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Two-Dimensional DOA Estimation Using One-Dimensional Search for Spherical Arrays

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Chinese Journal of Electronics 2019年第6期28卷 1259-1264页

作者： HUANG Qinghua feng Jiajun fang Yong key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai University

A Reduced-dimensional spherical harmonics MUSIC(RD-SHMUSIC) is proposed to solve the problem of high computational complexity of Multiple signal classification(MUSIC) algorithm for Twodimensional(2-D) Direction of arrival(DOA) *** proposed algorithm first expresses the spherical harmonic steering vector as a linear weight of a uniform phase vectors. Via the Lagrange multiplier method, we can get a new search function to estimate elevations. At second step, the algorithm expresses the steering vector in another form, a linear weight of a vector which is constructed by associated Legendre functions. A search function to estimate azimuths can also be *** proposed method only needs One dimensional(1-D) angle search, which means it has a large reduction of computational complexity compared to the traditional Spherical harmonics MUSIC(SHMUSIC). The simulation results show that the accuracy of the proposed method is better than Two-stage decoupled approach(TSDA)algorithm, and has close performance to that of SHMUSIC.

关键词： Direction of arrival estimation Spherical arrays Reduced-dimensional spherical harmonics MUSIC Computational complexity

A low-frequency and broadband wave-insulating vibration isolator based on plate-shaped metastructures

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1171-1188页

作者： Wei WEI feng GUAN Xin fang College of Intelligent Science National University of Defense TechnologyChangsha410073China Naval Research Academy Beijing100161China

A metamaterial vibration isolator,termed as wave-insulating isolator,is proposed,which preserves enough load-bearing capability and offers ultra-low and broad bandgaps for greatly enhanced wave *** consists of plate-shaped metacells,whose symmetric and antisymmetric local resonant modes offer several low and broad mode bandgaps although the complete bandgap remains high and *** bandgap mechanisms,vibration isolation properties,effects of key parameters,and robustness to complex conditions are *** experimentally demonstrated,the wave-insulating isolator can improve the vibration insulation in the ranges of[50 Hz,180 Hz]and[260 Hz,400 Hz]by 15 dB and 25 dB,respectively,in contrast to the conventional isolator with the same first resonant frequency.

关键词： metamaterial and metastructure vibration isolation bandgap wave insulation plate

Adaptive Control of Accumulative Error for Nonlinear Chaotic Systems

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International Journal of Automation and computing 2014年第5期11卷 527-535页

作者： fang-fang Zhang Shu-Tang Liu ke-Xin Liu School of Electrical Engineering and Automation Qilu University of Technology College of Control Science and Engineering Shandong University

We present an adaptive control scheme of accumulative error to stabilize the unstable fixed point for chaotic systems which only satisfies local Lipschitz condition, and discuss how the convergence factor affects the convergence and the characteristics of the final control strength. We define a minimal local Lipschitz coefficient, which can enlarge the condition of chaos control. Compared with other adaptive methods, this control scheme is simple and easy to implement by integral circuits in practice. It is also robust against the effect of noise. These are illustrated with numerical examples.

关键词： Adaptive control accumulative error chaotic systems fixed point convergence Lipschitz coefficient

Harmonizing models and observations: Data assimilation in Earth system science

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Science China Earth Sciences 2020年第8期63卷 1059-1068页

作者： Xin LI feng LIU Miao fang National Tibetan Plateau Data Center Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China key Laboratory of Remote Sensing of Gansu Province Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Models and observations are two fundamental methodological approaches in Earth system science(ESS). They evolve collaboratively and enhance one another. However, neither of these two approaches is perfect, and they have incompatibilities due to their methodological differences. The emergence of data assimilation(DA) has enabled these two approaches to develop in conjunction and form a harmonic ESS methodology. As a result, DA has shown a fresh vitality and applicability in ESS. This paper reviews the application of DA in the main branches of ESS, traces the coordinated evolution of DA with the methodologies of rationalism and empiricism, analyzes the relationships of DA with estimation theory and cybernetics, summarizes the advances of DA in China, and presents an outlook on the challenges facing the development of a uniform DA for ESS. DA theories and methods will continue to evolve and provide an increasingly mature methodology for enhancing the understanding and prediction of Earth as a system.

