Three-dimensional geochemical modeling of ore-forming elements is crucial for predicting deep mineralization.This approach provides key information for the quantitative prediction of deep mineral localization,three-di...Three-dimensional geochemical modeling of ore-forming elements is crucial for predicting deep mineralization.This approach provides key information for the quantitative prediction of deep mineral localization,three-dimensional fine interpolation,analysis of spatial distribution patterns,and extraction of quantitative mineral-seeking markers.The Yechangping molybdenum(Mo)deposit is a significant and extensive porphyry-skarn deposit in the East Qinling-Dabie Mo polymetallic metallogenic belt at the southern margin of the North China Block.Abundant borehole data on oreforming elements underpin deep geochemical predictions.The methodology includes the following steps:(1)Threedimensional geological modeling of the deposit was established.(2)Correlation,cluster,and factor analyses post delineation of mineralization stages and determination of mineral generation sequence to identify(Cu,Pb,Zn,Ag)and(Mo,W,mfe)assemblages.(3)A three-dimensional geochemical block model was constructed for Mo,W,mfe,Cu,Zn,Pb,and Ag using the ordinary kriging method,and the variational function was developed.(4)Spatial distribution and enrichment characteristics analysis of ore-forming elements are performed to extract geological information,employing the variogram and w(Cu+Pb+Zn+Ag)/w(Mo+W)as predictive indicators.(5)Identifying the western,northwestern,and southwestern areas of the mine with limited mineralization potential,contrasted by the northeastern and southeastern areas favorable for mineral exploration.展开更多
XRF and EDX analyses were carried out on 18 batches of representative raw samples to determine the distribution of major chemical elements in the petroleum source rocks of Donga and Yogou formations of Termit sediment...XRF and EDX analyses were carried out on 18 batches of representative raw samples to determine the distribution of major chemical elements in the petroleum source rocks of Donga and Yogou formations of Termit sedimentary basin. The chemical composition of these formations is dominated by silicon (Si), aluminum (Al) and iron (Fe). This is consistent with the oxide composition, which is also dominated by silicon oxide (SiO2), aluminum oxide (Al<sub>2</sub>O<sub>3</sub>) and iron monoxide (FeO). No less important chemical elements are calcium (Ca), potassium (K), sulfur (S), titanium (Ti), magnesium (Mg), manganese (Mn) and barium (Ba), as well as some of their oxides. All these major chemical elements are carried by silicate detrital minerals associated with pyrite and goethite and/or clay minerals such as kaolinite and interstratified illite, smectite and chlorite. This trend is illustrated by the values of the Si/Al and SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> ratios.展开更多
The particle composition and spatial distribution of landslide-induced dam bodies are critical geotechnical parameters for studying the hazards of dam-break floods.However,current research often neglects the influence...The particle composition and spatial distribution of landslide-induced dam bodies are critical geotechnical parameters for studying the hazards of dam-break floods.However,current research often neglects the influence of the initial particle composition and spatial distribution of the landslide on the particle composition and spatial distribution of the landslide dam.This study investigated the impact of initial particle size distribution,volume,and sliding length on the energy and velocity changes of characteristic particles during the sliding process and the spatial distribution of particle sizes in the landslide dam body.Numerical simulations and physical models were employed to examine the effects of sequential gradient arrangements(where particle sizes decrease from top to bottom)and four other different initial particle arrangements on the energy and velocity changes of particles and the spatial distribution of particle sizes in the dam body.The study reveals the characteristics of translational and rotational energy of different particles and the laws of mechanical energy conversion,obtaining the spatial distribution patterns of particle sizes in landslide-induced dams.The results show that under the sequential gradient arrangement,the energy dissipation of the landslide movement is lower,with larger particles mainly distributed at the distal end and smaller particles at the proximal end of the landslide dam.In contrast,under the reverse gradient arrangement,the energy dissipation of the landslide movement is higher,and the distribution pattern of the dam particles is opposite to that of the sequential gradient arrangement.For the other arrangement modes,the spatial distribution of dam particles falls between the aforementioned two.There is a positive correlation between particle size and translational kinetic energy within the particle flow during the landslide process,and rotational motion increases energy dissipation.Under constant slope conditions,sliding length does not affect the movement pattern of the particle flow or the spatial distribution of particles in the dam body.The findings of this study provide a scientific basis for the accurate simulation and prediction of dam-break flood processes.展开更多
A multi-index analysis including grain size, major and trace elements is performed on the surface sediments from the northeastern Beibu Gulf to trace the sources of the sediments and to understand the controlling fact...A multi-index analysis including grain size, major and trace elements is performed on the surface sediments from the northeastern Beibu Gulf to trace the sources of the sediments and to understand the controlling factors for elements distribution. The mean grain size exhibits a wide variation ranging from 0.09Φ to 8.05Φ with an average value of 5.33Φ. The average contents of major elements descend in an order of c(SiO_2)>c(Al_2O_3)>c(Fe_2O_3)>c(CaO)>c(MgO)>c(K_2O)>c(Na_2O)>c(TiO_2)>c(P_2O_5)>c(MnO), while those of trace elements exhibit a descending order of c(Sr)>c(Rb)>c(V)>c(Zn)>c(Cr)>c(Pb)>c(Ni)>c(Cu)>c(As). On the basis of elementary distribution characteristics and statistical analyses, the study area is divided into the four zones: Zone I is located in the northeastern coastal area of the gulf, which receives large amount of fluvial materials from local rivers in Guangxi and Guangdong, China, and the Qiongzhou Strait; Zone Ⅱ is located in the center of the study area, where surface sediments exhibits a multiple source; Zone Ⅲ is located in the Qiongzhou Strait, where surface sediments are dominated by materials from the Zhujiang River and Hainan; Zone IV is located in the southwest of the study area, where surface sediments are mainly originated from the Red River and Hainan. The statistical analyses of sediment geochemical characteristics reveal that the grain size, which is mainly influenced by hydrodynamics and mineral composition of terrigenous materials, is the leading factor controlling the elementary distribution.Meanwhile, impacts from anthropogenic activities and marine biogenic process will also be taken into consideration.展开更多
