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Experimental Study on Adsorption of Rare Earth Elements on Kaolinite and Halloysite 被引量:1
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作者 GAO Yuhong FAN Chenzi XU Hong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期80-82,共3页
1 Introduction The weathered crust rare earth deposits is one of the most significant rare earth deposits,which are mostly distributed in southern China,especially in the south of Jiangxi province(Chi et al.,2007).The... 1 Introduction The weathered crust rare earth deposits is one of the most significant rare earth deposits,which are mostly distributed in southern China,especially in the south of Jiangxi province(Chi et al.,2007).The compositions of these deposits,which are weathered from igneous rocks such as granite through biological,physical or chemical 展开更多
关键词 In Experimental study on Adsorption of Rare Earth Elements on Kaolinite and Halloysite REE than
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Development of a comprehensive finite element cervical spine model for studying neck injury of pilot
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作者 Lizhen Wang1,2,Qi Zhang2,Yubo Fan2,Ming Zhang1(1 Dept.of Health Technology and Informatics,The Hong Kong Polytechnic University,Hong Kong,China 2 School of Biological Science and Medical Engineering,Beihang University,Beijing,China) 《医用生物力学》 EI CAS CSCD 2009年第S1期103-104,共2页
Introduction-The cervical spine is subjected to injury frequently,especially among pilots who are usually on the condition of high acceleration.Injuries of the cervical spine will be potential risk of damage to the sp... Introduction-The cervical spine is subjected to injury frequently,especially among pilots who are usually on the condition of high acceleration.Injuries of the cervical spine will be potential risk of damage to the spinal cord,which could be result in life threatening 展开更多
关键词 Development of a comprehensive finite element cervical spine model for studying neck injury of pilot
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STUDY ON ENRICHMENT AND SEPARATION OF TRACE ELEMENTS WITH SILICA GELS MODIFIED BY HETEROCYCLIC AZO DYES
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作者 Ke An LI~2, Feng LIU, Shen Yang TONG (Department of Chemistry, Peking University, Beijing 100871) 《Chinese Chemical Letters》 SCIE CAS CSCD 1991年第8期633-636,共4页
Two types of modified silica gels were prepared by adsorption method and bonding method respectively. Enrichment and separation of trace metal ions have been done by using the column packed with modified silica gels.
关键词 HCI Br SG study ON ENRICHMENT AND SEPARATION OF TRACE ELEMENTS WITH SILICA GELS MODIFIED BY HETEROCYCLIC AZO DYES AZO TAH
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A study on some elements and their phases in sediments of Changjiang Estuary by X-ray spectrometer and X-ray diffractometer
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作者 Han Jiancheng, Li Li, Chen Qiming, Wu Xinran, Chen Banglin and Han QingpingDepartment of Chemistry, East China Normal University, Shanghai 200062, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1997年第1期121-125,共5页
INTRODUCTIONThe studies on the quantitative distribution of the conventional elements and their phases in the sediments of the Changjiang Estuary are of great importance to the understanding of the chemical processes ... INTRODUCTIONThe studies on the quantitative distribution of the conventional elements and their phases in the sediments of the Changjiang Estuary are of great importance to the understanding of the chemical processes of ion exchange, absorption, desorption and flocculation in the estuary. 展开更多
关键词 A study on some elements and their phases in sediments of Changjiang Estuary by X-ray spectrometer and X-ray diffractometer
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STUDY ON THE EXCITATION BEHAVIOUR OF RARE EARTH ELEMENTS IN DC ARC BY AXIAL-INTRODUCTION OF AEROSOL
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作者 游新国 江祖成 曾云鹗 《Journal of Rare Earths》 SCIE EI CAS CSCD 1990年第2期133-138,共6页
In order to eliminate influence of the carriers on the evaporation of rare earth elements in DC arc,a de- vice which introduces axially the sample aerosol has been designed to study the effects of controlled-atmos- ph... In order to eliminate influence of the carriers on the evaporation of rare earth elements in DC arc,a de- vice which introduces axially the sample aerosol has been designed to study the effects of controlled-atmos- phere,discharge current,electrode polarity and introduction direction of aerosol on the emission of rare earth elements in DC arc discharge.The influence of various matrices and carriers on the line density and excitation condition of rare earth elements have also been studied,then the related excitation mechnism is proposed. 展开更多
