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Density waves of vortex fluids on a sphere

Communications in Theoretical Physics 2025年第4期77卷 159-166页

作者： Yanqi Xiong Zhijun Zou Liang Luo Key Laboratory of Hunan Province on Information Photonics and Freespace Optical Communications School of Physics and Electronic ScienceHunan Institute of Science and TechnologyYueyang 414006China Graduate School of China Academy of Engineering Physics Beijing 100193China

We aim to find one highly nontrivial example of the solutions to the vortex fluid dynamical equation on the unit sphere(S^(2))and compare it with the numerical *** the rigid rotating steady solution for vortex fluids on S^(2)is already known to us,we consider the perturbations above *** decomposing the perturbation of the vortex number density and vortex charge density into spherical harmonics,we find that the perturbations are propagating *** be precise,the velocities for different single-mode vortex number density waves are all the same,while the velocities for single-mode vortex charge density waves depend on the degree of the spherical harmonics l,which is a signal of the existence of ***,we find that there is a beat phenomenon for the positive(or negative)vortex density *** simulation based on the canonical equations for the point vortex model agrees perfectly with our theoretical calculations.

关键词： quantum vortex 2D sphere superfluid density wave dispersion ome

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Position-aware pushing and grasping synergy with deep reinforcement learning in clutter

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CAAI Transactions on Intelligence technology 2024年第3期9卷 738-755页

作者： Min Zhao Guoyu Zuo Shuangyue Yu Daoxiong Gong Zihao Wang Ouattara Sie Intelligent Robotics Laboratory Faculty of Information TechnologyBeijing University of TechnologyBeijingChina Beijing Key Laboratory of Computational Intelligence and Intelligent Systems BeijingChina Laboratory of Biomechatronics and Intelligent Robotics(BIRO) Department of Mechanical and Aerospace EngineeringNorth Carolina State UniversityRaleighNorth CarolinaUSA

The positional information of objects is crucial to enable robots to perform grasping and pushing manipulations in *** effectively perform grasping and pushing manipu-lations,robots need to perceive the position information of objects,including the co-ordinates and spatial relationship between objects(e.g.,proximity,adjacency).The authors propose an end-to-end position-aware deep Q-learning framework to achieve efficient collaborative pushing and grasping in ***,a pair of conjugate pushing and grasping attention modules are proposed to capture the position information of objects and generate high-quality affordance maps of operating positions with features of pushing and grasping *** addition,the authors propose an object isolation metric and clutter metric based on instance segmentation to measure the spatial re-lationships between objects in cluttered *** further enhance the perception capacity of position information of the objects,the authors associate the change in the object isolation metric and clutter metric in cluttered environment before and after performing the action with reward function.A series of experiments are carried out in simulation and real-world which indicate that the method improves sample efficiency,task completion rate,grasping success rate and action efficiency compared to state-of-the-art end-to-end *** that the authors’system can be robustly applied to real-world use and extended to novel *** material is available at https://***/NhG\_k5v3NnM}{https://***/NhG\_k5v3NnM.

关键词： deep learning deep neural networks intelligent robots

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High-precision magnetic field measurement system based on a coherent population trapping magnetometer onboard the SATech-01 satellite

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science China(Technological sciences) 2025年第2期68卷 227-242页

作者： Hongbo XUE Wei SONG Haoran ZHAO Yiteng ZHANG Shanzhi YE Jindong WANG Ran TAO Peng SANG Keli CHEN Xingzi BI Bingjun CHENG Bin ZHOU Yongliang XUE Yingying TANG Liu LIU Jinsong LI Xiaocheng ZHU Baoquan LI Jinguo LIU Wen CHEN Xiaofeng ZHANG Yonghe ZHANG Lei LI State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Key Laboratory of Solar Activity and Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Key Laboratory of Electronics and Information Technology for Space Systems National Space Science CenterChinese Academy of SciencesBeijing 100190China State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Innovation Academy for Microsatellites Chinese Academy of SciencesShanghai 201304China

