期刊文献+
共找到251,295篇文章
< 1 2 250 >
每页显示 20 50 100
Paleoenvironmental Characteristics of Paleogene Lacustrine Source Rocks in the Western Bozhong Sag,Bohai Bay Basin,China:Evidence from Biomarkers,Major and Trace Elements
1
作者 WANG Xiang LIU Guangdi +6 位作者 SONG Zezhang SUN Mingliang WANG Xiaolin WANG Feilong CHEN Rongtao GENG Mingyang LI Yishu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第1期220-240,共21页
The organic matter(OM)enrichment mechanisms and depositional environment characteristics of lacustrine source rocks in the western Bozhong Sag,Bohai Bay Basin in Northeast China remain controversial.To address these i... The organic matter(OM)enrichment mechanisms and depositional environment characteristics of lacustrine source rocks in the western Bozhong Sag,Bohai Bay Basin in Northeast China remain controversial.To address these issues,based on Rock-Eval pyrolysis,kerogen macerals,H/C and O/C ratios,GC-MS,major and trace elements,the Dongying Formation Member(Mbr)3(E_(3)d_(3)),the Shahejie Formation mbrs 1 and 2(E_(2)s_(1+2)),and the Shahejie Mbr 3(E_(2)s_(3))source rocks in the western Bozhong Sag were studied.The above methods were used to reveal their geochemical properties,OM origins and depositional environments,all of which indicate that E_(2)s_(1+2)and E_(2)s_(3)are excellent source rocks,and that E_(3)d_(3)is of the second good quality.E_(3)d_(3)source rocks were formed under a warm and humid climate,mainly belong to fluvial/delta facies,the E_(3)d_(3)sediments formed under weakly oxidizing and freshwater conditions.Comparatively,the depositional environments of E_(2)s_(1+2)source rocks were arid and cold climate,representing saline or freshwater lacustrine facies,and the sediments of E_(2)s_(1+2)belong to anoxic or suboxic settings with large evaporation and salinity.During the period of E_(2)s_(3),the climate became warm and humid,indicating the freshwater lacustrine facies,and E_(2)s_(3)was characterized by freshwater and abundant algae.Moreover,compared with other intervals,the OM origin of E_(3)d_(3)source rocks has noticeable terrestrial input.The OM origin of the E_(2)s_(1+2)and E_(2)s_(3)are mainly plankton and bacteria.Tectonic subsidence and climate change have affected the changes of the depositional environment in the western Bozhong Sag,thus controlling the distribution of the source rocks,the geochemical characteristics in the three intervals of lacustrine source rocks have distinct differences.Overall,these factors are effective to evaluate the paleoenvironmental characteristics of source rocks by biomarkers,major and trace elements.The established models may have positive implications for research of lacustrine source rocks in offshore areas with few drillings. 展开更多
关键词 petroleum geology source rocks depositional environments biomarkers major elements trace elements Bozhong Sag
下载PDF
Genesis of the Nuri Cu-W-Mo Deposit,Tibet,China:Constraints from in situ Trace Elements and Sr Isotopic Analysis of Scheelite
2
作者 WANG Yiyun WU Zhishan +8 位作者 CHEN Wenqing DU Qing’an TANG Liwei SHI Hongzhao MA Guotao ZHANG Zhi LIANG Wei WU Bo MIAO Hengyi 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第1期117-131,共15页
The Nuri deposit is the only Cu-W-Mo polymetallic deposit with large-scale WO3 resources in the eastern section of the Gangdese metallogenic belt,Tibet,China.However,the genetic type of this deposit has been controver... The Nuri deposit is the only Cu-W-Mo polymetallic deposit with large-scale WO3 resources in the eastern section of the Gangdese metallogenic belt,Tibet,China.However,the genetic type of this deposit has been controversial since its discovery.Based on a study of the geological characteristics of the deposit,this study presents mineralization stages,focusing on the oxide stage and the quartz-sulfide stage where scheelite is mainly formed,referred to as Sch-A and Sch-B,respectively.Through LA-ICP-MS trace element and Sr isotope analyses,the origin,evolutionary process of the oreforming fluid and genesis of the ore deposit are investigated.Scanning Electron Microscope-Cathodoluminescence(SEMCL)observations reveal that Sch-A consists of three generations,with dark gray homogenous Sch-A1 being replaced by relatively lighter and homogeneous Sch-A2 and Sch-A3,with Sch-A2 displaying a gray CL image color with vague and uneven growth bands and Sch-A3 has a light gray CL image color with hardly any growth band.In contrast,Sch-B exhibits a‘core-rim’structure,with the core part(Sch-B1)being dark gray and displaying a uniform growth band,while the rim part(Sch-B2)is light gray and homogeneous.The normalized distribution pattern of rare earth elements in scheelite and Sr isotope data suggest that the early ore-forming fluid in the Nuri deposit originated from granodiorite porphyry and,later on,some country rock material was mixed in,due to strong water-rock interaction.Combining the O-H isotope data further indicates that the ore-forming fluid in the Nuri deposit originated from magmatic-hydrothermal sources,with contributions from metamorphic water caused by water-rock interaction during the mineralization process,as well as later meteoric water.The intense water-rock interaction likely played a crucial role in the precipitation of scheelite,leading to varying Eu anomalies in different generations of scheelite from the oxide stage to the quartz-sulfide stage,while also causing a gradual decrease in oxygen fugacity(fO2)and a slow rise in pH value.Additionally,the high Mo and low Sr contents in the scheelite are consistent with typical characteristics of magmatic-hydrothermal scheelite.Therefore,considering the geological features of the deposit,the geochemical characteristics of scheelite and the O-H isotope data published previously,it can be concluded that the genesis of the Nuri deposit belongs to porphyry-skarn deposit. 展开更多
