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Heavy Metal Contamination of Agricultural Soils in Taiyuan, China

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Pedosphere 2015年第6期25卷 901-909页

作者： liU Yong WANG Huifeng li Xiaoting li jinchang Institute of Loess Plateau Shanxi University

To evaluate the current state of the environmental quality of agricultural soils in Taiyuan City, a hotspot for China's industrial development, the concentrations of 8 heavy metals in soils were investigated by means of extensive sampling in farmlands, forestlands,and grasslands in the city. Statistical analyses and spatial distribution maps were used to identify the most significant heavy metal pollutants. The mean concentrations of As, Cd, Cu, Hg, Pb, Zn, Ni, and Cr were slightly higher than their background values in Taiyuan's topsoil, but were lower than the maximum permissible concentrations in the Chinese Environmental Quality Standard for agricultural soils. Farmland soils in Taiyuan had the highest average Cd, Cu, Hg, Pb, Zn, and Cr concentrations, but the As and Ni concentrations did not differ significantly among the farmland, forestland, and grasslands. Soil contamination by Cd, Cu, Hg, Pb,Zn, and Cr was mainly derived from farming practices, especially the use of sewage water for irrigation. In contrast, As and Ni might derive mainly from the soil parent material. The identification of heavy metal sources in agricultural soils may provide a basis for taking appropriate action to protect soil quality.

关键词： environmental pollution farming practices sewage irrigation soil parent material soil quality

Changes in wind activity from 1957 to 2011 and their possible influence on aeolian desertification in northern China

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Journal of Arid Land 2015年第6期7卷 755-764页

作者： li jinchang liU Haixia SU Zhizhu FAN Xiaohui State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Institute of Loess Plateau Shanxi University Historical Culture School Shanxi University

Wind activity is proved to have significant impacts on aeolian desertification. Clarifying the fluctuations and change trend of wind velocity is important for understanding their influence on aeolian desertification. In this study, we used a dataset of wind velocities collected from 93 meteorological stations across northern China from 1957 to 2011 to analyze the changes in wind activity during this period. We tested the monotonic and step（abrupt） trends for annual and seasonal data of mean wind velocity by using Mann-Kendall and Mann-Whitney tests, respectively. The results indicated that the annual mean wind velocity decreased by 0.83 m/s from 1957 to 2011. The decreasing trends were also significant（P〈0.01） for each season. The magnitude of the decrease was smallest in the east of northern China and largest in the west of northern China, and the most remarkable decrease occurred in the northwest of northern China. Abrupt decreases in annual and seasonal mean wind velocities occurred in the mid-1980 s, which was consistent with the changes in aeolian desertification since the mid-1980 s in northern China. As revealed by our study, although both modern aeolian desertification and ecosystem rehabilitation are affected by human activities to some extent, they are also likely to be strongly controlled by climate change, especially by wind activity.

关键词： wind velocity monotonic trend step trend aeolian desertification northern China

Simulating the effect of wind erosion on aeolian desertification process of Horqin sandy land and its significance on material cycle:a wind tunnel study

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Research in Cold and Arid Regions 2022年第1期14卷 43-53页

作者： CaiXia Zhang jinchang li Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China Shanxi Laboratory for Yellow River Institute of Loess PlateauShanxi UniversityTaiyuanShanxi 030006China

Samples from the Horqin sandy land were exposed to a series of wind velocities,and sink particles were collected at the end of the diffusion section of a wind *** sizes of collected samples show great variation because of the granularity difference of the surface *** original samples show lower average content of SiO_(2) and higher average content of Al _(2)O_(3),Fe_(2)O_(3),MgO,CaO,Na_(2)O,and K_(2)O than collected *** with other dust source areas in China,the Horqin sandy land had higher content of Zr,Ba,SiO_(2),Al_(2)O_(3) and K_(2)*** with the average upper continental crust(UCC)composition,surface samples were rich in the content of Y,Zr,Nb,Ba,La,*** characteristics of fine grain components of the Horqin sandy land differ from those from other dust source regions,because fine-grained particles in the Horqin sandy land were mostly derived from various local deposits formed in its unique depositional environments influenced by several tectonic activities.

