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Manipulating light radiation from a topological perspective

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Photonics Research 2020年第11期8卷 I0036-I0049页

作者： Xuefan Yin Chao Peng State Key Laboratory of Advanced Optical Communication Systems and Networks Department of ElectronicsPeking UniversityBeijing 100871China

Manipulating radiation is important for a variety of optoelectronic applications,such as on-chip lasers,energy-efficient grating couplers,and antennas for light detection and ranging.Although designing and optimizing those optoelectronic devices are usually believed to be an engineering-oriented task,recent research reveals that the principles underlying radiation manipulation are closely connected to the concept of topology—the study of properties that are invariant under continuous deformations.In this review,we summarize a series of advances of the physics,phenomena,and applications related to radiation manipulation,in which topological concepts were adopted.Radiation could carry energy escaping from the system,breaking the energy conservation.The non-Hermiticity of such systems brings quite different physical consequences when comparing with the Hermitian counterparts and,hence,also results in the emergence of many interesting and extraordinary phenomena.In particular,it is found that the perfect trapping of light can still be realized in such non-Hermitian systems because of the photonic realization of bound states in the continuum.The fundamental nature of bound states in the continuum has been identified to be topological:they are essentially topological defects of the polarization vector field in momentum space,depicted by a kind of topological invariant named topological charges.Therefore,manipulation of radiation channels can be realized by controlling the topological charge evolution in momentum space.It is also demonstrated that the photonic states accompanied with different topological charges generate vortex beams with unique far-field radiation patterns,and ultra-fast switching of such vortex beams is demonstrated according to this principle.The progresses of topological photonics upon light radiation show that the topology is not just mathematical convenience for depicting photonic systems,but has brought realistic consequences in manipulating light and will boost the applications of photonics and

关键词： polarization light consequences

Design considerations for re-functionalizing electrocatalytic materials

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Science China(Technological Sciences) 2023年第12期66卷 3355-3368页

作者： ZHANG DanTong peng chao XUE DongFeng Multiscale Crystal Materials Research Center Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Electrocatalytic materials are a critical bottleneck for the development of new energy economics.This review summarizes the unique physicochemical properties of topological,magnetic,and rare earth materials and their applications in the functionalization of electrocatalysts.Topological materials have unique band structures and geometric structures,and the interface difference in charge transport structures can give rise to topological insulators,topological superconductors,and Dirac metals.Magnetic materials possess distinctive electron spin-splitting configurations,and varying spin strengths induce disparate impacts on the intermediate equilibrium adsorption capability.Rare earth materials have unique f-electron roaming properties,broad atomic radius,and f-orbital configurations,which typically confer notable advantages in oxygen reduction reactions.Furthermore,the catalytic performance exhibits significant differences under an external alternating electric,thermal,and magnetic field.These new materials show great potential in the re-functionalization of electrocatalytic materials and are expected to lead the development of the next generation of emerging energy materials.

关键词： electrocatalysis topological materials magnetic materials rare earth materials

Non-IID federated learning via random exchange of local feature maps for textile IIoT secure computing

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Science China(Information Sciences) 2022年第7期65卷 16-31页

作者： Bo peng Mingmin CHI chao LIU School of Computer Science Shanghai Key Laboratory of Data Science Fudan University Zhongshan Pool Net Technology Co.Ltd. Zhongshan Fudan Joint Innovation Center 3. Zhengzhou Zhongke Institute of Integrated Circuit and System Application

