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Corrosion mechanism investigation of TiN/Ti coating and TC4 alloy for aircraft compressor application

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Chinese Journal of Aeronautics 2020年第6期33卷 1824-1835页

作者： Zhiping SUN guangyu he Qingjie MENG Yuqin LI Xiaodong TIAN School of Material Science and Engineering Chang'an UniversityXi'an 710064China Engineering Research Center of Transportation Materials of Ministry of Education Chang'an UniversityXi'an 710061China Science and Technology on Plasma Dynamics Laboratory Air Force Engineering UniversityXi'an 710038China

It is imperative to develop multifunctional erosion and corrosion resistant coatings for compressor blades of aircraft engines in harsh ***(Physical Vapor Deposition)technology has the advances in processing erosion-resistant coatings;however,the performance of PVD coatings to combat corrosion depends on various coating *** and comparing the corrosion performances of PVD TiN/Ti coating and uncoated TC4 alloy was the main objective of present *** 960 h salt spray corrosion and 116 h hot corrosion tests were conducted to simulate the grounding and working environments of the aircraft *** corrosion mechanisms due to the coating defects such as pinhole,columnar boundary and large grain were analyzed based on the OM,Confocal microscope,electrochemical measurements,SEM,XRD and EDS *** to the disordered state associated with the columnar boundary and the coating defect,nitrogen could be easily replaced by oxygen in the hot corrosion process,these structures were channels for fast diffusion of ***,the Gibbs energy changes of Ti oxidation and TiN oxidation were thermodynamically calculated according to the working condition of aircraft compressors,and considerable research effort was focused on mapping out the phase diagram of Ti,TiN and high pressure *** findings of this research can provide insights into developing multifunctional coatings for future aircraft engines.

关键词： Coaling defects Hot corrosion Microstructure Salt spray corrosion TiN/Ti coating

Analysis of Dynamic Appliance Flexibility Considering User Behavior via Non-intrusive Load Monitoring and Deep User Modeling

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CSEE Journal of Power and Energy Systems 2020年第1期6卷 41-51页

作者： Shaopeng Zhai Huan Zhou Zhihua Wang guangyu he School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 201100China Electric Power Dispatching and Communication Center State Grid Shanghai Municipal Electric Power CompanyShanghai 201200China

The research on non-intrusive load monitoring(NILM)and the growing deployment of home energy manage-ment system(heMS)have made it possible for households to have a detailed understanding of their power usage and to make appliances participate in demand response(DR)*** flexibility analysis helps the heMS dispatching appli-ances to participate in DR programs without violating user’s comfort *** this paper,a dynamic appliance flexibility analysis approach using the smart meter data is *** the training phase,the smart meter data is preprocessed by NILM to obtain user’s appliances usage behaviors,which is used to train the user *** operation,the NILM is used to infer recent appliances usage behaviors,and then the user model predicts user’s appliances usage behaviors in the DR period considering long-term behaviors dependences,correlations between appliances and temporal *** flexibility of each appliance is calculated based on the appliance characteristics as well as the predicted user’s appliances usage behaviors caused by the control of the *** heMS can choose the appliance with high flexibility to participate in the DR *** case study demonstrates the performance of the user model and illustrates how the appliance flexibility analysis is performed using a real-world case.

关键词： Appliance flexibility demandresponse home energy management system non-intrusive load monitoring user behavior

An assessment framework for branch parameter estimation of power systems

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Science China(Technological Sciences) 2012年第6期55卷 1631-1643页

作者： ZHU JianQuan LIU Feng MEI ShengWei he guangyu State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing I00084China

This paper proposes an assessment framework for branch parameter estimation of power systems,based on which the estimation accuracy can be improved and the estimation reliability can be *** proposed framework comprises three parts:1) Parameter credibility assessment to evaluate the credibility of original parameters in the case that their true values are unknown;2) estimation accuracy assessment to provide quantitative information about the validity of the estimation;3) parameter dominance assessment to find out the key parameters for the *** framework can be incorporated into the conventional parameter estimation process easily such that the accuracy and reliability of the estimation are *** implementation problems are addressed in *** are carried out on the IEEE 14-bus system,IEEE 30-bus system,and IEEE 300-bus system to show the correctness and effectiveness of the proposed assessment framework.

