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Non-intrusive reduced-order model for predicting transonic flow with varying geometries

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Chinese Journal of Aeronautics 2020年第2期33卷 508-519页

作者： Zhiwei SUN Chen WANG yu ZHENG Junqiang BAI Zheng LI Qiang xia Qiujun fu Research Institute of Unmanned Aerial Vehicle Northwestern Polytechnical UniversityXi’an 710072China Science and Technology on Space Physics Laboratory Beijing 100076China

A Non-Intrusive Reduced-Order Model(NIROM)based on Proper Orthogonal Decomposition(POD)has been proposed for predicting the flow fields of transonic airfoils with geometry *** provide a better reduced-order subspace to approximate the real flow field,a domain decomposition method has been used to separate the hard-to-predict regions from the full field and POD has been adopted in the regions *** Artificial Neural Network(ANN)has replaced the Radial Basis function(RBF)to interpolate the coefficients of the POD modes,aiming at improving the approximation accuracy of the NIROM for *** predicting the flow fields of transonic airfoils,the proposed NIROM has demonstrated a high performance.

关键词： Artificial Neural Network Domain decomposition Geometric parameters Non-Intrusive Reduced-Order Model Proper Orthogonal Decomposition Transonic flow

Metal-to-insulator transition in platinum group compounds

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Rare Metals 2024年第8期43卷 3460-3474页

作者： yu-Xuan xia Jian-Gang He Nuo-fu Chen Ji-Kun Chen School of New Energy North China Electric Power UniversityBeijing102206China School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China Key Laboratory of Advanced Materials and Devices for PostMoore Chips(Ministry of Education) School of Materials Science and EngineeringJniversity of Science and Technology BeijingBeijing 100083China

The metal-to-insulator transition(MIT) as usually achieved in 3d-orbital transitional metal(TM) compounds opens up a new paradigm in correlated electronics via triggering abrupt variations in their transportation *** to such 3d-orbital TM compounds,the MIT within the platinum group(Pg) element compounds based on the 4d-and 5d-orbital configurations is more complicated,owing to their elevation in the spinorbit coupling and meanwhile weakened intra-atomic Coulomb *** brings in a new freedom to regulate the balance in their metallic or semiconductive orbital configurations,while their MIT properties can be potentially combined with their spintronic properties to enable new electronic ***,we review the electronic transport and MIT behaviors within the existing family of Pg-containing compounds,particularly those showing first-order MIT behaviors that can be useful in correlated *** is also hoped that summarizing the presently reported Pg-containing MIT compounds will lead to the discovery of more new material families and/or new mechanisms associated with the Pg-containing compounds showing MIT properties.

关键词： Metal-to-insulator transition Platinum group compounds Electron correlation Spin-orbital coupling

A particle-resolved heat-particle-fluid coupling model by DEM-IMB-LBM

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2267-2281页

作者： Ming xia Jinlong fu Y.T.Feng Fengqiang Gong Jin yu Hunan Key Laboratory of Geomechanics and Engineering Safety Xiangtan UniversityXiangtan411105China Zienkiewicz Institute for Modelling Data and AISwansea UniversitySwanseaSA18EPUK School of Civil Engineering Southeast UniversityNanjing211189China fujian Research Center for Tunneling and Urban Underground Space Engineering Huaqiao UniversityXiamen361021China

Multifield coupling is frequently encountered and also an active area of research in geotechnical *** this work,a particle-resolved direct numerical simulation(PR-DNS)technique is extended to simulate particle-fluid interaction problems involving heat transfer at the grain *** this extended technique,an immersed moving boundary(IMB)scheme is used to couple the discrete element method(DEM)and lattice Boltzmann method(LBM),while a recently proposed Dirichlet-type thermal boundary condition is also adapted to account for heat transfer between fluid phase and solid *** resulting DEM-IBM-LBM model is robust to simulate moving curved boundaries with constant temperature in thermal *** facilitate the understanding and implementation of this coupled model for non-isothermal problems,a complete list is given for the conversion of relevant physical variables to lattice ***,benchmark tests,including a single-particle sedimentation and a two-particle drafting-kissing-tumbling(DKT)simulation with heat transfer,are carried out to validate the accuracy of our coupled *** further investigate the role of heat transfer in particle-laden flows,two multiple-particle problems with heat transfer are *** examples demonstrate that the proposed coupling model is a promising high-resolution approach for simulating the heat-particle-fluid coupling at the grain level.

