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Influencing factors of sediment deposition and their spatial variability in riparian zone of the Three Gorges Reservoir,China

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Journal of Mountain Science 2016年第8期13卷 1387-1396页

作者： WANG Bin-yan yan dong-chun WEN An-bang CHEN Jia-cun Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China

Many factors can affect the sediment deposition and soil erosion process in riparian zone, including terrain, sediment transport and water level fluctuations. Clarifying the factors influencing sediment deposition process in the riparian zone of the Three Gorges Reservoirs is an important problem to determine the key area of sediment deposition and its trend of development in the study area. In order to reveal the influence of these environmental factors on the sediment deposition in riparian zone of the Three Gorges Reservoir, this study investigated 1） the amount of deposited sediment in different environmental conditions, 2） the potential factors affecting sediment deposition in riparian zone of the Three Gorges Reservoir, 3） the relationship between the deposited sediment amount and these factors previously mentioned using correlation analysis, and 4） the influence of human activities considered as an additional factor. This study found that 1） slope gradient, elevation, inundating duration and human activities were the main factors influencing sedimentation in riparian zone of the Three Gorges Reservoir, and 2） the impact of each factor varied with spaces. Specifically, in the upper reach from Jiangjin to Fuling, human activities such as gravel dredging, bank revetment and ports and wharfs constructing disturbed considerable amounts of deposited sediment, as a result, there was no natural law to dictate the distribution. In the middle reach from Fuling to Fengjie, slope gradient and inundating duration were the controlling factors, and the sediment deposition amount was greater in the areas with a gentler slope or lower elevation. Water flow on gentler slopes generally had lower velocity, resulting in more sediment to deposit. Sites with lower elevations would be drowned by sediment-laden flow with a longer duration resulting from hydrologic regime controlled by the operating strategy of the Three Gorges Reservoir, leading to a larger amount of sediment deposit

关键词： Influencing Factors Spatial variability Sediment deposition Riparian zone Three GorgesReservoir

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Spatial distribution,sources and ecological risk assessment of heavy metals in Shenjia River watershed of the Three Gorges Reservoir Area

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Journal of Mountain Science 2017年第2期14卷 325-335页

作者： WANG Yong-yan WEN An-bang GUO Jin SHI Zhong-lin yan dong-chun Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China Chinese Academy of Sciences University Beijing 100049China Sichuan Electric Power Design Institute Chengdu 610072China

Surface soil/sediment samples were collected from the Water-Level Fluctuation Zone(WLFZ), cultivated land and forest land at 50 different grid points from Shenjia watershed, the Three Gorges Reservoir area in August 2013. The spatial distribution, sources and ecological risk assessment for Arsenic(As), Cadmium(Cd),Chromium(Cr), Copper(Cu), Nickel(Ni), Lead(Pb)and Zinc(Zn) were analyzed in this study. The results showed all tested metals had similar distribution patterns except Ni and Cr, with areas of high concentrations distributed in the southwest(WLFZ and watershed outlet) of the study area. Ni and Cr,which were highly positively correlated and present in high concentrations, were primarily distributed in the south and middle zones of the study area. Lower concentration areas of all metals were uniformly distributed west of the high-elevation zones and forest land. Factor analysis(FA) and factor analysismultiple linear regression(FA-MLR) showed that the major sources of Cd were fertilizer and traffic sources,which together accounted for 87% of Cd. As, Zn and Cu levels were primarily supplied by industrial and domestic sources, accounting for 76% of As, 75% of Cu and 67% of Zn. Surface soils/sediments of the study watershed contaminated by Cd represent a high ecological risk, whereas other metals represent low ecological risks. The potential ecological risk index(PERI) analysis indicated that it had a low(widerange) ecological risk and a moderate(small-range)ecological risk primarily distributed in the outlet of the study watershed. Fertilizers and traffic are the primary sources of Cd pollution, which should be more closely controlled for the purposes of water quality and ecological conservation.

