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Study on the flow structure in curved open channels with suspended vegetation using multi relaxation time lattice Boltzmann method

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Journal of Hydrodynamics 2024年第2期36卷 300-315页

作者： He-fang Jing Qiao-ling Zhang Wei-hong Wang Zong-ning Zhang School of Mathematics and Information Science North Minzu UniversityYinchuan750021China School of Civil Engineering North Minzu UniversityYinchuan750021China department of Basic courses Zhengzhou University of Science and TechnologyZhengzhou450064China

Suspended vegetation in rivers,lakes,reservoirs and canals can change flow structure,which will in turn affect the sediment transport and cause the variation of water ecological *** order to study the characteristics of bend flow through suspended vegetation,three-dimensional numerical simulations are carried out by using the multi-relaxation-time lattice Boltzmann method(MRT-LBM).The drag force induced by vegetation is added in the velocity correction in the equilibrium distribution and a hybrid format combined bounce and specular reflection scheme is applied in the solid-fluid *** the validation of this model,six cases are designed to conduct the numerical simulations according to the root depth and the arrangement of *** simulated results show that the suspended vegetation can redistribute the flow structure in curved open *** the arrangement of suspended vegetation,the main flow moves to the side without vegetation,and the distribution of velocity tends to be balanced when vegetation is arranged on the entire cross section,the range of circulating current is reduced from the whole cross section to the local position without vegetation,however,the circulating current can still exist in the curve where the suspended vegetation enters less than half of the water *** addition,it can also be concluded that the suspended vegetation can affect the lateral gradient of flow velocity,and the bed shear stress in the curved channel.

关键词： Multi-relaxation-time lattice Boltzmann method(MRT-LBM) suspended vegetation curved open channel circulating current bed shearstress

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Analytical solutions of equatorial geodesic motion in Kerr spacetime

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Chinese Physics C 2024年第4期48卷 222-239页

作者：刘岩孙兵 department of Physics Yantai UniversityYantai 264005China department of Basic courses Beijing University of AgricultureBeijing 102206China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

The study of Kerr geodesics has a long history,particularly for those occurring within the equatorial plane,which are generally ***,when compared with the classification introduced by one of the authors[***.D 105,024075(2022)],it becomes apparent that certain classes of geodesics,such as trapped orbits,still lack analytical ***,in this study,we provide explicit analytical solutions for equatorial timelike geodesics in Kerr spacetime,including solutions of trapped orbits,which capture the characteristics of special geodesics,such as the positions and conserved quantities of circular,bound,and deflecting ***,we determine the precise location at which retrograde orbits undergo a transition from counter-rotating to prograde motion due to the strong gravitational effects near a rotating black ***,the trajectory remains prograde for orbits with negative energy despite the negative angular ***,we investigate the intriguing phenomenon of deflecting orbits exhibiting an increased number of revolutions around the black hole as the turning point approaches the turning point of the trapped ***,we find that only prograde marginal deflecting geodesics are capable of traversing through the *** summary,our findings present explicit solutions for equatorial timelike geodesics and offer insights into the dynamics of particle motion in the vicinity of a rotating black hole.

关键词： geodesic motion analytical solutions equatorial plane Kerr spacetime

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Low-rank spectral estimation algorithm of learning Markov model

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Frontiers of Mathematics in China 2024年第3期19卷 137-155页

作者： Yongye ZHAO Shujun BI department of Basic courses Guangzhou Maritime UniversityGuangzhou 510725China department of Mathematics South China University of TechnologyGuangzhou 510640China

This paper proposes a low-rank spectral estimation algorithm of learning Markov ***,an approximate projection algorithm for the rank-constrained frequency matrix set is proposed,and thereafter its local Lipschitzian error bound ***,we propose a low-rank spectral estimation algorithm for estimating the state transition frequency matrix and the probability matrix of Markov model by applying the approximate projection algorithm to correct the maximum likelihood estimation of the frequency matrix,and prove that there is only a multiplying constant difference in estimation errors between the low-rank spectral estimation and the maximum likelihood estimation under appropriate ***,numerical comparisons with the prevailing maximum likelihood estimation,spectral estimation,and rank-constrained maxi-mum likelihood estimation show that the low-rank spectral estimation algorithm is effective.