关键词 trace elements in situ Sr isotopes tungsten mineralization Gangdese metallogenic belt TIBET
下载PDF
Mobility of Major and Trace Elements during the Bauxitization Processes in Ngaoundal Area (Adamawa Cameroon): Implication on Mining Perspectives
3
作者 André Sini Harouna Boukari +4 位作者 Ondoa Augustin Désiré Balla Djetenbe Beral Salomon Wangmené Awé Simon Djakba Basga Jean Pierre Nguetnkam 《Open Journal of Geology》 CAS 2024年第1期81-100,共20页
This study was focused to assess major and trace elements in bauxitic duricrusts from Ngaoundal and its surroundings in order to establish their mining interest. To this end, fieldworks, mineralogical and geochemical ... This study was focused to assess major and trace elements in bauxitic duricrusts from Ngaoundal and its surroundings in order to establish their mining interest. To this end, fieldworks, mineralogical and geochemical analyses were carried out. Four facies of duricrust were identified and characterized from the summit to the top of the slope of the Ngaoundal mountain: scoriaceous, pisolitic, nodular and massive. Mineralogical and geochemical analyses performed on 16 samples, revealed a significant concentration of Al<sub>2</sub>O<sub>3</sub> mainly in the scoriaceous facies (over 45% in grade), moderate in Fe<sub>2</sub>O<sub>3</sub> (averaging 23.69%) and SiO<sub>2</sub> (averaging 21.7%). Trace elements were generally low, excluding Cr (421 ppm on average), Zr (327 ppm on average and V (213 ppm on average). In addition, the limited quantities of alkalis (Na<sub>2</sub>O, K<sub>2</sub>O) and alkaline earths metals (MgO, CaO) coupled with the very high values of Chemical Index of Alteration (CIA) and Mineralogical Index of Alteration (MIA), (more than 99%) attest to the intense weathering of the studied materials. Allitization and monosiallitization constituted the crystallochemical phenomena that have led to the development of bauxitic minerals. More than 90% of gibbsite in scoriaceous facies, 52.21% - 76.01% of kaolinite in pisolitic facies and more than 40% of hematite in nodular facies were quantified. The relationships between the constitutive components indicated their interdependency during the bauxitization phenomenon. The mineralogical and geochemical properties highlighted the mining interest of the studied duricrusts to be valorized. 展开更多
关键词 Duricrust Bauxitization Phenomenon Mineralogical and Geochemical Characterization Major and trace elements Mining Potential
下载PDF
Evaluation of Trace Elements in the Soil of Typical Peach Orchards in Zunyi City
4
作者 Wenzhao LI Xiong YAN +5 位作者 Jun CHENG Xingyong WANG Changling SUI Xiangchun ZHANG Zhuang ZHAO Peng ZHOU 《Agricultural Biotechnology》 2024年第1期17-19,共3页
[Objectives]This study was conducted to clarify the enrichment and paucity of trace elements in the soil environment of peach orchards in Zunyi City,and to provide reference for supplementary application of microeleme... [Objectives]This study was conducted to clarify the enrichment and paucity of trace elements in the soil environment of peach orchards in Zunyi City,and to provide reference for supplementary application of microelement fertilizers and high-quality peach production in peach orchards.[Methods]Taking the soil of three typical peach orchards(Taoli Renjia peach orchard,Pengrui peach orchard and Taohuadao peach orchard)in Shenxi Town,Honghuagang District,Zunyi City as the research object,the contents of trace elements in soil were analyzed through field sampling and indoor determination of trace elements.[Results]The effective contents of trace elements in the soil of peach orchard bases in the study area were at a medium level,and the soil of the peach orchards was rich in available Fe and Se.The contents of available Cu,Mo and Mn were relatively rich.The contents of available B were not high overall.The contents of available Zn were at a moderate to low level overall.The soil of Taoli Renjia peach orchard was relatively rich in trace elements.[Conclusions]The research results can provide a scientific basis for the production of high-quality crispy peaches in peach orchards. 展开更多
关键词 Zunyi Soil in peach orchard trace elements EVALUATION
下载PDF
Distribution, health and ecological risk assessments of trace elements in Nigerian oil sands
5
作者 Odunayo T.Ore Festus M.Adebiyi 《Acta Geochimica》 EI CAS CSCD 2024年第1期59-71,共13页
