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Entropy evolution law of general quadratic state in a laser channel

Frontiers of physics 2025年第2期20卷 169-175页

作者： Xiang-Guo Meng Bao-Long Liang Jian-Ming Liu Xu-Cong Zhou School of Basic Medical Sciences Shandong Second Medical UniversityWeifang 261053China Shandong Provincial Key Laboratory of Optical Communication Science and Technology School of Physical Science and Information EngineeringLiaocheng UniversityLiaocheng 252059China

Using the integration within ordered products,we obtain the analytical density-operator evolution of the general quadratic state ρ_(0)in a laser channel,which always maintains the same form as the initial density operator ρ_(0).Introducing the differential representation of the von-Neumann entropy and two important resemble formulas,we analytically and numerically investigate the entropy evolution of the state ρ_(0)in a laser channel,which is determined by not only the competition of the gain and loss of the laser channel,but also the coefficients α,β of the initial quadratic state.

关键词： general quadratic state laser channel quantum entropy operator ordering integration within ordered product

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From single- to multi-modal remote sensing imagery interpretation: a survey and taxonomy

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science China(information sciences) 2023年第4期66卷 5-32页

作者： Xian SUN Yu TIAN Wanxuan LU Peijin WANG Ruigang NIU Hongfeng YU Kun FU Aerospace Information Research Institute Chinese Academy of Sciences Key Laboratory of Network Information System Technology(NIST) Aerospace Information Research Institute Chinese Academy of Sciences University of Chinese Academy of Sciences School of Electronic Electrical and Communication Engineering University of Chinese Academy of Sciences

Modality is a source or form of information. Through various modal information, humans can perceive the world from multiple perspectives. Simultaneously, the observation of remote sensing(RS) is multimodal. We observe the world macroscopically through panchromatic, Lidar, and other modal *** observation of remote sensing has become an active area, which is beneficial for urban planning,monitoring, and other applications. Despite numerous advancements in this area, there has still not been a comprehensive assessment that provides a systematic overview with a unified evaluation. Accordingly, in this survey paper, we first highlight the key differences between single-and multimodal RS imagery interpretation,then use these differences to guide our research survey of multimodal RS imagery interpretation in a cascaded structure. Finally, some potential future research directions are explored and outlined. We hope that this survey will serve as a starting point for researchers to review state-of-the-art developments and work on multimodal research.

关键词： multimodal remote sensing image interpretation feature fusion co-learning

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Transmission of orbital angular momentum modes in Angular Symmetry Fibers

Transmission of orbital angular momentum modes in Angular Sy...

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2024 Asia Communications and Photonics Conference, ACP 2024 and International Conference on information Photonics and Optical Communications, IPOC 2024

作者： Qin, Suwan Rao, Xiongfeng Yang, Li Department of Electronic Engineering and Information Science University of Science and Technology of China Key Laboratory of Electromagnetic Space Information Chinese Academy of Science Hefei China

We propose an angular symmetry fiber and demonstrate its capability for the transmission of optical orbital angular momentum modes by using numerical analysis based on finite element method. © 2024 IEEE.

ISBN: (纸本)9798350379266

关键词： Optical fibers

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Photonics-assisted intensity-modulation and direct-detection MIMO millimeter-wave system in the D-band

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Chinese Optics Letters 2025年第1期23卷 7-12页

作者： Jingwen Tan Peng Tian Jianjun Yu Xianming Zhao Xinglin Dou Long Zhang Xiongwei Yang YangHan Yi Wei Bing Zhang Qinyi Zhang Luhan Jiang Weiping Li Rahim Uddin Kaihui Wang Wen Zhou State Key Laboratory of ASIC and System Key Laboratory for Information Science of Electromagnetic Waves(MoE)School of Information Science and TechnologyFudan UniversityShanghai 200433China Beijing Hongshan Information Technology Research Institute Co. Ltd.Beijing 100176China

We experimentally demonstrate the transmission of discrete multi-tone(DMT)millimeter-wave(mm-wave)signals over a 1.2-km distance at the D-band(110–170 GHz)in a cost-effective intensity-modulation and direct-detection(IM/DD)communication *** the experiment,we successfully achieve the transmission of DMT-QPSK and DMT-16QAM mm-wave signals over multiple-input multiple-output(MIMO)*** the 1.2-km free-space transmission,the bit error rate(BER)of the DMT-16QAM is below the 25%soft decision forward error correction(25%SD-FEC)threshold of 4×10-2,with a maximum net bit rate of 24.62 Gbit/s achieved in this system.

