检索结果-南通市图书馆

Secondary Frequency Control Considering Optimized Power Support From Virtual Power Plant Containing Aluminum Smelter Loads Through VSC-HVDC Link

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2023年第1期11卷 355-367页

作者： Peng bao Wen zhang Yuxi zhang Key laboratory of Power System Intelligent Dispatch and Control of the Ministry of Education Shandong UniversityJinan 250061China

The growing number of renewable energy replacing conventional generators results in a loss of the reserve for frequency control in power systems,while many industrial power grids often have excess energy supply due to abundant wind and solar energy *** paper proposes a secondary frequency control(SFC)strategy that allows industrial power grids to provide emergency high-voltage direct current(HVDC)power support(EDCPS)for emergency to a system requiring power support through a voltage source converter(VSC)HVDC *** architecture including multiple model predictive control(MPC)controllers with periodic communication is designed to simultaneously obtain optimized EDCPS capacity and minimize adverse effects on the providing power support(PPS)***,a model of a virtual power plant(VPP)containing aluminum smelter loads(ASLs)and a high penetration of wind power is established for the PPS *** flexibility and controllability of the VPP are improved by the demand response of the *** uncertainty associated with wind power is considered by chance *** effectiveness of the proposed strategy is verified by simulation results using the data of an actual industrial power grid in Inner Mongolia,*** DC voltage of the VSCs and the DC in the potlines of the ASLs are also investigated in the simulation.

关键词： Secondary frequency control power support voltage source converter(VSC) high-voltage direct current(HVDC) model predictive control(MPC) virtual power plant(VPP) demand response

Improving inherent soil productivity underpins agricultural sustainability

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2023年第1期33卷 3-5页

作者： Jia bao zhang State Key laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China)

There is now increasing attention to how to raise global food production and security due to the expanding population *** and high yield of crops depends on soil quality improvement,which relies on inherent soil productivity *** in inherent soil productivity can provide a range of benefits for soil structure,microorganisms,nutrient cycling,and carbon *** underlying mechanisms related to inherent soil productivity improvement under different agricultural management practices on large scales need to be further ***,to achieve agricultural sustainability,efforts need to focus on developing technologies related to straw return,tillage management,and cover cropping and understanding their relationships with inherent soil productivity improvement.

关键词： soil crops return

Optimization Design of Minimum Total Resistance Hull Form Based on CFD Method

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2018年第3期32卷 323-330页

作者： zhang bao-ji zhang Sheng-long zhang Hui College of Ocean Science and Engineering Shanghai Maritime University Merchant Marine College Shanghai Maritime University

In order to reduce the resistance and improve the hydrodynamic performance of a ship, two hull form design methods are proposed based on the potential flow theory and viscous flow theory. The flow fields are meshed using body-fitted mesh and structured grids. The parameters of the hull modification function are the design variables. A three-dimensional modeling method is used to alter the geometry. The Non-Linear Programming(NLP) method is utilized to optimize a David Taylor Model Basin(DTMB) model 5415 ship under the constraints, including the displacement constraint. The optimization results show an effective reduction of the resistance. The two hull form design methods developed in this study can provide technical support and theoretical basis for designing green ships.

关键词： total resistance hull form design CFD technique Non-Linear Programming(NLP)

Numerical analysis for the matching of the core driven compression system in a double bypass engine

在线全文

学校读者我要写书评

暂无评论

航空动力学报 2011年第5期26卷 1066-1076页

作者： zhang Xin LIU bao-jie National Key laboratory of Science and Technology on Aero-Engine Aero-thermodynamics School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China

The numerical analysis for the matching of the core driven compression system in a double bypass variable cycle engine was presented in this *** system consists of a one-stage-core driven fan stage(CDFS),an inner bypass duct and a five-stage high pressure compressor(HPC),providing two basic operating modes: the single bypass mode and the double bypass *** vanes are necessary to realize the mode switch of the *** correct matching in the double bypass mode requires a proper combination of the mass flow,total pressure ratio and blade *** work capacity of the system decreases in the double bypass mode and the pressure ratio tends to decrease more for the CDFS and the front stages of the *** overall system efficiency is higher in the double bypass *** radial distributions of aerodynamic parameters are similar in different *** notable redistribution of mass flow downstream the CDFS in the single bypass mode leads to strong radial flows and additional mixing *** absolute flow angles into the inner bypass increase for the inner span and decrease for the outer span when the system is switched from the single bypass mode to the double bypass mode.

关键词： numerical analysis aerodynamic double bypass variable cycle engine core driven compression system core driven fan stage operating mode

Identifying Influential Spreaders in Complex Networks by Considering the Impact of the Number of Shortest Paths

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2021年第6期34卷 2168-2181页

作者： LUAN Yangyang bao Zhongkui zhang Haifeng School of Mathematical Science Anhui UniversityHefei 230601China

The study on how to identify influential spreaders in complex networks is becoming increasingly *** studies demonstrate that considering the shortest path length can improve the accuracy of identification,but which ignore the influence of the number of shortest *** many cases,even though the shortest path length of two nodes is rather larger,their interaction influence is also significant if the number of shortest paths between them is *** by this fact,the authors propose an improved centrality index(ICC)based on well-known closeness centrality and a semi-local iterative algorithm(semi-IA)to study the impact of the number of shortest paths on the identification of the influential *** comparing with several traditional centrality indices,such as degree centrality,k-shell decomposition,betweenness centrality and eigenvector centrality,the experimental results on real networks indicate that the ICC index and semi-IA have a better performance,regardless of the identification capability or the resolution.

