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Characteristics and sources of peroxyacetyl nitrate(PAN)in the rural North China Plain:Results from1-year continuous observations

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Journal of Environmental Sciences 2024年第4期138卷 719-731页

作者： Xin liu Xiaowei He Chenglong Zhang Yifei Song Shuyang Xie Chengtang liu Pengfei liu Yuanyuan Zhang Yujing Mu junfeng liu Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Peroxyacetyl nitrate(PAN)is an important photochemical pollutant in the troposphere,whereas long-term measurements are scarce in rural areas in North China Plain(NCP),resulting in unclear seasonal variations and sources of PAN in rural *** this study,we conducted a 1-year observation of PAN during 2021-2022 at the rural NCP *** average concentrations of PAN were 1.10,0.75,0.65,and 0.88 ppbv in spring,summer,autumn,and winter,respectively,with a 1-year average of 0.81±0.60 *** indicate that the loss of PAN through thermal decomposition in summer accounts for 43.2% of the total formed PAN,which is an important reason for the low concentration of PAN in *** speculate that since the correlation between PAN and O_(3) in winter is significantly lower than that in other seasons,the observed regional transport of PAN cannot be ignored in *** budget analysis,regional transport accounted for 12.8% and 55.9% of the observed PAN on the spring and winter pollution days,respectively,which showed that regional transport played key roles during the photochemical pollution of the rural NCP in *** potential source contribution function revealed that the transported PAN mainly comes from southern Hebei in *** winter,the transported PAN was mainly from Langfang,Hengshui,and southern *** findings may aid in understanding PAN variations in different seasons in rural areas and highlight the impact of regional transport on the PAN budget.

关键词： Photochemical pollution Peroxyacetyl nitrate(PAN) Seasonal variations Regional transport Rural area

Non-perturbative dynamics of flat-band systems with correlated disorder

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Chinese Physics B 2024年第9期33卷 547-551页

作者： Qi Li junfeng liu Ke liu Zi-Xiang Hu Zhou Li GBA Branch of Aerospace Information Research Institute Chinese Academy of SciencesGuangzhou 510535China Guangdong Provincial Key Laboratory of Terahertz Quantum Electromagnetics Guangzhou 510700China School of Physics and Materials Science Guangzhou UniversityGuangzhou 510006China Department of Physics and Chongqing Key Laboratory for Strongly Coupled Physics Chongqing UniversityChongqing 401331China University of Chinese Academy of Sciences Beijing 100039China

We develop a numerical method for the time evolution of Gaussian wave packets on flat-band lattices in the presence of correlated *** achieve this,we introduce a method to generate random on-site energies with prescribed *** verify this method with a one-dimensional(1D)cross-stitch model,and find good agreement with analytical results obtained from the disorder-dressed evolution *** allows us to reproduce previous findings,that disorder can mobilize 1D flat-band states which would otherwise remain *** explained by the corresponding disorder-dressed evolution equations,such mobilization requires an asymmetric disorder-induced coupling to dispersive bands,a condition that is generically not fulfilled when the flat-band is resonant with the dispersive bands at a Dirac point-like *** exemplify this with the 1D Lieb *** analytical expressions are not available for the two-dimensional(2D)system due to its complexity,we extend the numerical method to the 2D a–T3 model,and find that the initial flat-band wave packet preserves its localization when a=0,regardless of disorder and ***,when a̸=0,the wave packet shifts in real *** interpret this as a Berry phase controlled,disorder-induced wave-packet *** addition,we present density functional theory calculations of candidate materials,specifically Hg1−*** flat-band emerges near the G point(α=0)in the Brillouin zone.