The Nigerian oil sands represent the largest oil sand deposit in Africa, yet there is little published information on the distribution and potential health and ecological risks of trace elements in the oil resource. I... The Nigerian oil sands represent the largest oil sand deposit in Africa, yet there is little published information on the distribution and potential health and ecological risks of trace elements in the oil resource. In the present study, we investigated the distribution pattern of 18trace elements(including biophile and chalcophile elements) as well as the estimated risks associated with exposure to these elements. The results of the study indicated that Fe was the most abundant element, with a mean concentration of 22,131 mg/kg while Br had the lowest mean concentration of 48 mg/kg. The high occurrence of Fe and Ti suggested a possible occurrence of ilmenite(Fe TiO_(3)) in the oil sands. Source apportionment using positive matrix factorization showed that the possible sources of detected elements in the oil sands were geogenic, metal production, and crustal. The contamination factor, geo-accumulation index, modified degree of contamination, pollution load index, and Nemerow pollution index indicated that the oil sands are heavily polluted by the elements. Health risk assessment showed that children were relatively more susceptible to the potentially toxic elements in the oil sands principally via ingestion exposure route(HQ > 1E-04). Cancer risks from inhalation are unlikely due to CR < 1E-06 but ingestion and dermal contact pose severe risks(CR > 1E-04). The high concentrations of the elements pose serious threats due to the potential for atmospheric transport, bioaccessibility, and bioavailability. 展开更多
关键词 Biophile Chalcophile Oil sand Risk assessment trace element
下载PDF
Spatio-temporal variation of trace elements distributed over surface water of Upper Ganga River Basin in Western Himalayan Region
6
作者 Deepika DIMRI Ambika KUMAR +1 位作者 DeepakKumar MISHRA Archana SHARMA 《Journal of Mountain Science》 SCIE CSCD 2023年第1期145-162,共18页
The rivers draining from the Himalayan range distribute enormous amount of fresh water to the people living in downstream regions.Trace metals flowed with river water can lead to serious impact on ecological system an... The rivers draining from the Himalayan range distribute enormous amount of fresh water to the people living in downstream regions.Trace metals flowed with river water can lead to serious impact on ecological system and human health.Nevertheless,the documentation on trace elements of Himalayan rivers is inadequately documented.The current study deals with the spatial and temporal variability of the major and trace elements of Ganga river water in epirhithron,metarhithron and hyporhithron zone belonging to Himalayan segment.Water samples from nineteen monitoring locations were collected in pre-monsoon(May-June),monsoon(AugustSeptember)and post-monsoon(December)seasons and subjected to be assessed for 20 elements(Ag,Al,Ba,Cd,Ca,Cr,Cu,Fe,Ga,K,Mn,Mg,Na,Ni,Pb,Sr,Th,U,Zn,and Zr)using ICP-OES(Inductively Coupled Plasma-Optical Emission Spectrometer).Different water pollution indexes such as HPI(Heavy Metal Pollution Index),MI(Metal Index)and PI(Pollution Index)were used to describe current water quality status at each monitoring station under particular classified ecological zone.The studied stations in hyporhithron zone had the value of Metal Index(MI>1),indicating threshold of warning.Further,the highest values of HPI in hyporhithron zone correspond to poor water quality status.Sites with poor water quality were also found to be contaminated as per the Pollution Index(PI),exhibiting high concentrations for element(Fe).However,the epirhithron and metarhithron zone in Himalayan segment showed excellent water quality mainly contributed from natural sources.Cluster Analysis(CA)and Principal Component Analysis(PCA)were applied to identify the main influential sources for Ganga river water pollution.The Kriging interpolation method was also applied to prepare spatial distribution map of computed indexes(HPI,MI,and PI).With the help of index of local Moran’s I(LMI),identified spatial clusters and spatial outliers revealed the elevated concentration of most elements in hyporhithron zone.The dataset presented in this study would be convenient for government officials in developing more effective management policies and necessary steps to check and monitor the Ganga river water quality.It was also suggested that further investigations in terms of trace elemental sources and their role in self-purification properties of Ganga water can be addressed in future. 展开更多
关键词 trace elements Spatial variation Temporal variation Surface water Ganga River Basin ICP-OES
原文传递
Distribution and geochemical significance of trace elements in kerogens from Ediacaran–Lower Cambrian strata in South China
7
作者 Qian Deng Guanyu Zhao +2 位作者 Haozhe Wang Bin Cheng Zewen Liao 《Acta Geochimica》 EI CAS CSCD 2023年第1期50-62,共13页
