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Composite Model-free Adaptive Predictive Control for Wind Power Generation Based on Full Wind Speed

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CSEE Journal of Power and Energy Systems 2022年第6期8卷 1659-1669页

作者： Shuangxin Wang Jianshen li Zhongsheng Hou Qingye meng Meng LI School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China.Z.S.Hou is with the School of Electronic and Information EngineeringBeijing Jiaotong UniversityBeijing 100044China

Aiming at the problem that the existing model-based control strategy cannot fully reflect stochastic fluctuations of wind power,this paper presents a model-free adaptive predictive controller(MFAPC)for variable pitch systems with speed disturbance suppression.First,an improved small-world neural network with topology optimization is used for 15-second-ahead forecasting of wind speed,whose rolling time is 1s,and the predicted value serves as a feedforward to obtain the early compensation variation of the pitch angle.Second,a function of the multi-objective optimization at full wind speed with optimal power point tracking and minimum control variation is constructed,and an advanced one-step adaptive predictive control algorithm for wind power is proposed based on the online estimation and prediction of the time-varying pseudo partial derivative(PPD).In addition,the compound MFAPC framework is synthetically obtained,whose closed-loop effectiveness is verified by a BP-built pitch system based on the SCADA data with all working conditions.Robustness of the schemes has been analyzed in terms of parametric uncertainties and different operating conditions,and a detailed comparison is finally presented.The results show that the proposed MFAPC can not only effectively suppress the random disturbance of wind speed,but also meet the stability of wind power and the security of grid-connections for all operating conditions.

关键词： Feedforward correction full wind speed model-free adaptive predictive control(MFAPC) wind power wind speed prediction

NiSe_(2)-CoSe_(2) with a Hybrid Nanorods and Nanoparticles Structure for Efficient Oxygen Evolution Reaction

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Chinese Journal of Structural Chemistry 2022年第1期41卷 19-24页

作者： Meng LI ligang Feng School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

Hetero-structure induced high performance catalyst for oxygen evolution reaction(OER)in the water splitting reaction has received increased attention.Herein,we demonstrated a novel catalyst system of NiSe_(2)-CoSe_(2) consisting of nanorods and nanoparticles for the efficient OER in the alkaline electrolyte.This catalyst system can be easily fabricated via a low-temperature selenization of the solvothermal synthesized NiCo(OH)x precursor and the unique morphology of hybrid nanorods and nanoparticles was found by the electron microscopy analysis.The high valence state of the metal species was indicated by X-ray photoelectron spectroscopy study and a strong electronic effect was found in the NiSe_(2)-CoSe_(2) catalyst system compared to their counterparts.As a result,NiSe_(2)-CoSe_(2) exhibited high catalytic performance with a low overpotential of 250 mV to reach 10 mA·cm^(-2) for OER in the alkaline solution.Furthermore,high catalytic stability and catalytic kinetics were also observed.The superior performance can be attributed to the high valence states of Ni and Co and their strong synergetic coupling effect between the nanorods and nanoparticles,which could accelerate the charge transfer and offer abundant electrocatalytic active sites.The current work offers an efficient hetero-structure catalyst system for OER,and the results are helpful for the catalysis understanding.

关键词： oxygen evolution reaction NiSe_(2) CoSe_(2) hetero-structure electrocatalysis

Insights into spatio-temporal slow slip events offshore the Boso Peninsula in central Japan during 2011-2019 using GPS data

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Geodesy and Geodynamics 2022年第6期13卷 554-563页

作者： Meng LI li Yan Zhongshan Jiang Genru Xiao Faculty of Geomatics East China University of TechnologyNanchangJiangxi 330013China Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China Engineering Research Center for Seismic Disaster Prevention and Engineering Geological Disaster Detection of Jiangxi Province East China University of Technology(Earthquake Administration of Jiangxi Province)Nanchang 330013China

Using Global Positioning System(GPS)coordinate time series,we detect three transient slow slip events(SSEs)offshore the Boso Peninsula in central Japan during 2011-2019.To extract the tiny SSE signals obscured by the significant post-seismic deformation after the 2011 MW9.0 Tohoku earthquake,we develop a new GPS coordinate time series processing software to obtain these SSE-induced deformations from highnoise GPS data.In addition,we apply the principal component analysis-based inversion method(PCAIM)to get the spatio-temporal slip distribution of the three SSEs.The spatio-temporal evolutions of these slips reveal that the nucleation styles are different.Compared to the 2011 and 2018 SSEs,the 2013-2014 SSE displays faster slip spatio-temporal variation,deeper slip,shorter slip duration,minor seismic moment,and lower maximum slip rate.The 2018 SSE exhibits the most significant seismic moment,the maximum slip,and the maximum slip rate of these three SSEs.The spatio-temporal variations of the 2011 SSE are the most complex,containing two acceleration and deceleration phases.The slip zone expanded along the eastern side of the Boso Peninsula in the acceleration phase and shrank back in the deceleration phase.Furthermore,the recurrence interval of SSEs spans from 2.2 to 4 years during 2011-2019,suggesting that the recurrence interval might become shorter and non-periodic due to the enormous earthquake.After the 2013-2014 SSE,the recurrence interval of the SSE gradually returns to normal.Thus,we can infer that the SSE may occur every 4-7 years after the 2018 SSE if there is no large earthquake.