On July 27,2022,a high-precision system for measuring the magnetic field based on a coherent population trapping magnetometer(referred to as the CPT system)was launched onboard the Space Advanced technology demonstration satellite(SATech-01)by a ZK-1A *** payload comprises a scalar coherent population trapping magnetometer(CPTM),triaxial anisotropic magnetoresistance magnetometer(AMRM),and nano star tracker mounted on a non-magnetic telescopic tubular *** configuration enables synchronized measurement of scalar and vector geomagnetic fields,as well as the attitude,making the payload with its compact sensors suitable for applications on miniature satellite *** November 7,2022,the novel telescopic tubular mast was deployed in orbit,extending to a length of 5.28 *** CPTM,an absolute scalar magnetometer with an omnidirectional sensor,is the first China-developed quantum/atomic magnetometer successfully operating in *** orbit,the CPTM has sensitivity of~10 pT/Hz^(1/2) and can automatically operate under complex magnetic field *** difference between the scalar fields obtained using the CPTM and CHAOS model has a mean deviation of -3.73 nT and a standard deviation of 26.11 nT(1σ),without on-orbit calibration or *** miniaturized AMRM has a sensitivity of~0.3 nT/Hz^(1/2) and maintains stable and reliable operation in *** low-power and miniaturized nano star tracker has a measurement uncertainty of 14.23″(1σ)in *** mission has realized the on-orbit technical verification of the integrated and synchronized detection of the vector magnetic field and attitude and fully validated the system’s performance,automation level,and reliability.

关键词： magnetic field measurement system coherent population trapping magnetometer anisotropic magnetoresistance magnetometer nano star tracker non-magnetic telescopic tubular mast satellite

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Single-mode GaSb-based laterally coupled distributed-feedback laser for CO_(2)gas detection

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Chinese Physics B 2023年第10期32卷 443-447页

作者：韩实现严进一曹春芳杨锦杜安天陈元宇刘若涛王海龙龚谦 Key Laboratory of Terahertz Solid State Technology Shanghai Institute of Microsystem and Information TechnologyShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Shandong Provincial Key Laboratory of Laser Polarization and Information Technology School of Physics and Physical EngineeringQufu Normal UniversityQufu 273165China

We report on a GaSb-based laterally coupled distributed feedback(LC-DFB)laser with Cr gratings operating at 2004 nm for CO_(2)detection *** packaged with single-mode fiber pigtailed,the laser diode operates in the continuous-wave mode in a temperature range from-10℃to 60℃,with a maximum output power of 2 mW and a maximum side-mode suppression ratio over 30 ***-modulated absorption spectroscopy of CO_(2)demonstrates the applicability of the LC-DFB laser to tunable diode laser absorption ***,the diode junction temperature,which is measured by using the wavelength shift method,exhibits a maximum value of 17℃in the single-mode operation range.

关键词： semiconductor lasers quantum wells laser spectroscopy

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Sensitivity Improvements for Picosecond Ultrasonic Thickness Measurements in Gold and Tungsten Nanoscale Films

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Nanomanufacturing and Metrology 2024年第2期7卷 1-12页

作者： Jiaqi Dong Chengyuan Yao Yuanhao Zhu Shaojie Li Bowen Liu JinTao Fan Chunguang Hu Youjian Song Minglie Hu Key Laboratory of Opto-Electronic Information Science and Technology of Ministry of Education School of Precision Instruments and Opto-Electronics EngineeringTianjin UniversityTianjin 300072China State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Picosecond ultrasonics,as a nondestructive and noncontact method,can be employed for nanoscale metallic film thickness *** sensitivity of the system,which determines the measurement precision and practicability of this technique,is often limited by the weak intensity of the ultrasonic *** solve this problem,we investigate the distinct mechanisms involved in picosecond ultrasonic thickness measurement for two types of metals,namely tungsten(W)and gold(Au).For thickness measurement in W films,theory and simulation show that optimizing the pump and probe laser wavelengths,which determine the intensity and shape of the ultrasonic signal,is critical to improving measurement sensitivity,while for Au film measurements,where acoustic-induced beam distortion is dominant,the signal intensity can be optimized by selecting an appropriate aperture size and sample *** above approaches are validated in experiments.A dual-wavelength pump-probe system is constructed based on a passively mode-locked ytterbium-doped fiber *** smoothing method and multipeak Gaussian fitting are employed for the extraction of ultrasonic *** measurement precision is achieved in a series of W and Au films with thicknesses of 43-750 *** work can be applied to various high-precision,noncontact measurements of metal film thickness in the semiconductor industry.

