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A method has been developed in this paper to gain effective speckle reduction in medical ultrasound images. To exploit full knowledge of the speckle distribution, here maximum likelihood was used to estimate speckle parameters corresponding to its statistical mode. Then the results were incorporated into the nonlinear anisotropic diffusion to achieve adaptive speckle reduction. Verified with simulated and ultrasound images, we show that this algorithm is capable of enhancing features of clinical interest and reduces speckle noise more efficiently than just applying classical filters. To avoid edge contribution, changes of contrast-to-noise ratio of different regions are also compared to investigate the performance of this approach.  相似文献   
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Yuan-Ting Huang 《中国物理 B》2022,31(2):28502-028502
The effects of radiation on 3CG110 PNP bipolar junction transistors (BJTs) are characterized using 50-MeV protons, 40-MeV Si ions, and 1-MeV electrons. In this paper, electrical characteristics and deep level transient spectroscopy (DLTS) are utilized to analyze radiation defects induced by ionization and displacement damage. The experimental results show a degradation of the current gain and an increase in the types of radiation defect with increasing fluences of 50-MeV protons. Moreover, by comparing the types of damage caused by different radiation sources, the characteristics of the radiation defects induced by irradiation show that 50-MeV proton irradiation can produce both ionization and displacement defects in the 3CG110 PNP BJTs, in contrast to 40-MeV Si ions, which mainly generate displacement defects, and 1-MeV electrons, which mainly produce ionization defects. This work provides direct evidence of a synergistic effect between the ionization and displacement defects caused in PNP BJTs by 50-MeV protons.  相似文献   
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A method has been developed in this paper to gain effective speckle reduction in medical ultrasound images.To exploit full knowledge of the speckle distribution, here maximum likelihood was used to estimate speckle parameters corresponding to its statistical mode. Then the results were incorporated into the nonlinear anisotropic diffusion to achieve adaptive speckle reduction. Verified with simulated and ultrasound images,we show that this algorithm is capable of enhancing features of clinical interest and reduces speckle noise more efficiently than just applying classical filters. To avoid edge contribution, changes of contrast-to-noise ratio of different regions are also compared to investigate the performance of this approach.  相似文献   
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高考背景下不同省份的高中物理授课重点内容不同,导致同一所大学的新生物理基础参差不齐.这对物理基础薄弱的同学造成了很大的课堂学习和心理压力.我们对大学物理课程的教学内容进行课程思政的挖掘,教学模式上采用研讨式圆桌教学,充分调动学生学习积极性,对大学与中学物理教育衔接起到促进作用.在对学生物理知识传授的同时进行课程思政教育,使得大学物理课堂教学更具吸引性和内涵,提高教学育人效果,在潜移默化中实现立德树人.  相似文献   
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