关键词 line KCI study ON THE EXCITATION BEHAVIOUR OF RARE EARTH ELEMENTS IN DC ARC BY AXIAL-INTRODUCTION OF AEROSOL DC
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Neutron activation analysis (NAA) and geochemical studies of 38 elements in surface sediments from lower reach and estuary of Huanghe (Yellow) River 被引量:1
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《Acta Oceanologica Sinica》 SCIE CAS CSCD 1990年第2期227-246,共20页
Using a neutron activation analysis technique, which involves gamma-spectrometry with a Ge(Li) detector coupled to a S40 multichannel analyzer and interfaced to a PDP-11 computer, we determined thirty-eight elements i... Using a neutron activation analysis technique, which involves gamma-spectrometry with a Ge(Li) detector coupled to a S40 multichannel analyzer and interfaced to a PDP-11 computer, we determined thirty-eight elements in sediments from the lower reach (downstream from Jinan) and estuary of Huanghe. The results are discussed in this paper.From inter-elemental correlations, it ts found that a large number of metals (Mn.As, Co, Cr.Cs, Rb, Sc, Ti, Ta, V and Zn) correlate positively with Fe. Ba and Ca correlate positively with Al. Whereas some elements (e. g. , Ti and lanthanides) show no correlation with either Fe or Al. On the other hand, Hf and Zr show a negative correlation with Fe. Elements which tend to be scavenged by Fe and Al colloids or suspended particles are enriched in sediments at the Huanghe Estuary relative to its lower reach. On the other hand, the contents of some elements (e. g. , Zr,Hf,U, Ba, etc. )are higher in sediments from the lower reach of Huanghe than in the estuarine sediments,which may be related to the sorting during deposition of source materials. On the basis of their chemical property and geochemical behavior, the 38 elements we studied are classified into seven groups. (1) weathering-prone elements,group A:K,Rb, Cs and Na; (2) weathering-prone elements, group B:Mg, Ca, Ba and Al; (3) transition elements:Fe, Co.Ni, Zn, As, Sb, Mn, Cr, W,Mo,V, Ta and Sc; (4) rare elements:group A (Zr and Hf) and group B (Ti); (5) rare earth elements:the lanthanides; (6) halogens: Cl and Br; amd (7) natural radioactive elements:U and Th. The basis for this classification is discussed and we emphasize that geochemical associations of elements in the natural environment are not necessarily in accord with their chemical properties as dictated by position at the periodic table. 展开更多
关键词 YELLOW and geochemical studies of 38 elements in surface sediments from lower reach and estuary of Huanghe RIVER NAA
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Studies on diffusion and profiles of elements in deep-sea manganese nodules 被引量:1
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作者 Luo Shangde , Wang Lei and Huang Yipu Department of Oceanography, Xiamen University, Xiamen, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1989年第3期391-400,共10页
Elemental compositions are measured in manganese nodules collected from the Northern Mid-Pacific floor by inductively-coupled plasma atomic emission spectrometry (1CP-AES) and their growth rates are determined by radi... Elemental compositions are measured in manganese nodules collected from the Northern Mid-Pacific floor by inductively-coupled plasma atomic emission spectrometry (1CP-AES) and their growth rates are determined by radiometric methods. The result shows that depth distributions of elements in nodules vary with depth as follows; (i) increase, (ii) decrease and (iii) fluctuation. These internodule variations in elemental compositions are considered to be caused by diffusion and migration of elements in nodules and heterogeneities in textures of nodules. In the present paper, a diffusive model is used to elucidate the inward-increase profile of some elements in nodules. The effective diffusive coefficients are estimated to be of the order of 10-9 cm2/a for Ni, V and Zn in the nodules, which is less than the value reported for radionuclides. 展开更多
关键词 Studies on diffusion and profiles of elements in deep-sea manganese nodules DEEP
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STUDY ON FINITE ELEMENT METHODS OF THE EXTRUDATE SWELL PROBLEM(Ⅰ)NEWTONIAN FLUID 被引量:1
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作者 Fan Yu-ren Fan Xi-jun Lu Yong-xiang Zhejiang University,Hangzhou,P.R.China 《Journal of Hydrodynamics》 SCIE EI CSCD 1989年第4期46-58,共13页