关键词： Slow slip events(SSEs) GPS PCAIM Spatio-temporal evolution Boso peninsula

UNCONDITIONAL ERROR ANALYSIS OF VEMS FOR A GENERAliZED NONliNEAR SCHRODINGER EQUATION

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Journal of Computational Mathematics 2024年第2期42卷 500-543页

作者： Meng LI Jikun Zhao Shaochun Chen School of Mathematics and Statistics Zhengzhou UniversityZhengzhouHenan 450001China

In this work,we focus on the conforming and nonconforming leap-frog virtual element methods for the generalized nonlinear Schrodinger equation,and establish their unconditional stability and optimal error estimates.By constructing a time-discrete system,the error between the solutions of the continuous model and the numerical scheme is separated into the temporal error and the spatial error,which makes the spatial error τ-independent.The inverse inequalities in the existing conforming and new constructed nonconforming virtual element spaces are utilized to derive the L^(∞)-norm uniform boundedness of numerical solutions without any restrictions on time-space step ratio,and then unconditionally optimal error estimates of the numerical schemes are obtained naturally.What needs to be emphasized is that if we use the pre-existing nonconforming virtual elements,there is no way to derive the L^(∞)-norm uniform boundedness of the functions in the nonconforming virtual element spaces so as to be hard to get the corresponding inverse inequalities.Finally,several numerical examples are reported to confirm our theoretical results.

关键词： Conforming and nonconforming Virtual element methods Leap-frog scheme Generalized nonlinear Schrodinger system Unconditionally optimal error estimates

Second phase refining induced optimization of Fe alloying in Zn:Significantly enhanced strengthening effect and corrosion uniformity

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International Journal of Minerals,Metallurgy and Materials 2022年第4期29卷 796-806页

作者： Zhangzhi Shi Changheng li Meng LI Xiangmin li Luning Wang Beijing Advanced Innovation Center for Materials Genome Engineering Key Laboratory for Advanced Materials Processing of Ministry of EducationBeijing Laboratory of Metallic Materials and Processing for Modern TransportationSchool of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

Many non-toxic alloying elements,such as Fe,Ca,and Sr,have negligible solid solubilities in Zn matrix,leading to formation of coarse second phase particles.They exhibit low strengthening effects but highly detrimental to ductility.So refining second phase is a common pursuit for Zn alloys.The present paper takes Zn-0.3Fe alloy suffered from coarse FeZn_(13) second phase particles as a touchstone to testify microstructure refining effect through solidification with an accelerated speed and multi-pass rolling.FeZn_(13) particles are refined from 24 to 2μm,and Zn grains are refined to 5μm.As a result,the strengthening effect of Fe is enhanced significantly,with yield strength and the ultimate tensile strength of the alloy increased from 132 to 218 MPa and from 159 to 264 MPa,respectively.Furthermore,corrosion non-uniformity and penetration are much alleviated.These results show that microstructure refinement,especially on coarse intermetallic second phases,has a great potential to improve mechanical and degradation properties of biodegradable Zn alloys.

关键词： zinc alloys microstructure mechanical properties corrosion uniformity

Insight into deformation allocation in the multi-pass roll forming of a double-walled brazed tube

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Advances in Manufacturing 2023年第4期11卷 567-586页

作者： meng-Meng LIu Yu-li liu Heng li State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an710072People’s Republic of China

Deformation allocation is an important factor that affects 720°curling forming from copper-coated steel strips to double-walled brazed tubes(DWBTs).In this study,four schemes of deformation allocation,considering different weights of the total feed distance,are proposed,and a 3D finite element(FE)model of the multi-pass roll forming process for DWBT is developed and verified to investigate the cross-sectional evolution and deformation features.The results show the following.(i)In the 720°curling forming process from the steel strip into double-walled tubes,the curvature of the formed circular arc initially increases and then remains stable with roll forming,and the inner and outer tubes of the DWBT are formed in the third and fifth forming passes.Size forming can eliminate the gap between the double walls and improve the overall roundness.(ii)For different deformation allocations,the cross-sectional profiles of the roll-formed parts exhibit a discrepancy,and the deformation amount varies with the roll-forming process.The deformation amount in Scheme three is the maximum,and the cross-sectional profile deviates significantly from the ideal shape and fails to form a DWBT,which indicates that the deformation allocation is unsuitable.(iii)The roundness of the outer tube is better than that of the inner tube.Therefore,the roundness of the inner tube is the key to restricting the forming accuracy of the DWBT.Compared with Schemes one and two,Scheme four with a linear allocation of the total feed distance exhibits the best roundness,and the deformation allocation is reasonable;i.e.,when the contact points between the rollers and steel strip are in a straight line,the roundness of the DWBT is in good agreement with the ideal condition.

