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Frontiers in Energy 2019年第3期13卷 483-493页

作者： Xiang LI Wenzheng ZHANG Zhong HUANG Dehao JU Li HUANG Mingzhi feng Xingcai lu Zhen HUANG Key Laboratory of Power Machinery and Engineering Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China Shanghai Marine Diesel Engine Research Institute Shanghai 201108China

Liquefied natural gas (LNG), mainly composed of methane, is in progress to substitute diesel fuel in heavyduty marine engine for practical, economic, and environmental considerations. However, natural gas is relatively difficult to be ignited in a large bore combustion chamber. A combustion enhancement technique called prechamber turbulent jet ignition (TJI) can permit combustion and flame propagation in a largebore volume. To investigate the effect of air-fuel equivalence ratio and pre-mixed pressure on pre-chamber TJI of methane/air mixtures with multiple orifices in a large bore volume, experimental tests and computational simulations were implemented to study the discharge of hot turbulent jets from six orifices of the pre-chamber. Different initial pressures and air-fuel equivalence ratios were considered to analyze the characteristics of TJI. The asymmetry of the turbulent jet actuated from six different orifices were found due to the asymmetric orientation of the spark plug, resulting in the inhomogeneous distribution of combustion in the constant volume chamber, which should be considered seriously in the marine engine design. Besides,as the premixed pressure increases, it has more effect on the flame propagation and plays a more important role, as it further increases.

关键词： marine engine natural gas methane turbulent jet ignition (TJI) pre-chamber

Discriminative feature encoding for intrinsic image decomposition

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Computational Visual Media 2023年第3期9卷 597-618页

作者： Zongji Wang Yunfei Liu Feng Lu Key Laboratory of Network Information System Technology(NIST) Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100190China State Key Laboratory of Virtual Reality Technology and Systems School of Computer Science and EngineeringBeihang UniversityBeijing 100191China Peng Cheng Laboratory Shenzhen 518000China

Intrinsic image decomposition is an important and long-standing computer vision problem.Given an input image,recovering the physical scene properties is ill-posed.Several physically motivated priors have been used to restrict the solution space of the optimization problem for intrinsic image decomposition.This work takes advantage of deep learning,and shows that it can solve this challenging computer vision problem with high efficiency.The focus lies in the feature encoding phase to extract discriminative features for different intrinsic layers from an input image.To achieve this goal,we explore the distinctive characteristics of different intrinsic components in the high-dimensional feature embedding space.We define feature distribution divergence to efficiently separate the feature vectors of different intrinsic components.The feature distributions are also constrained to fit the real ones through a feature distribution consistency.In addition,a data refinement approach is provided to remove data inconsistency from the Sintel dataset,making it more suitable for intrinsic image decomposition.Our method is also extended to intrinsic video decomposition based on pixel-wise correspondences between adjacent frames.Experimental results indicate that our proposed network structure can outperform the existing state-of-the-art.

关键词： intrinsic image decomposition deep learning feature distribution data refinement

Effects of Electron Donating Ability of Substituents and Molecular Conjugation on the Electronic Structures of Organic Radicals

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Chemical Research in Chinese Universities 2023年第2期39卷 202-207页

作者： LI Pengyuan Feng Lu LI Guangyue BAI Fuquan International Joint Research Laboratory of Nano-Micro Architecture Chemistry Institute of Theoretical Chemistry and College of ChemistryJilin UniversityChangchun130021P.R.China College of Chemical Engineering North China University of Science and TechnologyTangshan063210P.R.China International Innovation Center for Forest Chemicals and Materials Nanjing Forestry UniversityNanjing210037P.R.China

The geometries and electronic structures of a series of electron donor-acceptor radical molecules have been studied theoretically.The computational results show that the introduction of substituents with strong electron donating ability into tri-(2,4,6-trichlorophenyl)methyl(TTM)radicals enables the radical molecules to form the non-Aufbau electronic structure.The difficulty of forming the non-Aufbau electronic structure decreases with the enhancement of the electron donating ability of the substituent,but the expansion of the molecular conjugated system is not conducive to the formation.The hybridization of different fragments in molecular orbitals results in the disproportionation of orbital energy level and forms a staggered energy level structure.The electronic structure of radical molecules can be adjusted by substituents and molecular skeleton profoundly,which is a very effective means for molecular design.

