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Frontiers of Architectural Research 2024年第2期13卷 305-318页

作者： Bo wan Dongyang wan Qiang sheng School of Architecture and Design Beijing Jiaotong UniversityBeijing 100044China

This paper,set against the backdrop of expanding urban rail networks and dynamic urban development,focuses on the distribution and evolution of commercial Points of Interests(POIs)within the central urban rail transit areas of *** study examines data from four different years-2008,2013,2017,and 2020-to observe the temporal evolution of commercial *** identifies stable explanatory variables affecting the distribution and evolution of commercial POIs,which include rail transit accessibility,characteristics of the working and residential population distribution around stations,and the construction intensity in the vicinity of station *** statistical analysis and model building,relatively stable linear regression equations were established,with R2 values generally maintained above 0.5(except for 2017).The study advances our understanding of the influence of rail transit on urban commercial spaces and how this influence shifts with temporal and urban developmental *** elucidates the correlation between changes in the number of businesses and spatial configuration,offering insights and information for urban planners and policy *** research also serves as a model for exploring the interplay between urban rail transit and commercial spaces in other major cities.

关键词： Urbanrail transit areas Spatial configuration Distributionand evolution of commercial POls

A Preconditioned Conjugate Gradient Method with Active Set Strategy for1-Regularized Least Squares

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Journal of the Operations Research Society of China 2018年第4期6卷 571-585页

作者： wan-you Cheng Dong-Hui Li College of Computer Dongguan University of TechnologyDongguan 523000GuangdongChina School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China

In the paper,we consider the l_(1)-regularized least square problem which has been intensively involved in the fields of signal processing,compressive sensing,linear inverse problems and statistical *** considered problem has been proved recently to be equivalent to a nonnegatively constrained quadratic programming(QP).In this paper,we use a recently developed active conjugate gradient method to solve the resulting QP *** improve the algorithm’s performance,we design a subspace exact steplength as well as a precondition *** performance comparisons illustrate that the proposed algorithm is competitive and even performs little better than several state-of-the-art algorithms.

关键词： Compressed sensing l_(1)-Regularized optimization Conjugate gradient method Precondition

Numerical simulations of propeller cavitation flows based on OpenFOAM

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Journal of Hydrodynamics 2020年第6期32卷 1071-1079页

作者： Min-sheng Zhao Wei-wen Zhao De-cheng wan Computational Marine Hydrodynamics Lab(CMHL) State Key Laboratory of Ocean EngineeringSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

In order to study the cavitation and hydrodynamic characteristics of propeller under uniform and non-uniform flows,numerical investigations are performed using interPhaseChangeDyMFoam in the open source computational fluid dynamics(CFD)software platform OpenFOAM with Schnerr-Sauer cavitation *** simulation results can be used as a reference to evaluate the working ability of a propeller in case of actual navigation.A new grid encryption method is adopted in the research to better capture the existence of vortex cavitation at the propeller *** method of function input is carried out in the study to simulate the condition of non-uniform flow and reduce the calculation *** unsteady dynamics are predicted by the Reynolds-averaged Navier-Stokes(RANS)method with a modified shear stress transport(SST)k−ωturbulence *** numerical results of the propeller such as cavitation shape and pressure distribution under uniform and non-uniform flow are analyzed and compared with each other.

关键词： OpenFOAM E779A propeller cavitation non uniform flow

A gate size estimation algorithm for data association filters

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Science in China(Series F) 2008年第4期51卷 425-432页

作者： wanG MingHui wan Qun you Zhisheng College of Computer Science and Engineering Sichuan University Chengdu 610064 China College of Electronics Engineering University of Electronic Science and Technology Chengdu 610054 China

The problem of forming validation regions or gates for new sensor measurements obtained when tracking targets in clutter is considered. Since the gate size is an integral part of the data association filter, this paper is intended to describe a way of estimating the gate size via the performance of the data association filter. That is, the gate size can be estimated by looking for the optimal performance of the data association filter. Simulations show that this estimation method of the gate size offers advantages over the common and classical estimation methods of the gate size, especially in a heavy clutter and/or false alarm environment.

