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Effect of Bowed/Leaned Vane on the Unsteady Aerodynamic Excitation in Transonic Turbine

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Journal of Thermal Science 2019年第1期28卷 133-144页

作者： LIU Jian qiao Weiyang duan Wenhua Turbomachinery Aerodynamics and Acoustics Lab (TAAL) School of Power and Energy Northwestern Polytechnical University

To investigate the effect of bowed/leaned vane configurations on the aerodynamic performance and aerodynamic excitation in transonic high-pressure turbine, the full three-dimensional viscous unsteady numerical simulation was performed by solving N-S equations based on SAS SST *** influence of bowed/leaned vanes on turbine efficiency and efficiency fluctuation was investigated. The action of vane modelling to the overall aerodynamic fluctuation level and the amplitude of each vane passing frequency were analyzed. By comparing instantaneous pressure fluctuation contours in the blade passage with space-time maps, the link of the pressure fluctuation on blade surface with flow distortions was achieved, which can reveal the mechanism of the impact of the vane modelling. As the results suggest, the turbine efficiency is promoted with positively leaned and bowed vane modelling, and the fluctuation of stage turbine efficiency is repressed, which contributes to the smooth running of the turbine stage. The blade aerodynamic excitation on the rotor blade is characterized by the motion of vane trailing edge shock system, and the vane configurations can reduce the fluctuation level on the rotor blade surface effectively. For the positively leaned vane configuration, the aerodynamic excitations at the root and tip region are affected by the impact of the amplitude of the first harmonic, whereas they are reduced with the decrease of the amplitude of the second and higher harmonics at midspan. For the positively bowed vane, aerodynamic excitation is repressed by reducing the amplitude of the third harmonic at the root region, and the first harmonic at the tip region, and the amplitude of each harmonic is reduced at the middle region.

关键词： transonic turbine leaned bowed aerodynamic performance aerodynamic excitation numerical simulation

Effects of Freestream Turbulence,Reynolds Number and Mach Number on the Boundary Layer in a Low Pressure Turbine

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Journal of Thermal Science 2023年第4期32卷 1393-1406页

作者： duan Wenhua qiao Weiyang CHEN Weijie ZHAO Xinyu Turbomachinery Aerodynamics and Acoustics Lab(TAAL) School of Power and EnergyNorthwestern Polytechnical UniversityXi’an710129China

In order to investigate the aerodynamics of a high speed low pressure turbine works in high Mach number and low Reynold number environment,the effect of freestream turbulence(FST)on the boundary layer development on the high speed low pressure turbine under different Reynolds numbers(Re)is numerically *** eddy simulation is adopted here with a subgrid scale model of Wall Adapting Local Eddy viscosity(WALE).Cases with Re ranging from 100000 to 400000 under an exit Mach number(Ma)of 0.87 have been considered at low and high FST levels.A low Ma case(0.17)under very low Re has also been studied under both low and high *** is found that higher Re or FST level leads to earlier *** has a greater effect than FST on the development of boundary *** effect of FST on the boundary layer depends on the *** boundary layer development shows totally different behaviors under different Ma.A separation bubble could be formed under low Ma while no attachment could be detected under high *** FST has a stronger effect on the separated boundary layer under low Ma,which could eliminate the separation in the present *** all the cases under low FST,the Kelvin-Helmholtz instability is the dominate mechanism in the transition *** the low Ma case with high FST,the streamwise streaks play a dominant role in the transition *** the high Ma cases with high FST,both the streamwise streaks and Kelvin-Helmholtz instability work in the transition *** streamwise streaks play a more important role when the Re increased.

关键词： freestream turbulence Reynolds number Mach number low pressure turbine boundary layer

Prediction of NO_(x)concentration using modular long short-term memory neural network for municipal solid waste incineration

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Chinese Journal of Chemical Engineering 2023年第4期56卷 46-57页

作者： Haoshan duan Xi Meng Jian Tang Junfei qiao Faculty of Information Technology Beijing University of TechnologyBeijing 100124China Beijing Laboratory of Smart Environmental Protection Beijing 100124China Beijing Key Laboratory of Computational Intelligence and Intelligent System Beijing 100124China Engineering Research Center of Intelligence Perception and Autonomous Control Ministry of Education Beijing 100124China

Air pollution control poses a major problem in the implementation of municipal solid waste incineration(MSWI).Accurate prediction of nitrogen oxides(NO_(x))concentration plays an important role in efficient NO_(x)emission *** this study,a modular long short-term memory(M-LSTM)network is developed to design an efficient prediction model for NO_(x)***,the fuzzy C means(FCM)algorithm is utilized to divide the task into several sub-tasks,aiming to realize the divide-and-conquer ability for complex ***,long short-term memory(LSTM)neural networks are applied to tackle corresponding sub-tasks,which can improve the prediction accuracy of the ***,a cooperative decision strategy is designed to guarantee the generalization performance during the testing or application ***,after being evaluated by a benchmark simulation,the proposed method is applied to a real MSWI *** the experimental results demonstrate the considerable prediction ability of the M-LSTM network.

