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Chemical formation and source apportionment of PM_(2.5) at an urban site at the southern foot of the Taihang mountains

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Journal of Environmental Sciences 2021年第5期33卷 20-32页

作者： Xiaoyong Liu Mingshi Wang Xiaole Pan Xiyue Wang Xiaolong Yue Donghui Zhang Zhigang Ma Yu Tian Hang Liu Shandong Lei Yuting Zhang Qi Liao Baozhu Ge Dawei Wang Jie Li Yele Sun Pingqing Fu Zifa Wang Hong He Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China state Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Henan Polytechnic University Jiaozuo 454003China Jiaozuo Ecological Environment Monitoring Center Jiaozuo 454003China Jiaozuo Environmental Science Research institute Jiaozuo 454003China Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China institute of Surface-Earth System Science Tianjin UniversityTianjin 300072China University of Chinese Academy of Sciences Beijing 100049China College of Earth Sciences University of Chinese Academy of SciencesBeijing 100049China

The region along the Taihang Mountains in the North China Plain(NCP) is characterized by serious fine particle pollution. To clarify the formation mechanism and controlling factors, an observational study was conducted to investigate the physical and chemical properties of the fine particulate matter in Jiaozuo city, China. Mass concentrations of the water-soluble ions(WSIs) in PM_(2.5) and gaseous pollutant precursors were measured on an hourly basis from December 1, 2017, to February 27, 2018. The positive matrix factorization(PMF) method and the FLEXible Particle(FLEXPart) model were employed to identify the sources of PM_(2.5). The results showed that the average mass concentration of PM_(2.5) was 111 μg/m^(3) during the observation period. Among the major WSIs, sulfate, nitrate, and ammonium(SNA) constituted 62% of the total PM_(2.5) mass, and NO_(3)^(-) ranked the highest with an average contribution of 24.6%. NH_(4)^(+) was abundant in most cases in Jiaozuo. According to chemical balance analysis, SO_(2)-4, NO_(3)^(-), and Cl^(-) might be present in the form of(NH_4)_(2)SO_4, NH_4NO_3, NH_4Cl, and KCl. The liquid-phase oxidation of SO_(2) and NO_(2) was severe during the haze period. The relative humidity and pH were the key factors influencing SO_(4)^(2-) formation. We found that NO_(3)^(-) mainly stemmed from homogeneous gas-phase reactions in the daytime and originated from the hydrolysis of N_(2)O_5 in the nighttime, which was inconsistent with previous studies. The PMF model identified five sources of PM_(2.5) : secondary origin(37.8%), vehicular emissions(34.7%), biomass burning(11.5%), coal combustion(9.4%), and crustal dust(6.6%).

关键词： PM_(2.5) Chemical components Source identification

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Multicolor Luminescent Carbon Nanoparticles： Synthesis, Supramolecular Assembly with Porphyrin, Intrinsic Peroxidase-Like Catalytic Activity and Applications

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Nano Research 2011年第9期4卷 908-920页

作者： Xiaohui Wang Konggang Qu Bailu Xu Jinsong Ren Xiaogang Qu Division of Biological Inorganic Chemistry State Key Laboratory of Rare Earth Resource Utilization Laboratory of Chemical Biology Changchun Institute Of Applied Chemistry Chinese Academy of Sciences Changchun Jilin 130022 China Graduate School of the Chinese Academy of Sciences Changchun Jilin 130022 China

Luminescent carbon nanoparticles （CNPs） are newcomers to the world of nanomaterials and have shown great impact in health and environmental applications as well as being promising building blocks for future nanodevices because of their fascinating photoluminescence and potential to serve as nontoxic replacements for traditional heavy-metals-based quantum dots. Herein, fluorescent CNPs have been prepared from candle soot by re fluxing with HNO3 and subsequently separated by a single centrifugation. The CNPs can be represented by the empirical formula C1Ho.677Oo.586No.o15Nao.069, and have a size of 20-100 nm, height of 3.0 nm, lifetime of 7.31 ns ＋ 0.06 ns and quantum yield of -1.7%. Further studies demonstrate that：（1）the as-prepared CNPs exhibit excellent stability in biological media and their luminescence intensity does not change with ionic strength or pH in the physiological and pathological range of pH 4.5-8.8; （2） CNPs can act as electron donors and transporters and porphyrin can assemble onto CNPs through electrostatic and ^-stacking interactions to form porphyrin-CNPs supramolecular composites; （3）CNPs have strong intrinsic peroxidase-like activity. Based on this intrinsic peroxidase activity, a simple, cheap, and highly selective and sensitive colorimetric and quantitative assay has been developed for the detection of glucose levels. This assay has been used to analyze real samples, such as diluted blood and fruit juice.