关键词： Spatial distribution Ecological risk assessment Water-level fluctuation zone Heavy metals Three Gorges Reservoir

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Tempo-spatial variations of sediment-associated nutrients and contaminants in the Ruxi tributary of the Three Gorges Reservoir, China

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Journal of Mountain Science 2018年第2期15卷 319-326页

作者： SHI Zhong-lin WANG Yong-yan WEN An-bang yan dong-chun CHEN Jia-cun Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China University of Chinese Academy of Sciences Beijing 100049 China

Ruxi River is a tributary of the Three Gorges Reservoir. This study examined the temporal and spatial dynamics in particle size characteristics and the associated nutrients and contaminants of the fluvial suspended and deposited sediments along the Ruxi River. Temporal variations in the particle size distribution of the suspended sediment are controlled mainly by differences in sediment source during different seasons. Total organic carbon （TOC）, total nitrogen （TN） and total phosphorous （TP） in the 〈 62 μm fraction of the suspended sediment exhibit considerably higher concentrations in spring, indicating high probability of algal blooms in the backwater areas. Downstream trends in the nutrient contents of 〈 62 pm deposited sediments imply the greatest potential for eutrophication in the backwater ends, where highest nutrient concentrations were detected. Assessment of metal contamination shows that the sediments deposited in the water-level fluctuation zone were moderately to strongly contaminated by Cadmium （Cd）, with a considerably high potential ecological risk. The findings reported have emphasized the impacts of reservoir impoundment on aquatic and/or terrestrial environment in this region. More information on physical, chemical and biological processes of sediment and sediment-associated materials are needed for developing ecologically sound policies management. environmentally and of water and sediment

关键词： Sediments Nutrients Trace metals Water-level fluctuation zone Ruxi tributary ThreeGorges Reservoir

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Using ^(137)Cs Tracing Methods to Estimate Soil Redistribution Rates and to Construct a Sediment Budget for a Small Agricultural Catchment in the Three Gorges Reservoir Region,China

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Journal of Mountain Science 2013年第3期10卷 428-436页

作者： JU Li WEN An-bang LONG Yi yan dong-chun GUO Jin Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences University of Chinese Academy of Sciences

Soil erosion and associated off-site sedimentation are threatening the sustainable use of the Three Gorges Dam. To initiate management intervention to reduce sediment yields, there is an increasing need for reliable information on soil erosion in the Three Gorges Reservoir Region （TGRR）. The purpose of this study is to use 137Cs tracing methods to construct a sediment budget for a small agricultural catchment in the TGRR. Cores were taken from a pond and from paddy fields, for laTCs measurements. The results show that the average sedimentation rate in the pond since 1963 is 1.50 g cm-2 yr-1 and the corresponding amount of sediment deposited is 1,553 t. The surface erosion rate for the sloping cultivated lands and the sedimentation rate in the paddy fields were estimated to be 3,770 t km-2 yr-1 and 2,600 t km-2 yr^1 respectively. Based on the estimated erosion and deposition rates, and the area of each unit, the post 197o sediment budget for the catchment has been constructed. A sediment delivery ratio of 0.5 has been estimated for the past 42 years. The data indicate that the sloping cultivated lands are the primary sediment source areas, and that the paddy fields are deposition zones. The typical land use pattern （with the upper parts characterized by sloping cultivated land and the lower parts by paddy fields） plays an important role in reducing sediment yield from agricultural catchments in the TGRR. A 137Cs profile for the sediment deposited in a pond is shownto provide an effective means of estimating the land surface erosion rate in the upstream catchment.

关键词： Pond deposition Soil erosion rate Sediment budget 137Cs Sediment delivery ratio Three Gorges Reservoir Region

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Reactive Plasma Sprayed TiN Coating and Its Thermal Stability

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Journal of Iron and Steel Research International 2007年第5期14卷 71-75页

作者： ZOU dong-li yan Dian-ran HE Ji-ning LI Xiang-zhi dong yan-chun ZHANG Jian-xin School of Materials Hebei University of Technology Tianjin 300132 China School of Materials Science andEngineering Harbin Institute of Technology Harbin 150001 Heilongjiang China

TiN coating was prepared by reactive plasma spraying in the Ar and N2 containing plasma jet. The resuits of XRD show that the TiN coating consists of TiN and Ti3 O, neither Ti2 N nor TiO2 phases. The toughening mechanism was characterized by analyzing the SEM morphologies of the TiN coating＇s indentation of microhardness and fracture surfaces. The results indicate that the coating possesses a high toughness. The adhesion strength among the TiN layers is 25.88 MPa, which is slightly lower than that of the Ni/AI bonding coating. The oxidation process of the RPS TiN coating is TiN→Ti3 O→TiO2.