关键词： Municipal solid waste incineration NO_(x)concentration prediction Modular neural network Model

Pigeon-inspired optimization:a new swarm intelligence optimizer for air robot path planning

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International Journal of Intelligent Computing and Cybernetics 2014年第1期7卷 24-37页

作者： Haibin duan Peixin qiao School of Automation Science and Electrical Engineering Beihang University(Beijing University of Aeronautics and AstronauticsBUAA)BeijingP.R.China

Purpose–The purpose of this paper is to present a novel swarm intelligence optimizer—pigeoninspired optimization(PIO)—and describe how this algorithm was applied to solve air robot path planning ***/methodology/approach–The formulation of threat resources and objective function in air robot path planning is *** mathematical model and detailed implementation process of PIO is *** experiments with standard differential evolution(DE)algorithm are also ***–The feasibility,effectiveness and robustness of the proposed PIO algorithm are shown by a series of comparative experiments with standard DE *** computational results also show that the proposed PIO algorithm can effectively improve the convergence speed,and the superiority of global search is also verified in various ***/value–In this paper,the authors first presented a PIO *** this newly presented algorithm,map and compass operator model is presented based on magnetic field and sun,while landmark operator model is designed based on *** authors also applied this newly proposed PIO algorithm for solving air robot path planning problems.

关键词： Evolutionary computation Robotics

Almost periodic solutions of memristive multidirectional associative memory neural networks with mixed time delays

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International Journal of Biomathematics 2024年第2期17卷 113-138页

作者： Yan Zhang Yuanhua qiao Lijuan duan Faculty of Science Beijing University of Technology Beijing 100124P.R.China Faculty of Information Technology Beijing University of Technology Beijing 100124P.R.China

Traditional biological neural networks cannot simulate the real situation of the abrupt synaptic connections between neurons while modeling associative memory of human *** this paper,the memristive multidirectional associative memory neural networks(MAMNNs)with mixed time-varying delays are investigated in the sense of Filippov ***,three steps are given to prove the existence of the almost periodic *** new lemmas are proposed to prove the boundness of the solution and the asymptotical almost periodicity of the solution by constructing Lyapunov ***,the uniqueness and global exponential stability of the almost periodic solution of memristive MAMNNs are investigated by a new Lyapunov *** sufficient conditions guaranteeing the properties of almost periodic solution are derived based on the relevant definitions,Halanay inequality and Lyapunov *** investigation is an extension of the research on the periodic solution and almost periodic solution of bidirectional associative memory neural ***,numerical examples with simulations are presented to show the validity of the main results.

关键词： Almost periodic solutions memristive multidirectional associative memory neural networks mixed time-varying delays global exponential stability

Global Well-posedness of the Stochastic Generalized Kuramoto-Sivashinsky Equation with Multiplicative Noise

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Acta Mathematicae Applicatae Sinica 2018年第3期34卷 566-584页

作者： Wei WU Shang-bin CUI Jin-qiao duan Science and Information College Qingdao Agricultural University Qingdao 266109 China Department of Mathematics Sun Yat-Sen University Guangzhou 510275 China Department of Applied Mathematics Illinois Institute of Technology Chicago IL 60616 USA Center for Mathematical Sciences Huazhong University of Science and Technology Wuhan 430074 China

Global well-posedness of the initial-boundary value problem for the stochastic generalized KuramotoSivashinsky equation in a bounded domain D with a multiplicative noise is studied. It is shown that under suitable sufficient conditions, for any initial data u0 ∈L2（D×Ω）, this problem has a unique global solution u in the space L2（Ω, C（[0, T ], L2（D））） for any T 〉 0, and the solution map u0 →u is Lipschitz continuous.