关键词： sink sand wind erosion aeolian process Horqin sandy land

Elemental composition and its environmental significance for the varicolored hills in the northern foothills of the Qilian Mountains of Sunan Yugur Autonomous County,China

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Research in Cold and Arid Regions 2015年第3期7卷 257-264页

作者： CaiXia Zhang XiaoZe li Zhong Sun jinchang li Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Institute of Loess Plateau Shanxi University

The varicolored hills in the northern foothills of the Qilian Mountains of northem China, in the Hexi Corridor of Gansu Province＇s Sunan Yugur Autonomous County, have given this region a unique geomorphology. In this paper, we describe the elemental composition, lithological characteristics, and source type of the sediments that formed the varicolored hills. We found that the major oxides that make up their sediments are SiO2, A12O3 and Na2O. These sediments had higher Fe2O3, MgO, CaO, and Na2O contents and lower SiO2, A12O3, K2O, and TiO2 contents than in the major Fangyan rock group of the Jianglang Mountains Danxia landform and the red paleosols that have accumulated in the Yaojia Formation of the Songliao Basin. The varicolored hills have developed their strong coloration as a result of oxidation or reduction of Fe. Our data suggest that the sediments developed from terrestrial detrital *** varicolored hills in the northern foothills of the Qilian Mountains of northem China, in the Hexi Corridor of Gansu Province＇s Sunan Yugur Autonomous County, have given this region a unique geomorphology. In this paper, we describe the elemental composition, lithological characteristics, and source type of the sediments that formed the varicolored hills. We found that the major oxides that make up their sediments are SiO2, A12O3 and Na2O. These sediments had higher Fe2O3, MgO, CaO, and Na2O contents and lower SiO2, A12O3, K2O, and TiO2 contents than in the major Fangyan rock group of the Jianglang Mountains Danxia landform and the red paleosols that have accumulated in the Yaojia Formation of the Songliao Basin. The varicolored hills have developed their strong coloration as a result of oxidation or reduction of Fe. Our data suggest that the sediments developed from terrestrial detrital deposits.

关键词： red bed varicolored hills Hexi Corridor Qilian Mountains

Land use and land cover change processes in China's eastern Loess Plateau

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Research in Cold and Arid Regions 2015年第6期7卷 722-729页

作者： jinchang li HaiXia liu Yong liu ZhiZhu Su ZiQiang Du Institute of Loess Plateau Shanxi University Historical Culture School Shanxi University

Using Landsat remote sensing images, we analyzed changes in each land use type and transitions among different land use types during land use and land cover change （LUCC） in Ningwu County, located in the eastern Loess Plateau of China, from 1990 to 2010. We found that grassland, woodland, and farmland were the main land use types in the study area, and the area of each type changed slightly from 1990 to 2010, whereas the area of water, construction land, and unused land increased greatly. For the whole area, the net change and total change were insignificant due to weak human activity intensity in most of the study area, and the LUCC was dominated by quasi-balanced two-way transitions from 1990 to 2010. The insignificant overall amount of LUCC appears to have resulted from offsetting of rapid increases in population, economic growth, and the im- plementation of a program to return farmland to woodland and grassland in 2000. This program converted more farmland into woodland and grassland from 2000 to 2010 than from 1990 to 2000, but reclamation of woodland and grassland for use as farmland continued from 2000 to 2010, and is a cause for concern to the local government.

关键词： land use and land cover change remote sensing forest restoration Ningwu County Loess Plateau

Characterizing changes in ecosystem service values in China's eastern Loess Plateau

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Research in Cold and Arid Regions 2015年第3期7卷 272-281页

作者： jinchang li HaiXia liu ZhiZhu Su Yong liu YongGang Yang Institute of Loess Plateau Shanxi University Historical Culture School Shanxi University

Human activities such as the implementation of ecological protection projects and expansion of construction land can cause complex land use changes that affect ecosystem service values （ESV）. In this study, we investigated changes in ESV in response to land use changes in Ningwu County, in eastern Loess Plateau of China. Our aim is to provide guidance for sustainable land use planning in this region. We used remote sensing to evaluate land use changes, and applied a fast, proxy-based method for evaluating ESVat three points in time： 1990, 2000, and 2010. More than 89% of the total ESV in Ningwu County was attributable to woodland and grassland. The ESV in western mountain areas show the greatest increase from 1990 to 2010, but ESV decreased the most in the low-elevation northeastern area of flat terrain These tradeoffs led to a slight net decrease （1.0%） in Ningwu County＇s total ESV. Although the decline in ESV was relatively low compared to the rate of economic growth, total ESV was much lower than global and national average levels at the end of the study period.

