The solidified structures of horizontally continuous casting（HCC） of super-thin slab and its relations with the current were studied under the electromagnetic vibration（EMV）.The results show that,under the action ...The solidified structures of horizontally continuous casting（HCC） of super-thin slab and its relations with the current were studied under the electromagnetic vibration（EMV）.The results show that,under the action of the periodical forces from EMV,the solidified structures of the super-thin slab of pure tin is greatly refined,and the extent of grain refinement is increased with the magnitude of alternating current.For the Sn-10%Pb alloy,it is shown that the EMV promotes the growth of equiaxed grains in the center of super-thin slab,and the grains are refined with the alternating current increasing.This is useful to prevent some solidification defects in the horizontally continuous casting of super-thin slab,such as columnar grains butting,porosity,inclusions and gases gathering,and composition segregation in the centre of slab.展开更多
Nonlinear mechanics for a super-thin elastic rod with the biological background of DNA super-coiling macromolecules is an interdisciplinary research area of classical mechanics and molecular biology. It is also a subj...Nonlinear mechanics for a super-thin elastic rod with the biological background of DNA super-coiling macromolecules is an interdisciplinary research area of classical mechanics and molecular biology. It is also a subject of dynamics and elasticity because elastic bodies are analyzed via the theory of dynamics. It is in frontiers of general mechanics （dynamics and control）. This dissertation is devoted to model a constrained super-thin elastic rod and analyze its stability in equilibrium. The existing research results are summarized. Analytical mechanics is systematically applied to model the elastic rod. The Schroedinger equation for complex curvatures or complex bending moments is, respectively, extended from the case of circular crosssections to that of non-circular ones. The equilibrium of a rod constrained on a surface is investigated.展开更多
The road surface of cement concrete in highway is easily cracked and even destroyed due to inhomogeneous subsiding of the road foundation. In this work, a super-thin-coating material is prepared in order to repair the...The road surface of cement concrete in highway is easily cracked and even destroyed due to inhomogeneous subsiding of the road foundation. In this work, a super-thin-coating material is prepared in order to repair the destroyed thin road surface, in which polymers and steel-fiber are added into ordinary concrete to form a steel fiber reinforced polymer-cement-based composite, the composite was successfully used to repair road surface. Microstructure and mechanical properties of the composites are measured and analyzed.展开更多
The influence of hydrochloric or sulphuric acid treatment on the electro-physical properties of superthin basalt fiber (STBF) made from Armenian basalt rocks was studied. Specific electric resistance for direct and al...The influence of hydrochloric or sulphuric acid treatment on the electro-physical properties of superthin basalt fiber (STBF) made from Armenian basalt rocks was studied. Specific electric resistance for direct and alternating currents, dielectric parameters of ε, and ε,, were measured. It is shown that specific resistance and dielectric parameters of super-thin basalt fiber change essentially after hydrochloric or sulphuric acid treatment. The temperature dependences of these parameters were studied, too, and their non–monotonic behavior was observed. The probable variation of mentioned STBF parameters is explained by different water absorption capacity of pores as a result of acid treatment.展开更多
目的构建一种基于深度学习的小肝癌磁共振影像超分辨重建模型,通过联合优化高频细节与解剖合理性,提升小肝癌病灶的影像细节可视性,提升小肝癌扩散加权成像(DWI)检查的图像质量及临床应用价值。方法回顾性分析2022年12月~2024年6月我院...目的构建一种基于深度学习的小肝癌磁共振影像超分辨重建模型,通过联合优化高频细节与解剖合理性,提升小肝癌病灶的影像细节可视性,提升小肝癌扩散加权成像(DWI)检查的图像质量及临床应用价值。方法回顾性分析2022年12月~2024年6月我院300例小肝癌患者的3 mm DWI数据。采用GE Discovery7503.0 T扫描仪采集图像,按8∶2比例随机分为训练集(n=240)和测试集(n=60)。构建双分支超分辨模型:内容分支通过级联梯度Transformer块提取全局特征,梯度分支通过梯度Transformer块增强结构信息;创新性引入:(1)交叉局部增强自注意力模块,以优化块内像素特征与全局上下文信息的交互;(2)通道-空间联合注意力层,通过动态权重分配增强关键解剖结构的可视性。由3名高年资放射科医师采用5分制Likert量表对原始弥散加权成像(ORDWI)和超分辨弥散加权成像(SRDWI)进行盲法评分,同时计算峰值信噪比、结构相似度等客观指标。结果SRDWI的主观评分优于ORDWI:肝结节信号特异性(3.41±0.53 vs 2.47±0.50)、正常肝实质均匀性(3.29±0.47 vs 2.78±0.42)、伪影干扰程度(2.56±0.52 vs 2.47±0.48)及整体图像质量(3.15±0.49 vs 2.67±0.48)上的主观评分优于ORDWI(P<0.001)。图像噪声水平(3.98±0.61 vs 2.87±0.46)超分后略有增加(P<0.05),但仍在临床可接受范围内,不影响关键特征的判读。客观指标显示SRDWI的峰值信噪比(34.65489 dB)和结构相似度(0.90365)均表现优异。结论该深度学习模型可显著提升3 mm-DWI图像质量,使薄层DWI的诊断效能接近常规厚层扫描水平,为小肝癌精准诊断提供技术支持。展开更多
基金Project(50674066)supported by the National Natural Science Foundation of China
文摘The solidified structures of horizontally continuous casting（HCC） of super-thin slab and its relations with the current were studied under the electromagnetic vibration（EMV）.The results show that,under the action of the periodical forces from EMV,the solidified structures of the super-thin slab of pure tin is greatly refined,and the extent of grain refinement is increased with the magnitude of alternating current.For the Sn-10%Pb alloy,it is shown that the EMV promotes the growth of equiaxed grains in the center of super-thin slab,and the grains are refined with the alternating current increasing.This is useful to prevent some solidification defects in the horizontally continuous casting of super-thin slab,such as columnar grains butting,porosity,inclusions and gases gathering,and composition segregation in the centre of slab.
