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Parallel photon avalanche nanoparticles for tunable emission and multicolour sub-diffraction microscopy

Nature Photonics 2025年 1-9页

作者： Dong, Hao Guan, Lin-Quan Qiao, Shuqian Liang, Yusen Zhu, Zhimin Zhang, Jin-Wen Wang, Xiao-Yong Ni, Yue Guo, Xin Lyu, Ze-Yu Yang, Xiang-Fei Sun, Ling-Dong Zhan, Qiuqiang Yan, Chun-Hua Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and Applications PKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic Chemistry College of Chemistry and Molecular Engineering Peking University Beijing China Centre for Optical and Electromagnetic Research National Centre for International Research on Green Optoelectronics Guangdong Provincial Key Laboratory of Optical Information Materials and Technology South China Academy of Advanced Optoelectronics South China Normal University Guangzhou China MOE Key Laboratory and Guangdong Provincial Key Laboratory of Laser Life Science Guangdong Engineering Research Centre of Optoelectronic Intelligent Information Perception South China Normal University Guangzhou China College of Chemistry and Chemical Engineering Lanzhou University Lanzhou China

Photon avalanche (PA) can generate upconversion luminescent emission that grows steeply as a function of excitation power, effectively exhibiting a high order of nonlinearity (N) that is attractive for applications ranging from photophysics studies to biophotonics. Besides the limitations in available material systems, PA is typically sustained by a single reservoir level, limiting the ability to modulate the chromaticity of the emission as well as leading to small values of N and large excitation thresholds. Here we report a parallel PA mechanism in holmium (Ho3+)-doped nanoparticles for tunable emission at room temperature. The intermediate 5I7 and 5I6 levels of Ho3+ serve as dual reservoir levels that create two parallel energy loops. This activates multiple emissive levels and enables red, green and blue PA emission under 965 nm continuous-wave excitation. By rationally engineering transition kinetics through controlling doping concentration and core/shell configuration, we demonstrate multicolour PA with large N values of 17–22 and mild excitation threshold of ~22 kW cm−2. Moreover, emission can be tailored from almost pure red to intense red, green and blue by modifying the host lattice and introducing additional cross-relaxation pathways by doping with Ce3+/Tm3+. When using the nanoparticles to label biological cells, we demonstrate multicolour imaging on a single-continuous-wave-beam microscope with lateral spatial resolution of 78 nm and 102 nm in the green–blue and red channel, respectively. These findings open the way for manufacturing nonlinear multicolour fluorophores for versatile optical and biological applications. © The Author(s), under exclusive licence to Springer Nature Limited 2025.

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Interaction analysis between induction motor loads and STATCOM in weak grid using induction machine model

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Journal of Modern Power Systems and Clean Energy 2018年第1期6卷 158-167页

作者： Ding WANG Xiaoming YUAN State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology

Static synchronous compensators(STATCOM)can be used as a reactive power compensation for induction motor(IM)loads due to its effective control and good *** voltage control(TVC)in a STATCOM has a great influence on voltage dynamics which is a significant concern in a system with many IM *** paper investigates the interaction between IM loads and TVC in a STATCOM under weak grid conditions from the viewpoint of active and reactive power flow.A corresponding induction machine model is proposed,based on which the interaction mechanism between IM loads and TVC in a STATCOM can be intuitively *** is shown that the negative damping component provided by TVC in a STATCOM can lead to system oscillation *** strength and the inertia constant of the induction machine affect the extent of such ***-domain simulation results of IM loads connected to an infinite system through a long transmission line,with STATCOM compensation implemented in MATLAB/Simulink,validate the correctness of the analyses.

关键词： Induction machine Small signal stability Static synchronous compensator(STATCOM) Terminal voltage control Weak grid

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Neural Network Prediction of Disruptions Caused by Locked Modes on J-TEXT Tokamak

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Plasma Science and technology 2013年第11期15卷 1154-1159页

作者：丁永华金雪松陈真真庄革 State Key Laboratory of Advanced Electromagnetic Engineering and Technology College of Electrical and Electronic Engineering Huazhong University of Science and Technology

Prediction of disruptions caused by locked modes using the Back-Propagation （BP） neural network is completed on J-TEXT tokamak. The network, which is based on the BP neural network, uses Mirnov coils and locked mode coils signals as input data, and outputs a signal including information of prediction of locked mode. The rate of successful prediction of locked modes is more than 90%. For intrinsic locked mode disruptions, the network can give a prewarning signal about 1 ms ahead of the locking-time. For the disruption caused by resonant magnetic perturbation （RMPs） locked modes, the network can give a prewarning signal about 10 ms ahead of the locking-time.