To promote the rational development and use of clean coal resources in China, data on the regional and age distribution of sulfur, arsenic and other harmful elements in Chinese coal was broadly collected, tested for c...To promote the rational development and use of clean coal resources in China, data on the regional and age distribution of sulfur, arsenic and other harmful elements in Chinese coal was broadly collected, tested for content, and analyzed. Coal in northwestern China is characterized by low to extremely low levels of sulfur; the coal of the Taiyuan Formation in northern China mainly has high-sulfur content; that of the Shanxi Formation is mainly characterized by low sulfur coal; and the Late Permian coal in southern China has overall higher sulfur content; other regions have low sulfur coal. The average content of harmful trace elements in the bulk of China's coal is similar to the corresponding content in the coal of the North America and the rest of the world, whereas the content of various elements (Hg, Sb and Se) is different in magnitude to the corresponding percentage in the crust. The average content of the elements Cr, Se, Co, Be, U, Br in Late Permian coal in S China ranks first in the country whereas the average content of Hg and CI in the coals of Late Carboniferous to Early Permian age in N China are the highest. The average content of Mn in Early and Middle Jurassic coal is higher in NW China. The high content of harmful elements in some coal should cause particular concern both in the development and utilization of coal.展开更多
Zhijin phosphorite is one of super large-scale medium-low grade and REE-bearing phosphorite deposit in Southwest of China. Previous investigations had revealed that this deposit contained appreciable amounts of rare e...Zhijin phosphorite is one of super large-scale medium-low grade and REE-bearing phosphorite deposit in Southwest of China. Previous investigations had revealed that this deposit contained appreciable amounts of rare earth elements (REE) reaching up to 1300 μg·g-1. In this paper, REE contents and existing state in single collophanite and dolomite mineral were further analyzed by ICP-MS and EPMA-1600 Electric Probe methods. The results indicated that REE content of collophanite was far more than that of dolomite, and increased with an increase of phosphor. There existed independent minerals of REE in single collophanite mineral, such as cerianite and monazite, but the amount of them was extremely little. No independent mineral of yttrium was found in this investigation. Presumedly, REE and yttrium were present in the form of ions in the lattices of collophanite. Based on above investigation, the two-stage reverse flotation technology was carried out to see the distribution of REE in flotation process. It was found that REE was mainly enriched in phosphate concentrate and recovered in the rough stage flotation. REE recovery of concentrate increased with an increase of P2O5 content and P2O5 recovery of concentrate. Under the optimum flotation condition, REE recovery was 79.25% in the rough stage flotation and 9.94% in scavenging flotation.展开更多
Data obtained from a comprehensive multidisciplinary oceanographic survey in the central and northern parts of the Taiwan Strait, 24°20′-26°00′N, 118°45°-121°00′E by the Fujian Institute of...Data obtained from a comprehensive multidisciplinary oceanographic survey in the central and northern parts of the Taiwan Strait, 24°20′-26°00′N, 118°45°-121°00′E by the Fujian Institute of Oceanology during the period May, 1983 through May, 1984, showed that the distributions of dissolved oxygen (DO), nitrate, dissolved inorganic phosphate and silicate concentrations here had obvious areal and seasonal characteristics that were mainly influenced by the seasonal circulation ofthree major water systems in the Taiwan Strait-- the Taiwan Strait Warm Water (TSWW), theZhejiang-Fujian Coastal Water (ZFCW), and the Northeastern Strait Warm Water (NESWW).展开更多
The risk of pharmacokinetic polyphenols-trace elements interaction may undesirable therapeutic outcomes. We evaluate the long-term use of silibinin, epigallocatechin (ECGC), quercetin and rutin on the absorption and t...The risk of pharmacokinetic polyphenols-trace elements interaction may undesirable therapeutic outcomes. We evaluate the long-term use of silibinin, epigallocatechin (ECGC), quercetin and rutin on the absorption and tissue distribution of zinc, copper and iron after single oral doses in rats. Five groups of rats were either with olive oil as control or with one of the polyphenols silibinin, EPGC, quercetin or rutin, administered orally as oily solutions for 30 days. At day 30, a solution contains sulphate salt of zinc, copper and iron was administered orally;3 hrs later blood samples, tissues of brain, kidney and liver were obtained for evaluation of the elements levels. The results showed that the polyphenols increased both serum and tissue levels of these elements compared with controls. This effect was relatively varied according to the structural differences among flavonoids. In conclusion, long-term use of supraphysiological doses of flavonoids increase absorption of Zn, Cu and Fe and their tissue availability in brain, kidney and liver;this effect seems to be different with variations in structural features.展开更多