Some trace elements(TEs),both bio-essential and redox-sensitive,are promising tracers of Earth’s surface processes.As an essential sedimentary organic matter,kerogen may have inherited and retained the key TEs from o... Some trace elements(TEs),both bio-essential and redox-sensitive,are promising tracers of Earth’s surface processes.As an essential sedimentary organic matter,kerogen may have inherited and retained the key TEs from organisms.In this study,the distribution of TEs in kerogens from two sections(Dongkanshang and Fengtan) in South China was analyzed to explore its biogeochemical significance during Ediacaran-Lower Cambrian.Compared with V and Zn,the relative concentrations of Co,Ni,Cu,and Mo were generally higher in kerogens than in the whole rocks.Enrichment of TEs in the kerogen was involved in the selective utilization of TEs by different organic precursors and the competition of sulfide in the depositional environment.The significant content of TEs in the kerogens from deep-water facies corresponded to a more negative δ^(13) Ckeras a result of the dominant taxa of chemo autotrophs with tremendous bioaccumulation potential for trace metals and the reduction conditions favorable for organic matter preservation.Furthermore,the content variations of trace elements in the kerogens coincided with the rise and fall of the Ediacaran biota,implying that the trace elements might have played an important role in early life evolution. 展开更多
关键词 trace elements KEROGEN Ediacaran-Early Cambrian Biogeochemical significance South China
下载PDF
Seasonal variations and health risk assessment of trace elements in the Badigad River,lesser Himalayas,Nepal
8
作者 Ramesh Raj Pant Kiran Bishwakarma +4 位作者 Kshitiz Kandel Sudip Poudel Jharana Nepal Bhanu Bhakta Neupane Virendra Bahadur Singh 《Acta Geochimica》 EI CAS CSCD 2023年第4期689-703,共15页
The consumption of contaminated river water can have severe effects on human health.This study aims to investigate the trace elements(TEs)content and their health risk assessment in the Badigad River Basin in the less... The consumption of contaminated river water can have severe effects on human health.This study aims to investigate the trace elements(TEs)content and their health risk assessment in the Badigad River Basin in the lesser Himalayas of Nepal.In total,44 water samples were collected from 22 different sites during the pre-monsoon and monsoon seasons,and 25 TEs were analyzed.Correlation matrix and principal component analysis(PCA)were used to analyze the potential relationship between the measured TEs and their source tracking.Furthermore,the water quality index(WQI),metal index(MI),and cancer index(CI)were evaluated.The TEs content in all samples were found to be within the WHO recommended guideline for drinking and domestic purposes.The dominancy order of the TEs was observed as Sr>Ba>Li>Rb>Zn>Cr>Sc>Mn>Ti>Cu>As>Ni>Co>U>V>Pb>Cs>Ga>Y>Tl>Th>Zr>Bi>Cd>Nb.The PCA analysis suggested that TEs could have natural,anthropogenic,and mixed origins.The WQI indicated that the river water is safe from a human health perspective.The MI suggested that Badigad River can be considered safer for drinking purposes,and the cancer index(CI)showed that all the reported TEs are at low-risk levels.The findings of this study could be useful for government agencies in developing more sustainable water management policies in the region.However,it is suggested that further investigations should be conducted in terms of other hydrogeochemical variables,including major ions,at spatiotemporal levels for the sustainability of the river basin. 展开更多
关键词 trace elements Water quality Health risk assessment Multivariate analysis Badigad River
下载PDF
Relationship of Trace Elements Concentration and Growth Rate in Alsidium triquetrum (Rhodophyta)
9
作者 Arsenio J. Areces Ruben Cabrera +1 位作者 Jhoana Díaz-Larrea Ligia Collado-Vides 《American Journal of Plant Sciences》 CAS 2023年第3期323-338,共16页
Minerals and trace elements content and concentration in marine algae vary depending on species morphology and physiology;as well as growing environmental conditions. Despite this variability, accumulation of magnesiu... Minerals and trace elements content and concentration in marine algae vary depending on species morphology and physiology;as well as growing environmental conditions. Despite this variability, accumulation of magnesium, and especially iron, seems to be common in Chlorophyta;while Rhodophyta and Heterokontophyta show higher affinity to manganese. The red agarophyte Alsidium triquetrum was used to analyze the relationship between metal concentration, environmental conditions and growth rate. Specimens grown in situ showed a large variability of Fe, Mn, Mg, and Al, in thallus tissue concentrations. Further, a compelling relationship between the growth rate and the thallus concentration of Mg and Mn, Zn, and Al was detecte. Manganese, unlike the other trace elements analyzed showed a positive linear relationship between growth rate and tissue content during the period of greatest vegetative growth. 展开更多
关键词 Alsidium Growth Rate MANGANESE trace elements
下载PDF
Trace Elements of Multi-stage Minerals and Titanite U-Pb Dating for the Gneisses from Liansan Island,Sulu UHPM Belt
10
作者 SONG Lihao CAO Yuting +4 位作者 XIE Tianhe CHEN Yuyao GAO Yuan WANG Songjie LI Xuping 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2023年第6期1640-1656,共17页