关键词： disruption locked mode BP neural network prediction

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Enhanced dynamo drive for the sawtooth relaxation process due to non-uniform resistivity distribution in a reversed field pinch

arXiv

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arXiv 2025年

作者： Yan, Wentan Zhu, Ping Li, Hong Liu, Wandong Luo, Bing Li, Haolong KTX Laboratory Department of Plasma Physics and Fusion Engineering University of Science and Technology of China Anhui Hefei230026 China State Key Laboratory of Advanced Electromagnetic Engineering and Technology International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics School of Electrical and Electronic Engineering Huazhong University of Science and Technology Hubei Wuhan430074 China Department of Nuclear Engineering and Engineering Physics University of Wisconsin-Madison MadisonWI53706 United States Hunan Province Key Laboratory Integration and Optical Manufacturing Technology College of Mathematics and Physics Hunan University of Arts and Science Hunan Changde415000 China Department of Physics School of Science Tianjin University of Science and Technology Tianjin300457 China

In this work, we use the three-dimensional resistive MHD code NIMROD to investigate the impact of resistivity inhomogeneity on the sawtooth process of an reversed field pinch (RFP) plasma. The simulation employs a non-uniform resistivity profile similar to experiments, which monotonically increases from the core to the edge as the temperature decreases. The resistivity inhomogeneity introduces an additional electric field in the plasma, which accelerates the inward diffusion of magnetic flux and changing the self sustained reversal state, hence significantly enhances the dynamo effect and the sawtooth process in the RFP plasma. Copyright © 2025, The Authors. All rights reserved.

关键词： Electric fields

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Fretting wear mechanism of GH4169 dovetail joint specimens treated with hybrid laser shock peening

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Tribology International 2025年 209卷

作者： Fang, Xiuyang Wang, Zheng Wahab, Magd Abdel Gong, Jianen Liu, Xiong Liu, Xing Cai, Zhenbing School of Mechanical Engineering Southwest Jiaotong University Chengdu610031 China Tribology Research Institute Key Lab of Advanced Technologies of Materials Southwest Jiaotong University Chengdu610031 China Soete Laboratory Department of Electrical Energy Metals Mechanical Constructions and Systems Faculty of Engineering and Architecture Ghent University Gent9000 Belgium College of Engineering Yuan Ze University Taiwan China Parallel and Distributed Systems Laboratory Jožef Stefan Institute Jamova cesta 39 LjubljanaSI-1000 Slovenia DongFang Electric Machinery Co. LTD Deyang618000 China State Key Laboratory of Advanced Electromagnetic Technology Huazhong University of Science and Technology Hubei Wuhan430074 China

Aero engine blade structure is prone to severe fretting wear under centrifugal forces and vibration loads, resulting in greatly reduced engine service life, which is a typical fretting damage problem. In this paper, without Absorbing layer Nanosecond Laser Shock Peening (wAN-LSP) and without Absorbing layer Nanosecond superimposed Femtosecond hybrid Laser Shock Peening (NF-LSP) are utilized to strengthen the surface of GH4169 dovetail joint specimens, which is a common material for engine blades, to explore its strengthening mechanism and fretting wear evolution law. The findings indicate that the surface roughness of the wAN-LSP specimen rises from 0.28 μm to 1.16 μm. The thermal effects of wAN-LSP lead to the formation of a molten layer roughly 10.97 μm thick on the surface, accompanied by numerous pits, ablation holes, and micro-cracks. In contrast, NF-LSP treatment effectively eliminates the surface oxidation defects made by the thermal effects of wAN-LSP, leading to a slight decrease in surface roughness. Both wAN-LSP and NF-LSP treatments enhance the surface hardness of the specimens, creating a plastic deformation layer roughly 400 μm deep, but the near surface hardness of NF-LSP treated specimen is further improved compared to that of the wAN-LSP specimen. The wear mechanism observed in the GH4169 dovetail joint specimens following wAN-LSP and NF-LSP treatment are identified as abrasive wear and oxidation wear. Initially, as the number of cycles raises, the wear volume of GH4169 specimen treated with wAN-LSP is higher than that of untreated specimen, but subsequently, it becomes lesser than that of the untreated specimen. This phenomenon results from the interplay between the molten layer and hardened layer. In the initial stage of wear, despite the surface strengthening of the wAN-LSP specimen, the presence of molten layer significantly diminishes the fretting wear resistance of the material. As wear progresses, the molten layer is removed, revealing the be

关键词： Abrasion

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Design of the Transmission Lines for 140 GHz ECRH System on HL-2A

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Plasma Science and technology 2014年第3期16卷 267-272页

作者：夏冬辉周俊饶军黄梅陆志鸿王贺陈罡宇王超卢波庄革 State Key Laboratory of Advanced Electromagnetic Engineering and TechnologyHuazhong University of Science and Technology Southwestern Institute of Physics

A new 140 GHz/2 MW/3 s electron cyclotron resonance heating （ECRH） system composed of two units is now being constructed on HL-2A. As a part of the system, two trans- mission lines marked No.7 ＆ 8 play the role of carrying microwave power from two gyrotrons to the tokamak port. Based on the oversized circular corrugated waveguide technology, an evacu~ ated transmission system with high power capability and high transmission efficiency is designed. Details are presented for the design of the corrugated waveguide, the layout of the proposed lines and the vacuum pumping system. Then mode conversion losses due to coupling, misalignment, bends and gaps are discussed to serve as a reference for analyzing the transmission efficiency and alignment. Finally, a dual-modes propagation case consisting of the HEll and LPn even modes is discussed.