The content and distribution pattern of rare earth elements(REEs)in surface sediments from the Eastern and Western Pacifi c Ocean,the Northern and Southern Atlantic Ocean,and the Southwestern Indian Ocean were explore...The content and distribution pattern of rare earth elements(REEs)in surface sediments from the Eastern and Western Pacifi c Ocean,the Northern and Southern Atlantic Ocean,and the Southwestern Indian Ocean were explored and the resources and geochemical characteristics of REEs in deep-ocean sediments from diff erent oceans were studied.The total REE abundances(ΣREE)in the diff erent oceans ranged as follows:Eastern Pacifi c,56.88–500.02μg/g;Western Pacifi c,290.68–439.94μg/g;Northern Atlantic,55.33–154.90μg/g;Southern Atlantic,40.83–69.30μg/g;and Southwestern Indian Ocean,20.24–64.76μg/g.Their corresponding LREE(La-Eu)/HREE(Gd-Lu)average values were 5.18,5.86,9.01,5.21,and 4.59,which indicated that the light REEs were all evidently enriched.δEu andδCe showed slight Eu-negative anomalies and signifi cant Ce-positive anomalies in all sediments.Although the contents of REEs in the sediments varied among the diff erent oceans,the distribution patterns of REEs were similar,and the correlation coeffi cient was greater than 0.9290.In the Eastern Pacifi c sediments,ΣREE showed a signifi cantly positive correlation with Co,Cu,Zn,Mn,Mo and a weak correlation with Fe.In the Western Pacifi c and Southern Atlantic sediments,ΣREE presented no obvious correlation and a weakly negative correlation with Co,Cu,Zn,Mn,Mo and Fe,respectively.ΣREE in the Southwestern Indian Ocean sediments positively correlated with Cu,Zn,Mn,Mo,Fe,and had a weakly negative correlation with Co.展开更多
The distribution of rare earth element (REE) forms in soils is given in the present paper on the basis of sequential fractionation and determination of 34 representative surface soils collected from all parts of China...The distribution of rare earth element (REE) forms in soils is given in the present paper on the basis of sequential fractionation and determination of 34 representative surface soils collected from all parts of China.Results obtained show that the extraction rate of water soluble and exchangeable REE had the odd-even phenomenon and that of organically bound REE from La to Lu tended to reduce gradually with the increase of atomic number.The stability of Sc and the activity and enrichment of Tm in soils are proposed.Furthermore,the paper makes a preliminary discussion on the differences in the concentration distribution of various forms of individual REE in some soils.展开更多
This paper presents the results of our recent studies on the upper mantle composition in the Qinling Belt and East China . It discusses the methods of estimating the upper mantle composition, its selected elements and...This paper presents the results of our recent studies on the upper mantle composition in the Qinling Belt and East China . It discusses the methods of estimating the upper mantle composition, its selected elements and its constitution characteristics .The results indicate that ore-forming elements on ore types and their distribution in this area are strongly controlled by the upper mantle heterogeneity .展开更多
Wetland is the conjunction of lake and terrene where human activities are concentrated. From the viewpoints of material transport and cycling in the terrene-lake system, wetland is the buffer where sand and mud, heavy...Wetland is the conjunction of lake and terrene where human activities are concentrated. From the viewpoints of material transport and cycling in the terrene-lake system, wetland is the buffer where sand and mud, heavy metals, pollutants and nutrients are tarried. In this paper, we provide a case study based on the temporal and spatial distribution of elements in the Wangling River catchment, a small sub-catchment of Longgan Lake in the middle reaches of the Yangtze River. We have found that wetland can buffer major heavy metals such as Cr, Cu, etc. significantly, but has a little buffer function to some active elements such as Fe and Mn, which are always transported as solutions. Human activities not only influence the distribution of elements, but also weaken the buffer function of wetland. Intensive human activities in the Longgan Lake area in the past 70 years have been recorded in stream, wetland and lake sediments, especially the human activity events such as deforesting and reclaiming on a large scale in 1958 and the 1980’s. Human activities caused the increase of sedimentation rates since the 1950’s, as well as the increase of elements’ concentrations. The extensive use of fertilizers and pesticides since the 1960’s have led to the increase of total P concentrations. Increasing SO-2 emission accelerate the process of cation exchange in soil, and enhance the leaching of Mn out of soils. Permanent storing of water causes the soil gleyification that also intensifies the leaching of Mn. These are two major reasons for the obvious increase of manganese concentrations in recent 20 years in Longgan Lake. Intensive human activities since the 1950s’ have intensified the population in this region and thus destroyed the buffer function of wetland.展开更多
Natural contents and distribution of trace elements in soils of the Dam River and Tuotuo River basins are demonstrated in this paper. By using contrasting methods. it is found that the content of trace elements of soi...Natural contents and distribution of trace elements in soils of the Dam River and Tuotuo River basins are demonstrated in this paper. By using contrasting methods. it is found that the content of trace elements of soil in the region is at the lower limit of the world's soil content level, that the tendency of the average trace element content in the four main types of soil is shown as: alpine mountain meadow soil>marsh soil>alpine mountain steppe soil> alpine mountain cryogenic soil. the average content of trace elements such as Cr. Co, Zn, Cu, Hg, Pb, Mo, Mn and Ni in the Dam River basin is higher than that of the Tuotuo River basin except that of the elements Ba and Sr. In addition. through correlation analysis. the relationship of intergrowth and association among soil elements are revealed.展开更多
The effect of the addition of rare earths in Fe-based high chromium alloy powders on elements distribution in matrix materials and mechanical properties were studied. The results show that the addition of cerium can i...The effect of the addition of rare earths in Fe-based high chromium alloy powders on elements distribution in matrix materials and mechanical properties were studied. The results show that the addition of cerium can increase the chromium amount in carbonides and increase the micro-hardness after carbonization and the wear-resistant property of materials.展开更多