关键词： ecosystem service values land use changes ecological protection projects remote sensing Ningwu County

M@B_9 and M@B_(10) molecular wheels containing planar nona-and deca-coordinate heavy group 11, 12, and 13 metals (M=Ag, Au, Cd, Hg, In, Tl)

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Science China Chemistry 2009年第7期52卷 900-904页

作者： MIAO ChangQing, GUO jinchang & li SiDian Institute of Materials Sciences and Department of Chemistry, Xinzhou Teachers’ University, Xinzhou 034000, China Institute of Materials Sciences and Department of Chemistry Xinzhou Teachers’ University Xinzhou 034000 China

A density functional and ab initio theory investigation on M@B9 and M@B10 molecular wheels containing planar nona-and deca-coordinate heavy group 11, 12 and 13 metals (M=Ag, Au, Cd, Hg, In, Ti) has been performed. These unusual clusters all prove to be true minima on the potential energy surfaces of the systems and σ+π double aromatic in nature. The first two vertical one-electron detachment energies of M@B-10 (M=Ag, Au) anions and first two ionization potentials of M@B9 (M=Ag, Au) and M@B10 (M=Cd, Hg) neutrals were calculated to aid future experiments. The cluster complexes designed in this work may expend the domain of planar hyper-coordinate elements to include heavy group 11, 12, and 13 metals and serve as interesting candidates to be targeted in experiments.

关键词： planar hyper-coordinate heavy metals density functional theory ab initio geometries electronic structures

Carbon-free D_(3d) [E_3ME_3]^(2-) (E=P,As;M=Ni,Pd,Pt):The smallest inorganic sandwich complexes with aromatic η~3-P_3^- and η~3-As_3^- ligands

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Science China Chemistry 2010年第4期53卷 940-944页

作者： MIAO ChangQing, CHEN Qiang, GUO jinchang & li SiDian Institute of Materials Science and Department of Chemistry, Xinzhou Teachers’ University, Xinzhou 034000, China Institute of Materials Science and Department of Chemistry Xinzhou Teachers’ University Xinzhou China

A density functional theory and wave function theory investigation on the possibility of carbon-free phosphametallocenes [P3MP3]2-and arsenametallocenes [As3MAs3]2- (M=Ni, Pd, Pt) is presented in this work. Staggered singlet D3d [E3ME3]2- (E=P, As)-the smallest inorganic metallocenes possible to construct-proved to be the global minima of the heptaatomic sys- tems and may be targeted in future experiments. Cyclo-P3- and cyclo-As3- turned out to possess similar aromaticity to cyclo-P5- and cyclo-As5- and may serve as effective ligands to sandwich a wide range of transition metals. The first vertical electron detachment energies of Cs [E3ME3]li+ monoanions with a staggered [E3ME3]2- sandwich core were predicted to be between 2.7 and 2.9 eV; the extent of stabilization by li+ suggests that such materials be viable targets for experimental characterization.

关键词： phosphorus arsenic sandwich complexes density functional theory geometries electronic structures.

Seasonal variation in dust events and the causes of the variation in the Tarim Basin,China

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Research in Cold and Arid Regions 2009年第2期1卷 143-150页

作者： jinchang li ZhiBao Dong ShuSheng He Institute of Loess Plateau Shanxi UniversityTaiyuan 030006China. Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of SciencesLanzhou 730000China.

We analyzed dust event occurrence and its seasonal distribution at 16 sites in the Tarim Basin,*** the overall frequency of dust events was the highest in spring in this region,its variation in other seasons could be classified into three patterns:(1) frequency of dust events in autumn > that in summer > that in winter(at the Kashi and Kuche sites);(2) frequency in summer > that in winter > that in autumn(at the Ruoqiang site);and(3) frequency in summer > that in autumn > that in winter(at all other areas of the Tarim Basin).The frequency of dust events and their seasonal variations in the Tarim Basin were mainly controlled by wind speed and locally available dust sources;the former was the key control when dust sources did not differ *** seasonal variation in evaporation had a smaller,but still significant effect on the frequency of dust events.

关键词： Tarim Basin dust events seasonal variation sand-blowing wind