Intermittent characteristics of turbulence induced by coherent structures （blobs） was clearly observed in the ion saturation current signal, density fluctuation, particle flux and heat flux in HT-7. It is obvious th...Intermittent characteristics of turbulence induced by coherent structures （blobs） was clearly observed in the ion saturation current signal, density fluctuation, particle flux and heat flux in HT-7. It is obvious that ion saturation current signal has deviated from Gaussian distribution and the skewness （S） and flatness （K） of signal increase radially outwards in the scrape-off layer （SOL）. Using conditional analysis （CA）, asymmetric character of the intermittent bursts are demonstrated. Owing to the radial propagation of the coherent structures, the particle density profile in SOL is non-exponential and flat outwards from the last close flux surface （LCFS）. It is found around LCFS that the large burst fluctuations （above 2.5 rms） are responsible for about 50% of the total particle transport. Burst events move radially outwards with Ee ~ B velocity, and the blob size can be calculated as 5r ~ V^rc. Our experiment shows that the blob size, life time and drift velocity experienced a pronounced decorrelation in the shear layer. The electrostatic Reynolds stress components become very strong and show a radially steep gradient in the proximity of the shear layer. These experimental findings may imply that the coherent structures are titled by the developed shear flow in the E × B shear layer.展开更多
针对坚果分类效率低、精确度低、成本高等问题,该文研究并设计了基于机器视觉的坚果尺寸检测系统,以核桃坚果为研究对象,对核桃的尺寸进行检测,以获取品质高、质量好的核桃。首先,通过工业相机对核桃图像进行采集;其次,利用视觉软件Hal...针对坚果分类效率低、精确度低、成本高等问题,该文研究并设计了基于机器视觉的坚果尺寸检测系统,以核桃坚果为研究对象,对核桃的尺寸进行检测,以获取品质高、质量好的核桃。首先,通过工业相机对核桃图像进行采集;其次,利用视觉软件Halcon进行Blob分析、分水岭阈值分割、矩形检测等方法进行图像处理,获取核桃尺寸的相关数据;最后,将被检测物尺寸的实时数据传输到工控机上,利用Visual Studio 2019软件实现数据通信。实验结果表明,该坚果尺寸检测系统稳定,能够保证较高的准确率。展开更多
基金supported by National Natural Science Foundation of China (Nos.10605028, 10675127, 10675126 and 10675124)
文摘Intermittent characteristics of turbulence induced by coherent structures （blobs） was clearly observed in the ion saturation current signal, density fluctuation, particle flux and heat flux in HT-7. It is obvious that ion saturation current signal has deviated from Gaussian distribution and the skewness （S） and flatness （K） of signal increase radially outwards in the scrape-off layer （SOL）. Using conditional analysis （CA）, asymmetric character of the intermittent bursts are demonstrated. Owing to the radial propagation of the coherent structures, the particle density profile in SOL is non-exponential and flat outwards from the last close flux surface （LCFS）. It is found around LCFS that the large burst fluctuations （above 2.5 rms） are responsible for about 50% of the total particle transport. Burst events move radially outwards with Ee ~ B velocity, and the blob size can be calculated as 5r ~ V^rc. Our experiment shows that the blob size, life time and drift velocity experienced a pronounced decorrelation in the shear layer. The electrostatic Reynolds stress components become very strong and show a radially steep gradient in the proximity of the shear layer. These experimental findings may imply that the coherent structures are titled by the developed shear flow in the E × B shear layer.
文摘针对坚果分类效率低、精确度低、成本高等问题,该文研究并设计了基于机器视觉的坚果尺寸检测系统,以核桃坚果为研究对象,对核桃的尺寸进行检测,以获取品质高、质量好的核桃。首先,通过工业相机对核桃图像进行采集;其次,利用视觉软件Halcon进行Blob分析、分水岭阈值分割、矩形检测等方法进行图像处理,获取核桃尺寸的相关数据;最后,将被检测物尺寸的实时数据传输到工控机上,利用Visual Studio 2019软件实现数据通信。实验结果表明,该坚果尺寸检测系统稳定,能够保证较高的准确率。