In this paper,environmental scanning electron microscopy (ESEM) is applied to characterizing the mineral and element distribution of chromite ore processing residue (COPR).The test results show that Cr-bearing brownmi...In this paper,environmental scanning electron microscopy (ESEM) is applied to characterizing the mineral and element distribution of chromite ore processing residue (COPR).The test results show that Cr-bearing brownmillerite occurs in the rim of COPR particle,while hydroandradite with Cr(Ⅵ) in its structure presents inside the COPR particle.Periclase and calcite occur in the interstitial area.Element analyses show that Ca,Fe and Al are distributed throughout the COPR particle,and Mg exists mostly in the interstitial area or on the particle surface.A lower content of Cr is evenly distributed in the COPR particle,while slightly higher concentration of Cr occurs inside the particle.It is suggested that it will take a relatively longer time for Cr to migrate out of COPR,especially for hexavalent chromium,so the leaching time and the particle size may be two important factors to affect the release of Cr(Ⅵ).展开更多
[Objective] The aim was to study the relation between solar radiation distribution and meteorological elements in Guangxi. [Method] Based on the observed data of solar radiation in Guangxi from 1995 to 2009, the total...[Objective] The aim was to study the relation between solar radiation distribution and meteorological elements in Guangxi. [Method] Based on the observed data of solar radiation in Guangxi from 1995 to 2009, the total radiation, solar distribution and interannual changes in Guangxi were analyzed. By dint of observed data in Nanning station, the annual, seasonal and monthly changes of net radiation in Nanning and the linear relation between total radiation, solar distribution characteristics and interannual changes were discussed. [Result] The global radiation of surface solar radiation in the low latitude was higher tan the high latitude, as Beihai>Nanning>Guilin. The solar radiation changes and the seasonal changes in different places varied, as summer>autumn>spring>winter. The total radiation and solar radiation hours were consistent. The total solar radiation and the low cloud was in negative relation, but was in positive relation with sunny weather. The total solar radiation was in positive relation with ground temperature, except in winter. [Conclusion] The study provided effective theoretical basis and data reference to the study of climate and development of solar energy.展开更多
Accumulation and releasing of trace metal elements on aluminum containing sediments of inner drinking water pipe is discussed,as studied from five variations effecting:raw water quality,chemical reagents,solution pH a...Accumulation and releasing of trace metal elements on aluminum containing sediments of inner drinking water pipe is discussed,as studied from five variations effecting:raw water quality,chemical reagents,solution pH and drinking water flow condition.In order to decrease the release of trace metal elements,and to ensure the pipe operation and human safety,water quality adjustment is suggested to avoid aluminum containing sediments formation in drinking distribution system.The maximum amounts of accumulation of common trace metal elements are given.Future trends of development in this field are also proposed.展开更多
A series of selective dissolution experiments were conducted on the hydrogenic ferromanganese crusts collected near Line Island to study the geochemistry of Mn, Fe, Cu, Co, Ni and Ti. Despite of the fact that the very...A series of selective dissolution experiments were conducted on the hydrogenic ferromanganese crusts collected near Line Island to study the geochemistry of Mn, Fe, Cu, Co, Ni and Ti. Despite of the fact that the very close intergrowth between amorphous ferric oxyhydroxides and δ-MnO2 exists in the hydrogenic ferromanganese crusts, there is no isomorphous substitution between iron and manganese. This is because the two elements in oxides have different crystal chemistry and geochemistry, such assertion being in agreement with the results of selective dissolution experiments. Transitional metal elements such as Cu, Co, Ni and Ti are enriched in different phases, i.e. Ni and Co are incorporated into δ-MnO2 while Cu and Ti are incorporated into ferric oxyhydroxides. The distributions of the elements in amorphous ferric oxyhydroxides and δ-MnO2 are controlled by the existing states of the elements in the seawater and the crystal chemistry and geochemistry of these elements/ions in oxides.展开更多
Data from Global Cancer Statistics show that breast cancer (BC) is the most common type of cancer among women, leading the number of deaths caused by cancer. The developments in diagnosis and treatment techniques for ...Data from Global Cancer Statistics show that breast cancer (BC) is the most common type of cancer among women, leading the number of deaths caused by cancer. The developments in diagnosis and treatment techniques for the BC, including chemotherapy and/or radiotherapy, increased the survival rates for this type of cancer. One late complication induced by BC treatment is the cardiotoxicity. This term comprises different cardiotoxic side effects, which include blood pressure alterations, myocardial ischemia, congestive heart failure and other damages. This study aimed to evaluate the cardiac alterations induced by radiotherapy and chemotherapy, simulating a treatment for BC in Wistar rats. It is, therefore, important to understand the mechanisms involved in the cardiotoxicity, in order to prevent women from this late effect, when they undergo BC treatments. The major interests in this work are in Low atomic weight elements as Sodium, because it is strongly related to cardiomyocyte contraction;Magnesium, because it is important in the cardiac metabolism;and Iron, because BC treatment induced cardiotoxicity can be associated to the oxidative stress. Changes that occur in unhealthy tissues in case to cardiovascular damages can be better understood when elemental compounds and structures of healthy tissues are known. Low Energy X-ray Fluorescence (LEXRF) technique was used to obtain elemental maps of low Z-elements providing a semi-quantitative analysis of the tissues evaluated under different conditions. Through the technique LEXRF we obtained elemental and absorption maps. The results showed more damages when associating chemotherapy and radiotherapy in comparison to myocardium healthy. Those images taken together with light microscopy, X-ray absorption and phase contrast images, satisfactorily characterize the cardiac tissue for the first time in the literature, from the structural and morphological points of view. LEXRF was carried out at TwinMic beamline in the ELETTRA Synchrotron Fa-cility, at the beamline TwinMic, in Trieste, Italy.展开更多
