The features of large-scale circulation, storm tracks and the dynamical relationship between them were examined by investigating Rossby wave breaking （RWB） processes associated with Eastern Pacific （EP） and Centra...The features of large-scale circulation, storm tracks and the dynamical relationship between them were examined by investigating Rossby wave breaking （RWB） processes associated with Eastern Pacific （EP） and Central Pacific （CP） E1-Nifio. During EP E1-Nino, the geopotential height anomaly at 500 hPa （Z500） exhibits a Pacific-North America （PNA） pattern. During CP EI-Nifio, the Z500 anomaly shows a north positive-south negative pattern over the North Pacific. The anomalous distributions of baroclinicity and storm track are consistent with those of upper-level zonal wind for both EP and CP EI-Nino, suggesting impacts of mean flow on storm track variability. Anticyclonic wave breaking （AWB） oczurs less frequently in EP EI-Nino years, while cyclonic wave breaking （CWB） occurs more frequently in CP EI-Nino years over the North Pacific sector. Outside the North Pacific, more CWB events occur over North America during EP Ei-NiNo. When AWB events occur less frequently over the North Pacific during EP EI-Nino, Z500 decreases locally and the zonal wind is strengthened （weakened） to the south （north）. This is because AWB events reflect a monopoie high anomaly at the centroid of breaking events. When CWB events occur more frequently over the North Pacific under CP EI-Nino conditions, and over North America under EP EI-Nino condition, Z500 increases （decreases） to the northeast （southwest）, since CWB events are related to a northeast-southwest dipole Z500 anomaly. The anomalous RWB events act to invigorate and reinforce the circulation anomalies over the North Pacific-North America region linked with the two types of EI-Nino.展开更多
The effect of calcium ions on the corrosion behavior of 3Cr low-alloy steel in CO2- containing sodium chloride solution was investigated by immersion test and electrochemical measurements. It is found that with the ad...The effect of calcium ions on the corrosion behavior of 3Cr low-alloy steel in CO2- containing sodium chloride solution was investigated by immersion test and electrochemical measurements. It is found that with the addition of Ca2＋ to CO2-containing solution, the crazing level of the corrosion scale on the specimen is much slighter than that of the specimen immersed in solution without Ca2＋. The pitting on the surface of the specimens immersed in the solution with Ca2＋ is relatively small and distributes uniformly all over the surface. The significant change in the anodic polarization curve is attributed to the deposition of the CaCO3. CaCO3 deposits on the specimen surface and gives a protection to the metal substrate. And with the anodic proceeding, the concentration of H＋ in the solution increases. The CaCO3 deposition dissolves in the low pH solution and the protection effect disappears.展开更多
基金jointly supported by the National Natural Science Foundation of China(Grant No.41275068)the Special Fund for Meteorology Research in the Public Interest(Grant No.GYHY201106017)the 973 Program(Grant No.2010CB428504)
文摘The features of large-scale circulation, storm tracks and the dynamical relationship between them were examined by investigating Rossby wave breaking （RWB） processes associated with Eastern Pacific （EP） and Central Pacific （CP） E1-Nifio. During EP E1-Nino, the geopotential height anomaly at 500 hPa （Z500） exhibits a Pacific-North America （PNA） pattern. During CP EI-Nifio, the Z500 anomaly shows a north positive-south negative pattern over the North Pacific. The anomalous distributions of baroclinicity and storm track are consistent with those of upper-level zonal wind for both EP and CP EI-Nino, suggesting impacts of mean flow on storm track variability. Anticyclonic wave breaking （AWB） oczurs less frequently in EP EI-Nino years, while cyclonic wave breaking （CWB） occurs more frequently in CP EI-Nino years over the North Pacific sector. Outside the North Pacific, more CWB events occur over North America during EP Ei-NiNo. When AWB events occur less frequently over the North Pacific during EP EI-Nino, Z500 decreases locally and the zonal wind is strengthened （weakened） to the south （north）. This is because AWB events reflect a monopoie high anomaly at the centroid of breaking events. When CWB events occur more frequently over the North Pacific under CP EI-Nino conditions, and over North America under EP EI-Nino condition, Z500 increases （decreases） to the northeast （southwest）, since CWB events are related to a northeast-southwest dipole Z500 anomaly. The anomalous RWB events act to invigorate and reinforce the circulation anomalies over the North Pacific-North America region linked with the two types of EI-Nino.
基金supported by the Chinese National Programs for High Technology Research and Development (No.2009AA063405-04)
文摘The effect of calcium ions on the corrosion behavior of 3Cr low-alloy steel in CO2- containing sodium chloride solution was investigated by immersion test and electrochemical measurements. It is found that with the addition of Ca2＋ to CO2-containing solution, the crazing level of the corrosion scale on the specimen is much slighter than that of the specimen immersed in solution without Ca2＋. The pitting on the surface of the specimens immersed in the solution with Ca2＋ is relatively small and distributes uniformly all over the surface. The significant change in the anodic polarization curve is attributed to the deposition of the CaCO3. CaCO3 deposits on the specimen surface and gives a protection to the metal substrate. And with the anodic proceeding, the concentration of H＋ in the solution increases. The CaCO3 deposition dissolves in the low pH solution and the protection effect disappears.