关键词： D-band discrete multi-tone intensity modulation and direct detection long-distance wireless transmission photonics-assisted technique

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Cooperative Optimization Method of UAV Swarm for Multi-objective High-Precision Location 5th

Cooperative Optimization Method of UAV Swarm for Multi-objec...

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5th Chinese Conference on Swarm Intelligence and Cooperative Control, CCSICC 2021

作者： Li, Bowen Ji, Xiaoting Huang, Yuanling School of Information System Engineering Information Engineering University Zhengzhou450001 China National Key Laboratory of Science and Technology on Blind Signal Processing Chengdu610041 China

ISBN: (纸本)9789811939976

In the field of electromagnetic radiation source location, using UAVs to locate the radiation source target has become a new location method. At present, the UAV swarm cooperative optimization method for high-precision location has some challenges, such as insufficient ability of multi-objective high-precision location, poor timeliness and so on. To solve these problems, this paper proposes a cooperative optimization method of UAV swarm for multi-objective location. Firstly, the multi-objective joint location accuracy is derived, which is taken as the objective function of swarm cooperative optimization. Secondly, in order to allocate multiple UAVs to multiple targets efficiently, the initialization strategy based on target isolation and the random allocation method of UAV based on probability are proposed. Finally, by combining the above improved strategies, an optimization method of UAV swarm cooperative location is proposed. Through the analysis of experimental results, the cooperative optimization method in this paper has obvious advantages in global optimization and convergence ability, which can improve the joint location accuracy and optimization speed. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Unmanned aerial vehicles (UAV)

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PERIODIC STATISTICAL ANALYSIS OF GAIT PHASE SEGMENTATION 10

PERIODIC STATISTICAL ANALYSIS OF GAIT PHASE SEGMENTATION

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10th International Symposium on Test Automation and Instrumentation, ISTAI 2024

作者： Fu, Mingkai Wang, Shaohong Ma, Chao Key Laboratory of Modern Measurement and Control Technology Ministry of Edu. Beijing Information Science and Technology Beijing China Beijing Key Lab of Measurement and Control of Mechanical and Electrical System Beijing Information Science and Technology Beijing China

ISBN: (纸本)9781837242672

In order to achieve accurate segmentation of gait phases for precise real-time control of lower limb exoskeleton robots, the periodic statistical analysis of human motion posture by using the inertial measurement unit is conducted. In current research, the data of forward and turning gait types were acquired and every gait type data were devised into eight for different gait phase segmentation. During the process, the phase division values for different types of subjects were calculated and the phase division of different subjects with the same gait type was calculated. The standard deviations for different gaits and phases for the same experimenter are all below 10, primarily oscillated around 4. For gait data from different subjects, the percentages at the same phase are all below 3. The results showed that the results from the feasible method could better accord with the characteristics of each stage of actual *** those results could provide reference for real-time judgment of gait phase and technical support for intelligent control of lower limb exoskeletons. © The Institution of engineering & technology 2024.

关键词： Exoskeleton (Robotics)

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Nonlocal inverse design of an ultrasonic lens for underwater manipulation of orbital angular momentum

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Physical Review Applied 2024年第2期22卷 024070页

作者： Chuanxin Zhang Fei Dai Xue Jiang Dean Ta Department of Biomedical Engineering School of Information Science and Technology State Key Laboratory of Integrated Chips and System

Acoustic orbital angular momentum (OAM) beams hold potential for underwater communications, particle manipulation, and biomedical applications. However, adapting air-based OAM technologies to the underwater environment presents unique challenges. In the underwater environment, the medium cannot be considered acoustically soft, and commonly used ultrasound frequencies have shorter wavelengths compared with air, necessitating new design approaches. Conventional underwater ultrasonic lens design methods often rely on simplified models that neglect nonlocal interactions and diffraction within the structure, therefore leading to suboptimal performance. We introduce a novel nonlocal inverse design method by integrating the full-wave models with the nondominated sorting genetic algorithm II (NSGA-II). This approach diverges from conventional phase-based design by optimizing the physical structure of the lens to account for nonlocal interactions within the material. We experimentally demonstrate the performance when generating high-purity OAM beams underwater. Our experimental results show that this method can generate high-purity OAM beams underwater, achieving over 90% purity for the OAM beams of topological charges from m = 1 to m = 4. This is a significant improvement compared with traditional methods, which typically reach 70–89% purity. These findings highlight the practical applicability of our method for nonlocally designing the ultrasonic lens, paving the way for advancements in beam performance for various applications.