关键词： Radical emitter Non-Aufbau electronic structure Molecular orbital characteristics Density functional theory and time-dependent density functional theory(DFT and TDDFT)

Cotton cultivation technology with Chinese characteristics has driven the 70-year development of cotton production in China

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Journal of Integrative Agriculture 2022年第3期21卷 597-609页

作者： Feng Lu CHI Bao-jie DONG He-zhong Zhengzhou Research Base State Key Laboratory of Cotton Biology School of Agricultural Sciences Zhengzhou University Cotton Research Center Shandong Academy of Agricultural Sciences College of Agricultural Science and Technology Shandong Agriculture and Engineering University

Since the founding of the People’s Republic of China in 1949,significant achievements have been made in cotton production in China.China has maintained its position as the world’s largest cotton producer for 33 years(1983–2015),with average annual increases of 3.5 and 3.9% in the unit yield and total output of cotton,respectively.Cotton production has played an extremely important role in the development of the national economy and the improvement of living standards.Although the cotton planting area has been reduced in recent years,the total output has remained relatively unchanged due to the continuous increase in the unit yield.China’s dominant position in global cotton production is undoubtedly attributed to the progress and development of cotton cultivation technology.Over the past 70 years,China has established a high-yielding and high-efficiency cotton cultivation mode that corresponds to its national conditions,including a large population and a limited land area.Furthermore,cotton cultivation technology is constantly being innovated and developed to keep pace with the times.In this paper,we review the development of cotton production and cultivation in China over the past 70 years,with a particular focus on the innovation and development of cotton cultivation technology with Chinese characteristics.This review is intended to provide guidance for the sustainable development of China’s cotton production in the future and to provide a reference for global cotton production.

关键词： China cotton cultivation technology outlook

China-US Trade Disputes in 2018： An Overview

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China & World Economy 2018年第5期26卷 83-103页

作者： Feng Lu National School of Development Peking University China.

The paper provides an overview of changes in the US policy stance toward China that have resulted in the currently unstable economic and trade relationship between the two countries. It reviews the trade and economic relationship between China and the US during the first year of the Trump Administration, summarizes the systematic changes in trade and external economic policies adopted by the Trump Administration in general, and particularly toward China, and observes the implementation of a hawkish trade policy that ignited dispute between the US and China. The main factors shaping the current situation are examined, including structural difficulties in the US economy, the characteristics of the Chinese institutional setting and policies that have become increasingly unacceptable to the US, the specific personal beliefs and positions of President Trump and his main aides in the economic and trade team, and short-term factors in the US internal political arena.

关键词： China dispute trade US

Si-induced insertion of Li into SiC to form Li-rich SiC twin crystal

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Particuology 2023年第3期74卷 56-63页

作者： Di Zhang Chenxi Zhang Feng Lu Hairong Jiang Fei Wei Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing100084China

The energy density of Li-ion batteries is closely related to the capacity and average voltage of cathode materials.Unfortunately,current cathode materials either have low capacity or voltage,which limits the development of high-energy-density Li-ion batteries.This has given challenge to many attempts to develop new cathode materials with high capacity and voltage.In this study,we find that Li easily inserts into the(111)plane of SiC in the presence of Si,and a well-organized Li-rich SiC twin crystal is formed.Ultraviolet-visible diffuse reflectance spectra and electrochemical test results suggest that this Li-rich SiC twin crystal possesses the band gap energy of 3.5 eV and charging capacity of 1979 mAh/g at the current density of 200 mA/g,making it a promising candidate for the cathode material in high-capacity Li-ion batteries.X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy results reveal that Si-induced Li insertion contributes to the changes in the surface species and structure of pristine SiC.These findings suggest that the Li-rich SiC twin crystal raises new possibilities for the development of high-capacity cathode materials and merits further investigation to expand its application scope.

关键词： Si Li insertion SiC Li-rich twin crystal CathodeLi-ion batteries

Neural network-based model predictive control with fuzzy-SQP optimization for direct thrust control of turbofan engine

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Chinese Journal of Aeronautics 2022年第12期35卷 59-71页

作者： Yangjing WANG Jinquan HUANG Wenxiang ZHOU Feng Lu Wenhao XU Jiangsu Province Key Laboratory of Aerospace Power System College of Energy and Power EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

A nonlinear model predictive control method based on fuzzy-Sequential Quadratic Programming(SQP)for direct thrust control is proposed in this paper for the sake of improving the accuracy of thrust control.The designed control system includes four parts,namely a predictive model,rolling optimization,online correction,and feedback correction.Considering the strong nonlinearity of engine,a predictive model is established by Back Propagation(BP)neural network for the entire flight envelope,whose input and output are determined with random forest algorithm and actual situation analysis.Rolling optimization typically uses SQP as the optimization algorithm,but SQP algorithm is easy to trap into local optimization.Therefore,the fuzzy-SQP algorithm is proposed to prevent this disadvantage using fuzzy algorithm to determine the initial value of SQP.In addition to the traditional three parts of model predictive control,an online correction module is added to improve the predictive accuracy of the predictive model in the predictive time domain.Simulation results show that the BP predictive model can reach a certain degree of predictive accuracy,and the proposed control system can achieve good tracking performance with the limited parameters within the safe range。

关键词： Direct thrust control Fuzzy-SQP algorithm Limit protection Neural network Nonlinear model predictive control Random forest Turbofan engine

