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Analysis of amino acid enantiomers in ambient aerosols:Effects and removal of coexistent aerosol matrix

Journal of Environmental Sciences 2024年第3期137卷 732-740页

作者： Ying Li Xiaoying Li Libin Wu Luhan Shi ShanWang pingqing fu Yingyi Zhang Senchao Lai The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of EducationSchool of Environment and EnergySouth China University of TechnologyGuangzhou 510006China Institute of Surface-Earth System Science School of Earth System ScienceTianjin UniversityTianjin 300072China now at Hong Kong University of Science and Technology Hong Kong 00852China

Amino acids(AAs)including D-and L-enantiomers are a group of organic nitrogen species in ambient aerosol.Due to the low abundances of AAs(level of ng/m^(3))and the matrix effects by coexistent components,it is challenging to quantify AA enantiomers in ambient aerosols especially under pollution conditions.In this study,we present an optimized method for analyzing AA enantiomers in atmospheric aerosol samples including a pretreatment process and the detection by high performance liquid chromatography coupled to a fuorescence detector(HPLC-FLD).Matrix effects caused by coexistent chemicals on AA enantiomers analysis in ambient aerosol samples were investigated especially for those collected in pollution episodes.The results revealed that the determination of AA enantiomers is significantly affected by the coexistent organic carbon(as a proxy of organic matter)and water-soluble ion of NH_(4)^(+).To remove the matrix effects,we applied a pretreatment using the solid phase extraction column coupled with alkaline adjustment to sample extract.After pretreatment,18 AAs including 6 pairs of D-and L-enantiomers(i.e.,leucine,isoleucine,valine,alanine,serine,and aspartic acid)can be successfully separated and quantified in aerosol samples by HPLC-FLD.The recoveries are in the range of 67%-106%.This method was successfully applied to the urban aerosol samples from pollution and non-pollution periods for AA enantiomers determination.We suggest that the concentrations of D-AAs and the ratio of D-AA/L-AA are indicative of the contribution of bacterial sources and the infuence of biomass burning.

关键词： Amino acid enantiomers Atmospheric aerosol Organic carbon Ammonia Chiral ratio

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A Tutorial on Quantized Feedback Control

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 5-17页

作者： Minyue fu IEEE the School of System Design and Intelligent Manufacturing Shenzhen Key Laboratory of Control Theory and Intelligent Systems and Centre for Control Science and TechnologySouthern University of Science and TechnologyShenzhen 518055China

In this tutorial paper, we explore the field of quantized feedback control, which has gained significant attention due to the growing prevalence of networked control systems. These systems require the transmission of feedback information, such as measurements and control signals, over digital networks, presenting novel challenges in estimation and control design. Our examination encompasses various topics, including the minimal information needed for effective feedback control, the design of quantizers, strategies for quantized control design and estimation,achieving consensus control with quantized data, and the pursuit of high-precision tracking using quantized measurements.

关键词： Consensus control high-precision control networked control quantized estimation quantized feedback control robust control

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Coupling Coordination Analysis of Cropland Intensification and Agroecosystem Services:Evidence from Loess Plateau in Shaanxi Province,China

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Chinese Geographical Science 2024年第3期34卷 401-419页

作者： fu Shaowu fu Mengyu QIU Menglong Center for Land Resource Research in Northwest China Shaanxi Normal UniversityXi’an 710119China

One of the greatest challenges in the agroecosystem is to improve cropland intensification while preserving agroecosystem services.While many studies have investigated the effect of cropland intensification on agroecosystem service,the interactive coupling and coordination among these factors remain largely unexplored.In view of this,this study performed a case study of the Loess Plateau in Shaanxi Province,China and constructed comprehensive evaluation models to quantify the cropland intensification and agroecosystem service in this area.Balance analysis and the coupling coordination degree model were used to evaluate the interactive relationship between cropland intensification and agroecosystem service,and statistical analysis and spatial autocorrelation were used to analyze the spatial characteristics and potential mechanism of the coupling coordination.Results show that both the cropland intensification and agroecosystem service in the study area were relatively low yet gradually increased from 2000 to 2020.Agroecosystem service lag was identified as the dominant unbalanced development type.Improving the supply capacity of agroecosystem services plays a key role in the balanced development of cropland in the Loess Plateau.The coupling coordination degree between cropland intensification and agroecosystem service ranges from basic coordination to serious incoordination.Therefore,cropland intensification practices in the area should be optimized to enhance this coordination degree.An upward trend was also observed in the coupling coordination degree from2000 to 2020.The withdrawal of marginal cropland in the Grain for Green program is one of the most important reasons for this trend,especially for the northern region.Around 83.6%of the high-high clusters are concentrated in the southern region of the Loess Plateau,whereas 70.5%of the low-low clusters are distributed in the northern region.These clustering characteristics are mainly attributed to the environmental suitability of these areas for agriculture and

