The Terreneuvian Epoch（541-521 Ma）is also an important period for metallogenesis in South China, as was represented by the widespread occurrences of Ni-Mo polymetallic layers on the antecedent shallow platform margi...The Terreneuvian Epoch（541-521 Ma）is also an important period for metallogenesis in South China, as was represented by the widespread occurrences of Ni-Mo polymetallic layers on the antecedent shallow platform margin and the V-enriched black shales in deeper slope-basin settings. In this study, we have measured Re-Os isochron ages of Ni-Mo polymetallic layers（Songlin, Niuchang, Sancha, Chuanpengwan）, V-rich black shales（Bahuang）, and non-metalliferous black shales（Shuidong） in the basal Niutitang Formation in Guizhou and Hunan province, South China. The Ni-Mo polymetallic layers and V-enriched black shales have similar Re-Os isochron ages, suggesting concurrent deposition of these two types of metalliferous ores. This suggestion is consistent with the traditional stratigraphic correlation by using the nodular phosphorite bed directly underlying these metalliferous layers as a stratigraphic marker. Furthermore, the metalliferous ores and non-metalliferous black shales have similar initial ^（187）Os/^（188） Os ratios of 0.8-0.9, arguing for a dominant seawater origin with minor contribution of hydrothermal activity. Furthermore, Re-Os isotopic data also imply that Ni-Mo and V ore might have derived from the same source. We suggest that the spatial distribution of metalliferous ores can be explained by the development of non-sulfidic anoxic-suboxic wedge（NSASW） in the slope-basin and sulfidic wedge in the previous platform margin. Upwelling of deep water first transects the mildly reduced, organic rich NSASW, in which V（V） is reduced to V（IV）, and is preferentially removed from seawater by organometallic complex formation. As a result, V-rich black shale deposits in the slope-basin of Yangtze Platform. Further movement of deep water into the sulfidic platform margin results in Ni-Mo polymetallic layer formation.展开更多
采用扫描电镜、透射电镜、金相显微镜、闪光焊接及力学性能测试,对国内某厂采用富氮钒微合金化生产的Φ40 mm HRB500抗震钢筋微合金析出强化效果、力学性能、金相显微组织、夹杂物、焊接及时效性进行了试验研究。结果表明：采用增氮降...采用扫描电镜、透射电镜、金相显微镜、闪光焊接及力学性能测试,对国内某厂采用富氮钒微合金化生产的Φ40 mm HRB500抗震钢筋微合金析出强化效果、力学性能、金相显微组织、夹杂物、焊接及时效性进行了试验研究。结果表明：采用增氮降钒工艺增加了细小弥散的钒析出相数量,析出相尺寸为10~30 nm,其中V（CN）析出物占总w（V）的79.35%,析出强化效果显著;钢中夹杂物尺寸小且数量少,A、B、D类夹杂小于1.0级,C类夹杂小于1.5级,有利于控制钢中微裂纹的萌生与扩展,改善钢筋塑韧性;钢筋强屈比（Rm实/ReL实）不小于1.27,均匀伸长率（Agt）不小于12%,抗震性能好;自然时效1个月后强度变化平缓,具有低应变时效性;焊接试样断口远离焊接接头、焊接性能良好;生产成本和钒氮微合金化工艺相比吨钢降低20元。展开更多
Lithium ion batteries(LIBs) represent one of the most promising solutions for environmentally friendly transportation such as electric vehicles. The demand for high energy density, low cost and environmentally friendl...Lithium ion batteries(LIBs) represent one of the most promising solutions for environmentally friendly transportation such as electric vehicles. The demand for high energy density, low cost and environmentally friendly batteries makes high-capacity cathode materials very attractive for future LIBs. Layered Li NixCoyMnzO2(x+y+z=1), Li-rich oxides and Li-V-O compounds have attracted much attention due to their high capacities in recent years. In this review, we focus on the state-of-the-art research activities related to Li NixCoyMnzO2, Li-rich oxides and Li-V-O compounds, including their structures, reaction mechanisms during cycling, challenges and strategies that have been studied to improve their electrochemical performances.展开更多