关键词： Acoustic wave phenomena Inverse problems Ultrasonics Underwater acoustics Acoustic metamaterials Lenses Angular momentum Ultrasound techniques

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Density waves of vortex fluids on a sphere

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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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Regularized automatic frequency response function acquisition of a milling robot operating in a high-dimensional workspace

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science China(Technological sciences) 2024年第6期67卷 1783-1797页

作者： LUO WenLong TANG XiaoWei MA Tao GUO QiuShuang XU YanYan YUAN Xing ZHANG Lei MAO XinYong School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan430074China State Key Laboratory of Smart Manufacturing for Special Vehicles and Transmission System Baotou014030China Wuhan Heavy Duty Machine Tool Group Corporation Wuhan430205China

Because robotic milling has become an important means for machining significant large parts,obtaining the structural frequency response function(FRF)of a milling robot is an important basis for machining process ***,because of its articulated serial structure,a milling robot has an enormous number of operating postures,and its dynamics are affected by the motion *** accurately obtain the FRF in the operating state of a milling robot,this paper proposes a method based on the structural modification *** the traditional excitation method,the proposed method uses robot joint motion excitation instead of hammering excitation to realize *** address the problem of the lack of information brought by motion excitation,which leads to inaccurate FRF amplitudes,this paper derives the milling robot regularization theory based on the sensitivity of structural modification,establishes the modal regularization factor,and calibrates the FRF *** to the commonly used manual hammering experiments,the proposed method has high accuracy and reliability when the milling robot is in different *** the measurement can be performed directly and automatically in the operation state,and the problem of inaccurate amplitudes is solved,the proposed method provides a basis for optimizing the machining posture of a milling robot and improving machining efficiency.

关键词： milling robot structural dynamics frequency response function automatic identification modal regularization factor high-dimensional workspace

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Evaluating coarse PM composition and sources based on bulk and molecular speciation of PM2.5 and PM10 in Nanjing, East China

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Journal of Environmental sciences 2025年第6期152卷 155-166页

作者： Wangnan Cui Zishu Wang Wei Feng Chao Qin Hong Liao Yuhang Wang Mingjie Xie Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution ControlSchool of Environmental Science and EngineeringNanjing University of Information Science&TechnologyNanjing 210044China Nuist Reading Academy Nanjing University of Information Science&TechnologyNanjing 210044China State Environmental Protection Key Laboratory of Monitoring and Analysis for Organic Pollutants in Surface Water Jiangsu Environmental Monitoring CenterNanjing 210036China School of Earth and Atmospheric Sciences Georgia Institute of TechnologyAtlanta GA 30332United States

To understand the differences in the composition and sources of PM_(2.5) and PM_(10) caused by coarse particles,integrated PM_(2.5) and PM_(10) samples were synchronously collected in Nanjing,East China,in summer 2020 and winter 2020/*** and molecular speciation and light absorption measurements of aerosol extractswere performed,followed by positivematrix factorization(PMF)based on the PM_(2.5) and PM_(10) data sets,*** difference in average concentrations of total bulk species between PM_(2.5) and PM_(10) was mainly caused by the distribution of considerable NO_(3)^(–),SO42–,Ca^(2+),and organic carbon(OC)in coarse *** PMinfluenced by abrasion products from tirewear and leaves contributed about half of the low-volatility n-alkanes in *** contribution of coarse PM to biomass burning tracers and water-soluble OC increased in winter when biomass combustion was excessively *** than 70%of sugar polyols were attributable to coarse PM in summer,and biomass burning could be an important source in *** light-absorbing organic chromophores were almost entirely associated with PM_(2.5),but water-soluble organic carbon(WSOC)exhibited stronger light absorption in PM_(10) extracts than in PM_(2.5) extracts possibly due to the influence of coarse PMon *** analysis indicated that biomass burning,aqueous-phase reactions,and processed dust were the main contributors of organic matter and its light absorption in *** primary and secondary sources made discernable contributions only in *** differences between PM_(2.5) and PM_(10) were likely attributed to mixing of crustal dust,combustion particles,and surface reactions.

关键词： Coarse particle Bulk species Organic molecular marker Light absorption Source apportionment

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