China

Photonic topological edge states in one-dimensional dimer chains have long been thought to be robust to structural perturbations by mapping the topological Su–Schrieffer–Heeger model of a solid-state ***,the edge states at the two ends of a finite topological dimer chain will interact as a result of near-field *** leads to deviation from topological protection by the chiral symmetry from the exact zero energy,weakening the robustness of the topological edge *** the aid of non-Hermitian physics,the splitting frequencies of edge states can be degenerated again,with topological protection recovered by altering the gain or loss strength of the *** point of coalescence is known as the exceptional point(EP).The intriguing physical properties of EPs in topological structures give rise to many fascinating and counterintuitive *** this work,based on a finite non-Hermitian dimer chain composed of ultra-subwavelength resonators,we propose theoretically and verify experimentally that the sensitivity of topological edge states is greatly affected when the system passes through the *** the EP of a non-Hermitian dimer chain,we realize a new sensor that is sensitive to perturbation of on-site frequency at the end of the structure and yet topologically protected from internal perturbation of site-to-site *** demonstration of a non-Hermitian topological structure with an EP paves the way for the development of novel sensors that are not sensitive to internal manufacturing errors but are highly sensitive to changes in the external environment.

关键词： structure. topological dimer

Efficient and stable wireless power transfer based on the non-Hermitian physics

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Chinese Physics B 2022年第1期31卷 37-44页

作者： Chao Zeng zhiwei guo Kejia Zhu Caifu Fan guo Li Jun Jiang Yunhui Li Haitao Jiang Yaping Yang Yong Sun Hong Chen MOE Key Laboratory of Advanced Micro-structured Materials School of Physics Sciences and EngineeringTongji UniversityShanghai 200092China Department of Electrical Engineering Tongji UniversityShanghai 201804China School of Automotive Studies Tongji UniversityShanghai 210804China

As one of the most attractive non-radiative power transfer mechanisms without cables,efficient magnetic resonance wireless power transfer(WPT)in the near field has been extensively developed in recent years,and promoted a variety of practical applications,such as mobile phones,medical implant devices and electric ***,the physical mechanism behind some key limitations of the resonance WPT,such as frequency splitting and size-dependent efficiency,is not very clear under the widely used circuit ***,we review the recently developed efficient and stable resonance WPT based on non-Hermitian physics,which starts from a completely different avenue(utilizing loss and gain)to introduce novel functionalities to the resonance *** the perspective of non-Hermitian photonics,the coherent and incoherent effects compete and coexist in the WPT system,and the weak stable of energy transfer mainly comes from the broken phase associated with the phase transition of parity-time *** on this basic physical framework,some optimization schemes are proposed,including using nonlinear effect,using bound states in the continuum,or resorting to the system with high-order parity-time ***,the combination of non-Hermitian physics and topological photonics in multi-coil system also provides a versatile platform for long-range robust WPT with topological ***,the non-Hermitian physics can not only exactly predict the main results of current WPT systems,but also provide new ways to solve the difficulties of previous designs.

关键词： wireless power transfer non-Hermitian physics topological edge states

Effect of toroidal mode coupling on explosive dynamics of m/n=3/1 double tearing mode

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Plasma Science and Technology 2024年第10期26卷 8-16页

作者： Xingqiang LU Ge GAO zhiwei MA Wei guo Xin LI College of Nuclear Equipment and Nuclear Engineering Yantai UniversityYantai 264005People’s Republic of China Institute for Fusion Theory and Simulation Department of PhysicsZhejiang UniversityHangzhou 310027People’s Republic of China

The CLT code was used to quantitatively study the impact of toroidal mode coupling on the explosive dynamics of the m/n=3/1 double tearing *** focus of this study was on explosive reconnection processes,in which the energy bursts and the main mode no longer dominates when the separation between two rational surfaces is relatively large in the medium *** development of higher m and n modes is facilitated by a relatively large separation between two rational surfaces,a small q_(min)(the minimum value of the safety factor),or low *** relationships between the higher m and n mode development,explosive reconnection rate,and position exchange of 3/1 islands are summarized for the first *** plays a more important role than q_(min)in enhancing the development of higher m and n *** a relatively large separation,the good development of higher m and n modes greatly reduces the reconnection rate and suppresses the development of the main mode,resulting in the main mode not being able to develop sufficiently large to generate the position changes of 3/1 islands.

