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Seasonal variation and sources of low molecular weight organic acids in precipitation in the rural area of Anshun

Chinese Science Bulletin 2011年第10期56卷 1005-1010页

作者： zhang yanlin LEE XinQing CAO Fang HUANG DaiKuan State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

Low molecular weight (LMW) organic acids are important and ubiquitous chemical constituents in the atmosphere.A comprehensive study of the chemical composition of precipitation was carried out from June 2007 to June 2008 at a rural site in Anshun,in the west of Guizhou Province,*** this period,118 rainwater samples were collected and the main LMW carboxylic acids were determined using ion *** average pH of rainwater was 4.89 which is a typical acidic *** most abundant carboxylic acids were formic acid (volume weight mean concentration:8.77 μmol L-1) and acetic acid (6.90 μmol L-1),followed by oxalic acid (2.05 μmol L-1).The seasonal variation of concentrations and wet deposition fluxes of organic acids indicated that direct vegetation emissions were the main sources of the organic *** concentrations were observed in winter and were ascribed to the low winter rainfall and the contribution of other air pollution sources northeast of the study *** ratio of formic and acetic acids in the precipitation ([F/A] T) was proposed as an indicator of pollution *** suggested that the pollution resulted from direct emissions from natural or anthropogenic *** with acid precipitation in other urban and rural areas in Guizhou showed that there was a decreasing contribution of LMW organic acids to free acidity and all anions in rainwater from urban to remote rural ***,it is necessary to control emissions of organic acids to reduce the frequency of acid rain,especially in rural and remote areas.

关键词：低分子量有机酸农村地区季节变化降水安顺平均浓度化学成分污染来源

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Impacts of canopy structure on the sub-canopy solar radiation under a deciduous forest based on fisheye photographs

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Research in Cold and Arid Regions 2023年第3期15卷 150-160页

作者： yanlin zhang XiaoLin Feng XiaoLi Chang LiMin Tie School of Earth Sciences and Spatial Information Engineering Hunan University of Science and TechnologyXiangtanHunan 411201China

Forest canopy in a deciduous forest has significant sheltering effects on the sub-canopy solar radiation,significantly influencing the energy balance of snow and permafrost beneath the forest and their spatial *** study employs a digital camera mounted with a fisheye lens to acquire photographs at various times in a growth cycle of the forest canopy at three selected sites in a deciduous forest near the Greater Khingan Mountains Forest Ecological Station,Northeast *** vegetation types and conditions at the selected sites include P1 in ***,P2 in Carex ***,and P3 in Betula *** necessary image processing,these photographs were used to identify the canopy structure and its impacts on the sub-canopy solar *** show that fisheye photographs can successfully capture the forest canopy structure and are useful in estimating the sub-canopy solar *** order of sheltering effects from the largest to the smallest on sub-canopy solar radiation at three selected sites is P3,P1,and P2,highly depending on the canopy *** sub-canopy solar radiation was calculated using fisheye photographs and an algorithm validated by in-situ observed solar radiation beneath the canopy at P1 and *** results are reasonable,although the accuracy seems compromised due to the mismatch of conditions for calculation and *** also show that the mean annual solar radiation above the canopy was about 148.3 W/m2 in 2018,and the mean annual solar radiation values beneath the canopy were about 90.0,123.8,and 61.0 W/m2 at P1,P2,and P3,with only 60%,84%,and 42%of the total solar radiation penetrating through the canopy,*** in winter,when the trees are leafless,the canopy sheltering effects cannot be ignored in dense *** the limitations,fisheye photographs and related algorithms are useful in investigating the forest canopy structure and its impacts on sub-canopy s

关键词： Solar radiation Forest structure Fisheye photograph Sub-canopy Deciduous forest

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δ^(15)N-stable isotope analysis of NH_(x): An overview on analytical measurements, source sampling and its source apportionment

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Frontiers of Environmental Science & Engineering 2021年第6期15卷 175-185页

作者： Noshan Bhattarai Shuxiao Wang Yuepeng Pan Qingcheng Xu yanlin zhang Yunhua Chang Yunting Fang State Key Joint Laboratory of Environmental Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Yale-NUIST Center on Atmospheric Environment Nanjing University of Information Science&TechnologyNanjing 210044China CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China

