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Carbon isotopes, sulfur isotopes, and trace elements of the dolomites from the Dengying Formation in Zhenba area, southern Shaanxi: Implications for shallow water redox conditions during the terminal Ediacaran

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Science China Earth Sciences 2015年第7期58卷 1107-1122页

作者： CHEN YaLi CHU XueLei ZHANG XingLiang ZHAI MingGuo State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences College of Earth Science University of Chinese Academy of Sciences State Key Laboratory for the Continental Dynamics Northwest University

Carbon isotope, sulfur isotope, and trace element(including Rare Earth elements, REE) analyses were conducted on the carbonates of the Dengying Formation at Lianghekou section in southern Shaanxi to reconstruct the terminal Ediacaran shallow-water environment on the northwestern margin of the Yangtze Platform. At Lianghekou section, samples in the middle 50-m of the Beiwan Member show characteristics of low ΣREE concentrations, no MREE-enriched REE distribution patterns, high Ce/Ce* values close to 1, and enriched redox-sensitive elements, whereas samples in the lower 30-m and upper 10-m show opposite characteristics of high ∑REE concentrations, MREE-enriched REE distribution patterns, low Ce/Ce* values around 0.6, and no redox-sensitive elements enriched, indicating that oxygenation did occur in the shallow water on the northwestern margin of the Yangtze Platform and redox conditions of the shallow water fluctuated from relatively oxygenated to anoxic and then back to oxygenated again. We propose that the anoxia appeared in middle of the Beiwan time may associate with the anoxic upwelled water. On one hand, abundant nutrients were brought in by this upwelling event, which stimulated the photosynthetic carbon fixation and increased the organic carbon burial under this anoxic condition, causing a peak of 3.6‰ in δ 13 C. On the other hand, because the anoxic upwelled water replaced the oxic shallow water, together with the increasing organic matter in the water column, bacterial sulfate reduction was enhanced and therefore quickly reduced the sulfate concentration, which eventually caused δ 34 S increasing to 50‰. However, as the upwelling gradually disappeared, δ 13 C and δ 34 SCAS values decreased as well in the late Beiwan time, indicating the shallow water went back to suboxic or oxic again.

关键词： Yangtze Platform southern Shaanxi Ediacaran trace elements carbon isotopes sulfur isotopes

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trace elements Loss Characteristics in Runoff Discharge from Tobacco-Growing Red Soil in Sichuan Province of China

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Journal of Agricultural Chemistry and Environment 2022年第3期11卷 163-183页

作者： Angelique Iradukunda Dan Zhang Tianhui Ye Eliezel Habineza Maoqiang Wang Henriette Peace Uwamahoro Philbert Mperejekumana Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China University of Chinese Academy of Sciences Beijing China Panzhihua Branch of Sichuan Tobacco Company Panzhihua China Department of Smart Agricultural Systems Graduate School Chungnam National University Daejeon Republic of Korea Department of Environmental engineering Chengdu University of Technology Chengdu China Key Laboratory of Agricultural Water Resources Hebei Key Laboratory of Soil Ecology Center for Agricultural Resources Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Shijiazhuang China Bioenergy and Environment Science & Technology Laboratory College of Engineering China Agricultural University Beijing China