关键词： cropland intensification agroecosystem services balance analysis coupling coordination degree Loess Plateau,China

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Refractory black carbon aerosols in rainwater in the summer of 2019 in Beijing:Mass concentration,size distribution and wet scavenging ratio

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Journal of Environmental Sciences 2023年第10期132卷 31-42页

作者： Shandong Lei Baozhu Ge Hang Liu Jiannong Quan Danhui Xu Yuting Zhang Weijie Yao Lu Lei Yu Tian Qi Liao Xiaoyong Liu Jie Li Jinyuan Xin Yele Sun pingqing fu Junji Cao Zifa Wang Xiaole Pan State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089China National Center for Climate Change Strategy and International Cooperation Ministry of Ecology and EnvironmentBeijing 100035China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Surface-Earth System Science Tianjin UniversityTianjin 300072China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100190China

Black carbon(BC)aerosols in the atmosphere play a significant role in climate systems due to their strong ability to absorb solar radiation.The lifetime of BC depends on atmospheric transport,aging and consequently on wet scavenging processes(in-cloud and below-cloud scavenging).In this study,sequential rainwater samples in eight rainfall events collected in 2 mm interval were measured by a tandem system including a single particle soot photometer(SP2)and a nebulizer.The results showed that the volume-weighted average(VWA)mass concentrations of refractory black carbon(rBC)in each rainfall event varied,ranging from 10.8 to 78.9μg/L.The highest rBC concentrations in the rainwater samples typically occurred in the first fraction from individual rainfall events.The geometric mean median mass-equivalent diameter(MMD)decreased under precipitation,indicating that rBC with larger sizes was relatively aged and preferentially removed by wet scavenging.A positive correlation(R2=0.73)between the VWA mass concentrations of rBC in rainwater and that in ambient air suggested the important contribution of scavenging process.Additionally,the contributions of in-cloud and below-cloud scavenging were distinguished and accounted for 74%and 26%to wet scavenging,respectively.The scavenging ratio of rBC particles was estimated to be 0.06 on average.This study provides helpful information for better understanding the mechanism of rBC wet scavenging and reducing the uncertainty of numerical simulations of the climate effects of rBC.

关键词： Refractory black carbon Wet deposition Size distribution

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A stochastic gradient-based two-step sparse identification algorithm for multivariate ARX systems

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Control Theory and Technology 2024年第2期22卷 213-221页

作者： Yanxin fu Wenxiao Zhao Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing100049China

We consider the sparse identification of multivariate ARX systems, i.e., to recover the zero elements of the unknown parameter matrix. We propose a two-step algorithm, where in the first step the stochastic gradient (SG) algorithm is applied to obtain initial estimates of the unknown parameter matrix and in the second step an optimization criterion is introduced for the sparse identification of multivariate ARX systems. Under mild conditions, we prove that by minimizing the criterion function, the zero elements of the unknown parameter matrix can be recovered with a finite number of observations. The performance of the algorithm is testified through a simulation example.

关键词： ARX system Stochastic gradient algorithm Sparse identification Support recovery Parameter estimation Strong consistency

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Dynamics of 2×2 matrix non-Hermitian quantum systems on Bloch sphere

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Communications in Theoretical Physics 2024年第4期76卷 66-71页

作者： Libin fu Graduate School of China Academy of Engineering Physics Beijing 100193China

