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A Rayleigh Wave Globally Optimal Full Waveform Inversion Framework Based on GPU Parallel Computing

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Journal of Geoscience and Environment Protection 2023年第3期11卷 327-338页

作者： Zhao Le Wei Zhang Xin Rong Yiming Wang Wentao Jin zhengxuan cao School of Geophysics and Geomatics China University of Geosciences Wuhan China Wuhan Geo-Detection Technology Co. Ltd. Wuhan China Zhejiang Design Institute of Water Conservancy & Hydro-Electric Power Co. Ltd. Hangzhou China

Conventional gradient-based full waveform inversion (FWI) is a local optimization, which is highly dependent on the initial model and prone to trapping in local minima. Globally optimal FWI that can overcome this limitation is particularly attractive, but is currently limited by the huge amount of calculation. In this paper, we propose a globally optimal FWI framework based on GPU parallel computing, which greatly improves the efficiency, and is expected to make globally optimal FWI more widely used. In this framework, we simplify and recombine the model parameters, and optimize the model iteratively. Each iteration contains hundreds of individuals, each individual is independent of the other, and each individual contains forward modeling and cost function calculation. The framework is suitable for a variety of globally optimal algorithms, and we test the framework with particle swarm optimization algorithm for example. Both the synthetic and field examples achieve good results, indicating the effectiveness of the framework. .

关键词： Full Waveform Inversion Finite-Difference Method Globally Optimal Framework GPU Parallel Computing Particle Swarm Optimization

High-energy-density plasma in femtosecond-laser-irradiated nanowire-array targets for nuclear reactions

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Matter and Radiation at Extremes 2022年第6期7卷 29-40页

作者： Defeng Kong Guoqiang Zhang Yinren Shou Shirui Xu Zhusong Mei zhengxuan cao Zhuo Pan Pengjie Wang Guijun Qi Yao Lou Zhiguo Ma Haoyang Lan Wenzhao Wang Yunhui Li Peter Rubovic Martin Veselsky Aldo Bonasera Jiarui Zhao Yixing Geng Yanying Zhao Changbo Fu Wen Luo Yugang Ma Xueqing Yan Wenjun Ma State Key Laboratory of Nuclear Physics and Technology and Key Laboratory of HEDP of the Ministry of EducationCAPTSchool of PhysicsPeking UniversityBeijing 100871China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China Key Laboratory of Nuclear Physics and Ion-Beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China School of Nuclear Science and Technology University of South ChinaHengyang 421001China INPAC and School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518055China Institute of Experimental and Applied Physics Czech Technical University in PragueHusova 240/511000 Prague 1Czech Republic ELI Beamlines Center Institute of Physics of the Czech Academy of Sciences25241 DolníBrezanyCzechia Cyclotron Institute Texas A&M UniversityCollege StationTexas 77843USA Laboratori Nazionali del Sud INFNvia Santa Sofia62Catania 95123Italy Beijing Laser Acceleration Innovation Center HuairouBeijing 101400China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuanShanxi 030006China

In this work,the high-energy-density plasmas(HEDP)evolved from joule-class-femtosecond-laser-irradiated nanowire-array(NWA)targets were numerically and experimentally *** results of particle-in-cell simulations indicate that ions accelerated in the sheath field around the surfaces of the nanowires are eventually confined in a plasma,contributing most to the high energy *** protons emitted from the front surfaces of the NWA targets provide rich information about the interactions that *** give the electron and ion energy densities for broad target parameter *** ion energy densities from NWA targets were found to be an order of magnitude higher than those from planar targets,and the volume of the HEDP was several-fold *** optimal target parameters,8%of the laser energy can be converted to confined protons,and this results in ion energy densities at the GJ/cm^(3) *** the experiments,the measured energy of the emitted protons reached 4 MeV,and the changes in energy with the NWA’s parameters were found to fit the simulation results *** measurements of neutrons from 2H(d,n)3He fusion with a yield of(24±18)×10^(6)/J from deuterated polyethylene NWA targets also confirmed these results.

关键词： irradiated confined eventually

Laser-induced damage thresholds of ultrathin targets and their constraint on laser contrast in laser-driven ion acceleration experiments

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High Power Laser Science and Engineering 2020年第4期8卷 91-97页

作者： Dahui Wang Yinren Shou Pengjie Wang Jianbo Liu Zhusong Mei zhengxuan cao Jianmin Zhang Pengling Yang Guobin Feng Shiyou Chen Yanying Zhao Joerg Schreiber Wenjun Ma State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China State Key Laborartory of Laser Interaction with Matter Northwest Institute of Nuclear TechnologyXi’an 710024China FakultatfurPhysik Ludwig-Maximilians-UniversityD-85748 GarchingGermany

Single-shot laser-induced damage threshold(LIDT)measurements of multi-type free-standing ultrathin foils were performed in a vacuum environment for 800 nm laser pulses with durationsτranging from 50 fs to 200 *** results show that the laser damage threshold fluences(DTFs)of the ultrathin foils are significantly lower than those of corresponding bulk *** band gap dielectric targets such as SiN and formvar have larger DTFs than semiconductive and conductive targets by 1–3 orders of magnitude depending on the pulse *** damage mechanisms for different types of targets are *** on the measurement,the constrain of the LIDTs on the laser contrast is discussed.