With the fast development of artificial intelligence(AI) and industrial Internet of Things(IIoT)technologies, it is challenging to deal with the problems of data privacy protection and secure computing.In recent years, federated learning(FL) is proposed to attack the challenges of learning shared models collaboratively while protecting security based on the data from cross-domain clients. However, data in the real environment is usually not independent and identically distributed(Non-IID) due to the differences in business, working environments, and data acquisition, and thus classic federated methods suffer from significant performance degradation. In this paper, a novel federated framework is proposed for secure textile fiber identification(Fed TFI) via cross-domain texture representation based on high-definition fabric images. In addition to sharing the gradient of Fed TFI, the local patch of feature maps between crossdomain clients is randomly exchanged to build a richer image texture feature distribution while protecting data security simultaneously for secure computing. Furthermore, a texture embedding layer is designed to provide a joint representation through similarity measure between triplet samples in low-dimensional space.To verify the effectiveness of the proposed framework, two textile image datasets, i.e., one public and the other we collected, are utilized to construct four Non-IID scenarios, including label skew, feature skew, and two combined skew scenarios. The experimental results confirm the effectiveness of our model to obtain better detection accuracies than benchmarks in four Non-IID scenarios by keeping data privacy for secure computing in fabric IIoT.

关键词： federated learning Federated learning Secure computing secure computing Industrial Internet of Things (IIoT) industrial Internet of Things (IIoT) machine vision Machine vision texture encoding Image classification image classification Non-IID

An observed nocturnal ozone transport event in the Sichuan Basin,Southwestern China

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Journal of Environmental Sciences 2024年第4期138卷 10-18页

作者： Ruyue Guo Guangming Shi Dan Zhang Yang Chen Chao Peng Chongzhi Zhai Fumo Yang Department of Environmental Science and Engineering Sichuan UniversityChengdu 610065China College of Carbon Neutrality Future Technology Sichuan UniversityChengdu 610065China National Engineering Research Center on Flue Gas Desulfurization Chengdu 610065China Chongqing Academy of Eco-Environmental Science Chongqing 401147China Research Center for Atmospheric Environment Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China Key Laboratory for Urban Atmospheric Environment Integrated Observation&Pollution Prevention and Control of Chongqing Chongqing 401147China

The ozone(O_(3))pollution in China drew lots of attention in recent years,and the Sichuan Basin(SCB)was one of the regions confronting worsening O_(3)pollution problem.Many previous studies have shown that regional transport is an important contributor to O_(3)pollution.However,very few features of the O_(3)profile during transport have been reported,especially in the border regions between different administrative divisions.In this study,we conducted tethered balloon soundings in SCB during the summer of 2020 and captured a nocturnal O_(3)transport event during the campaign.Vertically,the O_(3)transport occurred in the bottom of the residual layer,between 200 and 500 m above ground level.Horizontally,the transport pathway was directed from southeast to northwest based on the analysis of the wind field and air mass trajectories.The effect of transport in the residual layer on the surface O_(3)concentration was related to the spatial distribution of O_(3).For cities with high O_(3)concentrations in the upwind region,the transport process would bring clean air masses and abate pollution.For downwind lightly polluted cities,the transport process would slow down the decreasing or even increase the surface O_(3)concentration during the night.We provided observational facts on the profile features of a transboundary O_(3)transport event between two provincial administrative divisions,which implicated the importance of joint prevention and control measures.However,the sounding parameters were limited and the quantitative analysis was preliminary,more integrated,and thorough studies of this topic were called for in the future.

关键词： Ozone Sichuan basin Transport event Vertical profile

Periodic event-triggered secure consensus for networked mechanical systems under Denial-of-Service attacks

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Control Theory and Technology 2024年第1期22卷 1-13页

作者： Shiqi Zheng Zhipeng Li chao Zhai peng Shi School of Automation China University of GeosciencesWuhan430074HubeiChina School of Electrical and Electronic Engineering The University of AdelaideAdelaideSA5005Australia School of Electronic Electrical Engineering and PhysicsFujian University of TechnologyFuzhou350100FujianChina

This paper concentrates on the secure consensus problem of networked mechanical/Euler–Lagrange systems.First,a new periodic event-triggered(PET)secure distributed observer is proposed to estimate the leader information.The proposed distributed observer only relies on the PET data from its neighbors,which can significantly reduce the communication and computational burden.More importantly,it is secure in the sense that it can work normally regardless of the Denial-of-Service(DoS)attacks.Second,based on the proposed distributed observer,an adaptive fuzzy control law is proposed for each Euler–Lagrange system.A PET mechanism is integrated into the controller,which can reduce the control update.This is helpful for both energy saving and fault tolerance of actuators.Moreover,the PET mechanism naturally makes the controller easy to be implemented in digital platform.The property of fuzzy logic systems and Gronwall inequality are skillfully utilized to show the stability of the closed-loop system.Finally,the proposed control scheme is verified on real Euler–Lagrange systems,which contain a robot manipulator and several servo motors.

