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Experimental and numerical investigation of the impacts of rotor tip-rake on excitation forces of pump-jet propulsors

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Journal of Hydrodynamics 2024年第1期36卷 142-157页

作者： Xue-qin Ji xiao-song zhang Chen-jun Yang xiao-qian Dong State Key Laboratory of Ocean Engineering Marine Numerical Experiment CentreSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China CSSC Shanghai Marine Energy Saving Technology Co. Ltd.Shanghai200011China China Ship Scientific Research Center Shanghai Branch Shanghai200011China

The tip-clearance flow in a pump-jet propulsor exerts great impacts on the fluctuating pressures and resultant unsteady forces,which are important sources of structural vibrations and radiated noise *** blade geometry close to the tip is an important factor determining the vortex strength in the tip-clearance *** the open-water condition,the effects of raking the rotor tips on the duct-surface fluctuating pressures and the resultant unsteady forces acting on different components of the propulsor are investigated via physical model experiments and the numerical solution of Reynolds-averaged Navier-Stokes(RANS)equations coupled with the SST k-ωturbulence *** measured and simulated results of hydrodynamic pressures are consistent to each other,and the simulated flows help better understand why the fluctuating pressures change with the tip *** strong fluctuations of duct-surface pressures are caused by intensive tip separation *** duct-surface pressure fluctuations are effectively reduced by using the rake distribution near the tip towards blade back side and,for the combination of the five-bladed rotor and the seven-bladed stator,the resultant unsteady horizontal(and vertical)forces acting on the duct and stator are also reduced;while increasing rake leads to negative effect on pressure fluctuations and unsteady horizontal(and vertical)forces acting on all the components of the propulsor.

关键词： Pump-jet tip-clearance tip-rake fluctuating pressures excitation forces

Zinc protoporphyrin IX enhances chemotherapeutic response of hepatoma cells to cisplatin

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World Journal of Gastroenterology 2014年第26期20卷 8572-8582页

作者： Yang-Sui Liu Huan-Song Li Dun-Feng Qi jun zhang Xin-Chun Jiang Kui Shi xiao-jun zhang Xin-Hui zhang The Central Hospital of Xuzhou City Xuzhou Hospital Affiliated to Medical College of Southeast University

AIM: To investigate the effect of zinc protoporphyrin IX on the response of hepatoma cells to cisplatin and the possible mechanism involved.

关键词： Zinc protoporphyrin IX Heme oxygenase-1 Liver cancer cell lines Cisplatin Chemotherapy

A CAD-BEM geometry transformation method for face-based primary geometric input based on closed contour recognition

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Building Simulation 2024年第2期17卷 335-354页

作者： jun xiao Hao Zhou Shiji Yang Deyin zhang Borong Lin Department of Building Science School of ArchitectureTsinghua UniversityBeijing100084China Key Laboratory of Eco Planning&Green Building Ministry of EducationTsinghua UniversityBeijing100084China Institute for Urban Governance and Sustainable Development Tsinghua UniversityBeijing100084China

Performance analysis during the early design stage can significantly reduce building energy ***,it is difficult to transform computer-aided design(CAD)models into building energy models(BEM)to optimize building *** model structures for CAD and BEM are *** this study,geometry transformation methods was implemented in BES tools for the early design stage,including auto space generation(ASG)method based on closed contour recognition(CCR)and space boundary topology calculation *** program is developed based on modeling tools SketchUp to support the CAD format(like*.stl,*.dwg,*.ifc,etc.).It transforms face-based geometric information into a zone-based tree structure model that meets the geometric requirements of a single-zone BES combined with the other thermal parameter inputs of the *** addition,this study provided a space topology calculation method based on a single-zone BEM *** program was developed based on the SketchUp modeling tool to support additional CAD formats(such as*.stl,*.dwg,*.ifc),which can then be imported and transformed into*.*** to current methods mostly focused on BIM-BEM transformation,this method can ensure more modeling *** method was integrated into a performance analysis tool termed MOOSAS and compared with the current version of the transformation *** were tested on a dataset comprising 36 conceptual models without partitions and six real cases with detailed *** ensures a transformation rate of two times in any bad model condition and costs only 1/5 of the time required to calculate each room compared to the previous version.