关键词： Markov model low-rank spectral estimation error bound approximate projection

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Structural Setting of the South-West Cameroon Using Satellite Potential Field Derived from SGG-UGM-2 Gravity Data

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Journal of Geoscience and Environment Protection 2024年第8期12卷 43-61页

作者： Jean Aimé Mono basical Science department Advanced Technical Teacher Training School University of Douala Douala Cameroon

This study aims to improve knowledge of the structure of southwest Cameroon based on the analysis and interpretation of gravity data derived from the SGG-UGM-2 model. A residual anomaly map was first calculated from the Bouguer anomaly map, which is strongly affected by a regional gradient. The residual anomaly map generated provides information on the variation in subsurface density, but does not provide sufficient information, hence the interest in using filtering with the aim of highlighting the structures affecting the area of south-west Cameroon. Three interpretation methods were used: vertical gradient, horizontal gradient coupled with upward continuation and Euler deconvolution. The application of these treatments enabled us to map a large number of gravimetric lineaments materializing density discontinuities. These lineaments are organized along main preferential directions: NW-SE, NNE-SSW, ENE-WSW and secondary directions: NNW-SSE, NE-SW, NS and E-W. Euler solutions indicate depths of up to 7337 m. Thanks to the results of this research, significant information has been acquired, contributing to a deeper understanding of the structural composition of the study area. The resulting structural map vividly illustrates the major tectonic events that shaped the geological framework of the study area. It also serves as a guide for prospecting subsurface resources (water and hydrocarbons). .

关键词： SGG-UGM-2 Model Horizontal Gradient Bouguer Anomalies Potential Field Data

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Existence of Multiple Normalized Solutions for Schr?dinger-Choquard Equation with Mixed Nonlinearities

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Acta Mathematicae Applicatae Sinica 2024年

作者： Li-qin TANG Li WANG Jun WANG School of Mathematics Sun Yat-sen University department of Basic courses Hefei University of economics College of Science East China Jiaotong University

This paper considers the existence of multiple normalized solutions of the following SchrodingerChoquard equation where c,ε,μ> 0,N≥3,α∈(0,N),(N+α)/N

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Giant and controllable Goos–H?nchen shift of a reflective beam off a hyperbolic metasurface of polar crystals

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Chinese Physics B 2024年第1期 300-307页

作者：薛天李宇博宋浩元王相光张强付淑芳周胜王选章 Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of Educationand School of Physics and Electronic EngineeringHarbin Normal University department of Basic courses Guangzhou Maritime University

We conduct a theoretical analysis of the massive and tunable Goos–H¨anchen(GH) shift on a polar crystal covered with periodical black phosphorus(BP)-patches in the THz range. The surface plasmon phonon polaritons(SPPPs), which are coupled by the surface phonon polaritons(SPh Ps) and surface plasmon polaritons(SPPs), can greatly increase GH *** on the in-plane anisotropy of BP, two typical metasurface models are designed and investigated. An enormous GH shift of about-7565.58 λ0is achieved by adjusting the physical parameters of the BP-patches. In the designed metasurface structure, the maximum sensitivity accompanying large GH shifts can reach about 6.43 × 108λ0/RIU, which is extremely sensitive to the size, carrier density, and layer number of BP. Compared with a traditional surface plasmon resonance sensor, the sensitivity is increased by at least two orders of magnitude. We believe that investigating metasurface-based SPPPs sensors could lead to high-sensitivity biochemical detection applications.