关键词： flat-band system dynamics correlated disorder

Yolk-shell FeCu/NC electrocatalyst boosting high-performance zinc-air battery

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Nano Research 2024年第9期17卷 7918-7925页

作者： Chen Liang Tianyu Zhang Shilun Sun Aijuan Han Zenghui Qiu Haijun Xu junfeng liu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China College of Mathematics&Physics Beijing University of Chemical TechnologyBeijing 100029China Beijing Bioprocess Key Laboratory Beijing University of Chemical TechnologyBeijing 100029China

Iron-nitrogen-carbon single-atom catalysts(Fe-N-C SACs)are widely acknowledged for their effective oxygen reduction activity,however,their activity requires further ***,additional structural optimization is necessary to enhance mass transport and achieve higher power density in practical ***,using ZIF-8 as a template,we synthesized yolk-shell catalysts featuring complex sites of Fe single atoms and Cu nanoclusters(y-FeCu/NC)via partial etching and liquid-phase *** synthesized y-FeCu/NC catalyst exhibits high specific surface area and mesoporous *** with the advantages of highly active sites and yolk-shell structure,the y-FeCu/NC catalyst demonstrated outstanding catalytic performance in the oxygen reduction reaction,achieving a half-wave potential(E_(1/2))of 0.97 V in 0.1 M *** a practical energy device,Zn-air battery(ZAB)assembled with y-FeCu/NC catalyst achieved a remarkable power density of 356.3 mW·cm^(-2),representing an improvement of approximately 28.5%compared to its solid FeCu/NC ***,it showcased impressive stability,surpassing all control samples.

关键词： atomic Fe-N4 sites Cu nanoclusters yolk-shell structure oxygen reduction reaction zinc-air battery

Microstructures and Properties of Biomedical Mg-Zn-Sn-Zr Rolled Alloys

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 766-773页

作者：周生刚 ZHANG Daxin XU Yang DUAN Jihao LI Tao liu junfeng WANG Peng 曹勇 Faculty of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The as-cast Mg-2.0Zn-1.5Sn-xZr(x=0,0.4,0.6,0.8,1.0 wt%)alloy was rolled with the pressure less than 5%each *** microstructure,mechanical properties,corrosion properties and biocompatibility of the alloy were *** microstructure of the alloy was observed and analyzed by scanning electron microscope,and the tensile test was carried out by universal tensile *** corrosion resistance of the alloy in Hank's solution was studied by hydrogen evolution experiment and electrochemical test,and the biocompatibility of the alloy was tested by L929 *** results show that Mg-2Zn-1.5Sn-xZr alloy has excellent mechanical *** elongation of Mg-2Zn-1.5Sn-xZr alloy decreases with the increase of Zr content,but the tensile strength first increases and then decreases with the increase of Zr *** the Zr content is 0.8 wt%,the maximum tensile strength of the alloy is 235 *** results of hydrogen evolution experiment and electrochemical analysis show that the corrosion resistance of the alloy is the best when the Zr content is 0.8 wt%,and all the five alloys have high *** conclusion,the rolled alloy has good properties and has broad application prospects in the field of biomaterials.

关键词： magnesium alloy corrosion performance mechanical properties biocompatibility

Innovative Solutions for High-Performance Silicon Anodes in Lithium-Ion Batteries:Overcoming Challenges and Real-World Applications

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Nano-Micro Letters 2024年第9期16卷 341-384页

作者： Mustafa Khan Suxia Yan Mujahid Ali Faisal Mahmood Yang Zheng Guochun Li junfeng liu Xiaohui Song Yong Wang Institute for Energy Research Jiangsu UniversityZhenjiang 212013JiangsuPeople’s Republic of China School of Energy and Power Engineering Jiangsu UniversityZhenjiang 212013JiangsuPeople’s Republic of China School of Materials Science and Engineering Hefei University of TechnologyHefei 230009AnhuiPeople’s Republic of China

Silicon(Si)has emerged as a potent anode material for lithium-ion batteries(LIBs),but faces challenges like low electrical conductivity and significant volume changes during lithiation/delithiation,leading to material pulverization and capacity *** research on nanostructured Si aims to mitigate volume expansion and enhance electrochemical performance,yet still grapples with issues like pulverization,unstable solid electrolyte interface(SEI)growth,and interparticle *** review delves into innovative strategies for optimizing Si anodes’electrochemical performance via structural engineering,focusing on the synthesis of Si/C composites,engineering multidimensional nanostructures,and applying non-carbonaceous *** a stable SEI is vital to prevent electrolyte decomposition and enhance Li^(+)transport,thereby stabilizing the Si anode interface and boosting cycling Coulombic *** also examine groundbreaking advancements such as self-healing polymers and advanced prelithiation methods to improve initial Coulombic efficiency and combat capacity *** review uniquely provides a detailed examination of these strategies in real-world applications,moving beyond theoretical *** offers a critical analysis of these approaches in terms of performance enhancement,scalability,and commercial *** conclusion,this review presents a comprehensive view and a forward-looking perspective on designing robust,high-performance Si-based anodes the next generation of LIBs.