文摘Nonlinear mechanics for a super-thin elastic rod with the biological background of DNA super-coiling macromolecules is an interdisciplinary research area of classical mechanics and molecular biology. It is also a subject of dynamics and elasticity because elastic bodies are analyzed via the theory of dynamics. It is in frontiers of general mechanics （dynamics and control）. This dissertation is devoted to model a constrained super-thin elastic rod and analyze its stability in equilibrium. The existing research results are summarized. Analytical mechanics is systematically applied to model the elastic rod. The Schroedinger equation for complex curvatures or complex bending moments is, respectively, extended from the case of circular crosssections to that of non-circular ones. The equilibrium of a rod constrained on a surface is investigated.
文摘The road surface of cement concrete in highway is easily cracked and even destroyed due to inhomogeneous subsiding of the road foundation. In this work, a super-thin-coating material is prepared in order to repair the destroyed thin road surface, in which polymers and steel-fiber are added into ordinary concrete to form a steel fiber reinforced polymer-cement-based composite, the composite was successfully used to repair road surface. Microstructure and mechanical properties of the composites are measured and analyzed.
文摘The influence of hydrochloric or sulphuric acid treatment on the electro-physical properties of superthin basalt fiber (STBF) made from Armenian basalt rocks was studied. Specific electric resistance for direct and alternating currents, dielectric parameters of ε, and ε,, were measured. It is shown that specific resistance and dielectric parameters of super-thin basalt fiber change essentially after hydrochloric or sulphuric acid treatment. The temperature dependences of these parameters were studied, too, and their non–monotonic behavior was observed. The probable variation of mentioned STBF parameters is explained by different water absorption capacity of pores as a result of acid treatment.
文摘目的构建一种基于深度学习的小肝癌磁共振影像超分辨重建模型,通过联合优化高频细节与解剖合理性,提升小肝癌病灶的影像细节可视性,提升小肝癌扩散加权成像(DWI)检查的图像质量及临床应用价值。方法回顾性分析2022年12月~2024年6月我院300例小肝癌患者的3 mm DWI数据。采用GE Discovery7503.0 T扫描仪采集图像,按8∶2比例随机分为训练集(n=240)和测试集(n=60)。构建双分支超分辨模型:内容分支通过级联梯度Transformer块提取全局特征,梯度分支通过梯度Transformer块增强结构信息;创新性引入:(1)交叉局部增强自注意力模块,以优化块内像素特征与全局上下文信息的交互;(2)通道-空间联合注意力层,通过动态权重分配增强关键解剖结构的可视性。由3名高年资放射科医师采用5分制Likert量表对原始弥散加权成像(ORDWI)和超分辨弥散加权成像(SRDWI)进行盲法评分,同时计算峰值信噪比、结构相似度等客观指标。结果SRDWI的主观评分优于ORDWI:肝结节信号特异性(3.41±0.53 vs 2.47±0.50)、正常肝实质均匀性(3.29±0.47 vs 2.78±0.42)、伪影干扰程度(2.56±0.52 vs 2.47±0.48)及整体图像质量(3.15±0.49 vs 2.67±0.48)上的主观评分优于ORDWI(P<0.001)。图像噪声水平(3.98±0.61 vs 2.87±0.46)超分后略有增加(P<0.05),但仍在临床可接受范围内,不影响关键特征的判读。客观指标显示SRDWI的峰值信噪比(34.65489 dB)和结构相似度(0.90365)均表现优异。结论该深度学习模型可显著提升3 mm-DWI图像质量,使薄层DWI的诊断效能接近常规厚层扫描水平,为小肝癌精准诊断提供技术支持。