关键词： Particle-fluid interaction Heat transfer Discrete element method(DEM) Lattice Boltzmann method(LBM) Dirichlet-type thermal boundary Direct numerical simulation

A trajectory shaping guidance law with field-of-view angle constraint and terminal limits

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Journal of Systems Engineering and Electronics 2022年第2期33卷 426-437页

作者： fu Shengnan ZHOU Guanqun xia Qunli School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Aerospace Technology Institute Beijing 100074China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

In this paper, a trajectory shaping guidance law,which considers constraints of field-of-view(FOV) angle, impact angle, and terminal lateral acceleration, is proposed for a constant speed missile against a stationary target. First, to decouple constraints of the FOV angle and the terminal lateral acceleration, the third-order polynomial with respect to the line-ofsight(LOS) angle is introduced. Based on an analysis of the relationship between the looking angle and the guidance coefficient,the boundary of the coefficient that satisfies the FOV constraint is obtained. The terminal guidance law coefficient is used to guarantee the convergence of the terminal conditions. furthermore, the proposed law can be implemented under bearingsonly information, as the guidance command does not involve the relative range and the LOS angle rate. Finally, numerical simulations are performed based on a kinematic vehicle model to verify the effectiveness of the guidance law. Overall, the work offers an easily implementable guidance law with closed-form guidance gains, which is suitable for engineering applications.

关键词： shaping guidance law field-of-view(FOV)constraint impact angle constraint terminal lateral acceleration constraint

Recent Progress in Networked Control Systems——A Survey

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International Journal of Automation and computing 2015年第4期12卷 343-367页

作者： yuan-Qing xia yu-Long Gao Li-Ping Yan Meng-Yin fu School of Automation Beijing Institute of Technology

For the past decades,networked control systems(NCSs),as an interdisciplinary subject,have been one of the main research highlights and many fruitful results from different aspects have been *** these growing research trends,it is significant to consolidate the latest knowledge and information to keep up with the research *** this paper,the results of different aspects of NCSs,such as quantization,estimation,fault detection and networked predictive control,are *** addition,with the development of cloud technique,cloud control systems are proposed for the further development of NCSs.

关键词： Networked control systems quantization filter data fusion fault detection networked predictive control cloud control systems.

An efficient parallel algorithm for DNS of buoyancy-driven turbulent flows

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Journal of Hydrodynamics 2019年第6期31卷 1159-1169页

作者： Yi-zhao Zhang Shu-ning xia yu-hong Dong Bo-fu Wang Quan Zhou Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China

In this paper,an explicit low-storage simplified M-stage Runge-Kutta(SRK)scheme for high Reynolds-number incompressible flows is *** the SRK scheme,the Poisson equation is solved only once in the final substage of each time *** taking advantage of the SRK scheme and the advanced hybrid MPI+MPI model,we have developed an efficient parallel solver for buoyancy-driven turbulent *** spatial and temporal accuracies of the solver are validated with Taylor-Green vortex *** the RK and SRK schemes are implemented for the simulation of turbulent Rayleigh-Benard convection as well as Rayleigh-Taylor *** results show that the SRK scheme can save approximately 20%of the computation time.

关键词： Direct numerical simulation(DNS) parallel algorithm turbulent flows

Extracellular and Intracellular Calcium both Involved in the Jasmonic Acid Induced Calcium Mobilization in Arabidopsis thaliana

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Agricultural Sciences in China 2010年第4期9卷 497-503页

作者： SUN Qing-peng yu Yong-kun WAN Shan-xia ZHAO fu-kuan HAO yu-lan Department of Biotechnology Beijing University of Agriculture Beijing 102206 P.R.China Center of Tissue Culture Beijing University of Agriculture Beijing 102206 P.R.China

The objective of this experiment is to evaluate the role of intracellular and extracellular Ca2＋ and calmodulin （CAM） in jasmonic acid （JA） signaling. The laser scanning microscopy was used to detect the changes of [Ca2＋]cyt of Arabidopsis thaliana leaf cells which pretreated with different types of calcium channel blocker. Moreover, the expression of VSP, one of JA response genes, was also investigated after pretreated with the above blocker and antagonist of CaM. The results showed that extracellular and intracellular calcium both involved in the JA-induced Ca2＋ mobilization, and then Ca2＋ exerted its functions through activating the CaM or CaM related proteins. The apoplast calcium influx and the calcium release from the calcium stores are both involved in the JA-induced calcium mobilization, then the JA-induced Ca2＋ transmited the JA signal through CaM or CaM related proteins, and regulated the JA responsive genes.

