Being the two primary approaches for full-field kinematics measurements, both subset-based local digital image correlation （DIC） and finite element-based global DIC have been extensively studied. Nowadays, most comm...Being the two primary approaches for full-field kinematics measurements, both subset-based local digital image correlation （DIC） and finite element-based global DIC have been extensively studied. Nowadays, most commercial DIC systems employ local DIC algorithm because of its advantages of straight forward principle and higher efficiency. However, several researchers argue that global DIC can provide better displacement results due to the displacement continuity constraint among adjacent elements. As such, thoroughly examining the performance of these two different DIC methods seems to be highly necessary. Here, the random errors associated with local DIC and two global DIC methods are theoretically analyzed at first. Subsequently, based on the same algorithmic details and parameters during analyses of numerical and real experiments, the performance of the different DIC approaches is fairly compared. Theoretical and experimental results reveal that local DIC outperforms its global counterpart in terms of both displacement results and computational efficiency when element （subset） size is no less than 11 pixels.展开更多
Based on the analysis of element correlation,the Gibbs diagram,hydro-geochemical ion ratios,isoline maps of groundwater and soil,and change patterns of strontium content after normalization,the study examines water-ro...Based on the analysis of element correlation,the Gibbs diagram,hydro-geochemical ion ratios,isoline maps of groundwater and soil,and change patterns of strontium content after normalization,the study examines water-rock interaction of shallow groundwater in Dingtao area.The results suggest that strontium in the study area mainly comes from waterrock interactions,and the strata interacting with groundwater are the top of Quaternary and Neogene.The element correlation analysis shows that the formation of strontium-rich groundwater is sufficiently affected by sulfate and carbonate.The Gibbs diagram suggests that the chemical composition of groundwater is mainly influenced by water-rock interactions,accompanied by evaporation crystallization.c(Ca2++Mg2+)/c(HCO3-+SO42-)reflects that the main reactions in the groundwater system is weathering dissolution of carbonate and sulfate,and ion exchange takes place.c(Na+)/c(Cl-)indicates that Na+in groundwater may have waterrock interactions with rocks it flows through.c(Cl-)/c(Ca2+)indicates that the hydrodynamic condition in the pumping well is poor and the water circulation is slow.The study examines the macro isoline map change patterns,correlation curves of change of strontium content in groundwater and shallow soil,and correlation curves of change of strontium content in groundwater,shallow soil,and deep soil.The results suggest that the strontium content in the study area has the same change pattern in groundwater and in soil,which further indicates that strontium in the study area comes from water-rock interactions.展开更多
A multidisciplinary study of the sedimentology, geochemistry and mineralogy has been conducted to understand the linkage between marsh and alluvial sediments and also their potential sources in Eynak marsh, North of I...A multidisciplinary study of the sedimentology, geochemistry and mineralogy has been conducted to understand the linkage between marsh and alluvial sediments and also their potential sources in Eynak marsh, North of Iran. The influence of the upstream potential sources on recent sediment geochemistry has been discussed based on geochemical, sedimentological and mineralogical results. A spatial grain size distribution study was carried out to investigate the hydrodynamic and deposition system of the marsh. So, the surficial sediment sampling was carried out to describe the sedimentological parameters and elemental geochemistry of sediments in Eynak marsh. Mineralogical complexes are mainly made up of felsic minerals such as quartz, calcite, feldspar, pyrite, mica, and clay minerals (in very low values) indicated by high amounts of Al, Ca, and Ni. As expected, the mineralogy of sediments is controlled mainly by the rock formations. Also sediment textures are controlled by the hydrodynamic condition in the marsh. So its distribution has been influenced by distance from the entrance sediments to Eynak marsh. The results showed that there are no enrichments related to fine grain sediment distributions. An association of Al with the trace elements such as Sc, Y, La, Ce, and Zr indicates that their distributions are mainly controlled by the felsic rocks in the upstream. On the other side, due to the waste water entrance to the marsh, Ni and Pb concentration could be under the effects of anthropogenic activities around the marsh. Results represented high values for Mn concentration (min 462, max 1784 and average 1037 ppm) and it showed a significant correlation with Ca, Sr, and Mg. A redox habitat and constantly calm hydrodynamic circumstance in the study area, likely cause high concentration of Ca, Sr, and Mg, and Mn. And they are representing negative correlations with some elements such as Al, Be, Fe, K, and Na.展开更多
基金supported by the Science Fund of State Key Laboratory of Automotive Safety and Energy(KF16162)
文摘Being the two primary approaches for full-field kinematics measurements, both subset-based local digital image correlation （DIC） and finite element-based global DIC have been extensively studied. Nowadays, most commercial DIC systems employ local DIC algorithm because of its advantages of straight forward principle and higher efficiency. However, several researchers argue that global DIC can provide better displacement results due to the displacement continuity constraint among adjacent elements. As such, thoroughly examining the performance of these two different DIC methods seems to be highly necessary. Here, the random errors associated with local DIC and two global DIC methods are theoretically analyzed at first. Subsequently, based on the same algorithmic details and parameters during analyses of numerical and real experiments, the performance of the different DIC approaches is fairly compared. Theoretical and experimental results reveal that local DIC outperforms its global counterpart in terms of both displacement results and computational efficiency when element （subset） size is no less than 11 pixels.