关键词： Carbon nanoparticles luminescence supramolecular assembly peroxidase biosensing

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Ultrafast epitaxial growth of metre-sized single-crystal graphene on industrial Cu foil

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Science Bulletin 2017年第15期62卷 1074-1080页

作者： Xiaozhi Xu Zhihong Zhang Jichen Dong Ding Yi Jingjing Niu Muhong Wu Li Lin Rongkang Yin Mingqiang Li Jingyuan Zhou Shaoxin Wang Junliang Sun Xiaojie Duan Peng Gao Ying Jiang Xiaosong Wu Hailin Peng Rodney S. Ruoff Zhongfan Liu Dapeng Yu Enge Wang Feng Ding Kaihui Liu state Key Laboratory for Mesoscopic Physics School of Physics Peking University Beijing 100871 China Academy for Advanced Interdisciplinary studies Peking University Beijing 100871 China Center for Multidimensional Carbon Materials (CMCM) Institute for Basic Science (IBS) UIsan 689-798 Republic of Korea Centre for Nanochemistry College of Chemistry and Molecular Engineering Peking University Beijing 100871 China Department of Biomedical Engineering College of Engineering Peking University Beijing 100871 China College of Chemistry and Molecular Engineering Peking University Beijing 100871 China Collaborative Innovation Centre of Quantum Matter Beijing 100871 China International Centre for Quantum Materials Peking University Beijing 100871 China Department of Chemistry Ulsan National Institute of Science and Technology (UNIST) Ulsan 689-798 Republic of Korea Department of Physics South University of Science and Technology of China Shenzhen 518055 China School of Materials Science and Engineering Ulsan National Institute of Science and Technology (UNIST) Ulsan 689-798 Republic of Korea

A foundation of the modern technology that uses single-crystal silicon has been the growth of highquality single-crystal Si ingots with diameters up to 12 inches or larger. For many applications of graphene, large-area high-quality(ideally of single-crystal) material will be enabling. Since the first growth on copper foil a decade ago, inch-sized single-crystal graphene has been achieved. We present here the growth, in 20 min, of a graphene film of(5 ×50) cm^2 dimension with >99% ultra-highly oriented *** growth was achieved by:(1) synthesis of metre-sized single-crystal Cu(1 1 1) foil as substrate;(2)epitaxial growth of graphene islands on the Cu(1 1 1) surface;(3) seamless merging of such graphene islands into a graphene film with high single crystallinity and(4) the ultrafast growth of graphene *** achievements were realized by a temperature-gradient-driven annealing technique to produce single-crystal Cu(1 1 1) from industrial polycrystalline Cu foil and the marvellous effects of a continuous oxygen supply from an adjacent oxide. The as-synthesized graphene film, with very few misoriented grains(if any), has a mobility up to ~23,000 cm^2 V^(-1)s^(-1)at 4 K and room temperature sheet resistance of ~230 Ω/□. It is very likely that this approach can be scaled up to achieve exceptionally large and high-quality graphene films with single crystallinity, and thus realize various industrial-level applications at a low cost.

关键词： Single-crystal Industrial Cu Graphene Ultrafast Epitaxial

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From plant immunity to crop disease resistance

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Journal of Genetics and Genomics 2022年第8期49卷 693-703页

作者： Yan Zhao Xiaobo Zhu Xuewei Chen Jian-Min Zhou state Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China state Key Laboratory of Crop Gene Exploration and Utilization in Southwest China Sichuan Agricultural University at WenjiangChengduSichuan 611130China CAS Center for Excellence in Biotic Interactions University of Chinese Academy of SciencesBeijing 100049China Hainan Yazhou Bay Seed Laboratory SanyaHainan 572025China

Plant diseases caused by diverse pathogens lead to a serious reduction in crop yield and threaten food security *** improvement of plant immunity is considered as the most effective and sustainable approach to control crop *** the last decade,our understanding of plant immunity at both molecular and genomic levels has improved *** with advances in biotechnologies,particularly clustered regularly interspaced short palindromic repeat(CRISPR)/Cas9-based genome editing,we can now rapidly identify new resistance genes and engineer disease-resistance crop plants like never *** this review,we summarize the current knowledge of plant immunity and outline existing and new strategies for disease resistance improvement in crop *** also discuss existing challenges in this field and suggest directions for future studies.