关键词： HL-2A tokamak electron cyclotron resonance heating transmission line

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Multi-model Selection and Computation Resource Allocation Driven Cooperative Spectrum Sensing

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IEEE Internet of Things Journal 2025年

作者： Wang, Qian Zhu, Dehao Qian, Li Ping Gu, Tingting Liang, Ying-Chang Kam, Pooi-Yuen Zhejiang University of Technology Institute of Cyberspace Security Hangzhou310023 China ZJUT Research Center of Electromagnetic Space Security Binjiang Institute of Artificial Intelligence Hangzhou310056 China Zhejiang University State Key Laboratory of CAD and CG College of Electrical Engineering Hangzhou310027 China Chengdu611731 China School of Science and Engineering Shenzhen518172 China Center for Advanced Microelectronic Devices Suzhou215123 China

Cooperative spectrum sensing (CSS) plays a crucial role in this era of explosive Internet of Things with scarce spectrum resources, since it can effectively enhance the sensing accuracy with the cooperation of secondary users (SUs). However, most existing CSS algorithms primarily focus on increasing the cooperative detection accuracy, while neglecting the computational complexity or sensing latency. Therefore, we propose a deep learning (DL) driven CSS scheme with the consideration of dynamic multi-model selection and suitable resource allocation. Specifically, we first derive the closed-form expressions to fit and characterize the detection and false alarm probabilities of three popular DL models, including the convolutional neural network, the long short-term memory (LSTM) network and the hybrid convolutional LSTM network. Then, the problem of minimizing the cooperative sensing error is formulated under the constrains of limited computational resource and sensing latency. Finally, the cross-entropy algorithm is employed to dynamically select the most suitable cooperating SU set and their correspondingly matched models, to balance the sensing accuracy and computational complexity. Simulation results demonstrate that our CSS scheme are much more robust and computationally efficient compared to some well-known CSS algorithms, especially in achieving extremely high sensing accuracy at low transmit power or low received signal-to-noise ratio. © 2014 IEEE.

关键词： Convolutional neural networks

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Design of Digital Multi-Radian Phase Detector on J-TEXT

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Plasma Science and technology 2014年第10期16卷 974-977页

作者：李俊杨州军高丽刘明海庄革 School of Electrical and Electronic Engineering Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology

A real time system used to detect phase difference between two sinusoidal signals is proposed in this paper. The system is designed to process the phase signal of the far-infrared （FIR） hydrogen cyanide （HCN） interferometer on J-TEXT. It is based on zero-crossing detection and makes use of the digital circuit. Compared with a traditional zero-crossing phase detector, it doesn＇t need to sacrifice the time resolution to expand the phase range. The phase difference is divided into two parts, the integer part and the fraction part. In each detecting cycle, they are detected separately. It outputs digital signals that are more stable for transmission. A prototype was built on J-TEXT using discrete components. A practical method is proposed to deal with the counting error caused by the deviation of electronic components in manufacture. Reasonable results were obtained on the prototype. The phase resolution reaches 2π/64 in test, and can still be improved by raising the clock frequency.

关键词： phase detector multi-radian digital HCN interferometer

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Implementation of Automatic Process of Edge Rotation Diagnostic System on J-TEXT Tokamak

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Plasma Science and technology 2014年第8期16卷 789-793页

作者：张泽品程芝峰罗剑王之江张晓龙侯赛英成诚 State Key Laboratory of Advanced Electromagnetic Engineering and Technology College of Electrical and Electronic Engineering Huazhong University of Science and Technology

A spectral diagnostic control system （SDCS） is developed to implement automatic process of the edge rotation diagnostic system on the J-TEXT tokamak. The SDCS contains a control module, data operation module, data analysis module, and data upload module. The core of this system is a newly developed software ＂Spectra Assist＂, which completes the whole process by coupling all related subroutines and servers. The results of data correction and calculated rotation are presented. In the daily discharge of J-TEXT, SDCS is proved to have a stable performance and high efficiency in completing the process of data acquisition, operation and results output.

关键词： edge rotation diagnostic control system J-TEXT mixed programming

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Absolute and Convective Instabilities of Two-Plasmon Decay in an Inhomogeneous Magnetized Plasma

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Chinese Physics Letters 2015年第12期32卷 96-100页

作者：孙新锋江中和徐涛胡希伟庄革王璐王小红 State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and Technology

Three-wave resonant parametric decay instability of extraordinary wave decay into two upper hybrid waves in an inhomogeneous plasma is studied theoretically. Analytical expressions of the local absolute growth rate, convective amplification factor and threshold intensity are obtained. The calculated results show that the effects of magnetic field and ky （ICy is the component of the wavenumber of upper hybrid wave perpendicular to pump wave k0） on the growth rate, amplification factor and threshold intensity are extremely dependent on their strength. The absolute growth rate and convective amplification factor increase with the plasma density while the threshold decreases. Moreover, the expression indicates that the inhomogeneity scale length of density and linear damping will reduce the convective amplification factor.

关键词： ab Absolute and Convective Instabilities of Two-Plasmon Decay in an Inhomogeneous Magnetized Plasma TPD

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