The micro-laminated (ZrO2-Y2O3)/(Al2O3-Y2O3) composite films were prepared on the surface of Fe-13Cr alloy by an electrochemical process and a sintering process alternately. High-resolution field emission scanning...The micro-laminated (ZrO2-Y2O3)/(Al2O3-Y2O3) composite films were prepared on the surface of Fe-13Cr alloy by an electrochemical process and a sintering process alternately. High-resolution field emission scanning electron microscopy (FE-SEM) was used to characterize the laminated films, indicating that the micro-laminated (ZrO2-Y2O3)] (Al2O3-Y2O3) films have nano-structures. SEM, EDS and mass gain measurement were adopted to study the oxidation resistance of films on Fe-13Cr alloy. It is proved that such micro-laminated films are more effective than ZrO2-Y2O3 or Al2O3-Y2O3 films to resist the oxidation of the alloy, and the oxidation resistance is increased with increasing layers in micro-laminated films. These beneficial effects can be contributed to the mechanism, by which such micro-laminated (ZrOE- YEO3)/(Al2O3-Y2O3) composite film combines all the beneficial effects and overcomes all the disadvantages of both ZrOE- Y2O3 film and Al2O3-Y2O3 film during oxidation of alloy.展开更多
灰钙土在我国青甘宁地区,分布于半干旱和干旱荒漠草原带.主要成土特点:弱腐殖质积累、弱淋溶和弱钙积化.地表呈现荒漠化孔状结皮,其上生长的地衣和苔藓积累的有机质常超出土体各发生层2~5倍,腐殖质组成中,富里酸大于胡敏酸.CaCo_3在钙...灰钙土在我国青甘宁地区,分布于半干旱和干旱荒漠草原带.主要成土特点:弱腐殖质积累、弱淋溶和弱钙积化.地表呈现荒漠化孔状结皮,其上生长的地衣和苔藓积累的有机质常超出土体各发生层2~5倍,腐殖质组成中,富里酸大于胡敏酸.CaCo_3在钙积层中的积累量仅比 A 层和 C 层高2~4%,只表现出钙积化特征.土体硅铁铝比值4.6~7.8,Na_2O、MgO、CaO、K_2O 含量较高,CaSO_4淀积于 B 层和 C 层.全剖面含易溶盐,但以 BC 层和 C 层集中.粘土矿物以伊利石和绿泥石为主,占75~85%.展开更多
我们在河北阳原虎头梁的冻融褶皱砾石层顶部发现一层钙膜砾石.通过对钙膜明暗度曲线分析及其与氧同位素曲线的对比研究,结合14 C测年结果,得出虎头梁钙膜的发育时间介于40~21 ka BP之间.砾石钙膜的发育代表着曾经地下水位停留在此,...我们在河北阳原虎头梁的冻融褶皱砾石层顶部发现一层钙膜砾石.通过对钙膜明暗度曲线分析及其与氧同位素曲线的对比研究,结合14 C测年结果,得出虎头梁钙膜的发育时间介于40~21 ka BP之间.砾石钙膜的发育代表着曾经地下水位停留在此,说明在泥河湾古湖消亡后,桑干河下切初始阶段有过一段较长时间的停顿.根据河流阶地的高差及年龄数据,计算桑干河虎头梁段在21~7.6 ka BP、7.6~3.1 ka BP和3.1~0 ka BP 3个阶段的河流下切速率分别为1.8、4.2、2.9 mm·a^-1.这种下切速率的差异应主要是由气候变化造成的.展开更多
The Middle Triassic 'reefs' went through from NE to SW the whole region of Guizhou Province and rimmed a carbonate platform during the Middle Triassic Ladinian time, and represent a barrier 'reef' belt...The Middle Triassic 'reefs' went through from NE to SW the whole region of Guizhou Province and rimmed a carbonate platform during the Middle Triassic Ladinian time, and represent a barrier 'reef' belt of Triassic carbonate platform-margin. The barrier 'reef'展开更多
文摘The micro-laminated (ZrO2-Y2O3)/(Al2O3-Y2O3) composite films were prepared on the surface of Fe-13Cr alloy by an electrochemical process and a sintering process alternately. High-resolution field emission scanning electron microscopy (FE-SEM) was used to characterize the laminated films, indicating that the micro-laminated (ZrO2-Y2O3)] (Al2O3-Y2O3) films have nano-structures. SEM, EDS and mass gain measurement were adopted to study the oxidation resistance of films on Fe-13Cr alloy. It is proved that such micro-laminated films are more effective than ZrO2-Y2O3 or Al2O3-Y2O3 films to resist the oxidation of the alloy, and the oxidation resistance is increased with increasing layers in micro-laminated films. These beneficial effects can be contributed to the mechanism, by which such micro-laminated (ZrOE- YEO3)/(Al2O3-Y2O3) composite film combines all the beneficial effects and overcomes all the disadvantages of both ZrOE- Y2O3 film and Al2O3-Y2O3 film during oxidation of alloy.
文摘灰钙土在我国青甘宁地区,分布于半干旱和干旱荒漠草原带.主要成土特点:弱腐殖质积累、弱淋溶和弱钙积化.地表呈现荒漠化孔状结皮,其上生长的地衣和苔藓积累的有机质常超出土体各发生层2~5倍,腐殖质组成中,富里酸大于胡敏酸.CaCo_3在钙积层中的积累量仅比 A 层和 C 层高2~4%,只表现出钙积化特征.土体硅铁铝比值4.6~7.8,Na_2O、MgO、CaO、K_2O 含量较高,CaSO_4淀积于 B 层和 C 层.全剖面含易溶盐,但以 BC 层和 C 层集中.粘土矿物以伊利石和绿泥石为主,占75~85%.
文摘我们在河北阳原虎头梁的冻融褶皱砾石层顶部发现一层钙膜砾石.通过对钙膜明暗度曲线分析及其与氧同位素曲线的对比研究,结合14 C测年结果,得出虎头梁钙膜的发育时间介于40~21 ka BP之间.砾石钙膜的发育代表着曾经地下水位停留在此,说明在泥河湾古湖消亡后,桑干河下切初始阶段有过一段较长时间的停顿.根据河流阶地的高差及年龄数据,计算桑干河虎头梁段在21~7.6 ka BP、7.6~3.1 ka BP和3.1~0 ka BP 3个阶段的河流下切速率分别为1.8、4.2、2.9 mm·a^-1.这种下切速率的差异应主要是由气候变化造成的.
基金Project supported by the National Natural Science Foundation of China.
文摘The Middle Triassic 'reefs' went through from NE to SW the whole region of Guizhou Province and rimmed a carbonate platform during the Middle Triassic Ladinian time, and represent a barrier 'reef' belt of Triassic carbonate platform-margin. The barrier 'reef'