关键词： Data assimilation Model Observation Earth system science Methodology Philosophy of science Synthesis

High Fe‑Loading Single‑Atom Catalyst Boosts ROS Production by Density Effect for Efficient Antibacterial Therapy

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Nano-Micro Letters 2025年第2期17卷 187-203页

作者： Si Chen fang Huang Lijie Mao Zhimin Zhang Han Lin Qixin Yan Xiangyu Lu Jianlin Shi Department of Cardiology Shanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghai 200092People’s Republic of China Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 200050People’s Republic of China Shanghai Frontiers Science Center of Nanocatalytic Medicine School of MedicineTongji UniversityShanghai 200092People’s Republic of China

The current single-atom catalysts(SACs)for medicine still suffer from the limited active site ***,we develop a synthetic method capable of increasing both the metal loading and mass-specific activity of SACs by exchanging zinc with *** constructed iron SACs(h^(3)-FNC)with a high metal loading of 6.27 wt%and an optimized adjacent Fe distance of~4 A exhibit excellent oxidase-like catalytic performance without significant activity decay after being stored for six months and promising antibacterial ***,a“density effect”has been found at a high-enough metal doping amount,at which individual active sites become close enough to interact with each other and alter the electronic structure,resulting in significantly boosted intrinsic activity of single-atomic iron sites in h^(3)-FNCs by 2.3 times compared to low-and medium-loading ***,the overall catalytic activity of h^(3)-FNC is highly improved,with mass activity and metal mass-specific activity that are,respectively,66 and 315 times higher than those of commercial Pt/*** addition,h^(3)-FNCs demonstrate efficiently enhanced capability in catalyzing oxygen reduction into superoxide anion(O_(2)·^(−))and glutathione(GSH)*** in vitro and in vivo assays demonstrate the superior antibacterial efficacy of h^(3)-FNCs in promoting wound *** work presents an intriguing activity-enhancement effect in catalysts and exhibits impressive therapeutic efficacy in combating bacterial infections.

关键词： Nanocatalytic medicine Single-atom catalysts Reactive oxygen species(ROS) High metal loading Oxidase catalysis

Optimal tool design in micro-milling of difficult-to-machine materials

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Advances in Manufacturing 2023年第2期11卷 222-247页

作者： Lorcan O'Toole feng-Zhou fang Centre of Micro/Nano Manufacturing Technology(MNMT-Dublin) University College DublinDublin 4Ireland State key Laboratory of Precision Measuring Technology and Instruments Laboratory of Micro/Nano Manufacturing Technology(MNMT)Tianjin UniversityTianjin300072People's Republic of China

The limitations of significant tool wear and tool breakage of commercially available fluted micro-end mill tools often lead to ineffective and inefficient manufacturing,while surface quality and geometric dimensions remain unacceptably *** is especially true for machining of difficult-to-machine(DTM)materials,such as super alloys and *** conventional fluted micro-tool designs are generally down scaled from the macro-milling tool ***,simply scaling such designs from the macro to micro domain leads to inherent design flaws,such as poor tool rigidity,poor tool strength and weak cutting edges,ultimately ending in tool ***,in this article a design process is first established to determine optimal micro-end mill tool designs for machining some typical DTM materials commonly used in manufacturing orthopaedic implants and micro-feature *** design process focuses on achieving robust stiffness and mechanical strength to reduce tool wear,avoid tool chipping and tool breakage in order to efficiently machine very hard ***,static stress and deflection finite element analysis(FEA)is carried out to identify stiffness and rigidity of the tool design in relation to the maximum deformations,as well as the Von Mises stress distribution at the cutting edge of the designed *** analysis and further optimisation of the FEA results,a verified optimum tool design is established for micro-milling DTM *** experimental study is then carried out to compare the optimum tool design to commercial tools,in regards to cutting forces,tool wear and surface quality.