The present study attempted to evaluate the influence of human activity on major elements(Na_2O,MgO, Al_2O_3, SiO_2, K_2O, CaO, Fe_2O_3), and to find a method to explore correlations between major elements and human d...The present study attempted to evaluate the influence of human activity on major elements(Na_2O,MgO, Al_2O_3, SiO_2, K_2O, CaO, Fe_2O_3), and to find a method to explore correlations between major elements and human disturbances, according to geospatial theories and methods. The study results indicate that landscapes influence major elements in diverse ways: Al_2O_3 is closely related to road and mine landscapes; strong relationships exist between MgO, Fe_2O_3, CaO, and SiO_2 and roads;Na_2O, SiO_2, and Fe_2O_3 are unrelated to city landscapes;and Na_2O is unrelated to road and mine landscapes.展开更多
基金supported by the Key Research Project of China Geological Survey(Grant No.DD20230564)the Research Project of Natural Resources Department of Gansu Province(Grant No.202219)。
文摘Three-dimensional geochemical modeling of ore-forming elements is crucial for predicting deep mineralization.This approach provides key information for the quantitative prediction of deep mineral localization,three-dimensional fine interpolation,analysis of spatial distribution patterns,and extraction of quantitative mineral-seeking markers.The Yechangping molybdenum(Mo)deposit is a significant and extensive porphyry-skarn deposit in the East Qinling-Dabie Mo polymetallic metallogenic belt at the southern margin of the North China Block.Abundant borehole data on oreforming elements underpin deep geochemical predictions.The methodology includes the following steps:(1)Threedimensional geological modeling of the deposit was established.(2)Correlation,cluster,and factor analyses post delineation of mineralization stages and determination of mineral generation sequence to identify(Cu,Pb,Zn,Ag)and(Mo,W,mfe)assemblages.(3)A three-dimensional geochemical block model was constructed for Mo,W,mfe,Cu,Zn,Pb,and Ag using the ordinary kriging method,and the variational function was developed.(4)Spatial distribution and enrichment characteristics analysis of ore-forming elements are performed to extract geological information,employing the variogram and w(Cu+Pb+Zn+Ag)/w(Mo+W)as predictive indicators.(5)Identifying the western,northwestern,and southwestern areas of the mine with limited mineralization potential,contrasted by the northeastern and southeastern areas favorable for mineral exploration.
文摘XRF and EDX analyses were carried out on 18 batches of representative raw samples to determine the distribution of major chemical elements in the petroleum source rocks of Donga and Yogou formations of Termit sedimentary basin. The chemical composition of these formations is dominated by silicon (Si), aluminum (Al) and iron (Fe). This is consistent with the oxide composition, which is also dominated by silicon oxide (SiO2), aluminum oxide (Al<sub>2</sub>O<sub>3</sub>) and iron monoxide (FeO). No less important chemical elements are calcium (Ca), potassium (K), sulfur (S), titanium (Ti), magnesium (Mg), manganese (Mn) and barium (Ba), as well as some of their oxides. All these major chemical elements are carried by silicate detrital minerals associated with pyrite and goethite and/or clay minerals such as kaolinite and interstratified illite, smectite and chlorite. This trend is illustrated by the values of the Si/Al and SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> ratios.
基金reported in this manuscript is funded by the National Natural Science Foundation of China(Grant No.52130904).
文摘The particle composition and spatial distribution of landslide-induced dam bodies are critical geotechnical parameters for studying the hazards of dam-break floods.However,current research often neglects the influence of the initial particle composition and spatial distribution of the landslide on the particle composition and spatial distribution of the landslide dam.This study investigated the impact of initial particle size distribution,volume,and sliding length on the energy and velocity changes of characteristic particles during the sliding process and the spatial distribution of particle sizes in the landslide dam body.Numerical simulations and physical models were employed to examine the effects of sequential gradient arrangements(where particle sizes decrease from top to bottom)and four other different initial particle arrangements on the energy and velocity changes of particles and the spatial distribution of particle sizes in the dam body.The study reveals the characteristics of translational and rotational energy of different particles and the laws of mechanical energy conversion,obtaining the spatial distribution patterns of particle sizes in landslide-induced dams.The results show that under the sequential gradient arrangement,the energy dissipation of the landslide movement is lower,with larger particles mainly distributed at the distal end and smaller particles at the proximal end of the landslide dam.In contrast,under the reverse gradient arrangement,the energy dissipation of the landslide movement is higher,and the distribution pattern of the dam particles is opposite to that of the sequential gradient arrangement.For the other arrangement modes,the spatial distribution of dam particles falls between the aforementioned two.There is a positive correlation between particle size and translational kinetic energy within the particle flow during the landslide process,and rotational motion increases energy dissipation.Under constant slope conditions,sliding length does not affect the movement pattern of the particle flow or the spatial distribution of particles in the dam body.The findings of this study provide a scientific basis for the accurate simulation and prediction of dam-break flood processes.