关键词： Silicon anode Energy storage Nanostructure Prelithiation Binder

Engineering hydrophobic protective layers on zinc anodes for enhanced performance in aqueous zinc-ion batteries

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Journal of Energy Chemistry 2024年第10期97卷 1-11,I0001页

作者： Taofeng Li Suxia Yan Hongyu Dong Yang Zheng Kun Ming Ying Chen Haitao Li Guochun Li Zhixia He Weimin Li Quan Wang Xiaohui Song junfeng liu Edison Huixiang Ang Yong Wang Institute for Energy Research Jiangsu UniversityZhenjiang 212013jiangsuChina Natural Sciences and Science Education National Institute of EducationNanyang Technological UniversitySingapore 63766Singapore School of Mechanical Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina Shenzhen Cllege of Advanced Technology University of Chinese Academy of SciencesShenzhen 518055GuangdongChina Shandong Zhongke Advanced Technology Co. LtdJinan 250101ShandongChina School of Materials Science and Engineering HefeiUniversity of TechnolgyHefei230009AnhuiChi

Aqueous zinc-ion batteries possess substantial potential for energy storage applications;however,they are hampered by challenges such as dendrite formation and uncontrolled side reactions occurring at the zinc *** our investigation,we sought to mitigate these issues through the utilization of in situ zinc complex formation reactions to engineer hydrophobic protective layers on the zinc anode *** robust interfacial layers serve as effective barriers,isolating the zinc anode from the electrolyte and active water molecules and thereby preventing hydrogen evolution and the generation of undesirable ***,the presence of numerous zincophilic sites within these protective layers facilitates uniform zinc deposition while concurrently inhibiting dendrite *** comprehensive evaluation of functional anodes featuring diverse functional groups and alkyl chain lengths,we meticulously scrutinized the underlying mechanisms influencing performance *** analysis involved precise modulation of interfacial hydrophobicity,rapid Zn^(2+)ion transport,and ordered deposition of Zn^(2+)***,the optimized anode,fabricated with octadecylphosphate(OPA),demonstrated exceptional performance *** Zn//Zn symmetric cell exhibited remarkable longevity,exceeding 4000 h under a current density of 2 mA cm^(-2)and a capacity density of 2 mA h cm^(-2),Furthermore,when integrated with a VOH cathode,the complete cell exhibited superior capacity retention compared to anodes modified with alternative organic molecules.

关键词： Aqueous zinc-ion batteries Hydrophobic protective layers Zinc anode stability Dendrite growth inhibition Energy storage

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基于UWB的综采工作面推进度测量系统

工矿自动化 2024年第4期50卷 33-40页

作者：刘清刘军锋北京天玛智控科技股份有限公司北京101399

针对目前综采工作面推进度的测量和计算方式存在费时费力、累计误差大、传感器损坏后无法重新计算等问题,提出了一种基于UWB测距技术的综采工作面推进度实时测量系统。该系统采用矿用本安型测距分站与测距标志卡组合的方式,通过无线通... 详细信息