关键词： Plant immunity Disease resistance Resistance genes Molecular breeding Genetic engineering Crops

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Influences of sea ice on eastern Bering Sea phytoplankton

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Chinese Journal of Oceanology and Limnology 2015年第2期33卷 458-467页

作者：周茜茜王鹏陈长平梁君荣李炳乾高亚辉 School of Life Sciences and Key Laboratory of Ministry of Education for Coastal and Wetland Ecosystems Xiamen University Tianjin International Joint Academy of Biotechnology and Medicine Salt Research institute China National Salt Industry Corporation state Key Laboratory of Marine Environmental Science Xiamen University

The influence of sea ice on the species composition and cell density of phytoplankton was investigated in the eastern Bering Sea in spring 2008. Diatoms, particularly pennate diatoms, dominated the phytoplankton community. The dominant species were Grammonema islandica （Grunow in Van Heurck） Hasle, Fragilariopsis cylindrus （Grunow） Krieger, F. oceanica （Cleve） Hasle, Navicula vanhoeffenii Gran, Thalassiosira antarctica Comber, T. gravida Cleve, T. nordenskioeldii Cleve, and T. rotula Meunier. Phytoplankton cell densities varied from 0.08× 10^4 to 428.8× 10^4 cells/L, with an average of 30.3× 10^4 cells/L. Using cluster analysis, phytoplankton were grouped into three assemblages defined by ice-forming conditions： open wate.r, ice edge, and sea ice assemblages. In spring, when the sea ice melts, the phytoplankton dispersed from the sea ice to the ice edge and even into open waters. Thus, these phytoplankton in the sea ice may serve as a “seed bank” for phytoplankton population succession in the subarctic ecosystem. Moreover, historical studies combined with these results suggest that the sizes of diatom species have become smaller, shifting from microplankton to nannoplankton-dominated communities.

关键词： phytoplankton sea ice Bering Sea community structure

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lahysiological links of circadian clock and biological clock of aging

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Protein & Cell 2017年第7期8卷 477-488页

作者： Fang Liu Hung-Chun Chang institute of Neuroscience State Key Laboratory of Neuroscience Key Laboratory of Primate Neurobiology CAS Center for Excellence in Brain Science and Intelligence Technology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200031 China University of Chinese Academy of Sciences Shanghai 200031 China

Circadian rhythms orchestrate biochemical and physi-ological processes in living organisms to respond the day/night cycle. In mammals, nearly all cells hold self- sustained circadian clocks meanwhile couple the intrinsic rhythms to systemic changes in a hierarchical manner. The suprachiasmatic nucleus （SCN） of the hypothalamus functions as the master pacemaker to initiate daily synchronization according to the photope-riod, in turn determines the phase of peripheral cellular clocks through a variety of signaling relays, including endocrine rhythms and metabolic cycles. With aging, circadian desynchrony occurs at the expense of peripheral metabolic pathologies and central neurode- generative disorders with sleep symptoms, and genetic ablation of circadian genes in model organisms resem- bled the aging-related features. Notably, a number of studies have linked longevity nutrient sensing pathways in modulating circadian clocks. Therapeutic strategies that bridge the nutrient sensing pathways and circadian clock might be rational designs to defy aging.

关键词： circadian rhythms SCN longevity

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Electrical tree degradation in high-voltage cable insulation:progress and challenges

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High Voltage 2020年第4期5卷 353-364页

作者： Jingang Su Boxue Du Jin Li Zhonglei Li Electric Power Research institute of state Grid Hebei Electric Power Supply Co.Ltd. Shijiazhuang 050021People's Republic of China School of Electrical and Information Engineering Tianjin UniversityWeijin Road 92Tianjin 300072People's Republic of China

High-voltage direct current(HVDC)and high-voltage alternating current(HVAC)cables are the most important equipment for high-voltage,large-capacity and long-distance power *** tree is a pre-breakdown phenomenon leading to failure of insulation materials,and it is the major issue that threatens the safe and stable operation of HVDC and HVAC cable *** study summarises and analyses the achievements in the research of electrical tree for HVDC and HVAC *** initiation mechanisms of the electrical tree,including Maxwell electro-mechanical stress,charge injection-extraction,charge trapping and electroluminescence theories,are elaborated for fully understanding the electrical degradation process in insulation ***,the influences of the high electric field,high temperature and mechanical stress on electrical tree behaviours are discussed,and the relationship between charge transport and the electrical tree is analysed and *** suppression methods of the electrical tree are put forward by introducing inorganic and organic additives into insulation materials,and the suppression mechanisms are presented from the viewpoints of the structure-property and microscale-macroscale ***,the electrical tree research studies are focused on the high-precision of initiation models,high-dependence of multi-physical fields and high-efficiency of suppression *** achievements provide theoretical support for improving the electrical performance of insulation materials,while it is a practical problem to explore their application feasibility in HVDC and HVAC cable.