基金This paper was supported by project of Customized Agricultural Geological Survey and Evaluation of Yam-Growing Regions in Heze Area of Dingtao County in Shangdong Province from 2016 Heze Ministry of Natural Resource’s financial project at the municipal level.
文摘Based on the analysis of element correlation,the Gibbs diagram,hydro-geochemical ion ratios,isoline maps of groundwater and soil,and change patterns of strontium content after normalization,the study examines water-rock interaction of shallow groundwater in Dingtao area.The results suggest that strontium in the study area mainly comes from waterrock interactions,and the strata interacting with groundwater are the top of Quaternary and Neogene.The element correlation analysis shows that the formation of strontium-rich groundwater is sufficiently affected by sulfate and carbonate.The Gibbs diagram suggests that the chemical composition of groundwater is mainly influenced by water-rock interactions,accompanied by evaporation crystallization.c(Ca2++Mg2+)/c(HCO3-+SO42-)reflects that the main reactions in the groundwater system is weathering dissolution of carbonate and sulfate,and ion exchange takes place.c(Na+)/c(Cl-)indicates that Na+in groundwater may have waterrock interactions with rocks it flows through.c(Cl-)/c(Ca2+)indicates that the hydrodynamic condition in the pumping well is poor and the water circulation is slow.The study examines the macro isoline map change patterns,correlation curves of change of strontium content in groundwater and shallow soil,and correlation curves of change of strontium content in groundwater,shallow soil,and deep soil.The results suggest that the strontium content in the study area has the same change pattern in groundwater and in soil,which further indicates that strontium in the study area comes from water-rock interactions.
文摘A multidisciplinary study of the sedimentology, geochemistry and mineralogy has been conducted to understand the linkage between marsh and alluvial sediments and also their potential sources in Eynak marsh, North of Iran. The influence of the upstream potential sources on recent sediment geochemistry has been discussed based on geochemical, sedimentological and mineralogical results. A spatial grain size distribution study was carried out to investigate the hydrodynamic and deposition system of the marsh. So, the surficial sediment sampling was carried out to describe the sedimentological parameters and elemental geochemistry of sediments in Eynak marsh. Mineralogical complexes are mainly made up of felsic minerals such as quartz, calcite, feldspar, pyrite, mica, and clay minerals (in very low values) indicated by high amounts of Al, Ca, and Ni. As expected, the mineralogy of sediments is controlled mainly by the rock formations. Also sediment textures are controlled by the hydrodynamic condition in the marsh. So its distribution has been influenced by distance from the entrance sediments to Eynak marsh. The results showed that there are no enrichments related to fine grain sediment distributions. An association of Al with the trace elements such as Sc, Y, La, Ce, and Zr indicates that their distributions are mainly controlled by the felsic rocks in the upstream. On the other side, due to the waste water entrance to the marsh, Ni and Pb concentration could be under the effects of anthropogenic activities around the marsh. Results represented high values for Mn concentration (min 462, max 1784 and average 1037 ppm) and it showed a significant correlation with Ca, Sr, and Mg. A redox habitat and constantly calm hydrodynamic circumstance in the study area, likely cause high concentration of Ca, Sr, and Mg, and Mn. And they are representing negative correlations with some elements such as Al, Be, Fe, K, and Na.