Gneisses with anatectic characteristics from the Liansan island in the Sulu UHPM(ultra-high pressure metamorphic)belt were studied for petrography,titanite U-Pb dating and mineral geochemistry.Three origins of garnets... Gneisses with anatectic characteristics from the Liansan island in the Sulu UHPM(ultra-high pressure metamorphic)belt were studied for petrography,titanite U-Pb dating and mineral geochemistry.Three origins of garnets are distinguished:metamorphic garnet,peritectic garnet and anatectic garnet,which are formed in the stages of peak metamorphism,retrograde anatexis and melt crystallization,respectively.The euhedral titanite has a high content of REE and high Th/U ratios,which is interpreted as indicating that it was newly-formed from an anatectic melt.The LA-ICP-MS titanite U-Pb dating yields 214-217 Ma ages for the titanite(melt)crystallization.The distribution of trace elements varies in response to the different host minerals at different stages.At the peak metamorphic stage,Y and HREE are mainly hosted by garnet,Ba and Rb by phengite,Sr,Nb,Ta,Pb,Th,U and LREE by allanite and Y,U and HREE by zircon.During partial melting,Y,Pb,Th,U and REE are released into the melt,which causes a dramatic decline of these element contents in the retrograde minerals.Finally,titanite absorbs most of the Nb,U,LREE and HREE from the melt.Therefore,the different stages of metamorphism have different mineral assemblages,which host different trace elements. 展开更多
关键词 partial melting multi-stage minerals trace element migration titanite U-Pb dating Sulu UHPM belt
下载PDF
Origin of the Dashuigou Independent Tellurium Deposit at the Southeastern Qinghai-Tibet Plateau:Based on the Abundances of Trace Elements in the Country Rocks
11
作者 Jianzhao Yin Shoupu Xiang +2 位作者 Haoyu Yin Hongyun Shi Yuhong Chao 《Advances in Geological and Geotechnical Engineering Research》 2023年第4期41-55,共15页
Through a detailed study of the abundances and spatial-temporal distribution patterns of Te,Bi,As,Se,Cu,Pb,Zn,Au,and Ag in the rock types of different geological epochs in the Dashuigou independent tellurium deposit,a... Through a detailed study of the abundances and spatial-temporal distribution patterns of Te,Bi,As,Se,Cu,Pb,Zn,Au,and Ag in the rock types of different geological epochs in the Dashuigou independent tellurium deposit,and in combination with other research findings of previous researchers in this area,the authors conclude as follows:Abundances of the main ore-forming elements Te,Bi,As,Se,Au,and Ag are not high in the regional geological background,generally lower or close to their respective crustal Clark values,but almost all altered country rocks contain high levels of ore-forming elements.This indicates that the deposit’s ore-forming elements do not come from the country rocks.This also indicates that the geological thermal events that cause alteration and mineralization originate from depths and may be related to mantle plumes.Considering the distribution pattern of these ore-forming elements in the ore bodies’hanging wall and footwall,the metallogenic mechanism may be as follows:Mineralization is not achieved through lateral secretion in the horizontal or near horizontal direction,but rather through the upward movement and emplacement of deep ore-forming elements driven by geological processes such as mantle plumes.In addition,the migration of deep ore-forming elements is not achieved through dispersed infiltration between overlying rock particles,but through non widespread concentrated penetrating channels.This type of channel is likely to be the expansion structures where faults from different directions intersect,or where linear faults intersect with circular structures. 展开更多
关键词 Origin of ore-forming elements The Dashuigou independent tellurium deposit trace element abundance The country rocks The mantle plume
下载PDF
Mineralogy,distribution,occurrence and removability of trace elements during the coal preparation of No.6 coal from Heidaigou mine 被引量:12
12
作者 Xiangfei Bai Yue Wang Wenhua Li 《International Journal of Coal Science & Technology》 EI CAS 2014年第4期402-420,共19页
Optical microscopy and scanning electron microscopy in conjunction with energy dispersed X-ray spectrometry(SEM–EDX)were used to study the minerals and the concentrations of 33 trace elements in No.6 coal from Heidai... Optical microscopy and scanning electron microscopy in conjunction with energy dispersed X-ray spectrometry(SEM–EDX)were used to study the minerals and the concentrations of 33 trace elements in No.6 coal from Heidaigou mine.The distributions,organic affinity and removability of 18 trace elements were studied by float-sink experiments.A determination of the maceral groups was also undertaken.A high mineral content,dominated by kaolinite,was found in No.6 coal from Heidaigou mine.The bauxite content was relatively high and it was mainly present as individual particles in fusinite lumens or was intimately intergrown with carbonate minerals.The pyrite and quartz contents were low.Some marcasite with a parallel twin structure was observed by cross-polar reflected light.A small amount of bean-like goyazite was present in the calcite.The weighted trace element content in Heidaigou formations is relatively low,which is beneficial for coal processing and utilization.The concentrations of Ga,Hg,Pb,Se,Th,Ta are relatively high compared with the average values of Chinese coals.As,Hg,Mo,Ge,Ga,Ta,Ti,W,Mn are mainly present in minerals while B,Be,Th,P,Sc,Sr,V,Y,Yb are mainly found in organic matter.As,Ge,Hg,Mo are mainly present in sulfides and Be,Th,P,Sc,Sr,Y,Yb are mainly present in inertinite.B and V are mainly present in vitrinite.The high organic affinity and the low theoretical removability of most trace elements cause difficulties in removing them during coal preparation. 展开更多
