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Macroscopic model and statistical model to characterize electromagnetic information of a digital coding metasurface

National Science Review 2024年第3期11卷 159-171页

作者： Rui Wen Shao jun Wei Wu Zheng Xing Wang Hui Xu Han Qing Yang Qiang Cheng tie jun Cui Institute of Electromagnetic Space Southeast University State Key Laboratory of Millimeter Waves Southeast University Peng Cheng Laboratory Pazhou Laboratory(Huangpu)

A digital coding metasurface is a platform connecting the digital space and electromagnetic wave space, and has therefore gained much attention due to its intriguing value in reshaping wireless channels and realizing new communication architectures. Correspondingly, there is an urgent need for electromagnetic information theory that reveals the upper limit of communication capacity and supports the accurate design of metasurface-based communication systems. To this end, we propose a macroscopic model and a statistical model of the digital coding metasurface. The macroscopic model uniformly accommodates both digital and electromagnetic aspects of the meta-atoms and predicts all possible scattered fields of the digital coding metasurface based on a small number of simulations or measurements. Full-wave simulations and experimental results show that the macroscopic model is feasible and accurate. A statistical model is further proposed to correlate the mutual coupling between meta-atoms with covariance and to calculate the entropy of the equivalent currents of digital coding metasurface. These two models can help reconfigurable intelligent surfaces achieve more accurate beamforming and channel estimation, and thus improve signal power and coverage. Moreover, the models will encourage the creation of a precoding codebook in metasurface-based direct digital modulation systems, with the aim of approaching the upper limit of channel capacity. With these two models, the concepts of current space and current entropy, as well as the analysis of information loss from the coding space to wave space, is established for the first time, helping to bridge the gap between the digital world and the physical world, and advancing developments of electromagnetic information theory and new-architecture wireless systems.

关键词： electromagnetic information theory current entropy current space digital coding metasurface macroscopic model statistical model

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Stable,intense supercontinuum light generation at 1 kHz by electric field assisted femtosecond laser filamentation in air

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Light(Science & Applications) 2024年第2期13卷 354-365页

作者： Yaoxiang Liu Fukang Yin tie-jun Wang Yuxin Leng Ruxin Li Zhizhan Xu See Leang Chin State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics and CAS Center for Excellence in Ultra-intense Laser ScienceChinese Academy of SciencesShanghaiChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina Centre d’Optique Photonique et Laser(COPL)and Département de physiquede génie physique et d’optiqueUniversitéLavalQuébecQuébecCanada

Supercontinuum(SC)light source has advanced ultrafast laser spectroscopy in condensed matter science,biology,physics,and *** to the frequently used photonic crystal fibers and bulk materials,femtosecond laser filamentation in gases is damage-immune for supercontinuum generation.A bottleneck problem is the strong jitters from filament induced self-heating at kHz repetition rate *** demonstrated stable kHz supercontinuum generation directly in air with multiple mJ level pulse *** was achieved by applying an external DC electric field to the air plasma *** pointing jitters of the 1 kHz air filament induced SC light were reduced by more than 2 *** stabilized high repetition rate laser filament offers the opportunity for stable intense SC generation and its applications in air.

关键词： intense repetition light

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一种小型化人工表面等离激元传感系统——实现自适应和高灵敏的气体检测

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Engineering 2024年第4期35卷 86-94页

作者： Xuanru Zhang Jia Wen Zhu tie jun Cui State Key Laboratory of Millimeter Waves and Institute of Electromagnetic Space Southeast UniversityNanjing 210096China School of Information Science and Engineering Southeast UniversityNanjing 210096China School of Microelectronics Southeast UniversityNanjing 210096China

Resonantly enhanced dielectric sensing has superior sensitivity and accuracy because the signal is measured from relative resonance shifts that are immune to signal *** applications in the Internet of Things(IoT),accurate detection of resonance frequency shifts using a compact circuit is in high *** proposed an ultracompact integrated sensing system that merges a spoof surface plasmon resonance sensor with signal detection,processing,and wireless communication.A softwaredefined scheme was developed to track the resonance shift,which minimized the hardware circuit and made the detection adaptive to the target resonance.A microwave spoof surface plasmon resonator was designed to enhance sensitivity and resonance *** integrated sensing system was constructed on a printed circuit board with dimensions of 1.8 cm×1.2 cm and connected to a smartphone wirelessly through Bluetooth,working in both frequency scanning mode and resonance tracking mode and achieving a signal-to-noise ratio of 69 dB in acetone vapor *** study provides an ultracompact,accurate,adaptive,sensitive,and wireless solution for resonant sensors in the IoT.