Agricultural sources and non-agricultural emissions contribute to gaseous ammonia(NH_(3))that plays a vital role in severe haze *** and quantitative contributions of these sources to ambient PM_(2.5)(particulate matter with an aerodynamic equivalent diameter below 2.5µm)concentrations remains *** nitrogen isotopic composition(δ^(15)N)of NH_(3)and NH_(4)+(δ^(15)N(NH_(3))andδ^(15)N(NH_(4)+),respectively)can yield valuable information about its sources and associated *** review provides an overview of the recent progress in analytical techniques forδ^(15)N(NH_(3))andδ^(15)N(NH_(4)+)measurement,sampling of atmospheric NH_(3)and NH_(4)+in the ambient air and their sources signature(e.g.,agricultural *** fuel),and isotope-based source apportionment of NH_(3)in urban *** study highlights that collecting sample that are fully representative of emission sources remains a challenge in fingerprintingδ^(15)N(NH_(3))values of NH_(3)emission ***,isotopic fractionation during NH_(3)gas-to-particle conversion under varying ambient field conditions(e.g.,relative humidity,particle pH,temperature)remains unclear,which indicates more field and laboratory studies to validate theoretically predicted isotopic fractionation are ***,this study concludes that lack of refinedδ^(15)N(NH_(3))fingerprints and full understanding of isotopic fractionation during aerosol formation in a laboratory and field conditions is a limitation for isotope-based source apportionment of NH_(3).More experimental work(in chamber studies)and theoretical estimations in combinations of field verification are necessary in characterizing isotopic fractionation under various environmental and atmospheric neutralization conditions,which would help to better interpret isotopic data and our understanding on NH_(x)(NH_(3)+NH_(4)+)dynamics in the atmosphere.

关键词： Aerosol ammonium Atmospheric gaseous ammonia Isotope fingerprinting Isotope-based source apportionment Ammonia gas-to-particle conversion

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Development and test of hydraulic driven remote transporter

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International Journal of Agricultural and Biological Engineering 2021年第2期14卷 72-80页

作者： Jiaxue Li Shanjun Li yanlin zhang Mingdi Liu Zhiyuan Gao College of Engineering Huazhong Agricultural UniversityWuhan 430070China Guangdong Polytechnic college Zhaoqing 526000GuangdongChina China Agriculture(Citrus)Research System Wuhan 430070China Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River Ministry of Agriculture and Rural AffairsWuhan 430070China Citrus Mechanization Research Base Ministry of Agriculture and Rural AffairsWuhan 430070China National R&D Center for Citrus Preservation Wuhan 430070China

To solve the problems of the traditional orchard conveyor,such as inflexible steering,a complex structure,poor stability and no power grid coverage,a remote-controlled rail conveyor powered by hydraulic pressure for mountainous orchards was designed and *** stress analysis was carried out on a full-load trailer to obtain the maximum traction force,which met the requirement of the climbing slope of the transport *** key components of the conveyor were developed,such as the hydraulic transmission,the control system,safety protection devices,limiting devices,the throttle and decompression actuator,the counterweight tension and the *** the theoretical calculations of key components,an orchard conveyor powered by diesel and hydraulic pressure was ***,the working performance of the transporter was tested through functionality,driving speed,system pressure and remote-controlled *** test results showed that the climbing angle of the transporter can reach 50°,the uphill load can reach 840 kg,the downhill load can reach 1100 kg,and the average running speed is 0.77 m/s;the driving speed ranges from 0.29 m/s to 1.08 m/s,and the system pressure ranges from 3.2 MPa to 10 *** driving speed and system pressure are significantly affected by the load,and the remote control distance can reach 455 *** technical specifications of the transporter meet all the design requirements,and the problem of stable operation of the transporter without power grid coverage has been *** research results can well meet the practical application requirements of mountain orchard transportation without power grid coverage and provide theoretical reference for the design of key components of mountain orchard transportation machinery.

关键词： mountain orchard conveyor hydraulic drive remote control

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A coupled catalyst composed of CoFe_(2)O_(4) magnetic nanoparticle and[HMIM]Br-FeCl_(3) to intensify the oxidative desulfurization of FCC diesel

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Green Chemical Engineering 2021年第4期2卷 441-449页

作者： yanlin zhang Xinyu zhang Guangren Yu Xiaochun Chen Ahmed A.Abdeltawab Hany El-Hamshary Beijing Key Laboratory of Membrane Science and Technology&College of Chemical Engineering Beijing University of Chemical TechnologyBeijing100029China Department of Chemistry College of ScienceKing Saud UniversityRiyadh11451Saudi Arabia