关键词： Kuramoto-Sivashinsky equation stochastic partial differential equations multiplicative noise well-posedness

Tailoring the mechanical properties of bulk metallic glasses via cooling from the supercooled liquid region

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Science China(Technological Sciences) 2023年第1期66卷 173-180页

作者： ZHANG LangTing duan YaJuan WANG YunJiang YANG Yong qiao JiChao School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 710072China Department of Physics Barcelona Research Center in Multiscale Science and TechnologyInstitute of Energy TechnologiesUniversitat PolitecnicadeCatalunyaBarcelona08019Spain State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China Department of Mechanical Engineering College of EngineeringCity University of Hong KongHong Kong 999077China Department of Materials Science and Engineering College of EngineeringCity University of Hong KongHong Kong 99077China Innovation Center NPU-ChongqingChongqing 401135China

Structural rejuvenation is vital and attractive for modulating the energetic state and structural heterogeneity of bulk metallic glasses(BMGs). In this paper, we show that cooling a BMG from a supercooled liquid region at laboratory rates can reverse the relaxation enthalpy lost during the preceding structural relaxation. Increasing the cooling rate is beneficial for enhancing atomic mobility and dynamic mechanical relaxation intensity. Therefore, this rejuvenation methodology promotes tailoring the mechanical properties of BMGs and provides a comprehensive understanding of the rejuvenation mechanism.

关键词： bulk metallic glass thermal rejuvenation supercooled liquid region mechanical relaxation structural heterogeneity

Toward an Ecological Civilization:China’s Progress as Documented by the Second National General Survey of Pollution Sources

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Engineering 2021年第9期7卷 1336-1341页

作者： Minghui Xie Huabo duan Peng Kang Qi qiao Lu Bai State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Key Laboratory of Coastal Urban Resilient Infrastructures(Shenzhen University) Ministry of EducationUnderground Polis AcademyCollege of Civil and Transportation EngineeringShenzhen UniversityShenzhen 518060China

The relationship between environmental quality and economic growth has been a hot topic for *** years of rapid industrialization and urbanization,China’s environmental challenges are approaching a turning *** the principles of ecological civilization construction,China is on its way to maintaining high-quality and green economic *** 10 June 2020,the Chinese Government reported the key findings of the Second National General Survey of Pollution Sources(fiscal year 2017),which provides strong quantitative evidence of progress toward ecological *** terms of our comparison between the two National General Surveys in 2007 and 2017,it was found that environmental pollution,measured in terms of many wastewater and air emission pollutant discharges,is decreasing despite the steady growth in economic activities—and at a noticeably fast *** national and local governments can adopt some of China’s ecological civilization practices,within their own individual contexts.

关键词： Ecological civilization National General Survey of Pollution Sources Green development Sustainable development

沙库巴曲缬沙坦钠片与盐酸贝那普利治疗慢性心力衰竭患者的疗效对比

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中国医药指南 2025年第1期23卷 107-109页

作者：段秋艳赵连山李巧北京水利医院内科北京100036

目的对比慢性心力衰竭盐酸贝那普利与沙库巴曲缬沙坦钠片的疗效。方法回顾性选取2021年1月至2023年1月北京水利医院慢性心力衰竭患者120例,依据用药方法分为沙库巴曲缬沙坦钠片组、盐酸贝那普利组两组,各60例。统计分析两组心功能分级... 详细信息

目的对比慢性心力衰竭盐酸贝那普利与沙库巴曲缬沙坦钠片的疗效。方法回顾性选取2021年1月至2023年1月北京水利医院慢性心力衰竭患者120例,依据用药方法分为沙库巴曲缬沙坦钠片组、盐酸贝那普利组两组,各60例。统计分析两组心功能分级、心功能超声指标、6 min步行距离(6MWT)、生物标志物水平、不良反应及主要心血管不良事件(MACE)发生情况。结果用药后,沙库巴曲缬沙坦钠片组患者的心功能分级优于盐酸贝那普利组,心脏指数(CI)、左心室射血分数(LVEF)、左心室质量指数(LVMI)、6MWT均高于盐酸贝那普利组,左房内径(LA)、左心室收缩末期内径(LVESD)、左心室舒张末期内径(LVEDD)、N末端B型利钠肽前体(NT-proBNP)、C反应蛋白(CRP)、降钙素原(PCT)水平均低于盐酸贝那普利组,不良反应发生率和MACE总发生率均低于盐酸贝那普利组(均P<0.05)。结论慢性心力衰竭患者治疗中沙库巴曲缬沙坦钠片改善心功能及预后的疗效较盐酸贝那普利显著。

关键词：慢性心力衰竭盐酸贝那普利沙库巴曲缬沙坦钠片心功能分级心功能超声