针对目前综采工作面推进度的测量和计算方式存在费时费力、累计误差大、传感器损坏后无法重新计算等问题,提出了一种基于UWB测距技术的综采工作面推进度实时测量系统。该系统采用矿用本安型测距分站与测距标志卡组合的方式,通过无线通信实现对综采工作面巷道推进度的实时测量。在综采工作面端头液压支架布置测距分站,在回采巷道固定标志点悬挂测距标志卡,通过巷道内UWB无线信号测距,当即将开采到最近的测距标志卡位置时,撤掉该处测距标志卡,后续测距标志卡接替进行巷道推进度的测量与计算,依此循环往复,不断进行更替测量。结合采煤工艺,建立了依据采煤机位置和液压支架动作的限幅中值平均滤波模型,该模型将限幅滤波、中值滤波、算术平均滤波深度融合,以剔除海量数据中由于受到测量、遮挡等影响而造成的测量偏差较大的无效数据,同时消除有效数据中的最大和最小偏差数据,进一步保证了通过算术平均运算得到的测量值的准确性和有效性,实现了综采工作面推进度的连续测量。地面测试结果表明,测距分站1的最大误差为0.32 m,误差小于0.2 m的占比为84.62%;测距分站2的最大误差为0.48 m,误差小于0.2 m的占比为76.92%。井下工业性试验结果表明:该系统与矿方实测数据日平均推进度差值为0.13 m,证明了UWB测距技术在井下巷道条件下测距的可行性和基于采煤工艺的推进度测量模型的准确性。

关键词：综采工作面推进度测量 UWB测距双边双向测距法限幅中值平均滤波模型

中国企业供应链上游国外垄断程度的时空特征及其创新效应研究

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地理研究 2024年第10期43卷 2580-2601页

作者：季建文刘峻峰南开大学经济学院天津300071 苏州科技大学商学院苏州215009 复旦大学与苏州国际发展集团有限公司联合培养博士后科研工作站苏州215301

已有文献聚焦供应链上游国外垄断程度并从宏观视角开展经济学实证计量研究,但未重视其在经济地理学视角下时空演变的典型事实特征及其对微观企业创新的影响。本文借助2007—2022年A股上市公司制造业企业数据,解读供应链上游国外垄断程... 详细信息

已有文献聚焦供应链上游国外垄断程度并从宏观视角开展经济学实证计量研究,但未重视其在经济地理学视角下时空演变的典型事实特征及其对微观企业创新的影响。本文借助2007—2022年A股上市公司制造业企业数据,解读供应链上游国外垄断程度的时空动态分异特征,并分析其与企业创新之间的关系。研究发现:①时间维度上,中国制造业企业供应链上游国外垄断程度整体呈现波动下降的趋势。分行业来看,中国各行业供应链上游国外垄断程度差异明显,资源缺乏与技术差距成为特定行业供应链上游国外垄断程度较高的重要原因,反映了资源和技术禀赋是影响中国制造业发展的核心因素。②空间维度上,东部地区的供应链上游国外垄断程度高于中西部地区,但中西部地区的供应链上游国外垄断程度逐步提高,垄断重心呈现出“东南→东北→西南”的地理迁移特征。③供应链上游国外垄断程度对企业创新的影响呈非对称的U型曲线特征,且供应链上游国外垄断程度对非国有、东部地区和较差金融背景等类型企业创新的影响更为敏感。

关键词：供应链上游国外垄断企业创新时空演化

金库与抗币:国共关系视野下浙东抗日根据地的对敌金融斗争

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史林 2024年第2期 195-203,220页

作者：姜建忠刘俊峰杭州师范大学民国浙江史研究中心 311121

浙东抗日根据地是抗日战争期间,华中新四军在浙江东部杭州湾两岸建立的抗日根据地。根据地地处富庶的长三角地区,是各方势力争夺的重要区域。浙东根据地在初创阶段,采用灰色隐蔽斗争策略,采取禁用伪币、维持法币的金融斗争措施。随着三... 详细信息

浙东抗日根据地是抗日战争期间,华中新四军在浙江东部杭州湾两岸建立的抗日根据地。根据地地处富庶的长三角地区,是各方势力争夺的重要区域。浙东根据地在初创阶段,采用灰色隐蔽斗争策略,采取禁用伪币、维持法币的金融斗争措施。随着三北游击根据地的创建,在国共摩擦的背景下,浙东区党委采取建立金库、发行金库兑换券的措施,来解决财政经济困难。面对法币持续贬值,根据地采取既联合又限制的政策,建立自己的银行,发行本位货币,并妥善处理与法币的关系。从金融斗争的结果看,这些措施发展了根据地经济,增强了抗日力量。在金融斗争过程中浙东抗日根据地展现出的与其他根据地的差异,反映了抗日战争时期根据地金融建设的复杂性、艰巨性。

关键词：国共关系视野浙东抗日根据地金融斗争