By casting evolution to the Bloch sphere,the dynamics of 2×2 matrix non-Hermitian systems are investigated in detail.This investigation reveals that there are four kinds of dynamical modes for such systems.The different modes are classified by different kinds of fixed points,namely,the elliptic point,spiral point,critical node,and degenerate point.The Hermitian systems and the unbroken PT non-Hermitian cases belong to the category with elliptic points.The degenerate point just corresponds to the systems with exceptional point(EP).The topological properties of the fixed point are also discussed.It is interesting that the topological charge for the degenerate point is two,while the others are one.By casting evolution to the Bloch sphere,the dynamics of 2×2 matrix non-Hermitian systems are investigated in detail.This investigation reveals that there are four kinds of dynamical modes for such systems.The different modes are classified by different kinds of fixed points,namely,the elliptic point,spiral point,critical node,and degenerate point.The Hermitian systems and the unbroken non-Hermitian cases belong to the category with elliptic points.The degenerate point just corresponds to the systems with exceptional point(EP).The topological properties of the fixed point are also discussed.It is interesting that the topological charge for the degenerate point is two,while the others are one.

关键词： non-Hermitian quantum system two-level system dynamics on the Bloch sphere PT-symmetry fixed points

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Oligodendrocytes in central nervous system diseases:the effect of cytokine regulation

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Neural Regeneration Research 2024年第10期19卷 2132-2143页

作者： Chengfu Zhang Mengsheng Qiu Hui fu Center for Cognition and Brain Disorders The Affiliated Hospital of Hangzhou Normal UniversityHangzhouZhejiang ProvinceChina Department of Psychiatry National Clinical Research Center for Mental Disordersand National Center for Mental DisordersThe Second Xiangya Hospital of Central South UniversityChangshaHunan ProvinceChina Institute of Life Sciences Key Laboratory of Organ Development and Regeneration of Zhejiang ProvinceCollege of Life and Environment SciencesHangzhou Normal UniversityHangzhouZhejiang ProvinceChina Key Laboratory of Aging and Cancer Biology of Zhejiang Province School of Basic Medical SciencesHangzhou Normal UniversityHangzhouZhejiang ProvinceChina

Cytokines including tumor necrosis factor, interleukins, interferons, and chemokines are abundantly produced in various diseases. As pleiotropic factors, cytokines are involved in nearly every aspect of cellular functions such as migration, survival, proliferation, and differentiation. Oligodendrocytes are the myelin-forming cells in the central nervous system and play critical roles in the conduction of action potentials, supply of metabolic components for axons, and other functions. Emerging evidence suggests that both oligodendrocytes and oligodendrocyte precursor cells are vulnerable to cytokines released under pathological conditions. This review mainly summarizes the effects of cytokines on oligodendrocyte lineage cells in central nervous system diseases. A comprehensive understanding of the effects of cytokines on oligodendrocyte lineage cells contributes to our understanding of central nervous system diseases and offers insights into treatment strategies.

关键词： astrocyte central nervous system disease CXC chemokine cytokine interferonγ interleukin microglia oligodendrocyte oligodendrocyte precursor cell tumor necrosis factorα

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Airborne particulate matter pollution in urban China: a chemical mixture perspective from sources to impacts

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National Science Review 2017年第4期4卷 593-610页

作者： Ling Jin Xiaosan Luo pingqing fu Xiangdong Li Department of Civil and Environmental Engineering The Hong Kong Polytechnic University International Center for Ecology Meteorology and Environment School of Applied Meteorology Nanjing University of Information Science & Technology State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of Sciences

Rapid urban and industrial development has resulted in severe air-pollution problems in developing countries such as China, especially in highly industrialized and populous urban clusters. Dissecting the complex mixtures of airborne particulate matter(PM) has been a key scientific focus in the last two decades,leading to significant advances in understanding physicochemical compositions for comprehensive source apportionment. However, identifying causative components with an attributable link to population-based health outcomes remains a huge challenge. The microbiome, an integral dimension of the PM mixture, is an unexplored frontier in terms of identities and functions in atmospheric processes and human health. In this review, we identify the major gaps in addressing these issues, and recommend a holistic framework for evaluating the sources, processes and impacts of atmospheric PM pollution. Such an approach and the knowledge generated will facilitate the formulation of regulatory measures to control PM pollution in China and elsewhere.