关键词： Spoof surface plasmons Internet of Things Integrated sensing Resonance tracking Microwave sensing

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Demonstration of controlled high-dimensional quantum teleportation

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 1-6页

作者： Min-Yu Lv Xiao-Min Hu Neng-Fei Gong tie-jun Wang Yu Guo Bi-Heng Liu Yun-Feng Huang Chuan-Feng Li Guang-Can Guo CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Centerfor Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China State Key Laboratory of Information Photonics and Optical Communications School of ScienceBeijing University of Posts and TelecommunicationsBeijing 100876China

Controlled quantum teleportation(CQT), which is regarded as the prelude and backbone for a genuine quantum internet, reveals the cooperation, supervision, and control relationship among the sender, receiver, and controller in the quantum network within the simplest unit. Compared with low-dimensional counterparts, high-dimensional CQT can exhibit larger information transmission capacity and higher superiority of the controller's authority. In this article, we report a proof-of-principle experimental realization of three-dimensional(3D) CQT with a fidelity of 97.4% ± 0.2%. To reduce the complexity of the circuit, we simulate a standard 4-qutrit CQT protocol in a 9×9-dimensional two-photon system with high-quality operations. The corresponding control powers are 48.1% ± 0.2% for teleporting a qutrit and 52.8% ± 0.3% for teleporting a qubit in the experiment, which are both higher than the theoretical value of control power in 2-dimensional CQT protocol(33%). The results fully demonstrate the advantages of high-dimensional multi-partite entangled networks and provide new avenues for constructing complex quantum networks.

关键词： high dimension quantum information quantum teleportation quantum nonlocality

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Ultrafast modulable 2DEG Huygens metasurface

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Photonics Research 2024年第5期12卷 1004-1015页

作者： HONGXIN ZENG XUAN CONG SHIQI WANG SEN GONG LIN HUANG LAN WANG HUAJIE LIANG FENG LAN HAOYI CAO ZHENG WANG WEIPENG WANG SHIXIONG LIANG ZHIHONG FENG ZIQIANG YANG YAXIN ZHANG tie jun CUI Terahertz Communication Laboratory School of Electronic Science and EngineeringUniversity of Electronic Science and Technology of ChinaChengdu 611730China Zhangjiang Laboratory Shanghai 201210China Yangtze Delta Region Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou 313098China National Key Laboratory of Solid-State Microwave Devices and Circuits Hebei Semiconductor Research InstituteShijiazhuang 050051China Institute of Electromagnetic Space and State Key Laboratory of Millimeter Waves Southeast UniversityNanjing 210096China

Huygens metasurfaces have demonstrated remarkable potential in perfect transmission and precise wavefront modulation through the synergistic integration of electric resonance and magnetic ***,prevailing active or reconfigurable Huygens metasurfaces,based on all-optical systems,encounter formidable challenges associated with the intricate control of bulk dielectric using laser equipment and the presence of residual thermal effects,leading to limitations in continuous modulation ***,we present an ultrafast electrically driven terahertz Huygens metasurface that comprises an artificial microstructure layer featuring a two-dimensional electron gas(2DEG)provided by an AlGaN/GaN heterojunction,as well as a passive microstructure *** precise manipulation of the carrier concentration within the 2DEG layer,we effectively govern the current distribution on the metasurfaces,inducing variations in electromagnetic resonance modes to modulate terahertz *** modulation mechanism achieves high efficiency and contrast for terahertz wave *** investigations demonstrate continuous modulation capabilities of up to 6 GHz,a modulation efficiency of 90%,a transmission of 91%,and a remarkable relative operating bandwidth of 55.5%.These significant advancements substantially enhance the performance of terahertz metasurface ***,our work not only enables efficient amplitude modulation but also introduces an approach for the development of high-speed and efficient intelligent transmissive metasurfaces.

