Magneto-mechanical coupling vibration arises in the in-vessel components of Tokamak devices especially during the plasma disruption. Strong electromagnetic forces cause the structures to vibrate while the motion in tu...Magneto-mechanical coupling vibration arises in the in-vessel components of Tokamak devices especially during the plasma disruption. Strong electromagnetic forces cause the structures to vibrate while the motion in turn changes the distribution of the electromagnetic field. To ensure the Tokamak devices operating in a designed state, numerical analysis on the coupling vibration is of great importance. This paper introduces two numerical methods for the magneto-mechanical coupling problems. The coupling term of velocity and magnetic flux density is manipulated in both Eulerian and Lagrangian description, which brings much simplification in numerical implementation. Corresponding numerical codes have been developed and applied to the dynamic simulation of a test module in J-TEXT and the vacuum vessel of HL-2M during plasma disruptions. The results reveal the evident influence of the magnetic stiffness and magnetic damping effects on the vibration behavior of the in-vessel structures. Finally, to deal with the halo current injection problem, a numerical scheme is described and validated which can simulate the distribution of the halo current without complicated manipulations.展开更多
For safe operation with active water cooling plasma facing components （PFCs） to handle a large input power over a long pulse discharge, some design optimization, R＆D and maintenance were accomplished to improve the...For safe operation with active water cooling plasma facing components （PFCs） to handle a large input power over a long pulse discharge, some design optimization, R＆D and maintenance were accomplished to improve the in-vessel components. For the purpose of large plasma current （1 MA） operation, the previous separated top and bottom passive stabilizers in the low field were electrical connected to stabilize plasma in the case of vertical displace events （VDEs）. The design and experiments are described in this paper展开更多
针对现有的视网膜血管分割方法对微细血管分割精度低的问题,在多尺度单通道线性追踪(MSLTA:Multi-Scale Single-Channel Linear Track)的图像分割方法基础上,提出了一种新的、有效的视网膜血管分割方法。采用Gabor滤波预处理以增强血管...针对现有的视网膜血管分割方法对微细血管分割精度低的问题,在多尺度单通道线性追踪(MSLTA:Multi-Scale Single-Channel Linear Track)的图像分割方法基础上,提出了一种新的、有效的视网膜血管分割方法。采用Gabor滤波预处理以增强血管信息,利用MSLTA算法获得最初的血管网络,采用连通域标记的去噪方法,去除图像上的斑点噪声,分割出最终的血管。利用国际上公开的DRIVE(Digital Retinal Images for Vessel Extraction)数据库的视网膜图像进行实验,并与现有的常规算法做了对比。多组实验结果表明,该方法的平均精确度达到95.37%,能很好地保留微细血管。展开更多
基金the National Magnetic Confinement Fusion Program of China(Grant 2013GB113005)the National Natural Science Foundation of China(Grants51577139 and 51407132)for funding in part
文摘Magneto-mechanical coupling vibration arises in the in-vessel components of Tokamak devices especially during the plasma disruption. Strong electromagnetic forces cause the structures to vibrate while the motion in turn changes the distribution of the electromagnetic field. To ensure the Tokamak devices operating in a designed state, numerical analysis on the coupling vibration is of great importance. This paper introduces two numerical methods for the magneto-mechanical coupling problems. The coupling term of velocity and magnetic flux density is manipulated in both Eulerian and Lagrangian description, which brings much simplification in numerical implementation. Corresponding numerical codes have been developed and applied to the dynamic simulation of a test module in J-TEXT and the vacuum vessel of HL-2M during plasma disruptions. The results reveal the evident influence of the magnetic stiffness and magnetic damping effects on the vibration behavior of the in-vessel structures. Finally, to deal with the halo current injection problem, a numerical scheme is described and validated which can simulate the distribution of the halo current without complicated manipulations.
文摘For safe operation with active water cooling plasma facing components （PFCs） to handle a large input power over a long pulse discharge, some design optimization, R＆D and maintenance were accomplished to improve the in-vessel components. For the purpose of large plasma current （1 MA） operation, the previous separated top and bottom passive stabilizers in the low field were electrical connected to stabilize plasma in the case of vertical displace events （VDEs）. The design and experiments are described in this paper
文摘针对现有的视网膜血管分割方法对微细血管分割精度低的问题,在多尺度单通道线性追踪(MSLTA:Multi-Scale Single-Channel Linear Track)的图像分割方法基础上,提出了一种新的、有效的视网膜血管分割方法。采用Gabor滤波预处理以增强血管信息,利用MSLTA算法获得最初的血管网络,采用连通域标记的去噪方法,去除图像上的斑点噪声,分割出最终的血管。利用国际上公开的DRIVE(Digital Retinal Images for Vessel Extraction)数据库的视网膜图像进行实验,并与现有的常规算法做了对比。多组实验结果表明,该方法的平均精确度达到95.37%,能很好地保留微细血管。
