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Deep Learning Based Signal Detector for OFDM Systems

China Communications 2023年第12期20卷 66-77页

作者： Guangliang Pan Wei Wang Minglei Li Key Laboratory of Dynamic Cognitive System of Electromagnetic Spectrum Space Ministry of Industry and Information TechnologyCollege of Electronic and Information EngineeringNanjing University of Aeronautics and AstronauticsNanjing 211106China College of Control Science and Engineering China University of Petroleum(East China)Qingdao 266580China

In this paper,we propose a novel deep learning(DL)-based receiver design for orthogonal frequency division multiplexing(OFDM)*** entire process of channel estimation,equalization,and signal detection is replaced by a neural network(NN),and hence,the detector is called a NN detector(N^(2)D).First,an OFDM signal model is *** analyze both temporal and spectral characteristics of OFDM signals,which are the motivation for ***,the generated data based on the simulation of channel statistics is used for offline training of bi-directional long short-term memory(Bi-LSTM)***,a discriminator(F)is added to the input of Bi-LSTM NN to look for subcarrier transmission data with optimal channel gain(OCG),which can greatly improve the performance of the ***,the trained N^(2)D is used for online recovery of OFDM *** performance of the proposed N^(2)D is analyzed theoretically in terms of bit error rate(BER)by Monte Carlo simulation under different parameter *** simulation results demonstrate that the BER of N^(2)D is obviously lower than other algorithms,especially at high signal-to-noise ratios(SNRs).Meanwhile,the proposed N^(2)D is robust to the fluctuation of parameter values.

关键词： channel estimation deep learning OFDM optimal channel gain signal detection

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A Measurement Amplification Method for TSV Weak Resistance 3

A Measurement Amplification Method for TSV Weak Resistance

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2022 3rd International Conference on Electrical technology and Automatic Control, ICETAC 2022

作者： Gong, Tao Zeng, Sheng Chen, Si Lu, Xiangjun Shao, Dengyun School of Materials Science and Engineering Xia Men University of Technology Xiamen361024 China Nanjing Electronic Devices Institute Nanjing210016 China Science and Technology on Reliability Physics and Application of Electronic Component Laboratory The Fifth Electronics Research Institute of the Ministry of Industry and Information Technology Guangzhou511370 China

In the TSV electromigration test process, this paper has carried out relevant research on how to accurately measure TSV resistance and make it conducive to the observation of standard instruments, aiming at the problem that the resistance value of TSV reaches the magnitude of a microburst. Observing the resistance value change in the electromigration process is challenging. This paper analyzes and designs a measurement circuit for TSV. This circuit uses the cascade of an integrated amplifier. It combines with the four-probe method to amplify the TSV resistance change signal based on accurate measurement of TSV resistance, which is more conducive to the measurement of standard instruments and makes it easier to observe the change of resistance when TSV electromigration occurs. © Published under licence by IOP Publishing Ltd.

关键词： Electromigration

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Evidence of Spin Density Waves in La3Ni2O7−δ

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Physical Review Letters 2024年第25期132卷 256503-256503页

作者： Kaiwen Chen Xiangqi Liu Jiachen Jiao Muyuan Zou Chengyu Jiang Xin Li Yixuan Luo Qiong Wu Ningyuan Zhang Yanfeng Guo Lei Shu State Key Laboratory of Surface Physics Department of Physics School of Physical Science and Technology ShanghaiTech Laboratory for Topological Physics Shanghai 201210 China Shanghai Research Center for Quantum Sciences Shanghai 201315 China

The recently discovered superconductivity with critical temperature Tc up to 80 K in the double-layer Nickelate La3Ni2O7−δ under pressure has drawn great attention. Here, we report the positive muon spin relaxation (μ+SR) study of polycrystalline La3Ni2O6.92 under ambient pressure. Zero-field μ+SR experiments reveal the existence of magnetic order in La3Ni2O6.92 with TN=154 K. The weak transverse field μ+SR measurements reveal the bulk nature of magnetism. In addition, a small quantity of oxygen deficiencies can greatly broaden the internal magnetic field distribution sensed by muons.