基金The National Programme on Global Change and Air-Sea Interaction of China under contract Nos GASI-GEOGE-03,GASI-04-01-02 and GASI-GEOGE-05the National Natural Science Foundation of China under contract Nos 41476047,41106045,41506012 and 41206045
文摘A multi-index analysis including grain size, major and trace elements is performed on the surface sediments from the northeastern Beibu Gulf to trace the sources of the sediments and to understand the controlling factors for elements distribution. The mean grain size exhibits a wide variation ranging from 0.09Φ to 8.05Φ with an average value of 5.33Φ. The average contents of major elements descend in an order of c(SiO_2)>c(Al_2O_3)>c(Fe_2O_3)>c(CaO)>c(MgO)>c(K_2O)>c(Na_2O)>c(TiO_2)>c(P_2O_5)>c(MnO), while those of trace elements exhibit a descending order of c(Sr)>c(Rb)>c(V)>c(Zn)>c(Cr)>c(Pb)>c(Ni)>c(Cu)>c(As). On the basis of elementary distribution characteristics and statistical analyses, the study area is divided into the four zones: Zone I is located in the northeastern coastal area of the gulf, which receives large amount of fluvial materials from local rivers in Guangxi and Guangdong, China, and the Qiongzhou Strait; Zone Ⅱ is located in the center of the study area, where surface sediments exhibits a multiple source; Zone Ⅲ is located in the Qiongzhou Strait, where surface sediments are dominated by materials from the Zhujiang River and Hainan; Zone IV is located in the southwest of the study area, where surface sediments are mainly originated from the Red River and Hainan. The statistical analyses of sediment geochemical characteristics reveal that the grain size, which is mainly influenced by hydrodynamics and mineral composition of terrigenous materials, is the leading factor controlling the elementary distribution.Meanwhile, impacts from anthropogenic activities and marine biogenic process will also be taken into consideration.
文摘To promote the rational development and use of clean coal resources in China, data on the regional and age distribution of sulfur, arsenic and other harmful elements in Chinese coal was broadly collected, tested for content, and analyzed. Coal in northwestern China is characterized by low to extremely low levels of sulfur; the coal of the Taiyuan Formation in northern China mainly has high-sulfur content; that of the Shanxi Formation is mainly characterized by low sulfur coal; and the Late Permian coal in southern China has overall higher sulfur content; other regions have low sulfur coal. The average content of harmful trace elements in the bulk of China's coal is similar to the corresponding content in the coal of the North America and the rest of the world, whereas the content of various elements (Hg, Sb and Se) is different in magnitude to the corresponding percentage in the crust. The average content of the elements Cr, Se, Co, Be, U, Br in Late Permian coal in S China ranks first in the country whereas the average content of Hg and CI in the coals of Late Carboniferous to Early Permian age in N China are the highest. The average content of Mn in Early and Middle Jurassic coal is higher in NW China. The high content of harmful elements in some coal should cause particular concern both in the development and utilization of coal.
基金the Natural Science Foundation of Guizhou Province (QianKeHe J[2005]2098)
文摘Zhijin phosphorite is one of super large-scale medium-low grade and REE-bearing phosphorite deposit in Southwest of China. Previous investigations had revealed that this deposit contained appreciable amounts of rare earth elements (REE) reaching up to 1300 μg·g-1. In this paper, REE contents and existing state in single collophanite and dolomite mineral were further analyzed by ICP-MS and EPMA-1600 Electric Probe methods. The results indicated that REE content of collophanite was far more than that of dolomite, and increased with an increase of phosphor. There existed independent minerals of REE in single collophanite mineral, such as cerianite and monazite, but the amount of them was extremely little. No independent mineral of yttrium was found in this investigation. Presumedly, REE and yttrium were present in the form of ions in the lattices of collophanite. Based on above investigation, the two-stage reverse flotation technology was carried out to see the distribution of REE in flotation process. It was found that REE was mainly enriched in phosphate concentrate and recovered in the rough stage flotation. REE recovery of concentrate increased with an increase of P2O5 content and P2O5 recovery of concentrate. Under the optimum flotation condition, REE recovery was 79.25% in the rough stage flotation and 9.94% in scavenging flotation.
文摘Data obtained from a comprehensive multidisciplinary oceanographic survey in the central and northern parts of the Taiwan Strait, 24°20′-26°00′N, 118°45°-121°00′E by the Fujian Institute of Oceanology during the period May, 1983 through May, 1984, showed that the distributions of dissolved oxygen (DO), nitrate, dissolved inorganic phosphate and silicate concentrations here had obvious areal and seasonal characteristics that were mainly influenced by the seasonal circulation ofthree major water systems in the Taiwan Strait-- the Taiwan Strait Warm Water (TSWW), theZhejiang-Fujian Coastal Water (ZFCW), and the Northeastern Strait Warm Water (NESWW).
文摘The risk of pharmacokinetic polyphenols-trace elements interaction may undesirable therapeutic outcomes. We evaluate the long-term use of silibinin, epigallocatechin (ECGC), quercetin and rutin on the absorption and tissue distribution of zinc, copper and iron after single oral doses in rats. Five groups of rats were either with olive oil as control or with one of the polyphenols silibinin, EPGC, quercetin or rutin, administered orally as oily solutions for 30 days. At day 30, a solution contains sulphate salt of zinc, copper and iron was administered orally;3 hrs later blood samples, tissues of brain, kidney and liver were obtained for evaluation of the elements levels. The results showed that the polyphenols increased both serum and tissue levels of these elements compared with controls. This effect was relatively varied according to the structural differences among flavonoids. In conclusion, long-term use of supraphysiological doses of flavonoids increase absorption of Zn, Cu and Fe and their tissue availability in brain, kidney and liver;this effect seems to be different with variations in structural features.