关键词： particle size source apportionment molecular tracer chemical speciation airborne microbiome bioavailability mixture toxicity cohort study

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Evolutionary processes and sources of high-nitrate haze episodes over Beijing,Spring

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Journal of Environmental Sciences 2017年第4期29卷 142-151页

作者： Ting Yang Yele Sun Wei Zhang Zifa Wang Xingang Liu pingqing fu Xiquan Wang State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Aviation Meteorological Center of China Beijing 100021 China State Key Laboratory of Water Environment Simulation School of Environment Beijing Normal University Beijing 100089 China

Rare and consecutive high-nitrate haze pollution episodes were observed in Beijing in spring2012. We present detailed characterization of the sources and evolutionary mechanisms of this haze pollution, and focus on an episode that occurred between 15 and 26 April. Submicron aerosol species were found to be substantially elevated during haze episodes, and nitrates showed the largest increase and occupation（average： 32.2%） in non-refractory submicron particles（NR-PM1）, which did not occur in other seasons as previously reported. The haze episode（HE） was divided into three sub-episodes, HEa, HEb, and HEc. During HEa and HEc, a shallow boundary layer, stagnant meteorological conditions, and high humidity favored the formation of high-nitrate concentrations, which were mainly produced by three different processes —daytime photochemical production, gas-particle partitioning, and nighttime heterogeneous reactions — and the decline in visibility was mainly induced by NR-PM1.However, unlike HEa and HEc, during HEb, the contribution of high nitrates was partly from the transport of haze from the southeast of Beijing — the transport pathway was observed at ~800–1000 m by aerosol Lidar —and the decline in visibility during HEb was primarily caused by PM（2.5）. Our results provide useful information for air quality improvement strategies in Beijing during Spring.

关键词： Haze Nitrate Sources Lidar Aerosol Chemical Speciation Monitor Boundary layer

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Degradation behaviors of Nabumetone and its metabolite during UV/monochloramine process:Experimental and theoretical study

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Journal of Environmental Sciences 2024年第8期142卷 103-114页

作者： Xiang Tu Yunsong Bai Qing fu Sheng Chang Kunfeng Zhang Yang Pan Ruiyang Xiao Yifu fu Qi Zhang State Key Laboratory of Environmental Criteria and Risk Assessment State Environmental Protection Key Laboratory of Drinking Water Source ProtectionResearch Centre of Lake EnvironmentNational Engineering Laboratory for Lake Pollution Control and Ecological RestorationChinese Research Academy of Environmental SciencesBeijing 100012China School of Environmental Science and Engineering Suzhou University of Science and TechnologySuzhou 215009China Institute of Environmental Engineering School of Metallurgy and EnvironmentCentral South UniversityChangsha 410083China School of Forestry Northeast Forestry UniversityHarbin 150040China

This study investigated degradation behaviors of a nonsteroidal anti-inflammatory drug Nabumetone(NMT)and its major metabolite 6-methoxy-2-naphthylacetic acid(MNA)in the coupling process of ultraviolet and monochloramine(UV/NH2Cl).The second-order rate constants of the contaminants reacting with reactive radicals(HO·,Cl·,Cl_(2)·-,and CO_(3)·^(-))were determined by laser flash photolysis experiments.HO·and Cl·contributed predominantly with 52.3%and 21.7%for NMT degradation and 60.8%and 22.3%for MNA degradation.The presence of chlorides retarded the degradation of NMT,while promoted the destruction of MNA,which was ascribed to the photosensitization effects of MNA under UV irradiation.Density functional theory(DFT)calculations revealed that radical adduct formation(RAF)was dominant pathway for both HO·and Cl·reacting with the contaminants,and hydrogen atom transfer(HAT)preferred to occur on side chains of NMT and MNA.NMT reacted with NO_(2)·through single electron transfer(SET)with the second-order rate constant calculated to be 5.35×10^(7)(mol/L)^(-1)sec^(-1),and the contribution of NO_(2)·was predicted to be 13.0%of the total rate constant of NMT in pure water,which indicated that NO_(2)·played a nonnegligible role in the degradation of NMT.The acute toxicity and developmental toxicity of NMT were enhanced after UV/NH_(2)Cl treatment,while those of MNA were alleviated.The transformation products of both NMT and MNA exhibited higher mutagenicity than their parent compounds.This study provides a deep understanding of the mechanism of radical degradation of NMT and MNA in the treatment of UV/NH2Cl.

关键词： UV/NH_(2)Cl Reactive species Degradation kinetics Reaction mechanism Degradation products

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