关键词 trace elements OCCURRENCE Organic affinity-Removability Heidaigou coal
下载PDF
Impact of coal gangue on the level of main trace elements in the shallow groundwater of a mine reclamation area 被引量:17
13
作者 Li Wei Chen Longqian +2 位作者 Zhou Tianjian Tang Qibao Zhang Ting 《Mining Science and Technology》 EI CAS 2011年第5期715-719,共5页
Coal gangue is the most used filling material during reclamation of areas suffering subsidence from min- ing. Main trace element levels (F, As, Hg, and Pb) in shallow groundwater in the reclamation area may be affecte... Coal gangue is the most used filling material during reclamation of areas suffering subsidence from min- ing. Main trace element levels (F, As, Hg, and Pb) in shallow groundwater in the reclamation area may be affected by leaching from the gangue. This can has an impact on the application of the water for agricul- tural irrigation or use as drinking water. Therefore, it is of great significance to understand the effect coal gangue has on the shallow groundwater of a reclaimed area. We studied the effect of coal gangue on fluo- rine, arsenic, mercury, and lead levels in the shallow groundwater of a reclamation area by testing the water and the coal gangue. One well near the reclamation area was used as a control well and element levels in water from this well and from the soil next to the well were also measured. The results show that the levels of these elements are increasing in the reclamation area over time. The increase in fluorine, arsenic, mercury, and lead in monitor wells varies from 7.42% to 8.26%, from 7.13% to 7.90%, from 4.85% to 6.48%, and from 4.69% to 6.42%, respectively. Fluorine and arsenic levels are lower in monitor wells than in the control water. The other elements are found in greater concentration than in the control. The Nemerow index also indicates that the shallow groundwater in the reclamation area I is moderately affected by the back-filling coal gangue, while the shallow groundwater in the reclamation area II and III are slightly affected by the back-filling coal gangue. This shallow groundwater could be used for agri- cultural irrigation or for drinking. 展开更多
关键词 Coal gangue Main trace elements Shallow groundwater Reclamation area Nemerow index
下载PDF
Experiment of Coal Leaching and Study of the Separation of Trace Elements 被引量:6
14
作者 LIU Guijian 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2000年第2期386-390,共5页
Leaching is an important way of separation of trace elements from coal. Based on leaching experiments, the content of trace elements separated out from coal is related to their existing state and content in coal, the ... Leaching is an important way of separation of trace elements from coal. Based on leaching experiments, the content of trace elements separated out from coal is related to their existing state and content in coal, the duration of leaching process, temperature of leaching liquor and its acidity and basicity. The higher the temperature of leaching liquor and the longer the leaching time, the higher the contents of separated trace elements will be. In the course of leaching, the pH values of leaching liquors change and different trace elements are affected differently by the pH values. 展开更多
关键词 Leaching experiment trace elements influence factors separation of trace element
下载PDF
Changes of Serum Trace Elements, AFP, CEA, SF, T3, T4 and IGF-Ⅱ in Different Periods of Rat Liver Cancer 被引量:5
15
作者 Hong-xu Zhang Dan-dan Liu +5 位作者 Bai-jie Jin Ya-wei Wang Qi Liu Ru-bing Duan Peng Zhao Ming-xia Ma 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2011年第4期301-305,共5页
Objective: Based on liver cancer model built in SD rats, the contents of trace elements (Cu, Fe, Zn, Ca and Mg), AFP, CEA, SF, TH and IGF-II in serum were measured at different stages to explore the molecular changes ... Objective: Based on liver cancer model built in SD rats, the contents of trace elements (Cu, Fe, Zn, Ca and Mg), AFP, CEA, SF, TH and IGF-II in serum were measured at different stages to explore the molecular changes during the rat liver cancer development. Methods: The SD rat liver cancer model was built by using diethylnitrosamine (DENA) as the mutagen. During 16 weeks of DENA gavage, blood samples were taken in the 14th, 28th, 56th, 77th, 105th and 112th days respectively after the first day of gavage with DENA, then the contents of five trace elements (Cu, Fe, Zn, Ca and Mg), T3, T4, IGF-II, AFP, CEA and SF in serum were determined. Results: During the development of the rat liver cancer, in the test group, the Cu content significantly increased in serum, while the contents of Fe, Zn and Ca significantly decreased. The content of Mg showed no significant change. AFP and CEA of the test group showed same expression level with the control group; while the content of SF was lower than that of the control group when cancerization appeared. T3 and T4 increased at the first stage and then went down, and the content of IGF-II was always high. Conclusion: Cu, Fe, Zn, Ca, T3, T4, SF and IGF-II are closely related to the development of liver cancer. The changes of their contents in the development of cancer could enlighten the researches on cancer pathogenesis and prevention. 展开更多