关键词： Output regulation Mechanical/Euler-Lagrange systems Periodic event-triggered mechanism Denial-of-Service attacks

Design and implementation of accelerator control monitoring system

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Nuclear Science and Techniques 2023年第4期34卷 102-114页

作者： chao Yuan Wei Zhang Tao Ma Min Yue peng-peng Wang Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

IMPCAS has constructed and currently manages a large number of accelerator facilities. However, the current accelerator monitoring methods are unable to satisfy all of the device requirements. The accelerator control monitoring system(ACMS) was created and established to provide an efficient and accurate accelerator control monitoring system. It enables automatic alerting of problems with accelerator control systems and infrastructure. It utilizes a big data distributed stream processing engine and open-source monitoring tools. Metrics, logs, and EPICS PV values are the major three types of data that it monitors. Prometheus is primarily used to monitor metrics such as network traffic, hardware devices, and software operations. Graylog is used to monitor logs created by various applications and systems. We also created the EPICS Pulsar connector software, which allows us to transfer PV values to the Pulsar messaging cluster and use the Flink compute engine for real-time monitoring. The designed data management module allows users to define alert rules in a variety of ways. The ACMS enables the separation of the Flink business system and alarm rules. Users may use the data management module to add or alter alarm rules in real-time without having to restart the alarm software. This reduces the effect of alarm flooding when the accelerator reaches the beam shifting or shutdown condition and dramatically enhances alarm efficiency. The main components of the ACMS may be deployed in clusters, making it extremely versatile. Experimental results demonstrated that it has a higher throughput than the Phoebus Alarm system and can handle millions of monitoring indicators. The ACMS employs a modular framework that is very scalable. Long-term stability analyses were performed at the SESRI and HIRFL facilities. It achieved all of the intended goals and could greatly improve the accident handling efficiency while minimizing the failure time of the accelerator control system.

关键词： EPICS ACMS Pulsar Flink Graylog Prometheus

Edge and lithium concentration effects on intercalation kinetics for graphite anodes

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Journal of Energy Chemistry 2024年第3期90卷 337-347,I0009页

作者： Keming Zhu Denis Kramer Chao Peng School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048ShanxiChina Faculty of Mechanical Engineering Helmut-Schmidt UniversityHamburg 22043Germany School of Engineering University of SouthamptonSouthampton SO171BJUK Multiscale Crystal Materials Research Center Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055GuangdongChina

Graphite interfaces are an important part of the anode in lithium-ion batteries(LIBs),significantly influencing Li intercalation kinetics.Graphite anodes adopt different stacking sequences depending on the concentration of the intercalated Li ions.In this work,we performed first-principles calculations to comprehensively address the energetics and dynamics of Li intercalation and Li vacancy diffusion near the no n-basal edges of graphite,namely the armchair and zigzag-edges,at high Li concentration.We find that surface effects persist in stage-Ⅱ that bind Li strongly at the edge sites.However,the pronounced effect previously identified at the zigzag edge of pristine graphite is reduced in LiC_(12),penetrating only to the subsurface site,and eventually disappearing in LiC_(6).Consequently,the distinctive surface state at the zigzag edge significantly impacts and restrains the charging rate at the initial lithiation of graphite anodes,whilst diminishes with an increasing degree of lithiation.Longer diffusion time for Li hopping to the bulk site from either the zigzag edge or the armchair edge in LiC_(6) was observed during high state of charge due to charge repulsion.Effectively controlling Li occupation and diffusion kinetics at this stage is also crucial for enhancing the charge rate.