关键词： Precision machining Micro-milling Difficult-to-machine(DTM) Tool wear Micro-tool design Surface quality

Effect of back pressure on the grinding performance of abrasive suspension flow machining

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Advances in Manufacturing 2022年第1期10卷 143-157页

作者： Ming-Hui fang Tao Yu feng-feng Xi Department of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200444People’s Republic of China Shanghai University of Engineering Science Shanghai 201620People’s Republic of China Department of Aerospace Engineering Ryerson UniversityTorontoCanada

Abrasive suspension flow machining(ASFM)is an advanced finishing method that uses an abrasive suspension slurry for grinding and chamfering as well as the finishing of inaccessible *** study examines the effect of back pressure on the grinding characteristics of an abrasive suspension flow during the grinding of slender holes.A numerical model was developed to simulate the abrasive suspension flow in a slender hole and was verified experimentally using injector nozzle grinding equipment under different grinding pressures and back *** is shown that the ASFM with back pressure not only eliminates the cavitation flow in the spray hole,but also increases the number of effective abrasive particles and the flow *** the back pressure during the grinding process can increase the Reynolds number of the abrasive suspension flow and reduce the thickness of the boundary layer in the slender ***,increasing the back pressure can improve the flow rate of the injector nozzle and its grinding performance.

关键词： Abrasive suspension flow machining(ASFM)Back pressure Injector nozzle Grinding performance

习近平关于新质生产力重要论述的理论体系和实践指向研究

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新疆师范大学学报（哲学社会科学版） 2025年第1期46卷 60-68页

作者：方世南苏州大学东吴智库苏州大学马克思主义学院江苏省习近平新时代中国特色社会主义思想研究中心苏州大学基地江苏苏州215006

习近平总书记关于新质生产力重要论述深刻阐明了新质生产力的基本内涵、本质特征、鲜明标志、核心要素、形成规律以及实现路径等重大理论和实践问题,是具有重大原创性、标识性、系统性、实践性的理论创新成果,是习近平新时代中国特色社... 详细信息

习近平总书记关于新质生产力重要论述深刻阐明了新质生产力的基本内涵、本质特征、鲜明标志、核心要素、形成规律以及实现路径等重大理论和实践问题,是具有重大原创性、标识性、系统性、实践性的理论创新成果,是习近平新时代中国特色社会主义思想的重要组成部分。习近平总书记关于新质生产力重要论述是在推进中国式现代化进程中形成的新的生产力理论,是指导我国经济社会高质量发展的学理化、体系化的理论体系,是具有深邃而丰富辩证法则的实践指向。

关键词：中国式现代化新质生产力重要论述理论体系实践指向

Effects of Inlet Circumferential Fluctuation on the Sweep Aerodynamic Performance of Axial Fans/Compressors

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Journal of Thermal Science 2013年第5期22卷 383-394页

作者： Xingmin Gui fang Zhu ke Wan Donghai Jin Aero-Engine Simulation Research Center Beijing University of Aeronautics and Astronautics

Swept blades have been widely used in the transonic fan/compressor of aircraft engines with the aids of 3D CFD simulation since the design concept of controlling the shock structure was firstly proposed and successfully tested by *** in the ***,some disadvantage phenomenon has also been induced by excessively 3D blade geometries on the structure stress insufficiency,vibration and *** confusion in the procedure of design practice leading us to recognize a new view on the flow mechanism of sweep aerodynamical induction: the new radial equilibrium established by the influence of inlet circumferential fluctuation(CF) changes the inlet flows of blading and induces the performance modification of axial fans/compressors *** view is verified by simplified models through numerical simulation and circumferentially averaged analysis in the present *** results show that the CF source items which originate from design parameters,such as the spanwise distributions of the loading and blading geometries,contribute to the changing of averaged incidence spanwise distribution,and further more affect the performance of axial fans/compressors with swept blades.

关键词： turbomachinery fans/compressors sweep aerodynamics quasi-3D method 3D flow