关键词： heterojunction precise surface

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基于精细神经元的类脑感知学习模型

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软件学报 2024年第3期35卷 1403-1417页

作者：张祎晨何干杜凯黄铁军北京大学计算机学院北京100871 北京大学人工智能研究院北京100871

大脑如何实现学习以及感知功能对于人工智能和神经科学领域均是一个重要问题.现有人工神经网络由于结构和计算机制与真实大脑相差较大,无法直接用于理解真实大脑学习以及处理感知任务的机理.树突神经元模型是一种对大脑神经元树突信息... 详细信息

大脑如何实现学习以及感知功能对于人工智能和神经科学领域均是一个重要问题.现有人工神经网络由于结构和计算机制与真实大脑相差较大,无法直接用于理解真实大脑学习以及处理感知任务的机理.树突神经元模型是一种对大脑神经元树突信息处理过程进行建模仿真的计算模型,相比人工神经网络更接近生物真实.使用树突神经网络模型处理学习感知任务对理解真实大脑的学习过程有重要作用.然而,现有基于树突神经元网络的学习模型大都局限于简化树突模型,无法完整建模树突的信号处理过程.针对这一问题,提出一种基于精细中型多棘神经元网络的学习模型,使得精细神经网络可以通过学习完成相应感知任务.实验表明,在经典的图像分类任务上,所提模型可以达到很好的分类性能.此外,精细神经网络对于噪声干扰有很强的鲁棒性.对网络特性进行进一步分析,发现学习后网络中的神经元表现出了刺激选择性这种神经科学中的经典现象,表明所提模型具有一定的生物可解释性,同时也表明刺激选择特性可能是大脑通过学习完成感知任务的一种重要特性.

关键词：大脑仿真类脑计算感知学习图像分类

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Lightning in a Forest (Wild) Fire: Mechanism at the Molecular Level

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Atmospheric and Climate Sciences 2024年第1期14卷 128-135页

作者： See Leang Chin Xueliang Guo Harmut Schroeder Huanbin Xu tie-jun Wang Ruxin Li Weiwei Liu Department of Physics and Center for Optics Photonics and Lasers (COPL) Laval University Quebec Canada Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Max Planck Institute of Quantum Optics Garching Germany State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai China Institute of Modern Optics Nankai University Tianjin China

The mechanism of lightning that ignites a forest fire and the lightning that occurs above a forest fire are explained at the molecular level. It is based on two phenomena, namely, internal charge separation inside the atmospheric cloud particles and the existence of a layer of positively charged hydrogen atoms sticking out of the surface of the liquid layer of water on the surface of rimers. Strong turbulence-driven collisions of the ice particles and water droplets with the rimers give rise to breakups of the ice particles and water droplets into positively and negatively charged fragments leading to charge separation. Hot weather in a forest contributes to the updraft of hot and humid air, which follows the same physical/chemical processes of normal lightning proposed and explained recently[1]. Lightning would have a high probability of lighting up and burning the dry biological materials in the ground of the forest, leading to a forest (wild) fire. The burning of trees and other plants would release a lot of heat and moisture together with a lot of smoke particles (aerosols) becoming a strong updraft. The condition for creating lightning is again satisfied which would result in further lightning high above the forest wild fire.

关键词： Forest Wild Fire Lightning Molecular Level

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Pulse repetition rate effect on the plasma inside femtosecond laser filament in air

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Chinese Optics Letters 2024年第1期22卷 135-140页

作者：尹富康王铁军刘尧香龙娟魏迎霞朱斌周凯南冷雨欣 State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics and CAS Center for Excellence in Ultra-intense Laser ScienceChinese Academy of SciencesShanghai 201800China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Laser Fusion Research Center and Science&Technology on Plasma Physics Laboratory China Academy of Engineering PhysicsMianyang 621999China

The characteristics of plasmas play an important role in femtosecond laser filament-based *** analysis is used to experimentally investigate the plasma density and its temperature of the air filament under different pulse repetition *** our experiments,the measured average plasma density of the filament is 1.54×10^(17)cm^(-3)and the temperature of the plasma is about 5100 K under 100 Hz pulse repetition *** plasma density decreases to1.43×10^(17)cm^(-3)and the temperature increases to 6230 K as the pulse repetition rate increases to 1000 *** experimental observation agrees with the numerical simulation by solving the nonlinear Schr?dinger equations with repetition rate related“low density hole”correction.