trace elements are found in small concentrations in soil, yet plants require them for physiological functions. The runoff process leads to soil fertility loss by shifting soil particles and elements, and deposits them to a different position. However, there is a lack of information about the amount of trace elements that flow in tobacco-growing red soil during the natural rainy seasons due to runoff. In this study, runoff discharge was collected from two different soil mulching conditions (straw and no straw) at 15?, in Miyi county of Sichuan province, to evaluate the characteristics of trace elements in runoff discharge. The runoff discharge was filtered to separate water (runoff) from sediment. The concentrations of the elements were analyzed in samples obtained from 9 erosive rainfall events, with 3 replications for every sample. The considered trace elements were Zinc (Zn), Copper (Cu), and Molybdenum (Mo). In addition, the total amount of each element loss per unit area (total loss) was also calculated statistically. The results revealed different concentrations and total losses for the selected trace elements. The total loss in runoff ranged from 10.82 to 194.05 mg/ha, 0.62 to 18.91 mg/ha, and 0.32 to 2.37 mg/ha for Zn, Cu, and Mo, respectively. The total loss in sediment ranged from 54.65 to 12036.34 mg/ha, 44.74 to 5285.30 mg/ha, and 1.78 to 399.82 mg/ha for Zn, Cu, and Mo, respectively. Rainfall intensity, runoff depth, and sediment yield showed distinct positive correlations with the trace elements losses. The loss reduced with the addition of straw in the experimental area. Since each trace element showed distinct characteristics in the runoff and sediment, it is crucial to assess the loss of trace elements in runoff discharge from different agronomic practices. In turn, various sustainable practices of preventing soil fertility loss will be identified.

关键词： trace elements Runoff Discharge Sediment Red Soil Tobacco Farming

trace elements in Mollusks, Crustaceans and Fish Commonly Consumed by the Catfish <i>Chrysichthys nigrodigitatus</i>Lacépède, 1803 from the Lake Togo-Lagoon of Aného Hydrosystem (Southern Togo)

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Journal of Environmental Protection 2021年第12期12卷 1185-1203页

作者： Kamilou Ouro-Sama Komlan Mawuli Afiademanyo Hodabalo Dheoulaba Solitoke Gnon Tanouayi Tchaa Esso-Essinam Badassan Koudjo Adje Koudjo Adje Sadikou Agbere Kissao Gnandi Laboratoire de Gestion Traitement et Valorisation des Déchets Département de Géologie et Environnement Faculté des Sciences Université de Lomé Lomé Togo Laboratoire d’Ecologie Animale et d’Ecotoxicologie Département de Zoologie et Biologie Animale Faculté des Sciences Université de Lomé Lomé Togo

The omnivorous fish species, C. nigrodigitatus feeds mainly on benthic organisms and may therefore consume contaminated food throughout its food web. This can lead to the bioaccumulation of contaminants such as trace elements in their tissues. However, fish consumption is a major pathway of human exposure to contaminants which may cause public health problems. The aim of the present study is to assess trace elements contamination in some species from the food web of C. nigrodigitatus. For this, 10 main food items of the silver catfish were collected at two sites from February to July 2017 and analyzed using an Atomic Absorption Spectrometer coupled with a hydride and cold vapour generator. The concentrations of trace elements varied greatly from one species to another and within each species. These values ranged from 0.007 mg/kg for Hg in C hippos to 354.84 mg/kg for Mn in P. fusca. The most contaminated species by trace elements were benthic organisms: M. perna (Cd, Pb, Hg), Pagurus sp. (Cr, Ni, Cu, Zn), G. paradoxa (As) and P. fusca (Mn). The average concentrations of trace elements found in species were, for the most part, above WHO standards except Hg in M. perna and G. paradoxa. The water-based bioconcentration factors (BCFw) reach 92.58 for Cd, 44.72 for Pb, 382.49 for Hg and 1514.34 for As in M. perna. It is therefore necessary to pay particular attention to this ecosystem and to put in place a better management plan.

关键词： C. nigrodigitatus Preys trace elements Contamination Lake Togo Aného Lagoon

Modelling of the relationship between trace elements and three species of sulfur in coal

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Journal of Environmental Sciences 1998年第2期10卷 89-95页

作者： Lu Xiao hua, Zeng Han cai National Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, China Wei Lu xian Center of Microanalysis, Wuhan University of Automobile Industry, Wuhan, China

Based on the determination of several trace elements in coal particulate of different specific gravity, three variables regression equations relate the contents of trace elements Be, Cd, Co, Pb, Cu, Ni, As and three species of sulfur in coal were well established. For elements Cd, Co, Pb, Cu and Ni, the regression equations were successfully used for prediction of these trace elements in individual part of coal with different specific gravity. Factor analysis was also used to analyze the data sets. The results showed that a three factor model can interpret the data sets reasonably. trace elements Cd, Co, Pb, Cu, Ni, inorganic sulfide and total sulfur in coal are high correlated with the first factor. trace elements Be, sulfate and organic sulfide are high correlated with the second factor and trace elements Cr and As are high correlated with the third factor. The factors can be interpreted by the chemical properties of these elements.