关键词： power systems assessment branch parameter estimation

On engineering implementation of the digital power system

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Science China(Technological Sciences) 2008年第11期51卷 2021-2030页

作者： he guangyu SUN YingYu CHANG NaiChao MEI ShengWei State Key Lab of Power Systems Departmet of Electrical EngineeringTsinghua UniversityBeijing 100084China

The narrow definition of the digital power system (DPS) is proposed. The architec- ture, features and key contents of the DPS are presented, which include intelligent dispatching system, hybrid automatic control system and data sharing platform. The successful construction of the DPS can greatly improve the performances of power system operating and dispatching, which mainly reflect a fundamental in- crease of the ability of avoiding catastrophes resulting from blackouts of power supply, a significant improvement of economic efficiency of power system opera- tion, and an improvement of decision efficiency of power system developing. The DPS describes a vision of the development of power system and the way to achieve this vision. At the same time, the paper also proposes the principles of the design and implementation of the DPS.

关键词： digital power system architecture intelligent dispatching center hybrid control data sharing platform

A review on ignition mechanisms and characteristics of magnesium alloys

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Journal of Magnesium and Alloys 2020年第2期8卷 329-344页

作者： Dong Han Jin Zhang Jinfeng Huang Yong Lian guangyu he University of Science and Technology 30 Xueyuan RoadHaidian DistrictBeijing 100083PR China Science and Technology on Plasma Dynamics Laboratory Air Force Engineering UniversityXi'anShanxi 710038PR China

Magnesium alloys have become more attractive because of their low density and electromagnetic shielding effectiveness in the aerospace ***,some unpredictable situation may lead to the ignition of magnesium *** this review,the thermodynamic conditions and transfer processes of magnesium alloys ignition are analyzed from the point of *** criteria of ignition are *** addition,ignitability and flammability test systems are *** a more suitable method to assess the potential ignition and flammability risks of magnesium alloys in extreme environments is ***,the ignition characteristics of magnesium alloys are discussed in *** was found that the ignition of magnesium alloys is a complex process determined by internal properties such as thermo-physical properties,oxide film properties,chemical compositions and geometrical parameters,as well as the external environment such as gas species,oxygen concentration and oxygen *** temperature is not physical constants of *** is not simply assumed that ignition may occur when the temperature of Mg alloys reaches a certain ignition ***,the unsolved issues in the ignition of magnesium alloys are pointed out and the future investigation are suggested for improving the safety and reliability of magnesium alloys in the aerospace applications.

关键词： Magnesium alloys Ignition mechanisms Ignition characteristics

Advances in sodium-ion batteries at low-temperature: Challenges and strategies

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Journal of Energy Chemistry 2024年第3期90卷 518-539,I0012页

作者： Haoran Bai Xiaohui Zhu Huaisheng Ao guangyu he Hai Xiao Yinjuan Chen Key Laboratory of Advanced Catalytic Materials and Technology Advanced Catalysis and Green Manufacturing Collaborative Innovation CenterChangzhou UniversityChangzhou 213164JiangsuChina Department of Chemistry Tsinghua UniversityBeijing 100084China

With the continuing boost in the demand for energy storage,there is an increasing requirement for batteries to be capable of operation in extreme environmental ***-ion batteries(SIBs) have emerged as a highly promising energy storage solution due to their promising performance over a wide range of temperatures and the abundance of sodium resources in the earth's *** to lithiumion batteries(LIBs),although sodium ions possess a larger ionic radius,they are more easily desolvated than lithium *** rthermore,SIBs have a smaller Stokes radius than lithium ions,resulting in improved sodium-ion mobility in the ***,SIBs demonstrate a significant decrease in performance at low temperatures(LT),which constrains their operation in harsh weather *** the increasing interest in SIBs,there is a notable scarcity of research focusing specifically on their mechanism under LT *** review explores recent research that considers the thermal tolerance of SIBs from an inner chemistry process perspective,spanning a wide temperature spectrum(-70 to100℃),particularly at LT *** addition,the enhancement of electrochemical performance in LT SIBs is based on improvements in reaction kinetics and cycling stability achieved through the utilization of effective electrode materials and electrolyte ***,the safety concerns associated with SIBs are addressed and effective strategies are proposed for mitigating these ***,prospects conducted to extend the environmental frontiers of commercial SIBs are discussed mainly from three viewpoints including innovations in materials,development and research of relevant theoretical mechanisms,and intelligent safety management system establishment for larger-scale energy storage SIBs.