关键词 DENA SD rats Liver cancer trace elements Biochemical components
下载PDF
Trace Elements in Sphalerite from the Dadongla Zn-Pb Deposit, Western Hunan-Eastern Guizhou Zn-Pb Metallogenic Belt, South China 被引量:3
16
作者 HU Yusi YE Lin +3 位作者 WEI Chen LI Zhenli HUANG Zhilong WANG Haoyu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2020年第6期2152-2164,共13页
The western Hunan-eastern Guizhou Zn-Pb metallogenic belt is one of the important Zn-Pb mineralization regions in China.The Dadongla deposit,located in the northeast of Guizhou Province,is one of the typical Zn-Pb dep... The western Hunan-eastern Guizhou Zn-Pb metallogenic belt is one of the important Zn-Pb mineralization regions in China.The Dadongla deposit,located in the northeast of Guizhou Province,is one of the typical Zn-Pb deposits in the region and has estimated resources more than 12 million metric tons(Mt)with an average grade of 4.11 wt%Zn+Pb.Its orebodies are hosted in the lower Cambrian Aoxi Formation dolomite,occurring as bedded,para-bedded in shape,and in conformity with the wall rock.The ore mineral assemblage is simple,dominated by sphalerite with minor pyrite and galena,and the gangue minerals are composed of dolomite,calcite with minor bitumen and barite.In view of the lack of geological and geochemical researches,the genesis of Zn-Pb ore is still unclear.Laser ablation-inductively coupled plasma mass spectrometry(LA-ICPMS)spot and mapping analyses were used to obtain sphalerite trace element chemistry in the Dadongla Zn-Pb deposit in Guizhou,China,aiming to constrain its ore genesis.The results show that sphalerite is characterized by the enrichment of Cd,Fe,Ge and Hg,corresponding with that of typical MVT deposits.Four zones were identified in the sphalerite crystal from Dadongla from the center to margin according to the color bands.in which the zone in the center,representing the early ore-stage sphalerite,is characterized by enrichment of Cd relatively,while the zone forming at late ore-stage is enriched in Ge and Hg relatively.The finding was controlled by differential leached metals content in ore-forming fluid from its source rock.Notably,critical element Ge trends to be enriched at the late ore-stage and follows a substitution of 2 Zn^2+(?)Ge^4++□(vacancy).Moreover,the calculated ore-forming temperature ranges from 79.9℃to 177.6℃by the empirical formula,which is similar to that of typical Mississippi Valley-type(MVT)deposits.Compared with the features of trace elements in sphalerite from different types of deposits,together with the geology,the Dadongla deposit belongs to an MVT Zn-Pb deposit. 展开更多
关键词 trace elements SPHALERITE LA-ICPMS MVT deposit Western Hunan-Eastern Guizhou Zn-Pb metallogenic belt
下载PDF
Geochemical characteristics of REY, Li, Ga trace elements in the No. 9 coal seam of the Daheng mine, Ningwu coalfield, Shanxi Province, China 被引量:5
17
作者 Jin-xi Wang Zhi-heng Fu +3 位作者 Ya-fan Hu Zhen Yang Jia-liang Ma Yu-zhuang Sun 《China Geology》 2021年第2期266-273,共8页
To understand the geochemical characteristics of the No.9 coal in the Daheng Mine of the Ningwu coalfield,the trace element analysis was conducted through X-ray fluorescence spectroscopy(XRF)and inductively coupled pl... To understand the geochemical characteristics of the No.9 coal in the Daheng Mine of the Ningwu coalfield,the trace element analysis was conducted through X-ray fluorescence spectroscopy(XRF)and inductively coupled plasma mass spectrometry(ICP-MS).The sedimentary environment was discussed according to the element geochemical parameters.The results show that Li,Ga,Hf,Zr,Nb,Th,and Ta are slightly enriched in the No.9 coal of Daheng Mine.The average value of the rare earth elements and yttrium(ΣREY)in coal here is 144.20μg/g(excluding parting),which is higher than the average value ofΣREY in the world’s coal and China’s coal.The light rare earth elements(LREY)are enriched.The content of Eu was 0.12‒2.10μg/g with an average of 0.57μg/g,and the Eu is obviously negatively abnormal.Most of the trace elements in the coal are positively correlated with the ash content,which shows that the occurrence of these trace elements is related to inorganic minerals.The results of sequential chemical extraction experiments show that rare earth elements mainly exist in coal in the form of aluminosilicate.The value of the Sr/Ba and the content of S reflect that the coal-forming environment was influenced by seawater.The values of V/Cr and Ni/Co reflect that the peat swamp is in an anaerobic environment and a strongly reducing environment during the coal-forming period. 展开更多
关键词 trace elements Rare earth elements GEOCHEMISTRY Coal Taiyuan Formation Mineral exploration engineering Shanxi Province China
下载PDF
