检索结果-南通市图书馆

A Numerical Study of the TipWake of aWind Turbine Impeller Using Extended Proper Orthogonal Decomposition

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2020年第5期16卷 883-901页

作者： weimin wu Chuande Zhou School of Mechanical and Power Engineering Chongqing University of Science&TechnologyChongqing401331China

The behavior of the tip wake of a wind turbine is one of the hot issues in the wind power *** problem can partially be tackled using Computational Fluid Dynamics(CFD).However,this approach lacks the ability to provide insights into the spatial structure of important high-order ***,with the horizontal axis wind turbine as the main focus,in this work,firstly,we conduct CFD simulations of the wind turbine in order to obtain a data-driven basis relating to multiple working conditions for further ***,these data are studied using an extended Proper Orthogonal Decomposition(POD)*** quantitative results indicate that the tip vortex in the wake has a complicated spatio-temporal morphological configuration in the higher-order extended POD *** radial velocity modes obtained are effective and credible,and such reconstructed flow of the tip vortex becomes clearer with the increase of the reconstruction ***,the changes of relatively high-order correlation coefficients are essentially affected by the periodic fusion of tip and central eddies in the wake.

关键词： Wind turbine tip vortex extended POD algorithm multi-level flow mode

Hybrid Modular Smart Transformer for Asymmetrically Bidirectional Power Flow Operation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第4期10卷 1384-1398页

作者： Kangan Wang Youngjong Ko Rongwu Zhu Siyu wu weimin wu Marco Liserre Shanghai Maritime University Shanghai 201306China Pukyong National University Busan 48513South Korea Harbin Institute of Technology(Shenzhen) Shenzhen 518000China Kiel University Kiel 24118Germany

The presence of renewable energy resources in LV distribution networks may lead to a distribution transformer,also known as a Smart Transformer(ST),experiencing the bidirectional power ***,the ST must have the capability to operate in both ***,the reverse power is less as compared to the forward power,thus the design of ST with the same capacity in both directions increases the hardware cost and decreases the system *** paper proposes a Hybrid-modular-ST(H-ST),composed of a mixed use of single active bridge-based series resonant converter and dual active bridge instead of complete use of uni-or bi-directional converter adopted in the conventional *** on the proposed H-ST,the impacts of power imbalance among cascaded modules in reverse operation mode are analyzed and then an effective solution based on reactive power compensation combined with the characteristics of the proposed architecture is *** simulation and experimental results clearly validate the effectiveness and feasibility of the theoretical analyses.

关键词： Cascaded H-bridge dual-active bridge series resonant converter smart transformer(ST) three-stage architecture

REPORT ON DETERMINATION OF THE REST MASS OF ELECTRON NEUTRINO WITH 3H β RAY SPECTROSCOPY

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 1990年第8期7卷 345-348页

作者： MEI Zhenyue KE Zunjian wu weimin ZHAO Zhengguo Department of Modern Physics University of Science and Technology of ChinaHefei 230026 CCAST(World Laboratory) Beijing 100039

With an iron free double focusing β ray spectrometer and Bergkvist electrostatic compensated Ti^(3)H and implantated tritium source,we studiedβray spectrum of 3H near the end *** found that if the rest mass of elect... 详细信息

关键词： point electrostatic spectrum

Collision and Deadlock Avoidance in Multi-Robot Systems Based on Glued Nodes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2022年第7期9卷 1327-1330页

作者： Zichao Xing Xinyu Chen Xingkai Wang weimin wu Ruifen Hu The authors are with the State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and ControlZhejiang UniversityHangzhou 310027China IEEE

Dear editor,In this letter,we would like to discuss a method to avoid collisions and deadlocks in multi-robot systems based on a new concept of glued *** terms of collision and deadlock avoidance,many methods are based on zone control which has two ***,unless all nodes are collision-free,the roadmap must be divided into disjoint zones,which increases the difficulty of applying the ***,each zone should be able to accommodate a robot,which leads to imprecision and waste of *** letter proposes the concept of glued nodes,which can dynamically determine the mutual influence between nodes based on the real-time sizes and paths of the *** on the glued nodes,this letter proposes a collision and deadlock avoidance algorithm,which can be applied to multi-robot systems with variable-sized robots and roadmaps with any *** experimental results indicate that the method proposed in this letter is effective and efficient.