基金Supported by the Basic Scientifi c Fund for National Public Research Institutes of China(No.2020Q10)and the China Ocean Mineral Resources R&D Association(Nos.DY135-E2-1-07,DY135-E2-4)。
文摘The content and distribution pattern of rare earth elements(REEs)in surface sediments from the Eastern and Western Pacifi c Ocean,the Northern and Southern Atlantic Ocean,and the Southwestern Indian Ocean were explored and the resources and geochemical characteristics of REEs in deep-ocean sediments from diff erent oceans were studied.The total REE abundances(ΣREE)in the diff erent oceans ranged as follows:Eastern Pacifi c,56.88–500.02μg/g;Western Pacifi c,290.68–439.94μg/g;Northern Atlantic,55.33–154.90μg/g;Southern Atlantic,40.83–69.30μg/g;and Southwestern Indian Ocean,20.24–64.76μg/g.Their corresponding LREE(La-Eu)/HREE(Gd-Lu)average values were 5.18,5.86,9.01,5.21,and 4.59,which indicated that the light REEs were all evidently enriched.δEu andδCe showed slight Eu-negative anomalies and signifi cant Ce-positive anomalies in all sediments.Although the contents of REEs in the sediments varied among the diff erent oceans,the distribution patterns of REEs were similar,and the correlation coeffi cient was greater than 0.9290.In the Eastern Pacifi c sediments,ΣREE showed a signifi cantly positive correlation with Co,Cu,Zn,Mn,Mo and a weak correlation with Fe.In the Western Pacifi c and Southern Atlantic sediments,ΣREE presented no obvious correlation and a weakly negative correlation with Co,Cu,Zn,Mn,Mo and Fe,respectively.ΣREE in the Southwestern Indian Ocean sediments positively correlated with Cu,Zn,Mn,Mo,Fe,and had a weakly negative correlation with Co.
文摘The distribution of rare earth element (REE) forms in soils is given in the present paper on the basis of sequential fractionation and determination of 34 representative surface soils collected from all parts of China.Results obtained show that the extraction rate of water soluble and exchangeable REE had the odd-even phenomenon and that of organically bound REE from La to Lu tended to reduce gradually with the increase of atomic number.The stability of Sc and the activity and enrichment of Tm in soils are proposed.Furthermore,the paper makes a preliminary discussion on the differences in the concentration distribution of various forms of individual REE in some soils.
文摘This paper presents the results of our recent studies on the upper mantle composition in the Qinling Belt and East China . It discusses the methods of estimating the upper mantle composition, its selected elements and its constitution characteristics .The results indicate that ore-forming elements on ore types and their distribution in this area are strongly controlled by the upper mantle heterogeneity .
文摘Wetland is the conjunction of lake and terrene where human activities are concentrated. From the viewpoints of material transport and cycling in the terrene-lake system, wetland is the buffer where sand and mud, heavy metals, pollutants and nutrients are tarried. In this paper, we provide a case study based on the temporal and spatial distribution of elements in the Wangling River catchment, a small sub-catchment of Longgan Lake in the middle reaches of the Yangtze River. We have found that wetland can buffer major heavy metals such as Cr, Cu, etc. significantly, but has a little buffer function to some active elements such as Fe and Mn, which are always transported as solutions. Human activities not only influence the distribution of elements, but also weaken the buffer function of wetland. Intensive human activities in the Longgan Lake area in the past 70 years have been recorded in stream, wetland and lake sediments, especially the human activity events such as deforesting and reclaiming on a large scale in 1958 and the 1980’s. Human activities caused the increase of sedimentation rates since the 1950’s, as well as the increase of elements’ concentrations. The extensive use of fertilizers and pesticides since the 1960’s have led to the increase of total P concentrations. Increasing SO-2 emission accelerate the process of cation exchange in soil, and enhance the leaching of Mn out of soils. Permanent storing of water causes the soil gleyification that also intensifies the leaching of Mn. These are two major reasons for the obvious increase of manganese concentrations in recent 20 years in Longgan Lake. Intensive human activities since the 1950s’ have intensified the population in this region and thus destroyed the buffer function of wetland.
文摘Natural contents and distribution of trace elements in soils of the Dam River and Tuotuo River basins are demonstrated in this paper. By using contrasting methods. it is found that the content of trace elements of soil in the region is at the lower limit of the world's soil content level, that the tendency of the average trace element content in the four main types of soil is shown as: alpine mountain meadow soil>marsh soil>alpine mountain steppe soil> alpine mountain cryogenic soil. the average content of trace elements such as Cr. Co, Zn, Cu, Hg, Pb, Mo, Mn and Ni in the Dam River basin is higher than that of the Tuotuo River basin except that of the elements Ba and Sr. In addition. through correlation analysis. the relationship of intergrowth and association among soil elements are revealed.
文摘The effect of the addition of rare earths in Fe-based high chromium alloy powders on elements distribution in matrix materials and mechanical properties were studied. The results show that the addition of cerium can increase the chromium amount in carbonides and increase the micro-hardness after carbonization and the wear-resistant property of materials.
基金Supported by National Natural Science Foundation of China (No. 50808091)
文摘In this paper,environmental scanning electron microscopy (ESEM) is applied to characterizing the mineral and element distribution of chromite ore processing residue (COPR).The test results show that Cr-bearing brownmillerite occurs in the rim of COPR particle,while hydroandradite with Cr(Ⅵ) in its structure presents inside the COPR particle.Periclase and calcite occur in the interstitial area.Element analyses show that Ca,Fe and Al are distributed throughout the COPR particle,and Mg exists mostly in the interstitial area or on the particle surface.A lower content of Cr is evenly distributed in the COPR particle,while slightly higher concentration of Cr occurs inside the particle.It is suggested that it will take a relatively longer time for Cr to migrate out of COPR,especially for hexavalent chromium,so the leaching time and the particle size may be two important factors to affect the release of Cr(Ⅵ).