关键词： toroidal mode coupling higher m and n modes explosive growth reconnection rate position change

一种电解车间智能红外轨道式巡检机器人的设计

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自动化应用 2024年第5期65卷 18-21页

作者：蒋胜胜李林苍郭志伟孙银彬张宇张烽沈阳工业大学电气工程学院辽宁沈阳110870

设计了一种用于电解车间检测电解极板短路故障的巡检机器人,并对其机械结构、硬件组成、控制系统及通信方式进行了分析。该机器人主要由机械结构、红外图像处理系统、控制系统和上位机组成。特殊的机械结构设计可保证机器人在单股轨道... 详细信息

设计了一种用于电解车间检测电解极板短路故障的巡检机器人,并对其机械结构、硬件组成、控制系统及通信方式进行了分析。该机器人主要由机械结构、红外图像处理系统、控制系统和上位机组成。特殊的机械结构设计可保证机器人在单股轨道上平稳运行;红外图像处理系统可精确识别电解槽中的故障点;控制系统采用主控和驱动控制的分层控制模式,有效降低了主控制器的运行负荷;上位机采用主流的Browser/client web架构,具有丰富的可视化功能,支持数据溯源。

关键词：巡检机器人故障识别电解车间红外图像

饮水型砷暴露人群皮肤损伤转归与尿砷甲基化代谢产物水平关系的研究

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中华地方病学杂志 2024年第6期43卷 446-451页

作者：李昕晔邓丹宇赵凡刘聪李梦昕狄震崔娜刘一君孔畅韦炳干李艳红夏雅娟郭志伟内蒙古医科大学公共卫生学院呼和浩特010110 内蒙古自治区疾病预防控制中心(内蒙古自治区预防医学科学院)科研与宣教处呼和浩特010080 杭锦后旗疾病预防控制中心地方病防治科巴彦淖尔015400 内蒙古自治区疾病预防控制中心(内蒙古自治区预防医学科学院)地方病预防控制所呼和浩特010080 中国科学院地理科学与资源研究所陆地表层格局与模拟院重点实验室北京100101

目的探讨饮水型砷暴露人群皮肤损伤转归与尿砷甲基化代谢产物水平的关系。方法采用整群抽样法,2004年(改水前)选取内蒙古自治区巴彦淖尔市饮水型地方性砷中毒病区的常住居民作为调查对象,并于2017年(改水后)对74名2004年调查对象进行跟... 详细信息

目的探讨饮水型砷暴露人群皮肤损伤转归与尿砷甲基化代谢产物水平的关系。方法采用整群抽样法,2004年(改水前)选取内蒙古自治区巴彦淖尔市饮水型地方性砷中毒病区的常住居民作为调查对象,并于2017年(改水后)对74名2004年调查对象进行跟踪随访。采集尿样,采用高效液相色谱电感耦合等离子体质谱仪检测尿砷甲基化代谢产物水平。根据《地方性砷中毒诊断》(WS/T 211-2015)评定调查对象皮肤损伤临床分度(正常、可疑、轻度、中重度)和2017年转归情况(好转、不变、加重),建立数据库并采用SPSS 25.0软件进行统计学分析。结果2004、2017年74例调查对象皮肤损伤临床分度构成(正常、可疑、轻度、中重度:2004年分别为38、18、4、14例,2017年分别为27、31、3、13例)比较,差异有统计学意义(χ^(2)=53.02,P<0.001)。与2004年比较,2017年调查对象尿中总砷(tAs)、无机砷(iAs)、一甲基胂(MMA)、二甲基胂(DMA)、无机砷百分比(iAs%)、一甲基胂与二甲基胂比值(MMA/DMA)水平均较低,差异均有统计学意义(Z=-8.24、-9.07、-7.81、-8.04、-8.24、-3.56,均P<0.001);二甲基胂百分比(DMA%)、一甲基化率(PMI)、二甲基化率(SMI)水平均较高,差异均有统计学意义(Z=-6.39、-8.24、-3.52,均P<0.001)。2004年不同皮肤损伤临床分度者2017年转归情况比较,差异有统计学意义(χ^(2)=30.80,P<0.001)。不同皮肤损伤转归者尿中tAs、iAs、MMA、DMA的变化量比较,差异均有统计学意义(H=10.62、9.35、8.80、9.13,均P<0.05)。结论改水可以显著降低砷暴露人群尿中tAs、iAs、MMA、DMA水平,饮水型砷暴露人群皮肤损伤转归可能与尿砷甲基化代谢产物tAs、iAs、MMA、DMA的变化量有关。

关键词：砷中毒甲基化皮肤损伤转归

Structural Dependence Learning Based on Self-attention for Face Alignment

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Machine Intelligence Research 2024年第3期21卷 514-525页

作者： Biying Li zhiwei Liu Wei Zhou Haiyun guo Xin Wen Min Huang Jinqiao Wang Foundation Model Research Center Institute of AutomationChinese Academy of SciencesBeijing100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing100083China Alpha(Beijing)Private Equity Beijing100083China School of Computer Science National University of Defense TechnologyChangsha410073China

Self-attention aggregates similar feature information to enhance the features. However, the attention covers nonface areas in face alignment, which may be disturbed in challenging cases, such as occlusions, and fails to predict landmarks. In addition, the learned feature similarity variance is not large enough in the experiment. To this end, we propose structural dependence learning based on self-attention for face alignment (SSFA). It limits the self-attention learning to the facial range and adaptively builds the significant landmark structure dependency. Compared with other state-of-the-art methods, SSFA effectively improves the performance on several standard facial landmark detection benchmarks and adapts more in challenging cases.