关键词： lock collision letter

Asymmetrical Fault Current Calculation Method and Influencing Factors Analysis of Droop-Controlled Inverters

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第2期10卷 562-573页

作者： Huimin Zhao Zhikang Shuai Jun Ge An Luo weimin wu Z.John Shen College of Electrical and Information Engineering Hunan UniversityChangsha 410006China Electrical Engineering Department Shanghai Maritime UniversityShanghai 201306China Department of Electrical and Computer Engineering Ilinois Institute of TechnologyChicagoIL 60616 USA

Since the fault dynamic of droop-controlled inverter is different from synchronous generators (SGs), protection devices may become invalid, and the fault overcurrent may damage power electronic devices and threaten the safety of the microgrid. Therefore, it is imperative to conduct a comprehensive fault analysis of the inverter to guide the design of protection schemes. However, due to the complexity of droop control strategy, existing literatures have simplified asymmetric fault analysis of droop-controlled inverters to varying degrees. Therefore, accurate fault analysis of a droop-controlled inverter is needed. In this paper, by analyzing the control system, an accurate fault model is established. Based on this, a calculation method for instantaneous asymmetrical fault current is proposed. In addition, the current components and current characteristics are analyzed. It was determined that fault currents are affected by control loops, fault types, fault distance and nonlinear limiters. In particular, the influences of limiters on the fault model, fault current calculation and fault current characteristics were analyzed. Through detailed analysis, it was found that dynamics of the control loop cannot be ignored, the fault type and fault distance determine fault current level, and part of the limiters will totally change the fault current trend. Finally, calculation and experimental results verify the correctness of the proposed method.

关键词： Asymmetrical fault analysis droop control fault current calculation method limiter transient fault characteristics

Sediment microbial fuel cell with floating biocathode for organic removal and energy recovery

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2012年第4期6卷 569-574页

作者： Aijie WANG Haoyi CHENG Nanqi REN Dan CUI Na LIN weimin wu State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150090China Department of Civil and Environmental Engineering Stanford UniversityStanfordCA 94305-4020USA

A sediment microbial fuel cell （SMFC） with three dimensional floating biocathode （FBC） was developed for the electricity generation and biodegradation of sediment organic matter in order to avoid negative effect of dissolved oxygen （DO） depletion in aqueous environments on cathode performance and search cost-effective cathode materials. The biocathode was made from graphite granules with microbial attachment to replace platinum （Pt）-coated carbon paper cathode in a laboratory-scale SMFC （3 L in volume） filled with river sediment （organic content 49±4 g. kg^-1 dry weight）. After start-up of 10 days, the maximum power density of 1.00W.m^-3 （based on anode volume） was achieved. The biocathode was better than carbon paper cathode catalyzed by Pt. The attached biofilm on cathode enhanced power generation significantly. The FBC enhanced SMFC performance further in the presence aeration. The SMFC was continuously operated for an over 120-day period. Power generation peaked within 24 days, declined gradually and stabilized at a level of 1/6 peak power output. At the end, the sediment organic matter content near the anode was removed by 29% and the total electricity generated was equal to 0.251 g of chemical oxygen demand （COD） removed.

