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Fast spreading of surface ozone in both temporal and spatial scale in Pearl River Delta

Journal of Environmental sciences 2024年第3期137卷 540-552页

作者： Tianhui Cao Haichao Wang Lei Li xiao Lu Yiming Liu Shaojia Fan school of Atmospheric sciences Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Guangdong Provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary Key Laboratory of Tropical Atmosphere-Ocean SystemMinistry of EducationZhuhai 519082China

Surface ozone(O_(3))is a major air pollutant and draw increasing attention in the Pearl River Delta(PRD),***,we characterize the spatial-temporal variability of ozone based on a dataset obtained from 57 national monitoring sites during *** results show that:(1)the seasonal difference of ozone distribution in the inland and coastal areas was significant,which was largely affected by the wind pattern reversals related to the East Asian monsoon,and local ozone production and destruction;(2)the daily maximum 8hr average(MDA8 O_(3))showed an overall upward trend by 1.11 ppbv/*** the trends in the nine cities varied differently by ranging from-0.12 to 2.51 ppbv/*** hot spots of ozone were spreading to southwestern areas from the central areas since *** ozone is becoming a year-round air pollution problem with the pollution season extending to winter and spring in PRD region.(3)at the central and southwestern PRD cities,the percentage of exceedance days from the continuous type(defined as≥3 days)was ***,the ozone concentration of continuous type was much higher than that of scattered exceedance type(<3 days).In addition,although the occurrence of continuous type starts to decline since2017,the total number of exceedance days during the continuous type is *** results indicate that it is more difficult to eliminate the continuous exceedance than the scatter pollution days and highlight the great challenge in mitigation of O_(3)pollution in these cities.

关键词： Surface ozone pollution Ozone trend Spatial and temporal variability Pearl River Delta Pollution mitigation

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Investigation of mechanical failure performance of a large-diameter shield tunnel segmental ring

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Journal of Zhejiang university-science A(applied Physics & Engineering) 2024年第5期25卷 411-428页

作者： Binyong GAO Renpeng CHEN Huaina WU Chengcheng ZHANG Meng FAN Chao xiao Research Center of Underground Space Advanced technology Hunan UniversityChangsha 410082China Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education Hunan UniversityChangsha 410082China Department of Civil Engineering Hunan UniversityChangsha 410082China china Construction No.5 Civil Engineering Co. Ltd.Changsha 410004China

The control criteria for structural deformation and the evaluation of operational safety performance for large-diameter shield tunnel segments are not yet clearly *** address this issue,a refined 3D finite element model was established to analyze the transverse deformation response of a large-diameter segmental *** analyzing the stress,deformation,and crack distribution of large-diameter segments under overload conditions,the transverse deformation of the segmental ring could be divided into four *** main reasons for the decrease in segmental ring stiffness were found to be the extensive development of cracks and the complete formation of four plastic *** deformation control value for the large-diameter shield tunnel segment is chosen as 8%o of the segment's outer diameter,representing the transverse deformation during the formation of the first semi-plastic hinge(i.e.,the first yield point)in the *** control value can serve as a reinforcement standard for preventing the failure of large-diameter shield tunnel *** flexural bearing capacity characteristic curve of segments was used to evaluate the structural strength of a large-diameter segmental *** was discovered that the maximum internal force combination of the segment did not exceed the segment ultimate bearing capacity curve(SUBC).However,the combination of internal force at 9°,85°,and 161°of the joints,and their symmetrical locations about the 0°-180°axis exceeded the joint ultimate bearing capacity curve(JUBC).The results indicate that the failure of the large-diameter segment lining was mainly due to insufficient joint strength,leading to an instability *** findings from this study can be used to develop more effective maintenance strategies for large-diameter shield tunnel segments to ensure their long-term performance.