关键词： Computer vision face alignment self-attention facial structure contextual information

Spatial changes and driving factors of lake water quality in Inner Mongolia, China

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Journal of Arid Land 2023年第2期15卷 164-179页

作者： REN Xiaohui YU Ruihong LIU Xinyu SUN Heyang GENG Yue QI Zhen ZHANG Zhuangzhuang LI Xiangwei WANG Jun ZHU Penghang guo zhiwei WANG Lixin XU Jifei Inner Mongolia Key Laboratory of River and Lake Ecology School of Ecology and EnvironmentInner Mongolia UniversityHohhot 010021China Key Laboratory of Mongolian Plateau Ecology and Resource Utilization Ministry of EducationHohhot 010021China

Lakes play important roles in sustaining the ecosystem and economic development in Inner Mongolia Autonomous Region of China,but the spatial patterns and driving mechanisms of water quality in lakes so far remain *** study aimed to identify the spatial changes in water quality and the driving factors of seven lakes(Juyanhai Lake,Ulansuhai Lake,Hongjiannao Lake,Daihai Lake,Chagannaoer Lake,Hulun Lake,and Wulannuoer Lake)across the longitudinal axis(from the west to the east)of Inner ***-scale research was conducted using the comprehensive trophic level index(TLI(Σ)),multivariate statistics,and spatial analysis *** results showed that most lakes in Inner Mongolia were weakly *** dissolved solids and salinity of lake water showed obvious zonation *** and phosphorus were identified as the main pollutants in lakes,with high average concentrations of total nitrogen and total phosphorus being of 4.05 and 0.21 mg/L,*** values of TLI(Σ)ranged from 49.14 to 71.77,indicating varying degrees of lake eutrophication,and phosphorus was the main driver of lake *** lakes of Inner Mongolia could be categorized into lakes to the west of Daihai Lake and lakes to the east of Daihai Lake in terms of salinity and TLI(Σ).The salinity levels of lakes to the west of Daihai Lake exceeded those of lakes to the east of Daihai Lake,whereas the opposite trend was observed for lake trophic *** intensity and mode of anthropogenic activities were the driving factors of the spatial patterns of lake water *** is recommended to control the impact of anthropogenic activities on the water quality of lakes in Inner Mongolia to improve lake ecological *** findings provide a more thorough understanding of the driving mechanism of the spatial patterns of water quality in lakes of Inner Mongolia,which can be used to develop strategies for lake ecosystem protection and water resources management i

关键词： salinity lake eutrophication lake water quality comprehensive trophic level index anthropogenic activities Daihai Lake Inner Mongolia

Indirect inverse substructuring identification method for coupling dynamic stiffness of vibrational structures

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Chinese Journal of Acoustics 2018年第2期37卷 241-256页

作者： LU Guangqing WANG Minqing WANG Bo CAO Renjing guo zhiwei PENG Wenbin LIU Yujun MOE Key Lab of Disasters Forecast and Control in Engineering Jinan University Guangzhou 510632 Research Institute of Shenzhen Northwestern Polytechnical University Shenzhen 518057 School of Marine Science and Technology Northwestern Polytechnical University Xi'an 710072

Coupling dynamic stiffness is a key parameter in vibrational analysis of complex coupled structures, for both estimation of structural vibrational characteristics and design of vibration control. An indirect method of inverse substructuring analysis to identify the stiffness is studied further by using frequency response functions that are tested on the models of coupled structures. The theoretical effectiveness of this method is here verified by two ＇mass-rubber＇ ex- perimental models constructed as two-level substructures with mono-coupling and tri-coupling connections, and the identification error is also analyzed. The coincidence of numerical and experimental results show that the indirect method has better feasibility and effectiveness than the existing direct method of inverse substructuring analysis, and with more applicable con- ditions and higher acceptable precision in determining the stiffness. It provides more solid theoretical basis for the stiffness identification by inverse substructuring analysis.

关键词：

Numerical simulation of cavitation around a Clark-Y hydrofoil with different LES models in OpenFOAM

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排灌机械工程学报 2018年第4期36卷 277-282页

作者： ZHU Ziming QIAN Zhongdong guo zhiwei YANG Bing State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhanHubei 430072China

A finite volume,multiphase solver in the framework of OpenFOAM was used to calculate the flow field of the cavitating flow over the Clark-Y hydrofoil. This solver used Transport Based Equation Model(TEM) to solve the liquid volume fraction,and utilized volume of fluid(VOF) technique to predict the interface between liquid and vapor phases. The simulation was designed to study the cavitation shedding and different fluid characteristics in the cloud cavitation regime when adopting two different Large Eddy Simulation(LES) models,namely,one equation eddy viscosity(one EqEddy) model and Smagorinsky model. It is shown that these two models can be used to study the cavitation shedding dynamics and predict the velocity profiles.

关键词： hydrofoil cavitation OpenFOAM Large Eddy Simulation