关键词： Graphite anode Edge Interface Lithium-ion batteries Density functional theory

Endovascular coiling versus microsurgical clipping for ruptured intracranial aneurysms:a meta-analysis and systematic review

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Chinese Neurosurgical Journal 2022年第4期8卷 268-283页

作者： Chao Peng Yu-hang Diao Shi-fei Cai Xin-yu Yang Department of Neurosurgery Tianjin Medical University General HospitalTianjinThe People’s Republic of China

Background:The purpose of this analysis is to evaluate the current evidence with regard to the effectiveness and safety between coiling and clipping in patients with ruptured intracranial aneurysms(RIAs).Methods:We performed a meta-analysis that compared clipping with coiling between July 2000 and September 2021.PubMed,EMBASE,and the Cochrane Library were searched for related articles systematically.And the treatment efficacy and postoperative complications were analyzed.Results:We identified three randomized controlled trials and thirty-seven observational studies involving 60,875 patients with ruptured cerebral aneurysms.The summary results showed that coiling was related a better quality of life(mRS0-2;OR=1.327;CI=1.093-1.612;p<0.05),a higher risk of mortality(OR=1.116;CI=1.054-1.180;p<0.05),higher rate of rebleeding(RR=1.410;CI=1.092-1.822;p<0.05),lower incidence of vasospasm(OR=0.787;CI=0.649-0.954;p<0.05),higher risk of hydrocephalous(RR=1.143;CI=1.043-1.252;p<0.05),lower risk of cerebral infarction(RR=0.669;CI=0.596-0.751;p<0.05),lower risk of neuro deficits(RR=0.720;CI=0.582-0.892;p<0.05),and a lower rate of complete occlusion(OR=0.495;CI=0.280-0.876;p<0.05).Conclusion:Coiling was significantly associated with a better life quality(mRS0-2),a lower incidence of postoperative complications,and a higher rate of mortality,rebleeding,hydrocephalous,and a lower rate of complete occlusion than clipping.

关键词： Ruptured intracranial aneurysms Coiling Clipping Meta-analysis

Artifacts in two-dimensional shear wave elastography of liver

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World Journal of Gastroenterology 2023年第21期29卷 3318-3327页

作者： Hui-peng Wang peng-chao Zheng Xue-Mei Wang Liang Sang Department of Ultrasound The First Hospital of China Medical UniversityShenyang 110001Liaoning ProvinceChina

BACKGROUND Artifacts are common when using two-dimensional shear wave elastography(2-D SWE)to measure liver stiffness(LS),but they are poorly recognized.AIM To investigate the presence and influence of artifacts in 2-D SWE of liver.METHODS We included 158 patients with chronic liver disease,who underwent 2-D SWE examination by a novice and an expert.A cross line at the center of the elastogram was drawn and was divided it into four locations:top-left,top-right,bottom-left,and bottom-right.The occurrence frequency of artifacts in different locations was compared.The influence of artifacts on the LS measurements was evaluated by comparing the elastogram with the most artifacts(EMA)and the elastogram with the least artifacts(ELA).RESULTS The percentage of elastograms with artifacts in the novice(51.7%)was significantly higher than that of the expert(19.6%)(P<0.001).It was found that both operators had the highest frequency of artifacts at bottom-left,followed by top-left and bottom-right,and top-right had the lowest frequency.The LS values(LSVs)and standard deviation values of EMAs were significantly higher than those of ELAs for both operators.An intraclass correlation coefficient value of 0.96 was found in the LSVs of EMAs of the two operators,and it increased to 0.98 when the LSVs of the ELAs were used.Both operators had lower stability index values for EMAs than ELAs,but the difference was only statistically significant for the novice.CONCLUSION Artifacts are common when using 2-D SWE to measure LS,especially for the novice.Artifacts may lead to the overestimation of LS and reduce the repeatability and reliability of LS measurements.

关键词： Ultrasound Elastography Artifact Liver