关键词： trace elements coal regression analysis factor analysis.

Sedimentary cycles of trace elements in Salawusu River Valley since 150 ka BP

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Journal of Geographical Sciences 2002年第1期12卷 65-71页

作者： YAO Chun-xia1,2, LI Bao-sheng1,2, JIN He-ling3, David Dian Zhang4, YAN Man-cun5, ZHU Yi-zhi2, LI Hou-xin1, ZHANG Yu-hong1, Luo Kai-li1 (1. Dept. of Geography, South China Normal University, Guangzhou 510631, China 2. State Key Laboratory of Loess CAS State Key Laboratory of Loess and Quarternary Geology Institute of Earth Environment Xi’an China (GRID:grid.9227.e) (ISNI:***) South China Normal University Dept. of Geography Guangzhou China (GRID:grid.263785.d) (ISNI:***) CAS State Key Laboratory of Loess and Quarternary Geology Institute of Earth Environment Xi’an China (GRID:grid.9227.e) (ISNI:***) CAS Cold and Arid Regions Environmental and Engineering Research Institute Lanzhou China (GRID:grid.9227.e) (ISNI:***) Hong Kong University Dept. of Geography and Geology China (GRID:grid.194645.b) (ISNI:***) Tsinghua University Dept. of Hydraulic Engineering Beijing China (GRID:grid.12527.33) (ISNI:***) South China Normal University Dept. of Geography Guangzhou China (GRID:grid.263785.d) (ISNI:***)

The paper makes some analyses on 11 trace elements in the Milanggouwan stratigraphical section in the Salawusu River valley, which is regarded as a prototype geology-palaeoclimate record since 150 ka BP. The results show that the content and variation of trace elements has experienced remarkably regular changes in the pace with coarse and fine sedimentary cycles of palaeo-aeolian sands to its overlying fluvio-lacustrine facies or/and palaeosols. The trace elements with chemical properties of relatively active (V, Sr, Cu, Ni, As) and relatively stable (P, Pb, Rb, Mn, Nb, Zr) are a manifestation of the corresponding 27 changeable cycles between peak and valley values, appearing a multi-fiuctuational process line of relative gathering and migration since then. The low numerical value distribution of these two types of trace elements in the aeolian sand facies represents erosion and accumulation under wind force during the cold-dry climate. Whereas their enrichments in both fluvio-lacustrine facies and palaeosols are related to the valley’s special low-lying physiognomic position between the Ordos Plateau and the Loess Plateau under the warm and humid climate conditions. The above relatively migrated and gathered change of the trace elements is the result of 27 climatic cycles of cold-dry and warm-humid, which is probably caused by repeated alternations of winter monsoon and summer monsoon in the Mu Us Sandy Land influenced by the climate vicissitudes in northern hemisphere during glacial and interglacial periods since 150 ka BP.

关键词： Salawusu River valley Milanggouwan section cycle trace elements 150 ka BP palaeoclimate

Preliminary study of the correlation between trace elements in human hair, liver and kidney by proton induced X-ray emission analysis

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Journal of Environmental Sciences 1989年第1期1卷 91-97页

作者： Zhang Yuanxun, Wang Xuepeng, Ying Jianhua, Qian Yine, Cheng Yuandi Shanghai hstitute of Nuclear Research， Acadenua Smica Shanghai China

This paper deals with the determination of trace elements in normal human hair, liver and kidney by Proton Induced X-ray Emission (PIXE) analysis. Sampling, specimen preparation and experimental procedures are described in detail. The accuracy of our system has been checked up with the determination of standard reference materials. The preliminary results on correlations between trace elements in human tissues are discussed. Application of the method described in the paper gives evidence in favour of the PIXE as a good tool on environmental life elements and health studies.