关键词： laser-induced damage threshold ultrathin targets laser-driven ion acceleration

Fabrication of large-area uniform carbon nanotube foams as near-critical-density targets for laser–plasma experiments

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High Power Laser Science and Engineering 2021年第2期9卷 209-214页

作者： Pengjie Wang Guijun Qi Zhuo Pan Defeng Kong Yinren Shou Jianbo Liu zhengxuan cao Zhusong Mei Shirui Xu Zhipeng Liu Shiyou Chen Ying Gao Jiarui Zhao Wenjun Ma State Key Laboratory of Nuclear Physics and Technology Center for Applied Physics and TechnologySchool of PhysicsPeking UniversityBeijing 100871China Beijing Laser Acceleration Innovation Center Beijing 101400China Institute of Guangdong Laser Plasma Technology Guangzhou 510540China

Carbon nanotube foams(CNFs)have been successfully used as near-critical-density targets in the laser-driven acceleration of high-energy ions and *** we report the recent advances in the fabrication technique of such *** the further developed floating catalyst chemical vapor deposition(FCCVD)method,large-area(>25 cm^(2))and highly uniform CNFs are successfully deposited on nanometer-thin metal or plastic foils as double-layer *** density and thickness of the CNF can be controlled in the range of 1−13 mg/cm^(3)and 10−200µm,respectively,by varying the synthesis *** dependence of the target properties on the synthesis parameters and the details of the target characterization methods are presented for the first time.

关键词： carbon nanotube foams laser-driven acceleration near-critical density targets ultraintense laser

Quantitative phase imaging based on holography:trends and new perspectives

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Light(Science & Applications) 2024年第7期13卷 1235-1277页

作者： Zhengzhong Huang Liangcai cao Department of Precision Instrument Tsinghua UniversityBeijing 100084China

In 1948,Dennis Gabor proposed the concept of holography,providing a pioneering solution to a quantitative description of the optical *** 75 years of development,holographic imaging has become a powerful tool for optical wavefront measurement and quantitative phase *** emergence of this technology has given fresh energy to physics,biology,and materials *** holography(DH)possesses the quantitative advantages of wide-field,non-contact,precise,and dynamic measurement capability for *** has unique capabilities for the propagation of optical fields by measuring light scattering with phase *** offers quantitative visualization of the refractive index and thickness distribution of weak absorption samples,which plays a vital role in the pathophysiology of various diseases and the characterization of various *** provides a possibility to bridge the gap between the imaging and scattering *** propagation of wavefront is described by the complex *** complex-value in the complex-domain is reconstructed from the intensityvalue measurement by camera in the ***,we regard the process of holographic recording and reconstruction as a transformation between complex-domain and real-domain,and discuss the mathematics and physical principles of *** review the DH in underlying principles,technical approaches,and the breadth of *** conclude with emerging challenges and opportunities based on combining holographic imaging with other methodologies that expand the scope and utility of holographic imaging even *** multidisciplinary nature brings technology and application experts together in label-free cell biology,analytical chemistry,clinical sciences,wavefront sensing,and semiconductor production.

关键词： holographic phase precise

Dynamic Setting Method of Assessment Indicators for Power Curves of Renewable Energy Sources Considering Scarcity of Reserve Resources

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 101-114页

作者： Minghao cao Jilai Yu the Department of Electrical Engineering Harbin Institute of TechnologyHarbinChina

With the increasing proportion of renewable energy sources(RESs)in power grid,the reserve resource(RR)scarcity for correcting power deviation of RESs has become a potential ***,the power curve of RES needs to be more rigorously *** RR scarcity varies during different time periods,so the values of assessment indicators should be dynamically *** assessment indicators in this paper include two aspects,i.e.,deviation exemption ratio and penalty ***,this paper proposes a method for dynamically calculating the supply capacity and RR cost,primarily taking into account the operating status of thermal units,forecast information of RES,and load ***,after clarifying the logical relationship between the degree of RR scarcity and the values of assessment indicators,this paper establishes a mapping function between *** on this mapping function,a dynamic setting method for assessment indicators is *** the future,RES will generally be equipped with battery energy storage systems(BESSs).Reasonably utilizing BESSs to reduce the power deviation of RESs can increase the expected income of ***,this paper proposes a power curve optimization strategy for RESs considering self-owned *** case study demonstrates that the dynamic setting method of assessment indicators can increase the revenue of RESs while ensuring that the penalty fees paid by RESs to the grid are sufficient to cover the RR ***,the power curve optimization strategy can help RESs further increase income and fully utilize BESSs to reduce power deviation.