关键词： Finite element model Transverse deformation response Upper overload Plastic hinges Flexural bearing capacity

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应淡化产业政策对中小企业发展的影响

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四川大学学报（哲学社会科学版） 2002年第3期 25-29页

作者：揭筱纹李平四川大学工商管理学院四川成都610064 电子科技大学应用数学学院四川成都610054

一国产业政策的提出和目标取向大都是善意的，但过细的产业政策原则上只适用于指导大型或特大型企业。对新兴古典组织试验模型的分析可以证明，不宜用过细的产业政策去抑制某些行业的中小企业发展，同时诱导中小企业在某些行业发展。... 详细信息

一国产业政策的提出和目标取向大都是善意的，但过细的产业政策原则上只适用于指导大型或特大型企业。对新兴古典组织试验模型的分析可以证明，不宜用过细的产业政策去抑制某些行业的中小企业发展，同时诱导中小企业在某些行业发展。否则，产业政策这个外部环境因素将对中小企业的发展影响很大，甚至有时直接关系到某些行业的中小企业能否存在。对中小企业应该淡化产业政策的影响，让中小企业通过社会组织试验，用成功和失败的经验证明其存在的社会价值。

关键词：产业政策中小企业企业发展

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A one-dimensional heat transfer model of the Antarctic Ice Sheet and modeling of snow temperatures at Dome A, the summit of Antarctic Plateau

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science china Earth sciences 2010年第5期53卷 763-772页

作者： CHEN BaiLian1,3, ZHANG RenHe2, SUN ShuFen1, BIAN LinGen2, xiao CunDe4,2 & ZHANG TingJun5 1 Institute of Atmospheric Physics, Chinese Academy of sciences, beijing 100029, china 2 Chinese Academy of Meteorological sciences, beijing 100081, china 3 Graduate university of Chinese Academy of sciences, beijing 100049, china 4 Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of sciences, Lanzhou 730000, china 5 The National Snow and Ice Data Center, university of Colorado, Boulder, CO 80309-0449, USA 1. Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China2. Chinese Academy of Meteorological Sciences Beijing 100081 China4. Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China5. The National Snow and Ice Data Center University of Colorado Boulder CO 80309-0449 USA

A vertical one-dimensional numerical model for heat transferring within the near-surface snow layer of the Antarctic Ice Sheet was developed based on simplified parameterizations of associated physical processes for the atmosphere, radiation, and snow/ice systems. Using the meteorological data of an automatic weather station (AWS) at Dome A (80°22′S, 70°22′E), we applied the model to simulate the seasonal temperature variation within a depth of 20 m. Comparison of modeled results with observed snow temperatures at 4 measurement depths (0.1, 1, 3, 10 m) shows good agreement and consistent seasonal variations. The model results reveal the vertical temperature structure within the near-surface snow layer and its seasonal variance with more details than those by limited measurements. Analyses on the model outputs of the surface energy fluxes show that: 1) the surface energy balance at Dome A is characterized by the compensation between negative net radiation and the positive sensible fluxes, and 2) the sensible heat is on average transported from the atmosphere to the snow, and has an evident increase in spring. The results are considered well representative for the highest interior Antarctic Plateau.

关键词： Antarctic Ice Sheet near-surface layer energy transfer numerical model

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Mechanism of Ta on the microstructure and properties of Fe-Mn damping alloys

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Tungsten 2024年第4期6卷 767-777页

作者： Gui-Xiang Liu Kun Zhang Chao Han xiao-Lin Shao Jun Lu Lin Zhang xiao-Song Jiang Zi-Xuan Wu Liu Yang The Second Sub-Institute Nuclear Power Institute of China Key Laboratory of Advanced Technologies of Materials Ministry of Education school of Materials science and Engineering Southwest Jiao tong University school of Engineering and Materials science Queen Mary University of London Institute for applied Materials (IAM-WK) Karlsruhe Institute of Technology (KIT)

Fe-Mn-Co-xTa alloys（x=0,1,2,3 wt.%） were fabricated using spark plasma sintering to explore the influence of Ta content on the microstructure,mechanical properties,and damping characteristics of Fe-17Mn-3Co damping *** micro structural analysis reveals the dominant presence of γ-austenite,ε-martensite,α'-martensite,and Co3Ta precipitates within the *** increments in Ta content exhibit proportional enhancements in hardness,tensile strength,and fracture elongation of the ***,these improvements in mechanical attributes are closely correlated with the generated second-phase *** the Ta content increases,there is a gradual augmentation in the formation of Co3Ta within the ***,the damping property initially experiences an ascent followed by a subsequent decline with rising Ta *** damping behavior finds its origins in multiple mechanisms,including grain boundary damping stemming from reduced grain size,interfacial damping induced by the generated Co3Ta,and dislocation *** is noteworthy that the emergence of the secondary phase wields a dual impact on damping *** the one hand,the proliferation of the second phase fosters increased interfaces for energy *** the other hand,these interfaces give rise to compressive stresses,constraining interface movement and thus impeding damping property enhancement.