关键词： Low-temperature Sodium-ion batteries Reaction kinetics Cycle stability Safety concerns of Sodium-ion batteries

Optimal power flow calculation in AC/DC hybrid power system based on adaptive simplified human learning optimization algorithm

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Journal of Modern Power Systems and Clean Energy 2016年第4期4卷 690-701页

作者： Jia CAO Zheng YAN Xiaoyuan XU guangyu he Shaowei HUANG The Ministry of Education Key Laboratory of Control of Power Transmission and Conversion Department of Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China

This paper employs an efficacious analytical tool,adaptive simplified human learning optimization(ASHLO)algorithm,to solve optimal power flow(OPF)problem in AC/DC hybrid power system,considering valve-point loading effects of generators,carbon tax,and prohibited operating zones of generators,*** algorithm,involves random learning operator,individual learning operator,social learning operator and adaptive *** compare and analyze the computation performance of the ASHLO method,the proposed ASHLO method and other heuristic intelligent optimization methods are employed to solve OPF problem on the modified IEEE 30-bus and 118-bus AC/DC hybrid test *** results indicate that the ASHLO method has good convergent property and ***,the impacts of wind speeds and locations of HVDC transmission line integrated into the AC network on the OPF results are systematically analyzed.

关键词： Adaptive simplified human learning optimization algorithm Optimal power flow AC/DC hybrid power system Valve-point loading effects of generators Carbon tax Prohibited operating zones

Modern power systems control centers:From EMS to AEMS

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Science China(Technological Sciences) 2009年第2期52卷 413-419页

作者： he guangyu SUN YingYun RUAN QianTu WANG Wei DONG ShuFeng Department of Electrical Engineering Tsinghua UniversityBeijing 100084China Shanghai Municipal Electric Power Company Shanghai 200122China

Traditional energy management system (EMS) plays an indispensable role in control centers of electric power systems. However, it also has several shortcomings, including lack of real-time closed-loop control, unreliable functional modules, and difficult to exchange data. The electric hybrid control theory (EHCT) has been proposed as an innovative and effective means to overcome these shortcomings. This paper argues that the EHCT provides a theoretical foundation for the advanced energy management system (AEMS) that can achieve multi-objective, near-optimal, and closed-loop control of electric power grids. This paper also discusses the significance for control centers to evolve from the traditional EMS to the AEMS. Furthermore, this paper points out that the traditional EMS can be considered as an integral part of the AEMS and that the AEMS can be built upon the traditional EMS. Thus, the resources that are currently available can be fully utilized to achieve near-optimal and closed-loop control of power system operations.

关键词： hybrid control multi-objective near-optimal control advanced energy management system event driven

Water-induced hydrogenation of graphene/metal interfaces at room temperature:Insights on water intercalation and identification of sites for water splitting

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Nano Research 2019年第12期12卷 3101-3108页

作者： guangyu he Qi Wang Hak Ki Yu Daniel Farias Yingchun Liu Antonio Politano Department of Chemistry Zhejiang UniversityHangzhou 310027China Department of Materials Science and Engineering and Department of Energy Systems Research Ajou UniversitySuwon 16499Republic of Korea Departamento de Ftsica de la Materia Condensada Universidad Autonoma de MadridMadrid 28049Spain Instituto"Nicolas Cabrera"and Condensed Matter Physics Center(IFIMAC) Universidad Autonoma de MadridMadrid 28049Spain Department of Physical and Chemical Sciences University of L'AquilaVia Vetoio 10L'Aquila 1-67100Italy CNR-IMM Istituto per la Microelettronica e Microsistemi VIII strada 5Catania 1-95121Italy

Though it is well recognized that the space between graphene cover and the metal substrate canact as a two-dimensional(2D)nanoreactor,several issues are still unresolved,including the role of the metal substrate,the mechanisms ruling water intercalation and the identification ofsites at which water is ***,we solve these issues by means of density functional theory and high-resolution electron energyloss spectroscopy experiments carried out on graphene grown on(111)-oriented Cu ***,we observe decomposition of H2O atroom temperature with only H atoms forming bonds with graphene and with buried OH groups underneath the graphene *** model discloses physicochemical mechanisms ruling the migration and decomposition of water on graphene/*** discover thatthe edge of graphene can be easily saturated by H through decomposition of H2O,which allows H2O to migrate in the subsurface region from thedecoupled edge,where H2O decomposes at room *** atoms produced by the decomposition of H2O initially form a chemicalbond with graphene for the lower energy barrier compared with other *** findings are essential to exploit graphene/Cu interfaces incatalysis and in energy-related applications.

关键词： graphene/metal interfaces intercalation water splitting room temperature