文摘[Objective] The aim was to study the relation between solar radiation distribution and meteorological elements in Guangxi. [Method] Based on the observed data of solar radiation in Guangxi from 1995 to 2009, the total radiation, solar distribution and interannual changes in Guangxi were analyzed. By dint of observed data in Nanning station, the annual, seasonal and monthly changes of net radiation in Nanning and the linear relation between total radiation, solar distribution characteristics and interannual changes were discussed. [Result] The global radiation of surface solar radiation in the low latitude was higher tan the high latitude, as Beihai>Nanning>Guilin. The solar radiation changes and the seasonal changes in different places varied, as summer>autumn>spring>winter. The total radiation and solar radiation hours were consistent. The total solar radiation and the low cloud was in negative relation, but was in positive relation with sunny weather. The total solar radiation was in positive relation with ground temperature, except in winter. [Conclusion] The study provided effective theoretical basis and data reference to the study of climate and development of solar energy.
基金This work was supported by City Collage of Science and Technology.Chongqing University and Chongqing HaiRun institute of energy saving research。
文摘Accumulation and releasing of trace metal elements on aluminum containing sediments of inner drinking water pipe is discussed,as studied from five variations effecting:raw water quality,chemical reagents,solution pH and drinking water flow condition.In order to decrease the release of trace metal elements,and to ensure the pipe operation and human safety,water quality adjustment is suggested to avoid aluminum containing sediments formation in drinking distribution system.The maximum amounts of accumulation of common trace metal elements are given.Future trends of development in this field are also proposed.
基金supported by China Ocean Mineral Resources Research and Development Association (COMRA) (DY105-05-01-05)China Ministry of Education (205089)China National Natural Science Foundation (40076015).
文摘A series of selective dissolution experiments were conducted on the hydrogenic ferromanganese crusts collected near Line Island to study the geochemistry of Mn, Fe, Cu, Co, Ni and Ti. Despite of the fact that the very close intergrowth between amorphous ferric oxyhydroxides and δ-MnO2 exists in the hydrogenic ferromanganese crusts, there is no isomorphous substitution between iron and manganese. This is because the two elements in oxides have different crystal chemistry and geochemistry, such assertion being in agreement with the results of selective dissolution experiments. Transitional metal elements such as Cu, Co, Ni and Ti are enriched in different phases, i.e. Ni and Co are incorporated into δ-MnO2 while Cu and Ti are incorporated into ferric oxyhydroxides. The distributions of the elements in amorphous ferric oxyhydroxides and δ-MnO2 are controlled by the existing states of the elements in the seawater and the crystal chemistry and geochemistry of these elements/ions in oxides.
文摘Data from Global Cancer Statistics show that breast cancer (BC) is the most common type of cancer among women, leading the number of deaths caused by cancer. The developments in diagnosis and treatment techniques for the BC, including chemotherapy and/or radiotherapy, increased the survival rates for this type of cancer. One late complication induced by BC treatment is the cardiotoxicity. This term comprises different cardiotoxic side effects, which include blood pressure alterations, myocardial ischemia, congestive heart failure and other damages. This study aimed to evaluate the cardiac alterations induced by radiotherapy and chemotherapy, simulating a treatment for BC in Wistar rats. It is, therefore, important to understand the mechanisms involved in the cardiotoxicity, in order to prevent women from this late effect, when they undergo BC treatments. The major interests in this work are in Low atomic weight elements as Sodium, because it is strongly related to cardiomyocyte contraction;Magnesium, because it is important in the cardiac metabolism;and Iron, because BC treatment induced cardiotoxicity can be associated to the oxidative stress. Changes that occur in unhealthy tissues in case to cardiovascular damages can be better understood when elemental compounds and structures of healthy tissues are known. Low Energy X-ray Fluorescence (LEXRF) technique was used to obtain elemental maps of low Z-elements providing a semi-quantitative analysis of the tissues evaluated under different conditions. Through the technique LEXRF we obtained elemental and absorption maps. The results showed more damages when associating chemotherapy and radiotherapy in comparison to myocardium healthy. Those images taken together with light microscopy, X-ray absorption and phase contrast images, satisfactorily characterize the cardiac tissue for the first time in the literature, from the structural and morphological points of view. LEXRF was carried out at TwinMic beamline in the ELETTRA Synchrotron Fa-cility, at the beamline TwinMic, in Trieste, Italy.
基金supported by the Youth Science Foundation (Grant Nos. 41101174 and 41301094)the Lead Strategic Project of the Chinese Academy of Sciences (Grant No. XDB03030507)+1 种基金the Hundred Young Talents Program of the Institute of Mountain Hazards and Environment (Grant No. SDSQB-2015-02)the Open Fund for Key Laboratory of Geoscience Spatial Information Technology of Ministry of Land and Resources (Grant No. KLGSIT2016-01)
文摘The present study attempted to evaluate the influence of human activity on major elements(Na_2O,MgO, Al_2O_3, SiO_2, K_2O, CaO, Fe_2O_3), and to find a method to explore correlations between major elements and human disturbances, according to geospatial theories and methods. The study results indicate that landscapes influence major elements in diverse ways: Al_2O_3 is closely related to road and mine landscapes; strong relationships exist between MgO, Fe_2O_3, CaO, and SiO_2 and roads;Na_2O, SiO_2, and Fe_2O_3 are unrelated to city landscapes;and Na_2O is unrelated to road and mine landscapes.