基金supported by the National Natural science Foundation of China (Nos. 41203037, 41272017, 41472089, 41402025)the Chinese Geological Survey Program (Nos. 12120113015500, 12120114039701, 1212010633903, 1212011120622, J(2010)KP010705)+2 种基金Laboratory of Paleontology and Stratigraphy Open-lab grant (133103)the Science and Technology Foundation of Guizhou (No. QKHJZ(2012)2163)the Talents Introduction Foundation of Guizhou University (No. GDRJHZ(2011)17)
文摘The Terreneuvian Epoch（541-521 Ma）is also an important period for metallogenesis in South China, as was represented by the widespread occurrences of Ni-Mo polymetallic layers on the antecedent shallow platform margin and the V-enriched black shales in deeper slope-basin settings. In this study, we have measured Re-Os isochron ages of Ni-Mo polymetallic layers（Songlin, Niuchang, Sancha, Chuanpengwan）, V-rich black shales（Bahuang）, and non-metalliferous black shales（Shuidong） in the basal Niutitang Formation in Guizhou and Hunan province, South China. The Ni-Mo polymetallic layers and V-enriched black shales have similar Re-Os isochron ages, suggesting concurrent deposition of these two types of metalliferous ores. This suggestion is consistent with the traditional stratigraphic correlation by using the nodular phosphorite bed directly underlying these metalliferous layers as a stratigraphic marker. Furthermore, the metalliferous ores and non-metalliferous black shales have similar initial ^（187）Os/^（188） Os ratios of 0.8-0.9, arguing for a dominant seawater origin with minor contribution of hydrothermal activity. Furthermore, Re-Os isotopic data also imply that Ni-Mo and V ore might have derived from the same source. We suggest that the spatial distribution of metalliferous ores can be explained by the development of non-sulfidic anoxic-suboxic wedge（NSASW） in the slope-basin and sulfidic wedge in the previous platform margin. Upwelling of deep water first transects the mildly reduced, organic rich NSASW, in which V（V） is reduced to V（IV）, and is preferentially removed from seawater by organometallic complex formation. As a result, V-rich black shale deposits in the slope-basin of Yangtze Platform. Further movement of deep water into the sulfidic platform margin results in Ni-Mo polymetallic layer formation.
文摘采用扫描电镜、透射电镜、金相显微镜、闪光焊接及力学性能测试,对国内某厂采用富氮钒微合金化生产的Φ40 mm HRB500抗震钢筋微合金析出强化效果、力学性能、金相显微组织、夹杂物、焊接及时效性进行了试验研究。结果表明：采用增氮降钒工艺增加了细小弥散的钒析出相数量,析出相尺寸为10~30 nm,其中V（CN）析出物占总w（V）的79.35%,析出强化效果显著;钢中夹杂物尺寸小且数量少,A、B、D类夹杂小于1.0级,C类夹杂小于1.5级,有利于控制钢中微裂纹的萌生与扩展,改善钢筋塑韧性;钢筋强屈比（Rm实/ReL实）不小于1.27,均匀伸长率（Agt）不小于12%,抗震性能好;自然时效1个月后强度变化平缓,具有低应变时效性;焊接试样断口远离焊接接头、焊接性能良好;生产成本和钒氮微合金化工艺相比吨钢降低20元。
文摘Lithium ion batteries(LIBs) represent one of the most promising solutions for environmentally friendly transportation such as electric vehicles. The demand for high energy density, low cost and environmentally friendly batteries makes high-capacity cathode materials very attractive for future LIBs. Layered Li NixCoyMnzO2(x+y+z=1), Li-rich oxides and Li-V-O compounds have attracted much attention due to their high capacities in recent years. In this review, we focus on the state-of-the-art research activities related to Li NixCoyMnzO2, Li-rich oxides and Li-V-O compounds, including their structures, reaction mechanisms during cycling, challenges and strategies that have been studied to improve their electrochemical performances.