关键词： geometry transformation building energy model computer aid design closed contour recognition

Baseline optimization for scalar magnetometer array and its application in magnetic target localization

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Chinese Physics B 2018年第6期27卷 213-219页

作者： Li-Ming Fan Quan Zheng Xi-Yuan Kang xiao-jun zhang Chong Kang College of Science Harbin Engineering University Harbin 150001 China College of Mechanical and Electrical Engineering Harbin Engineering University Harbin 150001 China College of Computer Science and Technology Harbin Engineering University Harbin 150001 China

Generally, a magnetic target can be described with six parameters, three describing the position and three describing the magnetic moment. Due to a lack of sufficient components from one magnetometer, we need more than one magnetometer when locating the magnetic target. Thus, a magnetometer array should be designed. The baseline of the array is an important factor that affects the localization accuracy of the target. In this paper, we focus on the localization of a static target by using a scalar magnetometer array. We present the scalar magnetometer array with a cross-shaped *** propose a method of determining the optimal baseline according to the parameters of the magnetometer and detection requirements. In the method, we use the traditional signal-to-noise ratio（SNR） as a performance index, and obtain the optimal baseline of the array by using the Monte Carlo method. The proposed method of determining the optimal baseline is verified in simulation. The arrays with different baselines are used to locate a static magnetic target. The results show that the location performance is better when using the array with the optimal baseline determined by the proposed method.

关键词： scalar magnetometer array baseline optimization Monte Carlo simulation magnetic anomaly

Feature Matching via Topology-Aware Graph Interaction Model

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 113-130页

作者： Yifan Lu Jiayi Ma xiaoguang Mei jun Huang xiao-Ping zhang the Electronic Information School Wuhan UniversityWuhan 430072China IEEE Tsinghua Berkeley Shenzhen Institute Shenzhen 518071China the Department of Electrical Computer and Biomedical EngineeringToronto Metropolitan UniversityToronto ON M5B 2K3Canada

Feature matching plays a key role in computer vision. However, due to the limitations of the descriptors, the putative matches are inevitably contaminated by massive *** paper attempts to tackle the outlier filtering problem from two aspects. First, a robust and efficient graph interaction model,is proposed, with the assumption that matches are correlated with each other rather than independently distributed. To this end, we construct a graph based on the local relationships of matches and formulate the outlier filtering task as a binary labeling energy minimization problem, where the pairwise term encodes the interaction between matches. We further show that this formulation can be solved globally by graph cut algorithm. Our new formulation always improves the performance of previous localitybased method without noticeable deterioration in processing time,adding a few milliseconds. Second, to construct a better graph structure, a robust and geometrically meaningful topology-aware relationship is developed to capture the topology relationship between matches. The two components in sum lead to topology interaction matching(TIM), an effective and efficient method for outlier filtering. Extensive experiments on several large and diverse datasets for multiple vision tasks including general feature matching, as well as relative pose estimation, homography and fundamental matrix estimation, loop-closure detection, and multi-modal image matching, demonstrate that our TIM is more competitive than current state-of-the-art methods, in terms of generality, efficiency, and effectiveness. The source code is publicly available at http://***/YifanLu2000/TIM.

关键词： Feature matching graph cut outlier filtering topology preserving

Survey on performance of vertical slot and nature-like fishways at Angu hydropower station, Southwest China

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Water Science and Engineering 2024年第1期17卷 83-91页

作者： jun-jian Sun Jia-yue Shi Qi zhang xiao-tao Shi jun-jun Tan PowerChina Huadong Engineering Corporation Limited Hangzhou 311122China Hubei International Science and Technology Cooperation Base of Fish Passage China Three Gorges UniversityYichang 443002China

