The NiCoCrAlY coatings strengthened by three nano-particles with the same addition were prepared on a Ni-base super alloy using laser cladding technique. The dry frictional wear behaviors of the coatings at 500 ℃ in ...The NiCoCrAlY coatings strengthened by three nano-particles with the same addition were prepared on a Ni-base super alloy using laser cladding technique. The dry frictional wear behaviors of the coatings at 500 ℃ in static air were investigated. The comparison was made with the coating without nano-particles. The results show that the wear mechanism of the NiCoCrAlY coatings with nano-particles, like the coating without nano-particles, is the delamination wear due to the strong plastic deformation and oxidative wear. However, the frictional coefficient of the coatings increases and presents the decrease trend with the increase of sliding distance after adding nano-particles. Moreover, the wear rate of the coatings with nano-particles is only 34.0%-64.5% of the coating without nano-particles. Among the three nano-particles, the improvement of nano-SiC on the high temperature wear resistance of the coating is the most significant.展开更多
The ocean surface currents are reconstructed from the satellite remote sensing data containing altimeter-derived sea surface height and QuikSCAT satellite-derived wind data. Based on the method proposed by Lagerloef, ...The ocean surface currents are reconstructed from the satellite remote sensing data containing altimeter-derived sea surface height and QuikSCAT satellite-derived wind data. Based on the method proposed by Lagerloef, a global weekly 0.5°×0.5°ocean surface current product was obtained over the period 2000 - 2008 by combining the geostrophic currents estimated from sea surface height with Ekman current estimated from the wind stress. Particularly, weight functions were introduced when calculating the Ekman currents to eliminate the discontinuity near 25°S and 25°N. These satellite-derived currents have been compared with TAO current meter and the SCUD product, respectively. The comparison showed that satellite-derived currents not only could capture the characteristics of ocean surface currents but also had high accuracy and reliability. The result showed that this innovatory method was effective.展开更多
The evolution of morphology, composition, thickness and corrosion resistance of the oxide film on pure Sn solder substrate submitted to high-temperature aging in 150 °C dry atmosphere was investigated. The result...The evolution of morphology, composition, thickness and corrosion resistance of the oxide film on pure Sn solder substrate submitted to high-temperature aging in 150 °C dry atmosphere was investigated. The results indicate that high-temperature aging accelerates the dehydration of Sn(OH)_(4)in the pre-existing native oxide film to form SnO_(2)and facilitates the oxidation of fresh Sn substrate, resulting in the gradual increase in oxide film thickness and surface roughness with prolonging aging time. However, the corrosion resistance of the film initially is enhanced and then deteriorated with an extending aging time. Besides, the formation and evolution mechanisms of the oxide film with aging time were discussed.展开更多
基金Project(20060287019)supported by the Research Fund for Doctoral Program of Higher Education of ChinaProject(kjsmcx07001)supported by the Opening Research Fund of Jiangsu Key Laboratory of Tribology,ChinaProject(BK2010267)supported by the Jiangsu Provincial Natural Science Foundation of Jiangsu Province,China
文摘The NiCoCrAlY coatings strengthened by three nano-particles with the same addition were prepared on a Ni-base super alloy using laser cladding technique. The dry frictional wear behaviors of the coatings at 500 ℃ in static air were investigated. The comparison was made with the coating without nano-particles. The results show that the wear mechanism of the NiCoCrAlY coatings with nano-particles, like the coating without nano-particles, is the delamination wear due to the strong plastic deformation and oxidative wear. However, the frictional coefficient of the coatings increases and presents the decrease trend with the increase of sliding distance after adding nano-particles. Moreover, the wear rate of the coatings with nano-particles is only 34.0%-64.5% of the coating without nano-particles. Among the three nano-particles, the improvement of nano-SiC on the high temperature wear resistance of the coating is the most significant.
基金supported by the National Natural Science Foundation of China(No.41306010,41276088 and 41206002)
文摘The ocean surface currents are reconstructed from the satellite remote sensing data containing altimeter-derived sea surface height and QuikSCAT satellite-derived wind data. Based on the method proposed by Lagerloef, a global weekly 0.5°×0.5°ocean surface current product was obtained over the period 2000 - 2008 by combining the geostrophic currents estimated from sea surface height with Ekman current estimated from the wind stress. Particularly, weight functions were introduced when calculating the Ekman currents to eliminate the discontinuity near 25°S and 25°N. These satellite-derived currents have been compared with TAO current meter and the SCUD product, respectively. The comparison showed that satellite-derived currents not only could capture the characteristics of ocean surface currents but also had high accuracy and reliability. The result showed that this innovatory method was effective.
基金financial support from CAS Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences。
文摘The evolution of morphology, composition, thickness and corrosion resistance of the oxide film on pure Sn solder substrate submitted to high-temperature aging in 150 °C dry atmosphere was investigated. The results indicate that high-temperature aging accelerates the dehydration of Sn(OH)_(4)in the pre-existing native oxide film to form SnO_(2)and facilitates the oxidation of fresh Sn substrate, resulting in the gradual increase in oxide film thickness and surface roughness with prolonging aging time. However, the corrosion resistance of the film initially is enhanced and then deteriorated with an extending aging time. Besides, the formation and evolution mechanisms of the oxide film with aging time were discussed.