关键词： Arabidopsis thaliana Ca2+ jasmonic acid CaM

Genetic pathogenesis of acephalic spermatozoa syndrome:past,present,and future

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Asian Journal of Andrology 2022年第3期24卷 231-237页

作者： yu Wang Ming-Fei xiang Na Zheng yun-xia Cao fu-Xi Zhu Reproductive Medicine Center Department of Obstetrics and GynecologyThe First Affiliated Hospital of Anhui Medical UniversityHefei 230022China NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract Anhui Medical UniversityHefei 230032China Key Laboratory of Population Health Across Life Cycle Anhui Medical UniversityMinistry of Education of the People’s Republic of ChinaHefei 230032China Anhui Province Key Laboratory of Reproductive Health and Genetics Anhui Medical UniversityHefei 230022China

Acephalic spermatozoa syndrome(ASS)is one of the most severe spermatogenic failures of all infertility in *** cognition of ASS has experienced a tortuous *** the past years,with the in-depth understanding of spermatogenesis and the emergence of new genetic research technologies,the unraveling of the genetic causes of spermatogenic failure has become highly *** these advances,we established a genetic background and made significant progress in the discovery of the genetic causes of *** is important to identify pathogenic genes and mutations in ASS to determine the biological reasons for the occurrence of the disease as well as provide genetic diagnosis and treatment strategies for patients with this *** this review,we enumerate various technological developments,which have made a positive contribution to the discovery of candidate genes for ASS from the past to the ***,we summarize the known genetic etiology of this phenotype and the clinical outcomes of treatments in the ***,we propose perspectives for further study and application of genetic diagnosis and assisted reproductive treatment in the future.

关键词： acephalic spermatozoa syndrome genetic pathogenesis male infertility

Unsteady state precipitation of M_(23)C_(6)carbides during thermal cycling in reduced activation steel manufactured by laser melting deposition

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Journal of Iron and Steel Research International 2023年第3期30卷 557-568页

作者： Ji-xin Hou fu-lin Zhang Zhi-xin xia yun-he yu Hai-ying fu Shu-hai Huang Qian An Chi Zhang Shagang School of Iron and Steel Soochow UniversitySuzhou 215021JiangsuChina School of Material Science and Engineering Tsinghua UniversityBeijing 100084China Center for fusion Science Southwestern Institute of PhysicsChengdu 610225SichuanChina Southwest Technology and Engineering Research Institute Chongqing 400050China

The temperature field distribution and thermal history of Fe-9Cr2WVTa reduced activation steel prepared by laser melting deposition(LMD)have been calculated with Gaussian and Ring laser beams,and the nucleation and growth behaviors of M_(23)C_(6)precipitates in the 1st,7th and 19th layers have been calculated using the modified classical nucleation theory and Svoboda Fischer Fratzl Kozeschnik *** energy distribution shows W-shape with Ring laser beam while it shows V-shape with Gaussian laser beam,which results in the more uniform M_(23)C_(6)size in the same layer with Ring laser *** in the bottom(i.e.,the 1st layer)have the minimum size and the size increases with the layer number with Gaussian and Ring laser *** temperature history,the instantaneous nucleation rate and the size evolution of M_(23)C_(6)have been systematically *** results indicate that the nucleation,growth and re-dissolution of precipitates in reduced activation steel depend on the amount of energy absorbed in the thermal cycle during *** continuous accumulation of energy during the thermal cycle leads to larger M_(23)C_(6)at the top *** unsteady state precipitation dynamics of M_(23)C_(6)carbides during thermal cycling are consistent with the simulation results.

关键词： Laser melting deposition Reduced activation steel Unsteady state precipitation Heat source model