关键词： Magnetic order Spin valves Muon spin relaxation & rotation

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Numerical modeling of GaN growth by MOCVD on metal substrate

Numerical modeling of GaN growth by MOCVD on metal substrate

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International Conference on Display technology, 2024

作者： Fang, Xiubo Pan, Kui Xia, Tianwen Chen, Qinzhong Zhang, Ke Hou, Qinglong Wu, Yongsheng Liu, Hengshan Sun, Jie Yan, Qun Guo, Tailiang National and Local United Engineering Laboratory of Flat Panel Display Technology College of Physics and Information Engineering Fuzhou University and Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou350100 China Fujian Acetron New Materials Co. Ltd Fuzhou350000 China Fujian Prima Optoelectronics Co. Ltd. Fuzhou350000 China Quantum Device Physics Laboratory Department of Microtechnology and Nanoscience Chalmers University of Technology Gothenburg41296 Sweden Rich Sense Electronics Technology Inc. Jinjiang362200 China

GaN materials have attracted great interest and have demonstrated remarkable potential in many fields. When growing GaN materials, substrate selection is of great importance. By virtue of their nominally unlimited size, easy removal, and excellent thermal conduction, metal substrates have been suggested as an alternative to the commonly used substrates such as sapphire. GaN growth on metal substrates, however, is still quite rare, and many aspects remain unexplored. This paper uses computational fluid dynamics to perform a three-dimensional numerical simulation of the GaNMOCVD reaction chamber. We investigated the influence of the graphite containers' rotational velocity and the metal matrix's temperature at various locations. When the pressure within the MOCVD chamber remains constant, increasing the graphite tray's rotational velocity enhances the temperature field distribution within the chamber. However, the flow field becomes unstable when the rotation rate exceeds 1000 rpm. Our findings serve as a crucial benchmark for the future parameter optimization of MOCVD growth of GaN on metals. © 2024 John Wiley and Sons Inc. All rights reserved.

关键词： Graphite

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High-Throughput Powder Diffraction Using White X-Ray Beam and a Simulated Energy-Dispersive Array Detector

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Engineering 2022年第3期8卷 81-88页

作者： Xiaoping Wang Weiwei Dong Peng Zhang Haoqi Tang Lanting Zhang Tieying Yang Peng Liu Hong Wang X.-D.Xiang Materials Genome Initiative Center&School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Academy for Advanced Interdisciplinary Studies Southern University of Science and TechnologyShenzhen 518055China Department of Materials Science and Engineering&Department of Physics Southern University of Science and TechnologyShenzhen 518055China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China Guangdong Provincial Key Laboratory of Energy Materials for Electric Power Southern University of Science and TechnologyShenzhen 518055China Guangdong-Hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and Devices Southern University of Science and TechnologyShenzhen 518055China

High-throughput powder X-ray diffraction(XRD)with white X-ray beam and an energy-dispersive detector array is demonstrated in this work on a CeO;powder sample on a bending magnet synchrotron beamline at the Shanghai Synchrotron Radiation Facility(SSRF),using a simulated energy-dispersive array detector consisting of a spatially scanning silicon-drift detector(SDD).Careful analysis and corrections are applied to account for various experimental hardware-related and diffraction angle-related *** resulting diffraction patterns show that the relative strength between different diffraction peaks from energy-dispersive XRD(EDXRD)spectra is consistent with that from angle-resolved XRD(ARXRD),which is necessary for analyzing crystal structures for unknown *** X-ray fluorescence(XRF)signal is collected *** counts from all pixels are integrated directly by energy,while the diffraction spectra are integrated by d-spacing,resulting in a much improved peak strength and signal-to-noise(S/N)ratio for the array *** comparison with ARXRD,the diffraction signal generated by a white X-ray beam over monochromic light under the experimental conditions is about 104 times *** full width at half maximum(FWHM)of the peaks in q-space is found to be dependent on the energy resolution of the detector,the angle span of the detector,and the diffraction *** is possible for EDXRD to achieve the same or even smaller FWHM as ARXRD under the energy resolution of the current detector if the experimental parameters are properly chosen.