关键词： Complex networks influential spreader number of shortest paths

Fabrication of green one-part geopolymer from silica-rich vanadium tailing via thermal activation and modification

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2022年第1期29卷 177-184页

作者： Shenxu bao Yongpeng Luo Yimin zhang Hubei Key laboratory of Mineral Resources Processing and Environment Wuhan University of TechnologyWuhan 430070China School of Resources and Environmental Engineering Wuhan University of TechnologyWuhan 430070China State Environmental Protection Key laboratory of Mineral Metallurgical Resources Utilization and Pollution Control Wuhan University of Science and TechnologyWuhan 430081China Hubei Collaborative Innovation Center for High Efficient Utilization of Vanadium Resources Wuhan University of Science and TechnologyWuhan 430081China

The aim of this investigation was to prepare geopolymeric precursor from vanadium tailing(VT)by thermal activation and *** activation,a homogeneous blend of VT and sodium hydroxide was calcinated at an elevated temperature and then modified with metakaolin to produce a geopolymeric *** the thermal activation,the VT was corroded by sodium hydroxide and then sodium silicate formed on the particle *** water was added,the sodium silicate coating dissolved to release silicon species,which created an alkaline solution *** metakaolin then dissolved in the alkaline environment to generate aluminum species,which was followed by *** VT particles were connected by a gel produced during geopolymerization,which yielded a geopolymer with excellent mechanical *** investigation not only improves the feasibility of using geopolymer technology for large-scale and in-situ applications,but also promotes the utilization of VT and other silica-rich solid wastes.

关键词： vanadium tailing thermal activation geopolymeric precursor compressive strength leaching behavior

Preparation of single-phase ammonium dimolybdate by combination process

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2012年第5期31卷 517-522页

作者： zhang bao XIA Xiaomei LI Qian School of Metallurgical Science and Engineering Central South University Changsha 410083 China

A novel method for the preparation of single-phase ammonium dimolybdate with industrial ammonium molybdate was studied. Various in- fluential factors were evaluated in the paper, including reaction temperature, reaction time, initial molybdenum concentration, initial NH_3 /Mo molar ratio, and stirring speed. Under the optimum experimental conditions, the crystallization rate of product is 85.23%. The X-ray diffraction (XRD) analysis and chemical analysis show that the product is single-phase ammonium dimolybdate, and no impurity phases exist. The scanning electronic microscope (SEM) image reveals uniform particle size, good particle dispersion, and no agglomeration between particles. Meanwhile, the final pH value of acidification was investigated. The total molybdenum recovery can reach up to 99.40%, and the main phases of acidification product are the same as those of raw material with the final pH value of 1.5. This determines that the acidification product can be used as a raw material to produce single-phase ammonium dimolybdate.

关键词： single-phase ammonium dimolybdate combination process crystallization rate phase composition total molybdenum recovery

Memory Analysis for Memristors and Memristive Recurrent Neural Networks

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2020年第1期7卷 96-105页

作者： Gang bao Yide zhang Zhigang Zeng Key laboratory of Cascaded Hydropower Stations Operation and Control Electrical Engineering and New EnergyChina Three Gorges UniversityYichang 443002and Hubei Key Laboratory of Applied Mathematics(Hubei University)Wuhan 430074China Department of Medical Engineering California Institute of TechnologyPasadenaCalifornia 91125 USA School of Artificial Intelligence and Automation Huazhong University of Science and Technologyand also with the Key Laboratory of Image Processing and Intelligent Control of Education Ministry of ChinaWuhan 430074China

Traditional recurrent neural networks are composed of capacitors, inductors, resistors, and operational *** neural networks are constructed by replacing resistors with memristors. This paper focuses on the memory analysis,i.e. the initial value computation, of memristors. Firstly, we present the memory analysis for a single memristor based on memristors’ mathematical models with linear and nonlinear ***, we present the memory analysis for two memristors in series and parallel. Thirdly, we point out the difference between traditional neural networks and those that are memristive. Based on the current and voltage relationship of memristors, we use mathematical analysis and SPICE simulations to demonstrate the validity of our methods.

关键词： Dopant drift memory memristive neural networks memristor

Thermal Transport Mechanism of Amorphous HfO_(2):A Molecular Dynamics Based Study

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第4期31卷 1052-1060页

作者： zhang Honggang WEI Han bao Hua University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai 200240China

Amorphous hafnium dioxide(a-HfO_(2))has attracted increasing interest in the application of semiconductor devices due to its high dielectric ***,the thermal transport properties of a-HfO_(2) are not well understood,which hinders its potential application in *** this work,we systematically investigate the thermal transport property of a-HfO_(2) using the molecular dynamics *** non-equilibrium molecular dynamics simulations reveal that the thermal conductivity of a-HfO;is length-dependent below 100 *** decomposed heat current further proves that the thermal transport of propagons and diffusons is sensitive to the system *** thermal conductivity is found to increase with temperature using Green-Kubo mode *** also quantify the contribution of each carrier to the thermal conductivity at different *** find that propagons are more important than diffusons in thermal transport at low temperatures(<100 K).In comparison,diffusons dominate heat transport at high *** have negligible contribution to the total thermal conductivity.

关键词： amorphous HfO2 molecular dynamics thermal conductivity mean free path size effect temperature effect