关键词： plasma spraying reactive plasma spraying TiN coating

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Microstructure and properties of Al_(2)O_(3)-ZrO_(2)-TiO_(2)composite coatings prepared by plasma spraying

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Rare Metals 2021年第7期40卷 1825-1834页

作者： Peng-Yue Gao Yu-Duo Ma Wen-Wei Sun Yong yang Chen Zhang Yu-Hang Cui yan-Wei Wang yan-chun dong School of Materials Science and Engineering Hebei University of TechnologyTianjin 300132China Key Laboratory for New Type of Functional Materials in Hebei Province Tianjin 300132China State Key Laboratory of Reliability and Intelligence of Electrical Equipment Tianjin 300132China

Al_(2)O_(3)-ZrO_(2)-TiO_(2)coatings were successfully prepared by plasma spraying Al_(2)O_(3)-ZrO_(2)composite powders with and without TiO_(2)*** effects of TiO_(2)on the phase composition,microstructure and properties of the Al_(2)O_(3)-ZrO_(2)coating were *** results show that the Al_(2)O_(3)-ZrO_(2)-TiO_(2)composite powder was composed of t-ZrO_(2),a-Al_(2)O_(3),m-ZrO_(2)and rutile,while the Al_(2)O_(3)-ZrO_(2)-TiO_(2)composite coating consisted of t-ZrO_(2),a-Al_(2)O_(3)and c-Al_(2)O_(3).The diffraction peaks of TiO_(2)could not be detected in the Al_(2)O_(3)-ZrO_(2)-TiO_(2)coating even up to10 wt%TiO_(2)*** reason may be that TiO_(2)was dissolved in the amorphous phase or formed solid solution with c-Al_(2)O_(3)phase in the coating during *** with the Al_(2)O_(3)-ZrO_(2)coating,the as-prepared Al_(2)O_(3)-ZrO_(2)-TiO_(2)coating had denser microstructure,less microcracks and more amorphous *** density of the Al_(2)O_(3)-ZrO_(2)-TiO_(2)coating increased with the increase of TiO_(2)*** Al_(2)O_(3)-ZrO_(2)-10 wt%TiO_(2)coating had the most uniform and dense microstructure,possessed higher toughness,adhesive strength and wear resistance compared with the Al_(2)O_(3)-ZrO_(2)coating,which was due to its lower porosity and more uniform microstructure.

关键词： Al_(2)O_(3)-ZrO_(2) Composite coatings Plasma spraying TiO_(2)

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The regional difference in engineering-control and tillage factors of Chinese Soil Loss Equation

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Journal of Mountain Science 2021年第3期18卷 658-670页

作者： CHEN Rui-yin yan dong-chun WEN An-bang SHI Zhong-lin CHEN Jia-cun LIU Yuan CHEN Tai-li Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China

Accurate assessment of soil erosion is an important prerequisite for controlling soil *** engineering-control(E)and tillage(T)factors are the keys for Chinese Soil Loss Equation(CSLE)to accurately evaluate water erosion in ***,the E and T factors can reflect the water and soil conservation effects of engineering-control and tillage *** in the current full coverage of soil erosion surveys in China(such as soil erosion dynamic monitoring),for the same practice,the E or T factors are assigned the same value across the *** selected 469 E and T factors data based on runoff plots from 73 publications,and they came from six soil and water conservation *** analysis,regression analysis,and nonparametric tests were used to determine the comparability of the data,and it was proved that the runoff plots dimensions are consistent with the local *** results of one-way ANOVA and nonparametric tests for E and T factors in different regions showed that the engineering-control practices have good soil and water conservation effects and weaken the regional differences of other environmental factors,so there were no significant differences in E factors between different ***,there were significant differences in T factors between different regions,and the geodetector was applied to explore the intrinsic driving force of the spatial distribution of T *** results of the geodetector showed that the dominant driving forces of the spatial distribution of different types of tillage practices were not completely the *** using CSLE to calculate water erosion,the E factor of the same practice can be used uniformly throughout the country,and the T factor needs to be considered and selected according to regional *** the same time,when choosing tillage practices in each water and soil conservation region,practices with better sediment reduction benefits should also be selected according to the regiona

关键词： Engineering-control factor Tillage factor Runoff plot Soil and water conservation regions Geodetector

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Changes in Land Use and Agricultural Production Structure Before and After the Implementation of Grain for Green Program in Western China–Taking Two Typical Counties as Examples

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Journal of Mountain Science 2014年第2期11卷 526-534页

作者： ZHOU Ping WEN An-bang yan dong-chun SHI Zhong-lin GUO Jin JU Zhan-sheng ZHANG Yi-lan The key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences

Soil erosion becomes a serious environmental problem in the world, especially in western China. An effective management practice called the Grain for Green Program(GGP), which was launched in 1999, aims to reduce soil and water loss and alleviate the ecological environment problem in western China. Two typical counties in western China, the Zhongxian(in Chongqing Municipality) and Ansai(in Shaanxi Province) were chosen to evaluate the dynamic changes of land use and agricultural production structure before and after the implementation of the Program in this paper. The results showed that the cultivated land area was reduced by 7.08% from 1989 to 2003. The cultivated land per person was decreased by 8.42% during 1999-2003. Moreover, the stability index of the secondary sector of the economy was increased from 0.91 in the period 1990-1999 to 0.94 in the following ten years. In addition, the stability index of tertiary economic sector increased from 0.88 to 0.92 in Zhongxian county. Meanwhile, the cultivated land area was reduced by 15.48% from 1990 to 1999. The soil erosion modulus was decreased by 33.33% from 1999 to 2006. Also, the stability index of secondary and tertiary economic sectors was 0.86 in the period 1998-2002. However, it decreased by 77% during 2002 to 2007 in Ansai County. These results imply that the Grain for Green Program had different impact on the two regions. Several effective strategies of soil and water conservation have been carried out to ameliorate the sustainable development of ecological environment and economy in these two counties of western China.

关键词： Cultivated land Stability index Agricultural production structure Grain for Green Program (GGP) Three Gorges Reservoir region Loess Plateau

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Multifractal characteristics and spatial variability of soil particle-size distribution in different land use patterns in a small catchment of the Three Gorges Reservoir Region,China

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Journal of Mountain Science 2021年第1期18卷 111-125页

作者： CHEN Tai-li SHI Zhong-lin WEN An-bang yan dong-chun GUO Jin CHEN Jia-cun LIU Yuan CHEN Rui-yin Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China Department of Resources and Environmental Engineering Sichuan Water Conservancy Vocational CollegeChengdu 611231China

Characterizing soil particle-size distribution is a key measure towards soil *** purpose of this study was to evaluate the multifractal characteristics of soil particle-size distribution among different land-use from a purple soil catchment and to generalize the spatial variation trend of multifractal parameters across the catchment.A total of 84 soil samples were collected from four kinds of land use patterns(dry land,orchard,paddy,and forest)in an agricultural catchment in the Three Gorges Reservoir Region,*** multifractal analysis method was applied to quantitatively characterize the soil particle size *** soil particle size distribution(PSD)multifractal parameters(D(0),D(1),D(2),(35)a(q),(35)f[a(q)],α(0))were ***,a geostatistical analysis was employed to reveal the spatial differentiation and map the spatial distribution of these *** multifractal characteristics were *** trend of generalized dimension spectrum of four land use patterns was basically consistent with the range of 0.8 to ***,orchard showed the largest monotonic decline,while the forest demonstrated the smallest decrease.D(0)of the four land use patterns were ranked as:dry land

关键词： Land use patterns Purple soil Multifractal characteristics Particle size distribution Geostatistics Spatial variability

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基于专利分析的CO_(2)氧化乙苯脱氢技术研究进展及趋势

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现代化工 2024年第10期44卷 8-14页

作者：董雁春中石化(上海)石油化工研究院有限公司上海201208

在当今石化产业链、供应链加速重构的大背景下,全球能源化工均聚焦于绿色化工,作为绿色低碳发展路径之一的CO_(2)氧化乙苯脱氢技术备受瞩目。通过对CO_(2)氧化乙苯脱氢技术的技术特点、专利技术发展趋势、研究现状进行分析发现,高性能... 详细信息

在当今石化产业链、供应链加速重构的大背景下,全球能源化工均聚焦于绿色化工,作为绿色低碳发展路径之一的CO_(2)氧化乙苯脱氢技术备受瞩目。通过对CO_(2)氧化乙苯脱氢技术的技术特点、专利技术发展趋势、研究现状进行分析发现,高性能催化剂研发是该领域的研究重点,其中,钒基、铁基催化剂是其重点发展方向。应加强高性能催化剂研发、优化工艺路线、设计节能反应器等方面工作,促进高校院所与企业合作,加快CO_(2)氧化乙苯脱氢技术工业化步伐。

关键词： CO_(2) 乙苯苯乙烯催化剂工艺专利分析

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