Ionic liquids have been extensively studied as solvents or catalysts for oxidative desulfurization(ODS)of diesel fuel,but it is still a challenge to reduce the desulfurization time and *** this work,a new highly efficient desulfurization system composed of CoFe_(2)O_(4) magnetic nanoparticle,[HMIM]Br-FeCl_(3) and H_(2)O_(2) was developed for the ODS of FCC diesel *** desulfurization performances were investigated including desulfurization time,temperature,volume ratio of IL/oil,O/S molar ratio,dosage of CoFe_(2)O_(4),FeCl_(3) content in ILs,regeneration,and reuse of catalyst and *** to the coupled catalytic roles of CoFe_(2)O_(4) magnetic nanoparticle and[HMIM]Br-FeCl_(3),where Co2t and Fe3t interact with H_(2)O_(2) to produce ·OH radical that converts S-compounds into sulfone and sulfoxide compounds,such a desulfurization system is highly effective in removing S-compound in diesel *** S-content in FCC diesel fuel was reduced from the original 272.8 ppm to 0.5 ppm with 99.82%S-removal efficiency after one step within 8 minunder the optimal conditions of 25℃,8 min,V(IL/oil)=1:10,O/S=20,5 wt%CoFe_(2)O_(4) dosage and n([HMIM]Br)/n(FeCl_(3))=1:1;the desulfurization performance is much better in desulfurization time and steps than other desulfurization systems reported *** desulfurization system can be regenerated and reused without remarkable loss of desulfurization activity.A desulfurization mechanism was proposed.

关键词： CoFe_(2)O_(4)magnetic nanoparticle Ferric chloride ionic liquids Oxidative desulfurization

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Initial residual stress experiment and simulation of thin-walled parts for layer removal method

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High Technology Letters 2018年第1期24卷 75-81页

作者：刘宇男 Wang Min Zan Tao Gao Xiangsheng zhang yanlin Beijing Key Laboratory of Advanced Manufacturing Technology College of Mechanical Engineering and Applied Electronics Technology Beijing University of Technology Beijing 100124 P. R. China Beijing Key Laboratory of Electrical Discharge Machining Technology Beiiing 100191 P. R. China Beijing Xinli Machinery Co. Ltd. Beijing 100039 P. R. China

Thin-walled parts have low stiffness characteristic. Initial residual stress of thin-walled blanks is an important influence factor on machining stability. The present work is to verify the feasibility of an initial residual stress measurement of layer removal method. According to initial residual stress experiment for casting ZL205 A aluminum alloy tapered thin-walled blank by a common method,namely hole-drilling method,three finite element models with initial residual stress are established to simulate the layer removal method in ABAQUS and ANSYS software. By analyzing the results of simulation and experiments,the cutting residual stress inlayer removal process has a significant effect on measurement results. Reducing cutting residual stress is helpful to improve accuracy of layer removal method.

关键词： initial residual stress thin-walled parts layer.removal method finite element

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A distributed scheme developed for eco-hydrological modeling in the upper Heihe River

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Science China Earth Sciences 2015年第1期58卷 36-45页

作者： YANG DaWen GAO Bing JIAO Yang LEI Hui Min zhang yanlin YANG HanBo CONG ZhenTao State Key Laboratory of Hydro-science and Engineering Department of Hydraulic EngineeringTsinghua University School of Water Resources and Environment China University of Geosciences Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

Modeling the hydrological processes at catchment scale requires a flexible distributed scheme to represent the catchment to- pography, river network and vegetation pattern. This study has developed a distributed scheme for eco-hydrological simulation in the upper Heihe River. Based on a 1 km x 1 km grid system, the study catchment is divided into 461 sub-catchments, whose main streams form the streamflow pathway. Furthermore, a 1 km grid is represented by a number of topographically similar ＂hillslope-valley＂ systems, and the hillslope is the basic unit of the eco-hydrological simulation. This model is tested with a simplified hydrological simulation focusing on soil-water dynamics and streamflow routing. Based on a 12-year simulation from 2001 to 2012, it is found that variability in hydrological behavior is closely associated with climatic and landscape condi- tions especially vegetation types. The subsurface and groundwater flows dominate the total river runoff. This implies that the soil freezing and thawing process would significantly influence the runoff generation in the upper Heihe basin. Furthermore, the runoff components and water balance characteristics vary among different vegetation types, showing the importance of coupling the vegetation pattern into catchment hydrological simulation. This paper also discusses the model improvement to be done in future study.

