在两种不同的真空度下 ,运用真空电弧炉熔炼合金制备试样 ;运用X射线衍射技术和晶相显微技术对试样进行了分析和讨论。结果表明 :用真空电弧炉熔炼合金能得到比较均匀的母合金熔体 ;由于Zr Al Cu Ni合金与铜型之间的润湿角很大 ,因而形...在两种不同的真空度下 ,运用真空电弧炉熔炼合金制备试样 ;运用X射线衍射技术和晶相显微技术对试样进行了分析和讨论。结果表明 :用真空电弧炉熔炼合金能得到比较均匀的母合金熔体 ;由于Zr Al Cu Ni合金与铜型之间的润湿角很大 ,因而形成玻璃能力强 ;高真空度、原材料成分的纯度是Zr Al Cu Ni合金形成玻璃态的重要因素 ;金属合金熔体随水冷铜型一起冷却 ,在真空度不高的条件下 ,由于合金熔体中的组元与空气中的氧、氢及氮反应形成晶核 ,而合金熔体与铜型之间的温度梯度不大 ,无法抑制晶核的生长 。展开更多
A novel algorithm for image edge detection is presented. This algorithm combines the nonsubsampled contourlet transform and the mathematical morphology. First, the source image is decomposed by the nonsubsampled conto...A novel algorithm for image edge detection is presented. This algorithm combines the nonsubsampled contourlet transform and the mathematical morphology. First, the source image is decomposed by the nonsubsampled contourlet transform into multi-scale and multi-directional subbands. Then the edges in the high-frequency and low-frequency sub-bands are respectively extracted by the dualthreshold modulus maxima method and the mathematical morphology operator. Finally, the edges from the high- frequency and low-frequency sub-bands are integrated to the edges of the source image, which are refined, and isolated points are excluded to achieve the edges of the source image. The simulation results show that the proposed algorithm can effectively suppress noise, eliminate pseudo-edges and overcome the adverse effects caused by uneven illumination to a certain extent. Compared with the traditional methods such as LoG, Sobel, and Carmy operators and the modulus maxima algorithm, the proposed method can maintain sufficient positioning accuracy and edge details, and it can also make an improvement in the completeness, smoothness and clearness of the outline.展开更多
文摘在两种不同的真空度下 ,运用真空电弧炉熔炼合金制备试样 ;运用X射线衍射技术和晶相显微技术对试样进行了分析和讨论。结果表明 :用真空电弧炉熔炼合金能得到比较均匀的母合金熔体 ;由于Zr Al Cu Ni合金与铜型之间的润湿角很大 ,因而形成玻璃能力强 ;高真空度、原材料成分的纯度是Zr Al Cu Ni合金形成玻璃态的重要因素 ;金属合金熔体随水冷铜型一起冷却 ,在真空度不高的条件下 ,由于合金熔体中的组元与空气中的氧、氢及氮反应形成晶核 ,而合金熔体与铜型之间的温度梯度不大 ,无法抑制晶核的生长 。
基金The National Key Technologies R&D Program during the 12th Five-Year Period of China(No.2012BAJ23B02)Science and Technology Support Program of Jiangsu Province(No.BE2010606)
文摘A novel algorithm for image edge detection is presented. This algorithm combines the nonsubsampled contourlet transform and the mathematical morphology. First, the source image is decomposed by the nonsubsampled contourlet transform into multi-scale and multi-directional subbands. Then the edges in the high-frequency and low-frequency sub-bands are respectively extracted by the dualthreshold modulus maxima method and the mathematical morphology operator. Finally, the edges from the high- frequency and low-frequency sub-bands are integrated to the edges of the source image, which are refined, and isolated points are excluded to achieve the edges of the source image. The simulation results show that the proposed algorithm can effectively suppress noise, eliminate pseudo-edges and overcome the adverse effects caused by uneven illumination to a certain extent. Compared with the traditional methods such as LoG, Sobel, and Carmy operators and the modulus maxima algorithm, the proposed method can maintain sufficient positioning accuracy and edge details, and it can also make an improvement in the completeness, smoothness and clearness of the outline.