关键词： insulation Electrical tree

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Potential Deformation and Its Application to the Diagnosis of Heavy Precipitation in Mesoscale Convective Systems

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Advances in Atmospheric Sciences 2017年第7期34卷 894-908页

作者： Na LI Lingkun RAN Linna ZHANG Shouting GAO Key Laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric Physics Chinese Academy of Sciences BeOing 100029 China state Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China Beijing Meteorological Bureau Beijing 100089 China

Many observational studies have shown that deformation, like vertical vorticity and divergence, is closely related to the occurrence and distribution of strong precipitation. In this paper, to involve deformation in precipitation diagnosis, a new parameter called potential deformation（PD） is derived and then applied to precipitation detection within a simulated mesoscale convective system（MCS）. It is shown that PD includes both stretching deformation and shearing deformation and shares similar characteristics with deformation insofar as it does not change with the rotating coordinate. Diagnosis of the simulated MCS reveals that PD performs well in tracing the MCS＇ precipitation. In terms of their distributional pattern, the large-value areas of PD are similar to the precipitation in the different development stages of the MCS. A detailed analysis of the physical processes contained within the PD shows that it can reflect the three-dimensional moisture variation,vertical wind shear and wind deformation within the MCS. These structures are usually a comprehensive reflection of the characteristics of the surface cold pool, rear inflow jet, downward cold air flow and upward warm moist flow within the precipitating convective cells. For this reason, the PD shows much stronger anomalies in the precipitating atmosphere than the non-precipitating atmosphere, which implies considerable potential for its application in detecting heavy precipitation within MCSs.

关键词： Precipitation convective vorticity moisture divergence mesoscale observational stretching downward coordinate

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Deregulation of brain insulin signaling in Alzheimer's disease

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Neuroscience Bulletin 2014年第2期30卷 282-294页

作者： Yanxing Chen Yanqiu Deng Baorong Zhang Cheng-Xin Gong Department of Neurology Second Affi liated Hospital School of Medicine Zhejiang University Department of Pathophysiology School of Basic Medical Sciences Tianjin Medical University Department of Neurochemistry Inge Grundke-Iqbal Research Floor New York State Institute for Basic Research inDevelopmental Disabilities

Contrary to the previous belief that insulin does not act in the brain, studies in the last three decades have demonstrated important roles of insulin and insulin signal transduction in various functions of the central nervous system. Deregulated brain insulin signaling and its role in molecular pathogenesis have recently been reported in Alzheimer＇s disease （AD）. In this article, we review the roles of brain insulin signaling in memory and cognition, the metabolism of amyloid 13 precursor protein, and tau phosphorylation. We further discuss deficiencies of brain insulin signaling and glucose metabolism, their roles in the development of AD, and recent studies that target the brain insulin signaling pathway for the treatment of AD. It is clear now that deregulation of brain insulin signaling plays an important role in the development of sporadic AD. The brain insulin signaling pathway also offers a promising therapeutic target for treating AD and probably other neurodegenerative disorders.

关键词： Alzheimer's disease APP metabolism brain insulin signaling glucose metabolism memory andcognition tau

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Bi-channel near-and far-field optical vortex generator based on a single plasmonic metasurface

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Photonics Research 2020年第6期8卷 986-994页

作者： QIAO JIANG YANJUN BAO JING LI LIFENG TIAN ToNG CUI LIN SUN BOWEN DU BOWEN LI BENFENG BAI JIA WANG HONGBO SUN Bo SHEN HAN ZHANG FENG LIN XING ZHU ZHEYU FANG School of Physics State Key Laboratory for Mesoscopic PhysicsAcademy for Advanced Interdisciplinary Studiesand Nano-optoelectronics Frontier Center of Ministry of EducationPeking UniversityBeiing 100871China Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technica/Institute of Physics and ChemistryChinese Academy of SciencesBeiing 100190China state Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentsTsinghua UniversityBeijing 100084China Collaborative Innovation Center of Quantum Matter BejingChina

With the recent development of the metasurface,generating an optical vortex in optical far or near fields is realized in various ***,to generate vortices in both the near and far fields simultaneously is still a challenge,although it has great potential in the future compact and versatile photonic ***,a bi-channel optical vortex generator in both the near and far fields is proposed and demonstrated within a single metasurface,where the surface plasmon vortex and the far-field optical vortex can be simultancously generated under circularly polarized *** ability of generating vortices with arbitrary topological charges is experimentally demon-strated,which agrces well with *** approach provides great freedom to integrate different vortex generators in a single device and ofers new opprtunities for integrated optical communications,trapping,and other related fields.

关键词： vortex generator generating

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