关键词： microbial fuel cell (MFC) sediment biocathode electricity generation organic removal

A Survey of Model Predictive Control Methods for Traffic Signal Control

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2019年第3期6卷 623-640页

作者： Bao-Lin Ye weimin wu Keyu Ruan Lingxi Li Tehuan Chen Huimin Gao Yaobin Chen IEEE the School of Mechanical and Electrical Engineering Jiaxing University the State Key Laboratory of Industrial Control Instituteof Cyber-Systems and Control Technology Zhejiang University the Department of Electrical and Computer Engineering Purdue School of Engineering and TechnologyIndiana University-Purdue University Indianapolis Mechanical Engineering and Mechanics Ningbo University

Enhancing traffic efficiency and alleviating(even circumventing) traffic congestion with advanced traffic signal control(TSC) strategies are always the main issues to be addressed in urban transportation systems. Since model predictive control(MPC) has a lot of advantages in modeling complex dynamic systems, it has been widely studied in traffic signal control over the past 20 years. There is a need for an in-depth understanding of MPC-based TSC methods for traffic networks. Therefore, this paper presents the motivation of using MPC for TSC and how MPC-based TSC approaches are implemented to manage and control the dynamics of traffic flows both in urban road networks and freeway networks. Meanwhile, typical performance evaluation metrics, solution methods, examples of simulations,and applications related to MPC-based TSC approaches are reported. More importantly, this paper summarizes the recent developments and the research trends in coordination and control of traffic networks with MPC-based TSC approaches. Remaining challenges and open issues are discussed towards the end of this paper to discover potential future research directions.

关键词： Autonomous vehicles coordination control mixed integer programming model predictive control system decomposition traffic flow models traffic signal control

Rotationally symmetric translating soliton of H^k-flow

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2010年第4期53卷 1011-1016页

作者： SHENG weimin & wu Chao Department of Mathematics,Zhejiang University,Hangzhou 310027,China 1. Department of Mathematics Zhejiang University Hangzhou 310027 China

This paper mainly considers the translating soliton of H k-flow for k > *** give the asymptotic expression of the entire rotationally symmetric translating soliton,and obtain non-convex 'Wing-like' solution as well as... 详细信息

关键词： H k-flow translating soliton 'Wing-like' solution

Enzyme activities and gene expression of starch metabolism provide insights into grape berry development

在线全文

学校读者我要写书评

暂无评论

Horticulture Research 2017年第1期4卷 277-292页

作者： Xudong Zhu Chaobo Zhang weimin wu Xiaopeng Li Chuan Zhang Jinggui Fang College of Horticulture Nanjing Agricultural UniversityNo 1 weigangNanjing210095China Institute of Horticulture Jiangsu Academy of Agricultural SciencesNo 50 Zhongling roadNanjing210014China

Grapes are categorized as a non-climacteric type of fruit which its ripening is not associated to important rises in respiration and ethylene *** starch metabolism shares a certain role in the carbohydrate metabolic pathways during grape berry development,and is regarded as an important transient pool in the pathway of sugar ***,the comprehensive role of starch and its contribution to the quality and flavor of grape berry have not been explored *** this study,the expression levels of genes enzyme activities and carbohydrate concentrations related to starch metabolism,were analyzed to understand the molecular mechanism of starch accumulation during grape berry *** results indicated that starch granules in grape berry were located at the chloroplast in the sub-epidermal tissues,acting as the temporary reserves of photosynthetic products to meet the needs for berry development,and relatively high starch contents could be detected at véraison ***,both ADP-glucose pyrophosphorylase(EC 2.***.7.27)and sucrose phosphate synthase(EC 2.***.1.14)involved in starch synthesis displayed elevated gene expression and enzymes activities in the sub-epidermal tissue,whileα-andβ-amylases involved in its degradation were highly transcribed and active in the central flesh,explaining the absence of starch in this last *** in the gene expression and activities of ADP-glucose pyrophosphorylase,β-amylase and sucrose phosphate synthase revealed that they were regulated by the circadian rhythms in the fruitlets compared with those in the *** the morphological,enzymological and transcriptional data in this study provide advanced understandings on the function of starch during berry development and ripening that are so important for berry *** study will further facilitate our understanding of the sugar metabolism in grape berry as well as in other plant species.

关键词： metabolism starch elevated