关键词： PIXE trace elements nuclear analysis human tissues.

BACKGROUND VALUES AND GEOCHEMICAL CHARACTERISTICS OF 15 trace elements IN THE SOURCE AREA OF THE YANGTZE RIVER

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Journal of Geographical Sciences 1991年第2期2卷 43-56页

作者： Zhang Licheng Zhou Kezhun Institute of Geography CAS

The natural contents and background values of 15trace elements Cu,Pb,Zn,Cd,Hg,As,Co,Ni,Cr,Se,Mn,Mo,Fe,V and F in water and sediments in the source area of the Yangtze River have been *** are presented and discussed wi... 详细信息

关键词： trace elements background Yangtze River source area of Yangtze River

Speciation Study of trace elements by Reversed Phase-High Performance Liquid Chromatography ( Ⅰ )——Simultaneous Determination of Cr( Ⅲ ) and Cr( Ⅵ )

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Chemical Research in Chinese Universities 1991年第1期7卷 37-41页

作者： Yao Xingdong , Liu Jinchun , Cheng Jieke Zeng Yun’ e (Department of Chemistry, Wuhan University, Wuhan ) To whom correspondence should be addressedPresent address: Department of Chemistry , Shantou University, Shantou.

Reported here is the Cr-speciation study by High Performance Liquid Chromatography (HPLC) using precolumn derivatization with ammonium pyrolidinyldithiocarbamate (APDC) and spectrophotometric detection. The rapid and sensitive method has been successfully applied to the analysis of environmental water. The chromatographic behavior of the two Cr-APDC chelates are illustrated with 'Solvophobic Theory'.

关键词： trace elements Chromatographic behavior Cr-APDC chelate

Role of calcium and other trace elements in the gastrointestinal physiology

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World Journal of Gastroenterology 2006年第20期12卷 3229-3236页

作者： P Kirchhoff JP Geibel Department of Surgery Yale University School of Medicine 333 Cedar StreetNew HavenCT 06520United States

Calcium is an essential ion in both marine and terrestrial organisms, where it plays a crucial role in processes ranging from the formation and maintenance of the skeleton to the regulation of neuronal function. The Ca^2＋ balance is maintained by three organ systems, including the gastrointestinal tract, bone and kidney. Since first being cloned in 1993 the Ca^2＋-sensing receptor has been expressed along the entire gastrointestinal tract, until now the exact function is only partly elucidated. As of this date it still remains to be determined if the Ca^2＋-sensing receptor is involved in calcium handling by the gastrointestinal tract. However, there are few studies showing physiological effects of the Ca^2＋-sensing receptor on gastric acid secretion and fluid transport in the colon. In addition, polyamines and amino acids have been shown to activate the Ca^2＋-sensing receptor and also act as allosteric modifiers to signal nutrient availability to intestinal epithelial cells. Activation of the colonic Ca^2＋-sensing receptor can abrogate cyclic nucleotide-mediated fluid secretion suggesting a role of the receptor in modifying secretory diarrheas like cholera. For many cell types changes in extracellular Ca^2＋ concentration can switch the cellular behavior from proliferation to terminal differentiation or quiescence. As cancer remains predominantly a disease of disordered balance between proliferation, termination and apoptosis, disruption in the function of the Ca^2＋-sensing receptor may contribute to the progression of neoplastic disease. Loss of the growth suppressing effects of elevated extracellular Ca^2＋ have been demonstrated in colon carcinoma, and have been correlated with changes in the level of CaSR expression.

关键词： Calcium trace elements Gastrointestinal physiology