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A nonlocal dispersal and time delayed HIV infection model with general incidences

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Applied Mathematics:A Journal of Chinese Universities 2024年第3期 448-457页

作者： WU Peng ZHANG Yu-huai WANG Ling School of Sciences Hangzhou Dianzi University School of Humanities and Management Zhejiang Chinese Medical University Public Foundational courses department Nanjing Vocational University of Industry Technology

Biologically, because of the impact of reproduction period and nonlocal dispersal of HIV-infected cells, time delay and spatial heterogeneity should be considered. In this paper, we establish an HIV infection model with nonlocal dispersal and infection age. Moreover, applying the theory of Fourier transformation and von Foerster rule, we transform the model to an integrodifferential equation with nonlocal time delay and dispersal. The well-posedness, positivity, and boundedness of the solution for the model are studied.

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Rank-generating functions and Poincaré polynomials of lattices in finite orthogonal space of even characteristic

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Frontiers of Mathematics in China 2024年第4期19卷 181-189页

作者： Feng XU Yanbing ZHAO Yuanji HUO Office of Academic Affairs Xuanhua Vocational College of Science and TechnologyZhangjiakou 075100China department of Basic courses Zhangjiakou Vocational and Technical CollegeZhangjiakou 075051China department of Mathematics Hebei North UniversityZhangjiakou 075000China

The geometry of classical groups over finite fields is widely used in many *** this paper,we study the rank-generating function,the characteristic polynomial,and the Poincarépolynomial of lattices generated by the or... 详细信息

关键词： Lattices orthogonal space of even characteristic rank-generating function characteristic polynomial Poincarépolynomial

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Design and preparation of highly crystalline K-intercalated W@PCN:an efficient material for aniline elimination

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Rare Metals 2024年第3期43卷 1337-1342页

作者： Hao-Fei Li Kai-Wen Yu Xiao-Bi Jing Lei Duan Yi-Yang Zhang School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou225002China School of Mechanical Engineering Yangzhou UniversityYangzhou225127China School of Material Science and Engineering Huazhong University of Science and TechnologyWuhan430071China School of Chemical Engineering and Materials Changzhou Institute of TechnologyChangzhou213032China department of Basic courses Army Engineering University of PLANanjing211101China

In this paper,we designed and prepared the polymeric carbon nitride-supported tungsten(W@PCN)*** were employed as the catalysts for photocatalytic oxidation of aniline in *** the process,H_(2)O_(2)was initially generated via the PCN-catalyzed *** by supported tungsten,aniline was oxidized by the in situ generated H_(2)O_(2)to obtain less toxicpoly aniline.

关键词： materials aniline crystalline

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Giant and controllable Goos—Hänchen shift of a reflective beam off a hyperbolic metasurface of polar crystals

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Chinese Physics B 2024年第1期33卷 428-435页

作者：薛天李宇博宋浩元王相光张强付淑芳周胜王选章 Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of Educationand School of Physics and Electronic EngineeringHarbin Normal UniversityHarbin 150025China department of Basic courses Guangzhou Maritime UniversityGuangzhou 510725China

We conduct a theoretical analysis of the massive and tunable Goos–Hänchen(GH) shift on a polar crystal covered with periodical black phosphorus(BP)-patches in the THz range. The surface plasmon phonon polaritons(SPPPs), which are coupled by the surface phonon polaritons(SPh Ps) and surface plasmon polaritons(SPPs), can greatly increase GH *** on the in-plane anisotropy of BP, two typical metasurface models are designed and investigated. An enormous GH shift of about-7565.58 λ_(0) is achieved by adjusting the physical parameters of the BP-patches. In the designed metasurface structure, the maximum sensitivity accompanying large GH shifts can reach about 6.43 × 10^(8) λ_(0)/RIU, which is extremely sensitive to the size, carrier density, and layer number of BP. Compared with a traditional surface plasmon resonance sensor, the sensitivity is increased by at least two orders of magnitude. We believe that investigating metasurface-based SPPPs sensors could lead to high-sensitivity biochemical detection applications.

关键词： Goos–H?nchen shift black phosphorus surface plasmon phonon polaritons sensitivity metasurfaces

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