关键词： Picosecond ultrasonics Thickness measurement Optical pump-probe Beam distortion technique

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Developing microwave-induced thermoacoustic tomography:System,application,and reconstruction

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Journal of Electronic science and technology 2023年第4期21卷 1-19页

作者： Shuang-Li Liu Wan-Ting Peng Xiao-Zhang Zhu Jian Song Xin Shang Hua Zhang Zhi-Qin Zhao School of Information Engineering Southwest University of Science and TechnologyMianyang621010China School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China Yunnan Key Laboratory of Computer Technologies Application Kunming University of Science and TechnologyKunming650500China

A microwave-induced thermoacoustic imaging(MITAT)system is a non-destructive physical medical imaging method that combines the advantages of the high contrast of microwave imaging and the high resolution of ultrasound *** uses the microwave as the excitation source and ultrasound as the information *** different kinds of biological tissue absorb electromagnetic energy,it results in localized temperature *** thermal expansion will induce ultrasonic signals(i.e.,thermoacoustic signals),known as the thermoacoustic *** microwave absorption image of the sample can be reconstructed by algorithm *** MITAT contrast depends on different dielectric parameters of different kinds of *** introduce the developed system and its *** addition,the challenges and prospects of MITAT for further development are discussed.

关键词： Application Microwave-induced thermoacoustic tomography(MITAT) Reconstruction System

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Quantum correlations in a chain-type quantum network

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Communications in Theoretical Physics 2024年第6期76卷 77-91页

作者： Xiaofei Qi Aihong Zhai Lihua Yang School of Mathematical Science Shanxi UniversityTaiyuan 030006China Key Laboratory of Complex Systems and Data Science of Ministry of Education Shanxi UniversityTaiyuan 030006China School of Mathematics and Information Technology Yuncheng UniversityYuncheng 044000China

A quantum network concerns several independent entangled resources and can create strong quantum correlations by performing joint measurements on some *** this paper,we discuss an n-partite chain network with each of two neighboring observers sharing an arbitrary Bell state and all intermediate observers performing some positive-operator-valued measurements with parameterλ.The expressions of all post-measurement states between any two observers are obtained,and their quantifications of Bell nonlocality,Einstein-Podolsky-Rosen steering and entanglement with different ranges ofλare respectively detected and analyzed.

关键词： quantum correlation nonlocality entanglement chain-type quantum network

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Outage Behaviors of Active Intelligent Reflecting Surface Enabled NOMA Communications

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Computer Modeling in engineering & sciences 2023年第10期137卷 789-812页

作者： Zhiping Lu Xinwei Yue Shuo Chen Weiguo Ma School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsState Key Laboratory of Wireless Mobile CommunicationsChina Academy of Telecommunications Technology(CATT)BeijingChina School of Information and Communication Engineering Beijing Information Science and Technology UniversityBeijing100101China