Effects of Common Mineral Trace Elements on Immune Function of Livestock and Poultry 被引量:1
18
作者 Li Hu Ning'an Mei +1 位作者 Yuping Yan Jianming Ruan 《Plant Diseases and Pests》 CAS 2021年第3期34-36,共3页
The effects of zinc(Zn), iron(Fe), selenium(Se), copper(Cu), manganese(Mn), chromium(Cr) and germanium(Ge) on immune function of livestock and poultry are discussed, in order to provide the reference for safe and reas... The effects of zinc(Zn), iron(Fe), selenium(Se), copper(Cu), manganese(Mn), chromium(Cr) and germanium(Ge) on immune function of livestock and poultry are discussed, in order to provide the reference for safe and reasonable use of trace elements. 展开更多
关键词 MINERALS trace elements Livestock and poultry Immune function
下载PDF
Selected ions and major and trace elements as contaminants in coal-waste dump water from the Lower and Upper Silesian Coal Basins(Poland)
19
作者 Lucyna Lewiriska-Preis Ewa Szram +5 位作者 Monika J.Fabianska Adam Nadudvari Magdalena Misz-Kennan Anna Abramowicz Lukasz Kruszewski Andrzej Kita 《International Journal of Coal Science & Technology》 EI CAS CSCD 2021年第4期790-814,共25页
Many temporary and permanent reservoirs of water occur on or near coal-waste dumps in the Lower-and Upper Silesian Coal Basins(Poland).Little or nothing is known of the degree to which their water chemistry might refl... Many temporary and permanent reservoirs of water occur on or near coal-waste dumps in the Lower-and Upper Silesian Coal Basins(Poland).Little or nothing is known of the degree to which their water chemistry might reflect(i)reservoir type,i.e.,whether permanent or temporary,(ii)level of coal-waste thermal activity,i.e.,whether inactive or self-heating or burnt-out or(iii)region,i.e.,whether the dumps are in Upper-or Lower Silesia.To provide some answers,concentrations of selected ions(NH_(4)^(+),HCO_(3)^(-),F^(-),Cl^(-),Br^(-),NO_(2)^(-),NO_(3)^(-),PO_(4)^(3-),SO_(4)^(2-))were determined by ion chromatography and of nineteen elements(Al,B,Ba,Ca,Cd,Cr,Cu,Fe,K,Li,Mg,Mn,Na,P,Pb,S,Si,Sr,Zn)by inductively coupled plasma mass spectrometry(ICP-MS).The data allow a number of the following observations.When permanent reservoirs are considered,there is a clear relationship between concentrations of ions and major and trace elements and dump thermal activity.The highest concentrations occur where the thermal activity is high as inorganic components are transformed into more water-soluble forms.As dump thermal activity shows a regional pattern,it follows also that elemental and ion concentrations in the dump waters show significant regional differences.In temporary reservoirs,concentrations of ions and major and trace elements are much lower and any correlations between components less significant than in the permanent reservoirs;these reservoirs exist for too short a time for any balance between coal waste-and water components to be established. 展开更多
关键词 Coal-waste dump water SELF-HEATING Main ion concentrations Major elements trace elements
下载PDF
Water quality,natural chemical weathering and ecological risk assessment of the contaminated area of vanadium ore in Yinhua River,China:Evidence from major ions and trace elements
20
作者 Delu Li Yong Xu +4 位作者 Xiaotuan Zhang Zhidong Yang Shaofei Wang Qianyang He Zhe Jia 《Acta Geochimica》 EI CAS CSCD 2022年第1期84-99,共16页
There are abundant vanadium ores in the Cambrian strata in southern Shaanxi,China.Many years of mining activities and surface leaching have polluted the surface water to a certain extent,but the researches on the wate... There are abundant vanadium ores in the Cambrian strata in southern Shaanxi,China.Many years of mining activities and surface leaching have polluted the surface water to a certain extent,but the researches on the water quality characteristics and pollution degree are relatively weak.This contribution was organized to investigate the surface water quality by general parameters,including TDS,Eh,pH,DO,TOC,COD,and EC,in the vanadium ore belt(Yinhua River basin).Major ions were determined to detect the water type and natural chemical weathering,while trace elements were used to illustrate their geochemical characteristics and ecological risk assessment of heavy metals.The study found that the surface water was weakly alkaline and mainly dominated from normal to pool grade.The particle size with1000–10,000 nm of suspended particles was the main carrier of organic matter.The concentration of HCO_(3)^(-)and SO_(4)^(2-)in the anions and Ca^(2+)and Mg^(2+)ions in the cations were relatively high,and the water type was Ca-Mg-HCO_(3)-SO_(4) type.Rock weathering had a great influence on surface water,and the weathering products were mainly silicate and carbonate.Compared with the Type river,the contents of V elements showed an obvious positive anomaly,which may be affected by mining activities of vanadium ore and the annual leaching of the tailings pond.As and Cd in the surface water was polluted seriously.The integrated pollution index suggested that the surface water pollution was serious,and the main stream was more serious with the increasing tailings ponds. 展开更多
关键词 Vanadium ore belt Surface water Water contamination Major ions trace elements
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部