关键词： Damping Fe–Mn–Co Mechanical properties Spark plasma sintering Ta

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Direct Adaptive Output-feedback Fuzzy Control of Arc Furnace

Direct Adaptive Output-feedback Fuzzy Control of Arc Furnace

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第24届中国控制与决策会议

作者： Ping Guan 1 , xiao-he Liu 1 , Ming-hui Li 1 , Li Xue 1 1. school of Automation, beijing Information science & technology university, beijing 100192

Arc furnace is the typical complex controlled system with three-phase strong coupling, high nonlinearity and uncertainty. The control requirement of arc furnace is also very strict. The direct adaptive output-feedback fuzzy control is presented. It is applied to electrode regulator systems of arc furnace, and the detailed design procedure of the adaptive output-feedback fuzzy control system is given. The state observer is designed to solve the immeasurable state. The adaptive fuzzy control is utilized to approach the uncertain term of output-feedback control. The adaptive law of the fuzzy rulers parameters is derived by Lyapunov function. The results of simulation show that this proposed control can restrain the external disturbances, and obtain much better dynamic and static characteristics.

关键词： adaptive control fuzzy control state observer arc furnace

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Understanding the Interfacial Energy Structure and Electron Extraction Process in Inverted Organic Solar Cells with Phosphine-Doped Cathode Interlayers

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Chinese Journal of Chemistry 2024年第12期42卷 1347-1354页

作者： Yi Yang Jingwen Wang Yang xiao Bowei Xu Jianhui Hou State Key Laboratory of Polymer Physics and Chemistry Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China State Key Laboratory of Chemical Resource Engineering College of Materials Science and EngineeringBeijing University of Chemical TechnologyBejing 100029China university of Chinese Academy of sciences Beijing 100049China

Comprehensive Summary Cathode interlayers(CILs)play an essential role in achieving efficient organic solar cells(OSCs).However,the electronic structure at the electrode/CIL/active layer interfaces and the underlying mechanisms for electron collection remain unclear,which becomes a major obstacle to develop high-performance ***,we investigate the relationship of the electron collection abilities of four cross-linked and n-doped CILs(c-NDI:P0,c-NDI:P1,c-NDI:P2,c-NDI:P3)with their electronic structure of space charge region at heterojunction *** accurately calculating the depletion region width according to the barrier height,doping density and permittivity,we put forward that the optimal thickness of CIL should be consistent with the depletion region width to realize the minimum energy *** a result,the depletion region width is largely reduced from 13 nm to 0.8 nm at the indium tin oxide(ITO)/c-NDI:P0 interface,resulting in a decent PCE of 17.7%for the corresponding inverted OSCs.

关键词： Organic solar cells Cathode interlayer Depletion region width Electric conductivity Electron transport Electron transfer Electron extraction process

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Two-stage aging treatment to accelerate aging kinetics without impairing strength in B_4C/7A04Al composite

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science china(Technological sciences) 2024年第8期67卷 2485-2492页

作者： CHEN YunTao MA GuoNan ZHU ShiZe WANG Dong xiao BoLv MA ZongYi Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China school of Materials science and Engineering University of Science and Technology of ChinaShenyang 110016China Centre of Excellence for Advanced Materials Dongguan 523808China

Aging treatments are the key process to obtain satisfactory strength for 7xxxAl alloys and their composites. However, traditional single-stage(SS) aging is time-consuming to reach a peak strength condition. In this study, an efficient 120℃ + 160℃ two-stage(TS) aging treatment was proposed on a B_4C/7A04Al composite fabricated via powder metallurgy(PM) technology, which could acquire similar peak-aging strength but only took about 15% of the time compared to traditional 120℃ SS aging. The evolution of precipitation during the TS aging was investigated, as well as those of the 7A04Al alloys for comparison. In the second stage aging process, the higher aging temperature accelerated the nucleation of η′ phases inside the grains and thus increased the density of precipitates. Moreover, the short aging time limited the coarsening of precipitates and the broadening of precipitatefree zones. The above factors were beneficial for quickly obtaining satisfactory precipitation strengthening effects. The B_4C/7A04Al composite exhibited slower aging kinetics than the 7A04Al alloy in the TS aging. Mg elements consumption by the chemical reaction between B impurities introduced by B_4C particles and the Al matrix was considered to potentially retard the aging kinetics of the B_4C/7A04Al composite. Nevertheless, the precipitation sequence was not affected.

