针对当前U-Net网络模型以及相关卷积网络在脊椎分割中分割边缘精度低,对目标的识别率低等问题,提出几种改进的语义分割网络模型。考虑到脊椎MRI图像中目标区域连续且集中,并存在复数微小区域,边缘特征丰富,运用新型卷积块替换标准卷积结...针对当前U-Net网络模型以及相关卷积网络在脊椎分割中分割边缘精度低,对目标的识别率低等问题,提出几种改进的语义分割网络模型。考虑到脊椎MRI图像中目标区域连续且集中,并存在复数微小区域,边缘特征丰富,运用新型卷积块替换标准卷积结构,利用多路径思想,融入复数编解码器结构,降低运算复杂度,提升边缘特征提取力度,应对不同的特征提取问题。模型在SpineWeb的High anisotropy MRIs of the lower back数据集2000张脊椎图像上做实验,运用训练好的模型对同组脊椎MRI图像作预测。实验结果显示,网络模型的预测结果与提供的真值标签在Dice系数以及Precision系数等几项评价指标上分别达到0.891和0.894。展开更多
The partial substitution of M （M=Sm, Nd, Pr） for La was performed in order to ameliorate the electrochemical hydrogen storage performance of RE–Mg–Ni-based A2B7-type electrode alloys. The La0.8–xMxMg0.2Ni3.35Al0....The partial substitution of M （M=Sm, Nd, Pr） for La was performed in order to ameliorate the electrochemical hydrogen storage performance of RE–Mg–Ni-based A2B7-type electrode alloys. The La0.8–xMxMg0.2Ni3.35Al0.1Si0.05 （M=Sm, Nd, Pr;x=0-0.4） electrode alloys were fabricated by casting and annealing and their microstructures were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The major phases （La, Mg）2Ni7 with the hexagonal Ce2Ni7-type structure and LaNi5 with the hexagonal CaCu5-type structure make up the basic microstructure of the experimental alloys. The discharge capacities of the as-cast and annealed alloys all gain their maximum values with the M （M=Sm, Nd, Pr） content varying. The electrochemical cycle stability of the as-cast and annealed alloys clearly rises with the M （M=Sm, Nd, Pr） content growing. Furthermore, the electrochemical kinetics of the alloys, including the high rate discharge ability, charge transfer rate, limiting current density and hydrogen diffusion coefficient, all present a increase trend at first and then decrease with the rising of M （M=Sm, Nd, Pr） content.展开更多
The crystal structure of astrophyllite K2Na(Fe, Mn, Mg,□)7[Ti2(Si4O12)2|O3](OH, F)4 has been refined. The dimensions of the triclinic unit cell are: a = 0.5359(2) nm,b = 1.1614(4) nm, c = 1.1861(4) nm, α= 113.16(2)&...The crystal structure of astrophyllite K2Na(Fe, Mn, Mg,□)7[Ti2(Si4O12)2|O3](OH, F)4 has been refined. The dimensions of the triclinic unit cell are: a = 0.5359(2) nm,b = 1.1614(4) nm, c = 1.1861(4) nm, α= 113.16(2)°, β= 103.04(2)°,γ= 94.56(2)°,V = 0.6495(5) nm3, Z= 1, space group P1, R=0.057 for 5308 reflections |Fo|>3σ|Fo|. According to structural and compositional differences the monoclinic astrophyllite K2NaNa(Fe, Mn)4Mg2Ti2[Si4O12]2(OH)4(OH, F)2 and astrophyllite should be considered as two different mineral species. Astrophyllite, monoclinic astrophyllite, bafertisite and lamprophyllite contain heteropolyhedral sheets which topologically are related with Si, O sheets of mica where one or several SiO4 tetrahedra are replaced by TiO n polyhedra. Therefore this heterophyllotitanosilicate series represents a kind of functional substitution in inorganic crystals.展开更多
文摘针对当前U-Net网络模型以及相关卷积网络在脊椎分割中分割边缘精度低,对目标的识别率低等问题,提出几种改进的语义分割网络模型。考虑到脊椎MRI图像中目标区域连续且集中,并存在复数微小区域,边缘特征丰富,运用新型卷积块替换标准卷积结构,利用多路径思想,融入复数编解码器结构,降低运算复杂度,提升边缘特征提取力度,应对不同的特征提取问题。模型在SpineWeb的High anisotropy MRIs of the lower back数据集2000张脊椎图像上做实验,运用训练好的模型对同组脊椎MRI图像作预测。实验结果显示,网络模型的预测结果与提供的真值标签在Dice系数以及Precision系数等几项评价指标上分别达到0.891和0.894。
基金Projects(51161015,51371094)supported by the National Natural Science Foundations of China
文摘The partial substitution of M （M=Sm, Nd, Pr） for La was performed in order to ameliorate the electrochemical hydrogen storage performance of RE–Mg–Ni-based A2B7-type electrode alloys. The La0.8–xMxMg0.2Ni3.35Al0.1Si0.05 （M=Sm, Nd, Pr;x=0-0.4） electrode alloys were fabricated by casting and annealing and their microstructures were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The major phases （La, Mg）2Ni7 with the hexagonal Ce2Ni7-type structure and LaNi5 with the hexagonal CaCu5-type structure make up the basic microstructure of the experimental alloys. The discharge capacities of the as-cast and annealed alloys all gain their maximum values with the M （M=Sm, Nd, Pr） content varying. The electrochemical cycle stability of the as-cast and annealed alloys clearly rises with the M （M=Sm, Nd, Pr） content growing. Furthermore, the electrochemical kinetics of the alloys, including the high rate discharge ability, charge transfer rate, limiting current density and hydrogen diffusion coefficient, all present a increase trend at first and then decrease with the rising of M （M=Sm, Nd, Pr） content.
基金in part by The National Natural Science Foundation of China (Grant No. 49872019) and Russian Scientific Foundation (Grant No. 99-05-35019).
文摘The crystal structure of astrophyllite K2Na(Fe, Mn, Mg,□)7[Ti2(Si4O12)2|O3](OH, F)4 has been refined. The dimensions of the triclinic unit cell are: a = 0.5359(2) nm,b = 1.1614(4) nm, c = 1.1861(4) nm, α= 113.16(2)°, β= 103.04(2)°,γ= 94.56(2)°,V = 0.6495(5) nm3, Z= 1, space group P1, R=0.057 for 5308 reflections |Fo|>3σ|Fo|. According to structural and compositional differences the monoclinic astrophyllite K2NaNa(Fe, Mn)4Mg2Ti2[Si4O12]2(OH)4(OH, F)2 and astrophyllite should be considered as two different mineral species. Astrophyllite, monoclinic astrophyllite, bafertisite and lamprophyllite contain heteropolyhedral sheets which topologically are related with Si, O sheets of mica where one or several SiO4 tetrahedra are replaced by TiO n polyhedra. Therefore this heterophyllotitanosilicate series represents a kind of functional substitution in inorganic crystals.
