Primitive mantle normalized Platinum group elements (PGE) concentration patterns for the Zhengziyanwo intrusion and Dashibao Formation basalts are of positive slope, similar to most of the world class magmatic Ni Cu P...Primitive mantle normalized Platinum group elements (PGE) concentration patterns for the Zhengziyanwo intrusion and Dashibao Formation basalts are of positive slope, similar to most of the world class magmatic Ni Cu PGE sulfide deposits. Characters of this intrusion and its related ores and Dashibao Formation basalts are their negative Pt anomaly and high concentration of Rh relative to Pt and Pd, facts being interpreted to be the results of crystallization and fractionation of Pt alloys and spinel phase free crystallization history for the magma, respectively. PGE parameters of the Dashibao Formation basalts are consistent with the general trend of those found for the Zhengziyanwo intrusion, and this might infer a genetic link between them.展开更多
Change in Arctic sea ice extent is one of the indicators of global climate changes. Spatio-temporal change and change patterns can be identified using various methods to facilitate human understanding global climate c...Change in Arctic sea ice extent is one of the indicators of global climate changes. Spatio-temporal change and change patterns can be identified using various methods to facilitate human understanding global climate changes. Three empirical orthogonal function(EOF) techniques are discussed and applied to decades of sea-ice concentration(SIC) dataset in Arctic area for identifying independent patterns. It was found that: 1) discrepancies exist in magnitude and scope for each EOF pattern, however, the first two leading EOFs of variability possess high similarities in structure and shape; 2) Even though there are somewhat differences in amplitude of each PC mode, the first two leading PC modes maintain consistent in overall trend and periodicity; 3) There are significant discrepancies and inconsistencies in the third and fourth leading EOF and PC modes. The accuracies of three techniques are further validated in representing the physical phenomena of SIC anomaly patterns.展开更多
Quantifying the aggregation patterns of urban population, economic activities, and land use are essential for understanding compact development, but little is known about the difference among the distribution characte...Quantifying the aggregation patterns of urban population, economic activities, and land use are essential for understanding compact development, but little is known about the difference among the distribution characteristics and how the built environment influences urban aggre-gation. In this study, five elements are collected in Wuhan, China, namely population density, floor area ratio, business POIs, road network and built-up area as the representative of urban population, economic activities and land use. An inverse S-shape function is employed to fit the elements’ macro distribution. An aggregation degree index is proposed to measure the aggregation level of urban elements. The kernel density estimation is used to identify the aggregation patterns. The spatial regression model is used to identify the built environment factors influencing the spatial distribution of urban elements. Results indicates that all urban elements decay outward from the city center in an inverse S-shape manner. The business Pointof- Interest (POI) density and population density are highly aggregated;floor area ratio and road density are moderately aggregated, whereas the built-up density is poorly aggregated. Three types of spatial aggregation patterns are identified: a point-shaped pattern, an axial pattern and a planar pattern. The spatial regression modeling shows that the built environment is associated with the distribution of the urban population, economic activities and land use. Destination accessibility factors, transit accessibility factors and land use diversity factors shape the distribution of the business POI density, floor area ratio and road density. Design factors are positively associated with population density, floor area ratio and built-up density. Future planning should consider the varying spatial concentration of urban population, economic activities and land use as well as their relationships with built environment attributes. Results of this study will provide a systematic understanding of aggregation of urban land use, popula-tion, and economic activities in megacities as well as some suggestions for planning and compact development.展开更多
The gelation properties of polyol acetal derivatives including 2,4-(3,4-dichlorobenzylidene)-D-sorbitol(DCBS), 1,3:2,4-di(3,4-dichlorobenzylidene)-D-sorbitol(DDCBS) and 1,3:2,5:4,6-tris(3,4-dichlorobenzyli...The gelation properties of polyol acetal derivatives including 2,4-(3,4-dichlorobenzylidene)-D-sorbitol(DCBS), 1,3:2,4-di(3,4-dichlorobenzylidene)-D-sorbitol(DDCBS) and 1,3:2,5:4,6-tris(3,4-dichlorobenzylidene)-D-mannitol(TDCBM) in 35 single solvents and 39 binary solvent mixtures have been studied. FTIR and XRD results suggest that the self-assembly patterns of the gelator will not change in either the single solvent component or the corresponding solvent mixtures, but the critical gelation concentration(CGC)will be influenced. The results of SEM and rheology showed that the formation of true gels at saturated concentrations. Improving the heating temperature may promote the dissolving of gelators which are even insoluble at the temperature of the solvent boiling point and change the gelation behaviors. FloryHuggins parameter(x) was used to predict the gelation behavior of DCBS in the mixed solvents, and it is shown that the x values for the mixed solvents that can be gelled by DCBS are either greater or smaller than those for the selected good solvents.展开更多
基金supported by NSFC(Grant Nos.40072037,40273025)NKBRSF Project(Grant No.G1999043200)
文摘Primitive mantle normalized Platinum group elements (PGE) concentration patterns for the Zhengziyanwo intrusion and Dashibao Formation basalts are of positive slope, similar to most of the world class magmatic Ni Cu PGE sulfide deposits. Characters of this intrusion and its related ores and Dashibao Formation basalts are their negative Pt anomaly and high concentration of Rh relative to Pt and Pd, facts being interpreted to be the results of crystallization and fractionation of Pt alloys and spinel phase free crystallization history for the magma, respectively. PGE parameters of the Dashibao Formation basalts are consistent with the general trend of those found for the Zhengziyanwo intrusion, and this might infer a genetic link between them.
