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Topologically protected entanglement switching around exceptional points

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Light(Science & Applications) 2024年第8期13卷 1631-1644页

作者： Zan tang Tian Chen Xing tang Xiangdong Zhang Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements of Ministry of Education Beijing Key Laboratory of Nanophotonics&Ultrafine Optoelectronic SystemsSchool of PhysicsBeijing Institute of Technology100081 BeijingChina

The robust operation of quantum entanglement states is crucial for applications in quantum information,computing,and communications^(1–3).However,it has always been a great challenge to complete such a task because of decoherence and ***,we propose theoretically and demonstrate experimentally an effective scheme to realize robust operation of quantum entanglement states by designing quadruple degeneracy exceptional *** encircling the exceptional points on two overlapping Riemann energy surfaces,we have realized a chiral switch for entangled states with high *** to the topological protection conferred by the Riemann surface structure,this switching of chirality exhibits strong robustness against perturbations in the encircling ***,we have experimentally validated such a scheme on a quantum walk *** work opens up a new way for the application of non-Hermitian physics in the field of quantum information.

关键词： exceptional quantum Riemann

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资产组合优化的多分形模型及实证分析

系统科学与数学 2016年第2期36卷 198-209页

作者：唐振鹏黄友珀罗雪玲福州大学经济与管理学院福州350116

将马尔科夫转换多分形模型引入均值-CVaR框架,构建资产组合优化的多分形模型,并给出最优组合投资策略的求解步骤.实证分析结果表明,基于多分形模型的组合策略在描述性统计分析、风险调整收益分析、经济表现分析以及策略稳定性分析中的... 详细信息

将马尔科夫转换多分形模型引入均值-CVaR框架,构建资产组合优化的多分形模型,并给出最优组合投资策略的求解步骤.实证分析结果表明,基于多分形模型的组合策略在描述性统计分析、风险调整收益分析、经济表现分析以及策略稳定性分析中的表现均优于基于CCC-GARCH模型的组合策略,考虑多分形性确实有助于改善资产组合策略.文章所构建的模型和实证结果为资产组合投资实践提供了有益的参考.

关键词：资产组合优化多分形性 MSM模型.

An economic way to achieve all-weather CO2 reduction

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National Science Review 2024年第3期11卷 46-47页

作者： Junwang tang Department of Chemical Engineering University College London

Utilising solar power to convert carbon dioxide（CO2） into hydrocarbon fuels presents an eco-friendly method to address dependence on fossil fuels and contribute to a net-zero CO2emission goal[1,2].

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UAV-assisted data collection for wireless sensor networks with dynamic working modes

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Digital Communications and Networks 2024年第3期10卷 805-812页

作者： Jie Chen Jianhua tang Shien-Ming Wu School of Intelligent Engineering South China University of TechnologyGuangzhou511442China

Wireless Sensor Network(WSN)is a cornerstone of Internet of Things(IoT)and has rich application *** this work,we consider a heterogeneous WSN whose sensor nodes have a diversity in their Residual Energy(RE).In this work,to protect the sensor nodes with low RE,we investigate dynamic working modes for sensor nodes which are determined by their RE and an introduced energy ***,we employ an Unmanned Aerial Vehicle(UAV)to collect the stored data from the heterogeneous *** aim to jointly optimize the cluster head selection,energy threshold and sensor nodes’working mode to minimize the weighted sum of energy con-sumption from the WSN and UAV,subject to the data collection rate *** this end,we propose an efficient search method to search for an optimal energy threshold,and develop a penalty-based successive convex approximation algorithm to select the cluster *** we present a low-complexity iterative approach to solve the joint optimization problem and discuss the implementation *** results justify that our proposed approach is able to reduce the energy consumption of the sensor nodes with low RE significantly and also saves energy for the whole WSN.

关键词： Unmanned aerial vehicle Wireless sensor networks Cluster heads Dynamic working modes

Highly effective design of high GFA alloys with different metalbased and various components by machine learning

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Science China(Technological Sciences) 2024年第5期67卷 1431-1442页

作者： tang YiChuan HE YiFan FAN ZhuoQun WANG ZhongQi tang ChengYing Guangxi Key Laboratory for Informational Materials School of Materials Science and EngineeringGuilin University of Electronic TechnologyGuilin541004China

The glass-forming ability(GFA)is of great significance for the development of novel functional metal-based metallic *** this study,seven popular machine learning(ML)algorithms were employed to design novel M-based(M=Fe,Co,Ni,Ti,Zr,and rare earth metal(RE))and X-component(X=2,3,4,5,6,and>6)alloys with excellent GFA.A GFA containing 6957 data points with structural analysis was *** engineering was used to analyze the importance and correlation of *** algorithms were utilized for GFA prediction,revealing that Xtreme Gradient Boosting Trees exhibited the strongest predictive capability,achieving a high accuracy of 94.0%,a true positive rate of 97.6%,and a root mean squared error of 0.3705 across the entire ***,the GFA of ternary to hexahydroxy alloys based on Fe,Co,Ni,Zr,Ti,and Y was predicted using all possible compositions generated through ***,a series of alloys with good GFA was successfully designed and *** present work suggests that the proposed ML method can be utilized to design novel multiple-M-based amorphous alloys with high GFA.