To restore dam-blocked natural fish migratory passages,a growing number of artificial fishways have been built in water conservancy and hydropower projects in *** Angu hydropower station involved diverse important fish habitats in the lower reaches of the Daduhe River in Southwest ***,a vertical slot fishway(VSF)and a nature-like fishway(NLF)were built near the backwater area of the reservoir to connect the upstream and downstream *** and aquatic ecological surveys were conducted after the completion of the project to estimate the fish passing effect of the two *** results indicated that both fishways were in effective operation and could maintain the desired hydrodynamic conditions and be used by several local fish *** the survey,149 fish from 15 species and 111 fish from 17 species were captured by the traps in the VSF and NLF,respectively,while 1263 fish from 27 species were found in the downstream *** species captured in the VSF were not found in the NLF,and vice versa,which implied the different preferences of ***,3789 signals including 2099 upward ones and 1690 downward ones were monitored with an ultrasonic fish detector at the inlet of the *** findings revealed the characteristics of fish species observed in and near the fishways and provided valuable insights into the different fish passing capabilities of VSFandNLF.

关键词： Vertical slot fishway Nature-like fishway Aguatic ecological survey Fishwaymonitoring Statistical analysis

Recent advances in vacancy engineering for reliable lithiumsulfur batteries

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Rare Metals 2024年第2期43卷 455-477页

作者： Wen-Dong Liu xiao Tang jun-An Feng Chao-Yue zhang Hao Liu Chuan Shi xiao-Xian Zhao Jian-jun Song College of Physics School of Chemistry and Chemical EngineeringQingdao UniversityQingdao266071China Faculty of Science Centre for Clean Energy TechnologySchool of Mathematical and Physical SciencesUniversity of Technology SydneySydneyNSW2007Australia Department of Chemistry College of ScienceHebei Agricultural UniversityBaoding071001China

The high-energy-density and low-cost features endow lithium-sulfur batteries with broad application ***,many drawbacks,especially the detrimental shuttle effect,have hindered the further development of *** response,a lot of new structures have been applied to suppress the shuttle effect and promote the development of ***,vacancy engineering has gained the attention of researchers due to its unique electronic *** review aims to analyze the application of vacancy engineering in ***,the electrochemistry of LSBs has been systematically discussed and the existing challenges as well as improvement tactics of LSBs have also been ***,the preparation methods and characterization technologies of various vacancies are summarized,including oxygen vacancies,sulfur vacancies,selenium vacancies,other anion vacancies,cation vacancies,*** latest applications of vacancy engineering in LSBs are also summarized in this ***,some prospects and insights for further investigation and practical application of vacancy engineering in LSBs are put forward.

关键词： Lithium-sulfur batteries(LSBs) Defects Vacancy engineering Electronic structure Shuttle effect

The Q-index and Connectivity of Graphs

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Journal of the Operations Research Society of China 2024年第2期12卷 505-519页

作者： Peng-Li zhang Li-Hua Feng Wei-jun Liu xiao-Dong zhang School of Mathematical Sciences MOE-LSCSHL-MACShanghai Jiao Tong UniversityShanghai 200240China School of Mathematics and Statistics Central South UniversityChangsha 410083HunanChina

A connected graph G is said to be k-connected if it has more than k vertices and remains connected whenever fewer than k vertices are *** this paper,for a connected graph G with sufficiently large order,we present a tight sufficient condition for G with fixed minimum degree to be k-connected based on the *** result can be viewed as a spectral counterpart of the corresponding Dirac-type condition.

关键词： Q-index Minimum degree k-connected

On the Monge–Kantorovich Mass Transfer Problem in Higher Dimensions

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1989-2004页

作者： xiao jun LU School of Mathematics Southeast UniversityNanjing 210096P.R.China

This paper mainly investigates the approximation of a global maximizer of the Monge–Kantorovich mass transfer problem in higher dimensions through the approach of nonlinear partial differential equations with Dirichlet *** an approximation mechanism,the primal maximization problem can be transformed into a sequence of minimization *** applying the systematic canonical duality theory,one is able to derive a sequence of analytic solutions for the minimization *** the final analysis,the convergence of the sequence to an analytical global maximizer of the primal Monge–Kantorovich problem will be demonstrated.

关键词： Monge-Kantorovich mass transfer singular variational problem canonical duality theory