关键词： femtosecond laser filamentation cumulative effects electron density

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面向合同信息抽取的动态多任务学习方法

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软件学报 2024年第7期35卷 3377-3391页

作者：王浩畅郑冠彧赵铁军东北石油大学计算机与信息技术学院黑龙江大庆163318 哈尔滨工业大学计算机科学与技术学院黑龙江哈尔滨150001

对于合同文本中要素和条款两类信息的准确提取,可以有效提升合同的审查效率,为贸易各方提供便利化服务.然而当前的合同信息抽取方法一般训练单任务模型对要素和条款分别进行抽取,并没有深挖合同文本的特征,忽略了不同任务间的关联性.因... 详细信息

对于合同文本中要素和条款两类信息的准确提取,可以有效提升合同的审查效率,为贸易各方提供便利化服务.然而当前的合同信息抽取方法一般训练单任务模型对要素和条款分别进行抽取,并没有深挖合同文本的特征,忽略了不同任务间的关联性.因此,采用深度神经网络结构对要素抽取和条款抽取两个任务间的相关性进行研究,并提出多任务学习方法.所提方法首先将上述两种任务进行融合,构建一种应用于合同信息抽取的基本多任务学习模型;然后对其进行优化,利用Attention机制进一步挖掘其相关性,形成基于Attention机制的动态多任务学习模型;最后针对篇章级合同文本中复杂的语义环境,在前两者的基础上提出一种融合词汇知识的动态多任务学习模型.实验结果表明,所提方法可以充分捕捉任务间的共享特征,不仅取得了比单任务模型更好的信息抽取结果,而且能够有效解决合同文本中要素与条款间实体嵌套的问题,实现合同要素与条款的信息联合抽取.此外,为了验证该方法的鲁棒性,在多个领域的公开数据集上进行实验,结果表明该方法的效果均优于基线方法.

关键词：多任务学习合同文本信息联合抽取注意力机制实体嵌套

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新时代党的“文化润疆”方略实施路径构建探析

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新疆大学学报（哲学社会科学版） 2024年第1期52卷 13-19页

作者：逯浩任东景温铁军新疆大学政治与公共管理学院新疆乌鲁木齐830046

文化润疆是新时代党的治疆方略的重要组成部分,是推动新疆民族工作高质量发展、维护社会稳定、铸牢中华民族共同体意识的系统工程。处理好中华民族共同体内部共同性和差异性的关键在于科学地处理好经济基础层面共同性和差异化的关系。... 详细信息

文化润疆是新时代党的治疆方略的重要组成部分,是推动新疆民族工作高质量发展、维护社会稳定、铸牢中华民族共同体意识的系统工程。处理好中华民族共同体内部共同性和差异性的关键在于科学地处理好经济基础层面共同性和差异化的关系。上层建筑意识形态领域的不协调现象,不能简单地归因于文化、习俗和民族意识的摩擦,而有其经济基础方面的深层次原因。新时代党的“文化润疆”方略实施路径构建应以铸牢中华民族共同体意识为主线,以新发展阶段、新发展理念和新发展格局引领“文化润疆”方略的内涵深化,着力推动上层建筑领域与经济基础领域的良性互动,以高质量发展打牢各民族共同富裕的经济基础,有意识地探索支撑各民族特有文化的、人与自然和谐共生的民族地区中国式现代化路径,以高度的民族文化自信为前提,激发各民族同胞对中华民族命运共同体的认同感和自豪感。

关键词：中国式现代化生态化转型民族共同富裕铸牢中华民族共同体意识

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