关键词： machine learning amorphous alloy feature engineering materials design glass forming ability

基于矩阵法的我国银行系统性风险传染效应检验

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统计与决策 2020年第2期36卷 141-145页

作者：唐振鹏冉梦黄蓝青福州大学经济与管理学院福州350116

文章运用信息熵相关原理构建银行间市场双边风险暴露矩阵,在信用违约冲击、流动性冲击的基础上新加入银行挤兑冲击,通过联合此三种冲击考察我国银行系统性风险的传染效应。研究表明:我国银行系统性风险传染效应呈先增长后减小的趋势,新... 详细信息

文章运用信息熵相关原理构建银行间市场双边风险暴露矩阵,在信用违约冲击、流动性冲击的基础上新加入银行挤兑冲击,通过联合此三种冲击考察我国银行系统性风险的传染效应。研究表明:我国银行系统性风险传染效应呈先增长后减小的趋势,新增考虑银行挤兑冲击时,传染效应将增强,各银行更易发生资不抵债的破产行为;银行自身的风险敞口越大,资产实力越弱,受到冲击而发生倒闭的可能性就越强,邮政储蓄银行的风险抵御能力较弱,需引起重视。

关键词：系统性风险银行间风险传染矩阵法

基于多分形的资产组合风险度量建模与实证研究

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系统工程学报 2019年第5期34卷 644-655页

作者：唐振鹏陈尾虹卢婷无福州大学经济与管理学院福建福州350116 福建省金融科技创新重点实验室福建福州350116

考虑资产收益率的多分形特征及资产组合收益率间的复杂相依结构,运用Markov switching multifractal(MSM)模型对资产收益建模并结合Copula函数刻画相依结构,构建了资产组合市场风险度量的Copula-MSM模型.以风险价值(VaR)和期望损失(ES)... 详细信息

考虑资产收益率的多分形特征及资产组合收益率间的复杂相依结构,运用Markov switching multifractal(MSM)模型对资产收益建模并结合Copula函数刻画相依结构,构建了资产组合市场风险度量的Copula-MSM模型.以风险价值(VaR)和期望损失(ES)作为市场风险度量工具,选取上证指数和恒生指数构成的资产组合进行实证分析,并比较Copula-MSM, Copula-GARCH和Copula-FIGARCH模型对VaR和ES风险测度的估计精度差异.实证结果表明,与Copula-GARCH和Copula-FIGARCH模型相比Copula-MSM能更准确的估计VaR和ES值,提高风险度量精度.

关键词：多分形风险度量马尔可夫转换多分形模型 Copula函数风险价值期望损失

Characteristic Analysis of Power Oscillations Caused by Disharmony Among Voltage-source-controlled Units in Three-terminal Local Power Grid

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1295-1308页

作者： Qiyi Yu Yi tang School of Electrical Engineering Southeast UniversityNanjing 210018China

Previous studies have demonstrated that disharmo-ny among voltage-source-controlled units(VSCUs)may occur on an alternating current(AC)transmission or distribution line under steady-state operating conditions(SSOCs)or quasi-static operating conditions(QSSOCs).As the studies on frequency dis-harmony have been expanded to multiple disharmonized vS-CUs in the local power grid,its adverse effects on AC lines and equivalent load(EL)at the bus without active voltage control ability(non-active bus)need to be investigated ***-ering the locality of disharmony and common topological con-nections among VSCUs,this paper adopts a Y-type three-termi-nal local power grid(LPG)as the research *** dishar-mony among the three VSCUs is ***,for the load at non-active bus,the formulas for single-phase instantaneous voltage,load current,load power,as well as average power un-der disharmony operating conditions(DOCs)are *** characteristic indicators of the above electrical quantities are defined,which can measure the amplification and reduction de-grees of the above electrical quantities before and after ***,for the line directly connected to VSCUs,the formulas for single-phase instantaneous line current and power and the average power under DOCs are *** character-istic indicators of power flow are defined,which can be used to quantify the peak amplification impact of oscillation before and after ***,the case study on the Y-type three-terminal LPG under the single-disharmony and the multi-dis-harmony switching scenarios indicates that the long-period pow-er oscillation caused by disharmony may occur in the load flow at the non-active bus and the line *** oscillation causes a serious decrease in load capability and a significant amplifica-tion of the peak of line power oscillation.

关键词： New power system power oscillation disharmony voltage-source-controlled unit(VSCU) characteristic analysis

Nuclear charge radius predictions by kernel ridge regression with odd-even effects

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Nuclear Science and Techniques 2024年第2期35卷 94-102页

作者： Lu tang Zhen-Hua Zhang Mathematics and Physics Department North China Electric Power UniversityBeijing 102206China Hebei Key Laboratory of Physics and Energy Technology North China Electric Power UniversityBaoding 071000China

The extended kernel ridge regression(EKRR)method with odd-even effects was adopted to improve the description of the nuclear charge radius using five commonly used nuclear *** are:(i)the isospin-dependent A^(1∕3) formula,(ii)relativistic continuum Hartree-Bogoliubov(RCHB)theory,(iii)Hartree-Fock-Bogoliubov(HFB)model HFB25,(iv)the Weizsacker-Skyrme(WS)model WS*,and(v)HFB25**** the last two models,the charge radii were calculated using a five-parameter formula with the nuclear shell corrections and deformations obtained from the WS and HFB25 models,*** each model,the resultant root-mean-square deviation for the 1014 nuclei with proton number Z≥8 can be significantly reduced to 0.009-0.013 fm after considering the modification with the EKRR *** best among them was the RCHB model,with a root-mean-square deviation of 0.0092 *** extrapolation abilities of the KRR and EKRR methods for the neutron-rich region were examined,and it was found that after considering the odd-even effects,the extrapolation power was improved compared with that of the original KRR *** strong odd-even staggering of nuclear charge radii of Ca and Cu isotopes and the abrupt kinks across the neutron N=126 and 82 shell closures were also calculated and could be reproduced quite well by calculations using the EKRR method.

关键词： Nuclear charge radius Machine learning Kernel ridge regression method