基金Project(41301420)supported by the National Natural Science Foundation of ChinaProject(12JJB005)supported by the Hunan Provincial Natural Science Foundation of China+1 种基金Project(2014VGE03)supported by the Key Lab of Virtual Geographic Environment from Ministry of Education,ChinaProject(LEND2013B04)supported by the NASA Key Laboratory of Land Environment and Disaster Monitoring,USA
文摘Change in Arctic sea ice extent is one of the indicators of global climate changes. Spatio-temporal change and change patterns can be identified using various methods to facilitate human understanding global climate changes. Three empirical orthogonal function(EOF) techniques are discussed and applied to decades of sea-ice concentration(SIC) dataset in Arctic area for identifying independent patterns. It was found that: 1) discrepancies exist in magnitude and scope for each EOF pattern, however, the first two leading EOFs of variability possess high similarities in structure and shape; 2) Even though there are somewhat differences in amplitude of each PC mode, the first two leading PC modes maintain consistent in overall trend and periodicity; 3) There are significant discrepancies and inconsistencies in the third and fourth leading EOF and PC modes. The accuracies of three techniques are further validated in representing the physical phenomena of SIC anomaly patterns.
基金The research was funded by the National Natural Science Foundation of China(grant number 41971368).
文摘Quantifying the aggregation patterns of urban population, economic activities, and land use are essential for understanding compact development, but little is known about the difference among the distribution characteristics and how the built environment influences urban aggre-gation. In this study, five elements are collected in Wuhan, China, namely population density, floor area ratio, business POIs, road network and built-up area as the representative of urban population, economic activities and land use. An inverse S-shape function is employed to fit the elements’ macro distribution. An aggregation degree index is proposed to measure the aggregation level of urban elements. The kernel density estimation is used to identify the aggregation patterns. The spatial regression model is used to identify the built environment factors influencing the spatial distribution of urban elements. Results indicates that all urban elements decay outward from the city center in an inverse S-shape manner. The business Pointof- Interest (POI) density and population density are highly aggregated;floor area ratio and road density are moderately aggregated, whereas the built-up density is poorly aggregated. Three types of spatial aggregation patterns are identified: a point-shaped pattern, an axial pattern and a planar pattern. The spatial regression modeling shows that the built environment is associated with the distribution of the urban population, economic activities and land use. Destination accessibility factors, transit accessibility factors and land use diversity factors shape the distribution of the business POI density, floor area ratio and road density. Design factors are positively associated with population density, floor area ratio and built-up density. Future planning should consider the varying spatial concentration of urban population, economic activities and land use as well as their relationships with built environment attributes. Results of this study will provide a systematic understanding of aggregation of urban land use, popula-tion, and economic activities in megacities as well as some suggestions for planning and compact development.
基金the financial support of the National Natural Science Foundation of China(No. 21476164)Tianjin Science and Technology Innovation Platform Program(No. 14TXGCCX00017)
文摘The gelation properties of polyol acetal derivatives including 2,4-(3,4-dichlorobenzylidene)-D-sorbitol(DCBS), 1,3:2,4-di(3,4-dichlorobenzylidene)-D-sorbitol(DDCBS) and 1,3:2,5:4,6-tris(3,4-dichlorobenzylidene)-D-mannitol(TDCBM) in 35 single solvents and 39 binary solvent mixtures have been studied. FTIR and XRD results suggest that the self-assembly patterns of the gelator will not change in either the single solvent component or the corresponding solvent mixtures, but the critical gelation concentration(CGC)will be influenced. The results of SEM and rheology showed that the formation of true gels at saturated concentrations. Improving the heating temperature may promote the dissolving of gelators which are even insoluble at the temperature of the solvent boiling point and change the gelation behaviors. FloryHuggins parameter(x) was used to predict the gelation behavior of DCBS in the mixed solvents, and it is shown that the x values for the mixed solvents that can be gelled by DCBS are either greater or smaller than those for the selected good solvents.