Distributed Adaptive Output Consensus of Unknown Heterogeneous Non-Minimum Phase Multi-Agent Systems

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自动化学报：英文版 2023年第4期10卷 997-1008页

作者： Wenji Cao lu Liu Gang feng Department of Biomedical Engineering City University of Hong KongHong Kong SARChina

This article addresses the leader-following output consensus problem of heterogeneous linear multi-agent systems with unknown agent parameters under directed graphs.The dynamics of followers are allowed to be non-minimum phase with unknown arbitrary individual relative degrees.This is contrary to many existing works on distributed adaptive control schemes where agent dynamics are required to be minimum phase and often of the same relative degree.A distributed adaptive pole placement control scheme is developed,which consists of a distributed observer and an adaptive pole placement control law.It is shown that under the proposed distributed adaptive control scheme,all signals in the closed-loop system are bounded and the outputs of all the followers track the output of the leader asymptotically.The effectiveness of the proposed scheme is demonstrated by one practical example and one numerical example.

关键词： Adaptive pole placement control heterogeneous multi-agent systems leader-following output consensus non-minimum phase

Effect of Glutinous Rice Flour on Mechanical Properties and Microstructure of Cement-based Materials

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Journal of Wuhan University of Technology(Materials Science) 2023年第2期38卷 394-400页

作者： feng Qi lu Bao WANG Dan Guangxi Key Lab of Road Structure and Materials Guangxi Transportation Science and Technology Group Co.LtdNanning5300007China Key Laboratory for Advanced Technology in Environment Protection of Jiangsu Province Yancheng Institute of TechnologyYancheng224051China Special Glass Key Lab of Hainan Province&State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou570228China

The mechanism of glutinous rice flour,a kind of natural admixture,on the hydration process,setting time,and microstructure of the Portland cement was investigated.The experimental results show that the glutinous rice flour has an obvious setting retarding effect on cement pastes.The optimal dosage of the glutinous rice flour is 3wt%.In this case,the initial and final setting time of the paste are delayed by 140 and185 min,respectively.The flexural and compressive strengths of the hardened paste are increased by 0.35%and 0.07%after 56 d of curing.The glutinous rice flour hinders the mineral dissolution process and decreases the concentration of calcium ion at the initial stage of hydration due to the complexation effect,thereby hindering the nucleation and growth of CH and C-S-H phases and prolonging the hydration process.However,C-S-H phases combine with the glutinous rice flour to contribute the bonding effect together,which compacts the microstructure of hardened cement pastes at the later hydration stage of cement pastes.Thus,in-depth investigation on the utilization of glutinous rice flour as the admixture for the Portland cement is expected to be meaningful for the control of hydration exothermic rate and setting time.

关键词： glutinous rice flour cement-based materials mechanical properties setting time

From non-carbon host toward carbon-free lithium-sulfur batteries

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Nano Research 2024年第3期17卷 1337-1365页

作者： Yanqi feng Hui Liu Qiongqiong lu School of Materials Science and Engineering Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic MaterialsShaanxi University of Science and TechnologyXi’an 710021China Institute of Materials Henan Key Laboratory of Advanced Conductor MaterialsHenan Academy of SciencesZhengzhou 450046China Leibniz Institute for Solid State and Materials Research(IFW)Dresden e.V. Helmholtzstraβe 2001069 DresdenGermany School of Materials&Environment Engineering Chengdu Technological UniversityChengdu 611730China

Lithium-sulfur(Li-S)batteries with advantages of high energy densities(2600 Wh·kg^(-1)/2800 Wh·L^(-1))and sulfur abundance are regarded as promising candidates for next-generation high-energy batteries.However,the conventional carbon host used in sulfur cathodes suffers from poor chemical adsorption towards Li-polysulfides(LPS)in liquid electrolyte and sluggish redox kinetics,leading to low capacity and rate capability.Besides,carbon host used in Li metal anode with the intrinsic property of poor lithiophilicity and high Li-nucleation barrier gives rise to uncontrollable dendrite growth and further battery failure.Therefore,non-carbon hosts with chemical adsorption toward LPS and catalytic activity for accelerating LPS redox conversion as well as lithiophilic property for guiding uniform Li deposition are proposed and demonstrated a high efficiency in both sulfur cathodes and Li metal anodes.In this review,the principle and challenges of Li-S batteries are first presented,then recent work using non-carbon hosts in Li-S batteries is summarized comprehensively,and the mechanism of non-carbon host in improving sulfur utilization and stabilizing Li metal anode is discussed in detail.Furthermore,remaining challenges and outlook on the implementation of non-carbon host for practical carbon-free Li-S batteries are also provided.

关键词： sulfur cathode Li metal anode polysulfides adsorption catalytic effect Li dendrite carbon-free lithium-sulfur batteries