关键词： Double-walled brazed tube(DWBT) Multi-pass roll forming Deformation allocation Cross-sectional profile Roundness

Towards applications of genome-scale metabolic model-based approaches in designing synthetic microbial communities

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Quantitative Biology 2023年第1期11卷 15-30页

作者： Huan Du Meng LI Yang liu Archaeal Biology Center Institute for Advanced StudyShenzhen UniversityShenzhen 518060China Shenzhen Key Laboratory of Marine Microbiome Engineering Institute for Advanced StudyShenzhen UniversityShenzhen 18060China

Background:Synthetic microbial communities,with different strains brought together by balancing their nutrition and promoting their interactions,demonstrate great advantages for exploring complex performance of communities and for further biotechnology applications.The potential of such microbial communities has not been explored,due to our limited knowledge of the extremely complex microbial interactions that are involved in designing and controlling effective and stable communities.Results:Genome-scale metabolic models(GEM)have been demonstrated as an effective tool for predicting and guiding the investigation and design of microbial communities,since they can explicitly and efficiently predict the phenotype of organisms from their genotypic data and can be used to explore the molecular mechanisms of microbehabitats and microbe-microbe interactions.In this work,we reviewed two main categories of GEM-based approaches and three uses related to design of synthetic microbial communities:predicting multi-species interactions,exploring environmental impacts on microbial phenotypes,and optimizing community-level performance.Conclusions:Although at the infancy stage,GEM-based approaches exhibit an increasing scope of applications in designing synthetic microbial communities.Compared to other methods,especially the use of laboratory cultures,GEM-based approaches can greatly decrease the trial-and-error cost of various procedures for designing synthetic communities and improving their functionality,such as identifying community members,determining media composition,evaluating microbial interaction potential or selecting the best community configuration.Future efforts should be made to overcome the limitations of the approaches,ranging from quality control of GEM reconstructions to community-level modeling algorithms,so that more applications of GEMs in studying phenotypes of microbial communities can be expected.

关键词： genome-scale metabolic modeling microbial community design interspecies interaction environmental impact community-level performance

Pluripotent stem cell derived inhibitory interneurons–principles and applications in health and disease

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Neural Regeneration Research 2020年第2期15卷 251-252页

作者： Francesca Keefe Meng LI Neuroscience and Mental Health Research Institute School of Medicine and School of Bioscience Cardiff University

Inhibitory interneurons are gamma-aminobutyric acid-ergic (GABAergic) nerve cells that act to maintain the appropriate excitation-inhibition balance, and synchronise the output of principle cells to generate rhythmic patterns of firing (Kessaris et al., 2014). This critical role, along with their brain-wide distribution, has led to the implication of interneurons in many neuropathologies, including schizophrenia, autism, dystonia and epilepsies (Marín, 2012).

关键词： cells act has led

Deep learning-based on-line image analysis for continuous industrial crystallization processes

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Particuology 2023年第3期74卷 173-183页

作者： Shiliang Zong Guangzheng Zhou Meng LI Xuezhong Wang Beijing City Key Laboratory of Enze Biomass and Fine Chemicals College of New Materials and Chemical EngineeringBeijing Institute of Petrochemical TechnologyBeijing102617China

In situ microscopic imaging is a useful tool in monitoring crystallization processes,including crystal nucleation,growth,aggregation and breakage,as well as possible polymorphic transition.To convert the qualitative information to be quantitative for the purpose of process optimization and control,accurate analysis of crystal images is essential.However,the accuracy of image segmentation with traditional methods is largely affected by many factors,including solid concentration and image quality.In this study,the deep learning technique using mask region-based convolutional neural network(Mask R-CNN)is investigated for the analysis of on-line images from an industrial crystallizer of 10 m^(3) operated in continuous mode with high solid concentration and overlapped particles.With detailed label points for each crystal and transfer learning technique,two models trained with 70,908 and 7,709 crystals respectively are compared for the effect of training data amount.The former model effectively segments the aggregated and overlapped crystals even at high solid concentrations.Moreover,it performs much better than the latter one and traditional multi-scale method both in terms of precision and recall,revealing the importance of large number of crystals in deep learning.Some geometrical characteristics of segmented crystals are also analyzed,involving equivalent diameter,circularity,and aspect ratio.

关键词： Continuous crystallization Crystal shape Image analysis Deep learning Instance segmentation Process analytical technology