关键词： High-throughput experiment White beam X-ray diffraction Energy-dispersive array detector Energy-dispersive X-ray diffraction Angle-resolved X-ray diffraction

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Dissipation-Induced Extended-Localized Transition

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Physical Review Letters 2024年第21期132卷 216301-216301页

作者： Yaru Liu Zeqing Wang Chao Yang Jianwen Jie Yucheng Wang Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Intense Laser Application Technology and College of Engineering Physics Shenzhen Technology University Shenzhen 518118 China Department of Physics Renmin University of China Beijing 100872 China Shenzhen Institute for Quantum Science and Engineering Southern University of Science and Technology Shenzhen 518055 China International Quantum Academy Shenzhen 518048 China Guangdong Provincial Key Laboratory of Quantum Science and Engineering Southern University of Science and Technology Shenzhen 518055 China

A mobility edge (ME), representing the critical energy that distinguishes between extended and localized states, is a key concept in understanding the transition between extended (metallic) and localized (insulating) states in disordered and quasiperiodic systems. Here we explore the impact of dissipation on a quasiperiodic system featuring MEs by calculating steady-state density matrix and analyzing quench dynamics with sudden introduction of dissipation. We demonstrate that dissipation can lead the system into specific states predominantly characterized by either extended or localized states, irrespective of the initial state. Our results establish the use of dissipation as a new avenue for inducing transitions between extended and localized states and for manipulating dynamic behaviors of particles.

关键词： Anderson localization Dissipative dynamics Localization 1-dimensional systems Quasicrystals

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A Conceptual Framework for Climate Change Mitigation Actions Employing In-space Geoengineering 74

A Conceptual Framework for Climate Change Mitigation Actions...

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74th International Astronautical Congress, IAC 2023

作者： Chesley, Bruce Matonti, Catello Leonardo Sonty, S. Sita Gutowska, Magdalena Romano, Marcello Teaching Science and Technology Inc. United States ASTRADORS Laboratory Mechanical & Aerospace Engineering Department Politecnico di Torino Italy Space Tango United States

The possibility of direct climate action from space in the form of reversible in-space geoengineering introduces novel concepts for large scale space systems and applications to achieve desirable long-term outcomes for planet Earth. The objective of this paper is to broadly address opportunities for innovation and collaboration in building and advancing the future vision of transformational in-space geoengineering architectures. In previous work the authors surveyed proposed space geoengineering approaches and provided top-level comparisons based on critical metrics, including sustainability and reversibility, scientific and engineering feasibility, cost, and time of execution. In this paper, we introduce a conceptual framework for in-space geoengineering. This framework offers a space-climate architecture framework for comparing different approaches and driving progress across the entire span of complex issues that are involved. These include mission specific considerations, policy and geo-political activities, economic/industrial viability, and operational aspects. We consider and preliminarily analyze each of these perspectives. In particular, regarding mission-specific considerations we consider: current state of the art, technology maturation roadmaps, design reference architectures (orbits, launch vehichles, number of satellites, technology Readiness Levels), and bases for conducting technical trade studies and systems engineering analyses. Regarding policy and geo-political activities, we discuss: state of the art in terms of analogous global endeavours/interventions, policy, legal precedents, norms, funding, international cooperation, standards, key policy actors (sovereign civil space stakeholders, sovereign national security stakeholders, UN, NGOs such as World Economic Forum, etc.). Regarding economic/industrial viability we explore: sovereign wealth funds' investment into key strategic space infrastructure, private capital sources' prioritization of sust

关键词： Climate Change Mitigation Planetary Sunshade Policy space-based Geoengineering space-Climate Architecture Framework technology Roadmap

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Optical vortex in a quasicrystal structure

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Optics Letters 2025年第10期50卷 3373-3376页