Active intelligent reflecting surface(IRS)is a novel and promising technology that is able to overcome the multiplicative fading introduced by passive *** this paper,we consider the application of active IRS to nonorthogonalmultiple access(NOMA)networks,where the incident signals are amplified actively through integrating amplifier to reflecting *** specifically,the performance of active/passive IRS-NOMA networks is investigated over large and small-scale fading *** to characterize the performance of active IRSNOMA networks,the exact and asymptotic expressions of outage probability for a couple of users,i.e.,near-end user n and far-end user m are derived by exploiting a 1-bit coding *** on approximated analyses,the diversity orders of user n and user m are obtained for active *** addition,the system throughput of active IRS-NOMA is discussed in the delay-sensitive *** simulation results are carried out to verify that:i)The outage behaviors of active IRS-NOMAnetworks are superior to that of passive IRS-NOMAnetworks;ii)As the reflection amplitude factors increase,the active IRS-NOMAnetworks are capable of furnishing the enhanced outage performance;and iii)The active IRS-NOMA has a larger system throughput than passive IRS-NOMA and conventional communications.

关键词： Active intelligent reflecting surface amplification noise non-orthogonal multiple access outage probability

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Effect of carbon material and surfactant on ink property and resulting surface cracks of fuel-cell microporous layers

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Chinese Journal of Chemical engineering 2024年第5期69卷 1-12页

作者： Zhekun Chen Weitong Pan Longfei Tang Xueli Chen Fuchen Wang Engineering Research Center of Resource Utilization of Carbon-containing Waste with Carbon Neutrality Ministry of EducationEast China University of Science and TechnologyShanghai 200237China Key Laboratory of Pressure Systems and Safety Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

Ensuring the consistency of electrode structure in proton-exchange-membrane fuel cells is highly desired yet challenging because of wide-existing and unguided cracks in the microporous layer(MPL). The first thing is to evaluate the homogeneity of MPL with cracks quantitatively. This paper proposes the homogeneity index of a full-scale MPL with an area of 50 cm~2, which is yet to be reported in the literature to our knowledge. Besides, the effects of the carbon material and surfactant on the ink and resulting MPL structure have been studied. The ink with a high network development degree produces an MPL with low crack density, but the ink with high PDI produces an MPL with low crack homogeneity. The polarity of the surfactant and the non-polarity of polytetrafluoroethylene(PTFE) are not mutually soluble,resulting in the heterogeneous PTFE distribution. The findings of this study provide guidelines for MPL fabrication.

关键词： Proton-exchange-membrane fuel cell Microporous layer Crack density Crack homogeneity Polytetrafluoroethylene distribution Surfactant

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Graph Convolutional Neural Network Based Emotion Recognition with Brain Functional Connectivity Network

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International Journal of Crowd science 2024年第4期8卷 195-204页

作者： Gao, Pengzhi Zheng, Xiangwei Wang, Tao Zhang, Yuang School of Information Science and Engineering Shandong Normal University Jinan250300 China State Key Laboratory of High-End Server & Storage Technology Jinan250300 China

Emotion recognition plays an important role in Human Computer Interaction (HCI) and the evaluation of human behavior based on emotional state is an important research topic. The purpose of emotion recognition is to automatically identify human’s emotional states by analyzing physiological or non-physiological signals. The conventional emotion classification methods cannot comprehensively leverage global and local features which are extracted from Electroencephalogram (EEG) signal generated after being stimulated. Therefore, we propose the graph convolutional neural network based emotion recognition with brain functional connectivity network (GERBN). Firstly, raw EEG data of the public DEAP and SEED datasets is preprocessed and adopted in this study. Secondly, emotion-related brain functional connection pattern is constructed using Phase-Locking Value (PLV) adjacency matrix to measure connectivity between the signals of different EEG channels according to phase synchronization. A novel graph structure is constructed where the EEG electrode channels are defined as the vertex, and the edge is strong connection of the binary brain network. Thirdly, the GERBN model that includes six layers is designed to classify and recognize emotional states on the two-dimensional emotional models of valence and arousal. Finally, extensive experiments are conducted on DEAP and SEED datasets. Experimental results demonstrate that the proposed method can improve classification accuracies, in which average accuracies of 80.43% and 88.47% on DEAP are attained on valence and arousal dimensions, respectively. On the SEED dataset, the accuracy reaches 92.37% higher than some of the other methods. © The author(s) 2024.

关键词： Electroencephalography

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