The problem of a creeping flow of Newtonian fluid extruded from a plane slit or a circular pipe.in the absence of gravity,is simulated successfully by using the continuous-pressure-element method,the discontinuous-pre... The problem of a creeping flow of Newtonian fluid extruded from a plane slit or a circular pipe.in the absence of gravity,is simulated successfully by using the continuous-pressure-element method,the discontinuous-pressure-element method,the consistant penalty method,the reduced integration penalty method and the modified reduced integration penalty method proposed by Oden.Through comparisons between these methods,it is convinced that the discontinuous-pressure interpolation schemes result in more accurate mass conservation and,consequently,more rapid convergence of the free-surface iteration than the continuous one does.The reduced integration penalty method can further reduce the cost of computation while retaining sufficient accuracy of the solution. 展开更多
关键词 NEWTONIAN FLUID study ON FINITE ELEMENT METHODS OF THE EXTRUDATE SWELL PROBLEM
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Comparative Study on Two Methods for Calculating the Gravitational Potential of a Prism
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作者 HAN Jiancheng SHEN Wenbin 《Geo-Spatial Information Science》 2010年第1期60-64,共5页
The determination of the gravitational potential of a prism plays an important role in physical geodesy and geophysics. However, there are few literatures that provide accurate approaches for determining the gravitati... The determination of the gravitational potential of a prism plays an important role in physical geodesy and geophysics. However, there are few literatures that provide accurate approaches for determining the gravitational potential of a prism. Discrete element method can be used to determine the gravitational potential of a prism, and can approximate the true gravitational potential values with sufficient accuracy (the smaller each element is, the more accurate the result is). Although Nagy's approach provided a closed expression, one does not know whether it is valid, due to the fact that this approach has not been confirmed in literatures. In this paper, a study on the comparison of Nagy's approach with discrete element method is presented. The results show that Nagy's formulas for determining the gravitational potential of a prism are valid in the domain both inside and outside the prism. 展开更多
关键词 gravitational potential of a prism Nagy approach discrete element method numerical comparison study
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The potential leaching and mobilization of trace elements from FGD-gypsum of a coal-fired power plant under water re-circulation conditions 被引量:3
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作者 Patricia Córdoba Iria Castro +1 位作者 Mercedes Maroto-Valer Xavier Querol 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2015年第6期72-80,共9页
Experimental and geochemical modelling studies were carried out to identify mineral and solid phases containing major, minor, and trace elements and the mechanism of the retention of these elements in Flue Gas Desulph... Experimental and geochemical modelling studies were carried out to identify mineral and solid phases containing major, minor, and trace elements and the mechanism of the retention of these elements in Flue Gas Desulphurisation(FGD)-gypsum samples from a coal-fired power plant under filtered water recirculation to the scrubber and forced oxidation conditions. The role of the p H and related environmental factors on the mobility of Li, Ni, Zn, As, Se, Mo, and U from FGD-gypsums for a comprehensive assessment of element leaching behaviour were also carried out. Results show that the extraction rate of the studied elements generally increases with decreasing the p H value of the FGD-gypsum leachates. The increase of the mobility of elements such as U, Se, and As in the FGD-gypsum entails the modification of their aqueous speciation in the leachates; UO2SO4, H2 Se, and HAs O2 are the aqueous complexes with the highest activities under acidic conditions.The speciation of Zn, Li, and Ni is not affected in spite of p H changes; these elements occur as free cations and associated to SO4 ^2 in the FGD-gypsum leachates. The mobility of Cu and Mo decreases by decreasing the p H of the FGD-gypsum leachates, which might be associated to the precipitation of Cu Se2 and Mo Se2, respectively. Time-of-Flight mass spectrometry of the solid phase combined with geochemical modelling of the aqueous phase has proved useful in understanding the mobility and geochemical behaviour of elements and their partitioning into FGD-gypsum samples. 展开更多
关键词 Geochemical modelling studies Trace elements Leaching Landfills FGD-gypsum ToF mass spectrometry
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