关键词： distributed scheme catchment discretization streamflow pathway hillslope parameterization the upper Heihe River

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Optimized design of the power consumption test of mountain orchard transporters

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International Journal of Agricultural and Biological Engineering 2021年第5期14卷 107-114页

作者： Jiaxue Li Muyuan Zhong yanlin zhang Xiulan Bao Shanjun Li Mingdi Liu Linghao Wang College of Engineering Huazhong Agricultural UniversityWuhan 430070China Guangdong Polytechnic College Zhaoqing 526000GuangdongChina National R&D Center for Citrus Preservation Wuhan 430070China China Agriculture(Citrus)Research System Wuhan 430070China Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River Ministry of Agriculture and Rural AffairsWuhan 430070China Citrus Mechanization Research Base Ministry of Agriculture and Rural AffairsWuhan 430070China

In order to study the influence rule of various factors on the operating power consumption of the traction orchard transporter and realize the optimal design of the operation power consumption of the transporter,according to the traditional experience and the existing research foundation,the monorail transporter test bench was designed and built on the basis of the whole structure and operation characteristics of the *** the motor frequency,track gradient and load as the investigation factors,and the driving shaft power,shaft power transmission and mechanical efficiency as the evaluation indices,the orthogonal test was conducted,and the range analysis of the influence effect was carried out according to the test *** primary and secondary orders of the influence of various factors were obtained that motor frequency was greater than track gradient and track gradient was greater than *** to the orthogonal test results,the second-order response surface method was used to establish the optimization model of the power consumption of the transporter,and the model was verified on the test *** results showed that the relative error between the model optimization value and the test value based on the response surface power optimization model was less than 10%,which indicated that the power optimization model had satisfactory *** research can provide a reference for the orchard conveyor to choose the parameter combination which can save power consumption and the motor that matches power consumption.

关键词： mountain orchard transporter power consumption orthogonal test optimization model analysis

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Study of seasonal snow cover influencing the ground thermal regime on western flank of Da Xing'anling Mountains,northeastern China

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Research in Cold and Arid Regions 2015年第6期7卷 666-674页

作者： XiaoLi Chang HuiJun Jin yanlin zhang HaiBin Sun Hunan University of Science and Technology State Key Laboratory of Frozen Soils Engineering Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Gen'he Meteorological Administration

Although many studies relevant to snow cover and permafrost have focused on alpine, arctic, and subarctic areas, there is still a lack of understanding of the influences of seasonal snow cover on the thermal regime of the soils in permafrost regions in the mid-latitudes and boreal regions, such as that on the westem flank of the Da Xing＇anling （Hinggan） Mountains, northeastern China. This paper gives a detailed analysis on meteorological data series from 2001 to 2010 provided by the Gen＇he Weather Station, which is located in a talik of discontinuous permafrost zone and with sparse meadow on the observation field. It is inferred that snow cover is important for the ground thermal regime in the middle Da Xing＇anling Mountains. Snow cover of 10-cm in thickness and five to six months in duration （generally November to next March） can reduce the heat loss from the ground to the atmosphere by 28%, and by 71% if the snow depth increases to 36 cm. Moreover, the occurrence of snow cover resulted in mean annual ground surface temperatures 4.7-8.2℃ higher than the mean annual air temperatures recorded at the Gen＇he Weather Station, The beginning date for stable snow cover establishment （SE date） and the initial snow depth （SDi） also had a great influences on the ground freezing process. Heavy snowfall before ground surface freeze-up could postpone and retard the freezing process in Gen＇he. As a result, the duration of ground freezing was shortened by at least 20 days and the maximum depth of frost penetration was as much as 90 cm shallower.

关键词： snow cover thermal regime ground freezing Da Xing'anling Mountains northeastern China

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Vegetation impact on the thermal regimes of the active layer and near-surface permafrost in the Greater Hinggan Mountains, Northeastern China

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Research in Cold and Arid Regions 2014年第5期6卷 511-520页

作者： XiaoLi Chang ShaoPeng Yu HuiJun Jin yanlin zhang State Key Laboratory of Frozen Soils Engineering Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Department of Geography Harbin College

The ground temperature and active layer are greatly influenced by vegetation in the Greater Hinggan Mountains in Northeastern ***,vegetation,as a complex system,is difficult to separate the influence of its different components on the ground thermal *** this paper,four vegetation types,including a Larix dahurica-Ledum palustre ***-Bryum forest（P1）,a ***-Betula fruticosa forest（P2）,a ***-Carex tato forest（P3） in the China Forest Ecological Research Network Station in Genhe,and a Carex tato swamp（P4） at the permafrost observation site in Yitulihe,have been selected to study and compare their seasonal and annual influence on the ground thermal *** show that the vegetation insulates the ground resulting in a relatively high ground temperature variability in the Carex tato swamp where there are no tree stands and shrubs when compared with three forested vegetation types present in the *** thickness,structure,and coverage are the most important factors that determine the insulating properties of the *** particular,the growth of ground cover,its water-holding capacity and ability to intercept snow exert a significant effect on the degree of insulation of the soil under the same vegetation.

关键词： vegetation types permafrost ground thermal regime Greater Hinggan Mountains

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