关键词： data association filter gate size optimal estimation

Probing the CP violating Hγγ coupling using interferometry

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Chinese Physics C 2019年第7期43卷 1-7页

作者： Xia wan you-Kai wang School of Physics &Information Technology Shaanxi Normal University

The diphoton invariant mass distribution from the interference between gg→H→γγ and gg→γγ is almost antisymmetric around the Higgs mass *** propose a new observable Aint,the ratio of the sign-reversed integral around MH(e.g.■)and the cross-section of the Higgs signal,to quantify this *** study Aint both in the Standard Model(SM)and new physics with various CP violating Hγγ *** in SM could reach a value of 10%,while for CP violating Hyy coupling Aint could range from 10% to-10%,which could probably be detected in the HL-LHC *** with both CP violating Hγγ and Hgg couplings is also studied,and its range of values is found to be slightly larger.

关键词： Higgs diphoton CP violation

An experimental study of salt expansion in sodium saline soils under transient conditions

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Journal of Arid Land 2017年第6期9卷 865-878页

作者： wan Xusheng you Zhemin WEN Haiyan William CROSSLEY School of Civil Engineering and Architecture Southwest Petroleum University Chengdu 610500 China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and Resources Chinese Academyof Sciences Lanzhou 730000 China College of Pastoral Agriculture Science and Technology State Key Laboratory of Grassland Agro-ecosystems Lanzhou University Lanzhou 730020 China School of Foreign Languages Southwest Petroleum University Chengdu 610500 China

Salt expansion in sulfate saline soils that are widely distributed in northwestern China causes serious infrastructural damages under low-temperature conditions. However, the mechanism of salt expansion under low temperatures is not clear. In this study, we conducted a series of cooling experiments combined with salt crystallization to study this mechanism, and employed an ionic model to calculate the supersaturation ratio of the solution. During the experiments, the strength and the process of salt expansion were examined under different cooling rates and various crystal morphologies. The relationship between temperature and supersaturation ratio under transient conditions was also considered. Results indicate that the initial supersaturation ratio of a sodium sulfate solution is closely related to environmental conditions, and that this ratio decreases with slowing the cooling rates and stabilizing the crystal forms. Higher initial supersaturation ratios lead to an increased non-steady-state zone, resulting in less salt expansion. On the other hand, chloride ion content has a distinct influence on the crystallization supersaturation ratio of the sodium sulfate solution, and higher chloride ion content can inhibit salt expansion in sodium saline soils. These findings help explain salt expansion mechanisms in complex conditions such as seasonally frozen soils, and thus help search for improved methods of preventing salt expansion in sulfate saline soils.

关键词： sulfate saline soil supersaturation ratio ionic model cooling rate salt expansion

Mapping the Information Trace in Local Field Potentials by a Computational Method of Two-Dimensional Time-Shifting Synchronization Likelihood Based on Graphic Processing Unit Acceleration

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Neuroscience Bulletin 2017年第6期33卷 653-663页

作者： Zi-Fang Zhao Xue-Zhu Li you wan Neuroscience Research Institute Peking UniversityBeijing 100191China Department of Neurobiology School of Basic Medical SciencesPeking UniversityBeijing 100191China Key Laboratory for Neuroscience Ministry of Education/National Health and Family Planning CommissionPeking UniversityBeijing 100191China

The local field potential（LFP） is a signal reflecting the electrical activity of neurons surrounding the electrode tip. Synchronization between LFP signals provides important details about how neural networks are organized. Synchronization between two distant brain regions is hard to detect using linear synchronization algorithms like correlation and coherence. Synchronization likelihood（SL） is a non-linear synchronization-detecting algorithm widely used in studies of neural signals from two distant brain areas. One drawback of non-linear algorithms is the heavy computational burden. In the present study, we proposed a graphic processing unit（GPU）-accelerated implementation of an SL algorithm with optional 2-dimensional time-shifting. We tested the algorithm with both artificial data and raw LFP data. The results showed that this method revealed detailed information from original data with the synchronization values of two temporal axes,delay time and onset time, and thus can be used to reconstruct the temporal structure of a neural network. Our results suggest that this GPU-accelerated method can be extended to other algorithms for processing time-series signals（like EEG and f MRI） using similar recording techniques.