关键词： aluminum matrix composites aging treatment powder metallurgy mechanical properties precipitation

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Interactive effects of soils,local environmental conditions and herbivores on secondary chemicals in tallow tree

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Journal of Plant Ecology 2024年第4期17卷 167-180页

作者： Li xiao Wei Huang Juli Carrillo Jianqing Ding Evan Siemann College of Life and Environmental science Central South University of Forestry and TechnologyChangsha 410004China National Engineering Laboratory of applied technology for Forestry&Ecology in Southern china Central South University of Forestry and TechnologyChangsha 410004China CAS Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074China Faculty of Land and Food Systems Centre for Sustainable Food SystemsBiodiversity Research CentreUniversity of British ColumbiaVancouver V6T 1Z4Canada State Key Laboratory of Crop Stress Adaptation and Improvement School of Life SciencesHenan UniversityKaifeng 475004China Biosciences Department Rice UniversityHoustonTX 77005USA

Plants produce secondary chemicals that may vary along with latitude due to changing abiotic and biotic stress gradients and local environmental *** apart the individual and combined effects of these different abiotic,such as soil nutrients,and biotic factors,such as soil biota and herbivores,on secondary chemicals is critical for understanding plant responses to changing *** conducted an experiment at different latitudes in china,using tallow tree(Triadica sebifera)seedlings sourced from a population at 31°*** seedlings were cultivated in gardens located at low,middle and high latitudes,with either local soil or soil from the original seed collection site(origin soil).The seedlings were exposed to natural levels of aboveground herbivores or had them *** secondary chemicals(both foliar and root),aboveground herbivores and soil characteristics were *** showed that most leaf and root secondary metabolites depended on the interaction of the experimental site and soil *** and root phenolic and tannin concentrations were higher at the middle latitude site,especially in the origin *** and foliar flavonoid concentrations increased when aboveground herbivores were *** communities depended strongly on soil *** different responses of tannins versus flavonoids suggest that these two chemical classes differ in their responses to the varying abiotic and biotic factors in these sites along *** together,our results emphasize the importance of considering the interactive effects of local environmental conditions,soil properties and herbivory in regulating plant chemical defenses.

关键词： phenolics tannins flavonoids abiotic factors soil characteristics Triadica sebifera

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Imide-pillared covalent organic framework protective films as stable zinc ion-conducting interphases for dendrite-free Zn metal anodes

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Journal of Energy Chemistry 2024年第10期97卷 470-477,I0010页

作者： xiaoman Ye Xuemei xiao Zhijing Wu Xin Wu Lin Gu Sheng Liu school of Chemical Engineering and technology Sun Yat-sen UniversityZhuhai 519082GuangdongChina The Key Lab of Low-Carbon Chemistry&Energy Conservation of Guangdong Province Sun Yat-sen UniversityGuangzhou 510275GuangdongChina

The notorious growth of zinc dendrite and the water-induced corrosion of zinc metal anodes(ZMAs)restrict the practical development of aqueous zinc ion batteries(AZIBs).In this work,a zinc metallized,imide-pillared covalent organic framework(ZPC)protective film has been engineered as a stable Zn^(2+)ion-conducting interphase to modulate interfacial kinetics and suppress side reactions for *** to bare Zn,ZPC@Zn exhibits a higher Zn^(2+)ionic conductivity,a larger Zn^(2+)transference number,a lower electronic conductivity,a smaller desolvation activation energy and correspondingly a significant suppression of corrosion,hydrogen evolution and Zn ***,the ZPC@Zn||ZPC@Zn symmetric cell obtains a cycling lifespan over 3000 h under 5 mA cm^(-2)for 1 mA h cm^(-2).The ZPC@Zn||NH_(4)V_(4)O_(10)coin-type full battery delivers a specific capacity of 195.8 mA h g^(-1)with a retention rate of78.5%at 2 A g^(-1)after 1100 cycles,and the ZPC@Zn||NH_(4)V_(4)O_(10) pouch full cell shows a retention of70.1%in reversible capacity at 3 A g^(-1)after 1100 *** present incorporation of imide-linked covalent organic frameworks in the surface modification of ZMAs will offer fresh perspectives in the search for ideal protective films for the practicality of AZIBs.

关键词： Aqueous zinc ion batteries Zinc metal anodes Surface modification Covalent organic frameworks Imide linkage

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