关键词： Renewable energy battery energy storage system(BESS) power curve assessment reserve service parameter setting

Zeros of Complete Symmetric Polynomials over Finite Fields

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Journal of Systems Science & Complexity 2024年第4期37卷 1772-1788页

作者： cao Wei School of Mathematics and Statistics Minnan Normal UniversityZhangzhou 363000China

Wan and Zhang(2021) obtained a nontrivial lower bound for the number of zeros of complete symmetric polynomials over finite fields,and proposed a problem whether their bound can be *** this paper,the author improves Wan-Zhang's bound from three *** proposed results are based on the estimates related to the number of certain permutations and the value sets of non-permutation polynomials associated to the complete symmetric *** the author believes that there are still possibilities to improve the bounds and hence Wan-Zhang's bound.

关键词： Complete symmetric polynomial finite field permutation polynomial value set

Bioinspired Closed-loop CPG-based Control of a Robotic Manta for Autonomous Swimming

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Journal of Bionic Engineering 2024年第1期21卷 177-191页

作者： Yiwei Hao Yonghui cao Yingzhuo cao Xiong Mo Qiaogao Huang Lei Gong Guang Pan Yong cao School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China Unmanned Vehicle Innovation Center Ningbo Institute of NPUNingbo 315103China Key Laboratory of Unmanned Underwater Vehicle Technology of Ministry of Industry and Information Technology Xi'an 710072China

Fish in nature exhibit a variety of swimming modes such as forward swimming,backward swimming,turning,pitching,etc.,enabling them to swim in complex scenes such as coral *** is still difficult for a robotic fish to swim autonomously in a confined area as a real ***,we develop an untethered robotic manta as an experimental platform,which consists of two flexible pectoral fins and a tail fin,with three infrared sensors installed on the front,left,and right sides of the head to sense the surrounding *** generate multiple swimming modes of the robotic manta and online switching of different modes,we design a closed-loop Central Pattern Generator(CPG)controller based on distance information and use a combination of phase difference and amplitude of the CPG model to achieve stable and rapid adjustment of yaw *** verify the autonomous swimming ability of the robotic manta in complex scenes,we design an experimental scenario with a concave *** experimental results show that the robotic manta can achieve forward swimming,backward swimming,in situ turning within the concave obstacle,and finally exit from the area safely while relying on the perception of external obstacles,which can provide insight into the autonomous exploration of complex scenes by the biomimetic robotic ***,the swimming ability of the robotic manta is verified by field tests.

关键词： Biomimetic robotic manta Central Pattern Generator Closed-loop control Backward swimming

Multi-scenario land use prediction and layout optimization in Nanjing Metropolitan Area based on the PLUS model

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Journal of Geographical Sciences 2024年第7期34卷 1415-1436页

作者： cao Ji cao Weidong cao Yuhong WANG Xuewei ZHANG Yizhen MA Jinji School of Geography and Tourism Anhui Normal UniversityWuhuAnhui241002China School of Ecology and Environment Anhui Normal UniversityWuhuAnhui241002China

The metropolitan area is a crucial spatial element in promoting new urbanization in *** possesses theoretical and empirical value in the determination of the evolutionary patterns and development trends necessary for regional integration and high-quality *** study focused on Nanjing Metropolitan Area,the first national metropolitan area in China,and established three development scenarios by combining ecological–economic spatial conflict(EESC)zones and national key ecological functional *** scenarios simulate the spatial distribution of future land use and land cover change(LUCC)using the development zone planning function of the patch generation land use simulation(PLUS)*** results show that:(1)Between 2000 and 2020,the most prominent characteristics of land use change were largely the massive expansion of built-up land and the significant decline of farmland,while changes in the area of ecological land were less evident.(2)EESC areas experienced significant changes over the past 20 years,but the overall level of conflict was *** land was the main land use type in the lowest-conflict area,while built-up land was the main land use type in the highest-conflict area.(3)From 2030 to 2050,further expansion of built-up areas is expected,with continued decrease of *** regulation of these land use changes can be achieved through different development zone *** economic development scenario had the largest built-up land area,while the ecological protection scenario had the largest farmland *** study simulates the spatial pattern changes in the metropolitan area based on spatial conflict patterns and national main functional area planning process,providing a scientific reference for future spatial planning and management.

关键词： land use change spatial conflict patch-generating simulation land use prediction Nanjing Metropolitan Area