关键词： Local field potential Synchronization Temporal Time-shifting Parallel computing

Conditional Genome Editing in the Mammalian Brain Using CRISPR-Cas9

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Neuroscience Bulletin 2021年第3期37卷 423-426页

作者： Haojie Sun Jie Zheng Ming Yi you wan Neuroscience Research Institute Department of NeurobiologySchool of Basic Medical SciencesPeking UniversityBeijing 100083China Key Laboratory for Neuroscience Ministry of Education/National Health Commission of ChinaPeking UniversityBeijing 100083China Department of Pathophysiology Huazhong University of Science and TechnologyWuhan 430030China

Neuronal ensembles with distinct morphological,biochemical,and functional identities are organized into complex circuits in the mammalian brain,and malfunction of specific neuronal types in different networks contributes to diverse pathological *** memory as an example,specific memories are held in a subset of neurons,referred to as engram cells.

关键词： Mammalian networks organized

On the Calculation of Lyapunov Indicators with Post-stabilization in a Weyl Field

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Chinese Journal of Astronomy and Astrophysics 2006年第2期6卷 125-140页

作者： Xin Wu Hong Zhang Xiao-sheng wan Department of Physics Nanchang University Nanchang 330047 Department of Astronomy Nanjing University Nanjing 210093

We present details of a work aiming at the overestimation of Lyapunov exponents defined by the geodesic deviation equations in the previous work. The geodesic deviation vector with post-stabilization is used to compute the fast Lyapunov indicator, considered to be a very sensitive tool for discrimination between ordered or weakly chaotic motions. We make a detailed study of the dynamics in the superposed Weyl field between a black hole and shell of octopoles by using the fast Lyapunov indicator with the Poincare surface of section. In particular, we examine the effects on the dynamics around the fixed points, of varying one of the three parameters （specific energy E, specific angular momentum L and octopolar moment 0）, while keeping the other two fixed, and identify the intervals of the varying parameter where the motion is regular or chaotic.

关键词： black hole physics - stars: circumstellar matter - chaos - methods:numerical

Vortex-Induced Vibration Response Features of A Submarine Multi-Span Pipeline via Towing Tank Experimental Tests

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China Ocean Engineering 2023年第2期37卷 175-189页

作者： XU wan-hai JIA Kun MA Ye-xuan SONG Zhi-you State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China

In offshore engineering, the phenomenon of free span often occurs, and the pipeline may have multiple free spans adjacent to each other, forming a multi-span pipeline. The interaction of different spans makes the structural vibration characteristics more complex, which may change the fatigue characteristics of the pipeline and affect the safety of the structure. In this paper, model tests were designed to explore the vortex-induced vibration(VIV) characteristics of multi-span pipelines and investigate the multi-span interaction mechanism. The experimental study mainly focused on the dynamic response of double-span pipelines, and further extended to triple-span pipelines, hoping that the results can be applied to more complex environment. The effects of span-length ratio, buried depth and axial force on VIV of the pipeline were investigated and discussed. The dynamic response of the pipeline varied with the span length. There was obvious interaction between different spans of multi-span pipelines, and the pipe-sediment interaction obviously affected the vibration characteristics of pipeline. The differences of pipeline burial depth and axial force changed the structural stiffness. With the increase of buried depth, the response amplitude presented a downward trend. The spanwise evolutions were asymmetric caused by the pipe-sediment interaction and multi-span interaction. The results can help to identify multi-span pipelines in engineering, and realize the prevention and control of free spans.

关键词： vortex-induced vibration submarine pipeline pipe-sediment interaction multi-span interaction