The Nanyangtian skarn-type scheelite deposit is an important part of the Laojunshan W-Sn polymetallic metallogenic region in southeastern Yunnan Province, China. The deposit comprises multiple scheelite ore bodies; mu...The Nanyangtian skarn-type scheelite deposit is an important part of the Laojunshan W-Sn polymetallic metallogenic region in southeastern Yunnan Province, China. The deposit comprises multiple scheelite ore bodies; multilayer skarn-type scheelite ore bodies are dominant, with a small amount of quartz vein-type ore bodies. Skarn minerals include diopside, hedenbergite, grossular, and epidote. Three mineralization stages exist： skarn, quartz- scheelite, and calcite. The homogenization temperatures of fluid inclusions in hydrothermal minerals that formed in different paragenetic phases were measured as follows： 221-423 ℃ （early skarn stage）, 177-260 ℃ （quartz- scheelite stage）, and 173-227 ℃ （late calcite stage）. The measured salinity of fluid inclusions ranged from 0.18% to 16.34% NaCleqv （skarn stage）, 0.35%-7.17% NaCleqv （quartz-scheelite stage）, and 0.35%-2.24% NaCleqv （late calcite vein stage）. Laser Raman spectroscopic studies on fluid inclusions in the three stages showed H2O as the main component, with N2 present in minor amounts. Minor amounts of CH4 were found in the quartz-scheelite stage. It was observed that the homogenization temperature gradu- ally reduced from the early to the late mineralization stages; moreover, δ^13CI, DB values for ore-bearing skarn in the mineralization period ranged from - 5.7%0 to - 6.9‰ and the corresponding δ^18OsMow values ranged from 5.8%0 to 9.1‰, implying that the ore-forming fluid was mainly sourced from magmatic water with a minor amount of meteoric water. Collectively, the evidence indicates thatthe formation of the Nanyangtian deposit is related to Laojunshan granitic magmatism.展开更多
Activity fragmentation provides a new approach for understanding the transformation of urban space and function in the information era. Numerous theoretical and empirical studies have been conducted on activity fragme...Activity fragmentation provides a new approach for understanding the transformation of urban space and function in the information era. Numerous theoretical and empirical studies have been conducted on activity fragmentation, but few studies have focused on the fragmentation of leisure activities. This study was intended to extend the extant literature by: 1) analysing the spatio-temporal fragmentation of physical and virtual leisure activities by using a dataset collected in Nanjing, China, and 2) evaluating the reasons of leisure activity fragmentation, as well as the potential spatial effect of activity fragmentation. The results indicated that virtual leisure activities are more fragmented than physical leisure activities, but the fragmentation of physical and virtual leisure activities varies on weekday and weekend, as well as in various locations and urban districts. In addition, the results suggested that sociodemographic factors and information and communication technology(ICT) variables distinctly affect the fragmentation of leisure activities. Meanwhile, the fragmentation of virtual leisure activities may enhance the transformation of traditional urban space by reallocating leisure activity times and locations.展开更多
文摘《美国经济评论》（American Economic Review）2006年5月第96卷第2期543～551页刊登了香港大学经济学家Bai Chong—En，Lu Jiangyong以及Tao Zhigang合作的一篇题为“国有企业改革的多重任务理论：来自中国的经验证据”（The Multitask Theory of State Enterprise Reform：Empirical Evidence from China）的论文。作者分析了中国国有企业改革的多重目标以及国有企业改革的民营化进程，并通过中国的数据进行了实证分析。
基金supported by the Natural Science Foundation of China (No.41373050)
文摘The Nanyangtian skarn-type scheelite deposit is an important part of the Laojunshan W-Sn polymetallic metallogenic region in southeastern Yunnan Province, China. The deposit comprises multiple scheelite ore bodies; multilayer skarn-type scheelite ore bodies are dominant, with a small amount of quartz vein-type ore bodies. Skarn minerals include diopside, hedenbergite, grossular, and epidote. Three mineralization stages exist： skarn, quartz- scheelite, and calcite. The homogenization temperatures of fluid inclusions in hydrothermal minerals that formed in different paragenetic phases were measured as follows： 221-423 ℃ （early skarn stage）, 177-260 ℃ （quartz- scheelite stage）, and 173-227 ℃ （late calcite stage）. The measured salinity of fluid inclusions ranged from 0.18% to 16.34% NaCleqv （skarn stage）, 0.35%-7.17% NaCleqv （quartz-scheelite stage）, and 0.35%-2.24% NaCleqv （late calcite vein stage）. Laser Raman spectroscopic studies on fluid inclusions in the three stages showed H2O as the main component, with N2 present in minor amounts. Minor amounts of CH4 were found in the quartz-scheelite stage. It was observed that the homogenization temperature gradu- ally reduced from the early to the late mineralization stages; moreover, δ^13CI, DB values for ore-bearing skarn in the mineralization period ranged from - 5.7%0 to - 6.9‰ and the corresponding δ^18OsMow values ranged from 5.8%0 to 9.1‰, implying that the ore-forming fluid was mainly sourced from magmatic water with a minor amount of meteoric water. Collectively, the evidence indicates thatthe formation of the Nanyangtian deposit is related to Laojunshan granitic magmatism.
基金Under the auspices of National Natural Science Foundation of China(No.41571146,41301166)
文摘Activity fragmentation provides a new approach for understanding the transformation of urban space and function in the information era. Numerous theoretical and empirical studies have been conducted on activity fragmentation, but few studies have focused on the fragmentation of leisure activities. This study was intended to extend the extant literature by: 1) analysing the spatio-temporal fragmentation of physical and virtual leisure activities by using a dataset collected in Nanjing, China, and 2) evaluating the reasons of leisure activity fragmentation, as well as the potential spatial effect of activity fragmentation. The results indicated that virtual leisure activities are more fragmented than physical leisure activities, but the fragmentation of physical and virtual leisure activities varies on weekday and weekend, as well as in various locations and urban districts. In addition, the results suggested that sociodemographic factors and information and communication technology(ICT) variables distinctly affect the fragmentation of leisure activities. Meanwhile, the fragmentation of virtual leisure activities may enhance the transformation of traditional urban space by reallocating leisure activity times and locations.