作者： Li, Chenying Qin, Xueyun Liu, Kun Zhang, Hao Zhou, Yujie Tai, Yuping Li, Xinzhong School of Physics and Engineering School of Chemistry and Chemical Engineering Henan University of Science and Technology Luoyang471023 China State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an710119 China

Analagous to the quasicrystal in solid physics, we reveal the properties of optical vortex (OV) in a photonic quasicrystal structure via interfering plane waves. The distribution of OVs possesses the rotational symmetry and the symmetric order agrees with the number of the plane waves. The OVs exhibit a long-range order along the radial directions. Further, the distribution and the signs of the topological charges (TCs) of OVs can be modulated via adjusting the initial phase difference between adjacent waves. In addition, the TCs are multiplied, and the orbital angular momentum and energy flow have been modulated and analyzed. This study opens up a novel, to the best of our knowledge, horizon for versatile OVs’ distribution, which will prompt several advanced applications such as multiple particle manipulation and quantum transport. © 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

关键词： Quasicrystals

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Multi-UAV Distributed Expulsion Based on Deep Reinforcement Learning

Multi-UAV Distributed Expulsion Based on Deep Reinforcement ...

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第43届中国控制会议

作者： Xiaoman Zhang Huaxin Qiu Yangzhu Wang Like Sun Changhao Sun Transportation Science and Engineering College Beihang University Flying College Beihang University Qian Xuesen Laboratory of Space Technology China Academy of Space Technology

ISBN: (数字)9789887581581

ISBN: (纸本)9798350366907

Aiming at the problem of collaborative expulsion in multiple unmanned aerial vehicles(UAVs),a method for maneuver decision-making based on deep reinforcement learning is ***,a reward function is designed based on the proximity of the single UAV to the enemy UAV,the constraints of task boundary,and the effectiveness of group expulsion.A framework for training multi-UAV collaborative expulsion is built on such a ***,the latest deep reinforcement learning algorithm is enhanced based on a training mechanism of the shared feature encoding *** simulation results show the rationality of the collaborative expulsion reward function design,the effectiveness of the maneuvering decision-making method,and the superiority of the training mechanism of the shared feature encoding network.

关键词： Multiple unmanned aerial vehicles collaborative expulsion deep reinforcement learning shared feature encoding network

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Taming Electrons in Pt/C Catalysts to Boost the Mesokinetics of Hydrogen Production

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Engineering 2022年第7期8卷 124-133页

作者： Wenyao Chen Wenzhao Fu Xuezhi Duan Bingxu Chen Gang Qian Rui Si Xinggui Zhou Weikang Yuan De Chen State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China Shanghai Synchrotron Radiation Facility Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201204China Department of Chemical Engineering Norwegian University of Science and TechnologyTrondheim N-7491Norway

Taming the electron transfer across metal–support interfaces appears to be an attractive yet challenging methodology to boost catalytic ***,we demonstrate a precise engineering strategy for the carbon surface chemistry of Pt/C catalysts—that is,for the electron-withdrawing/donating oxygencontaining groups on the carbon surface—to fine-tune the electrons of the supported metal *** the ammonia borane hydrolysis as an example,a combination of density functional theory(DFT)calculations,advanced characterizations,and kinetics and isotopic analyses reveals quantifiable relationships among the carbon surface chemistry,Pt charge state and binding energy,activation entropy/enthalpy,and resultant catalytic *** decoupling the influences of other factors,the Pt charge is unprecedentedly identified as an experimentally measurable descriptor of the Pt active site,contributing to a 15-fold increment in the hydrogen generation *** incorporating the Pt charge with the number of Pt active sites,a mesokinetics model is proposed for the first time that can individually quantify the contributions of the electronic and geometric properties to precisely predict the catalytic *** results demonstrate a potentially groundbreaking methodology to design and manipulate metal–carbon catalysts with desirable properties.

关键词： Mesokinetics model Catalyst descriptor Pt charge state Carbon surface chemistry Hydrogen generation activity

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