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燃煤细颗粒和颗粒团动力学特性的比较 被引量:6
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作者 赵兵 姚刚 +2 位作者 杨林军 陈厚涛 沈湘林 《中国电机工程学报》 EI CSCD 北大核心 2007年第8期1-4,共4页
为研究颗粒团的动力学特性,利用可视化技术对声波场中颗粒和颗粒团的声波夹带进行了实验研究。在相同的实验条件下,拍摄到大颗粒团和小颗粒的声波夹带位移振幅分别为12.6μm和12.5μm,相对应的张驰时间比约为1;用扫描电镜观测低压电称... 为研究颗粒团的动力学特性,利用可视化技术对声波场中颗粒和颗粒团的声波夹带进行了实验研究。在相同的实验条件下,拍摄到大颗粒团和小颗粒的声波夹带位移振幅分别为12.6μm和12.5μm,相对应的张驰时间比约为1;用扫描电镜观测低压电称冲击器(ELPI)收集到的颗粒和颗粒团,发现在同一级收集盘上,能收集到较大的颗粒团和较小的颗粒,再次证明了大颗粒团和相应的小颗粒具有相近的空气动力学特性。利用颗粒团的分形特性对可视化实验中颗粒团的声波夹带进行理论分析,计算得到实验中观测到的颗粒团和颗粒的张驰时间比为1.03,与实验结果吻合。这说明与相同质量的单颗粒相比,具有分形体特征的颗粒团的气流跟随性被增强,可能不利于利用惯性分离的方法脱除气流中的颗粒团。 展开更多
关键词 细颗粒 颗粒团 分形 张驰时间 动力学特性
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Growth Cartilage of Piglet: Correlation between MRI Characteristics and Histologic Findings and Measurements of T1 and T2 Relaxation Time 被引量:1
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作者 LIXiao-ming WANGRen-fa LIYong-gang TANGLi-hua YANGBo 《Journal of Nanjing Medical University》 2004年第5期244-249,共6页
Objective: To determine the correlation between MR signal characteristics and histologic findings of growth cartilage and identify the difference in transverse and longitudinal relaxation time between in vivo physeal ... Objective: To determine the correlation between MR signal characteristics and histologic findings of growth cartilage and identify the difference in transverse and longitudinal relaxation time between in vivo physeal and epiphyseal cartilage. Methods: Twenty-four knees including distal femora and proximal tibia of 12 2-week-old piglets were imaged at 1.5 Tesla GE MR scanner. The comparison between signal intensity on MRI and architecture in corresponding histologic sections was made. T2 and T1 values were measured by means of multiecho spin-echo sequences and by using inversion-recovery-series, respectively. Results: MRI delineated five different regions between the metaphysis and secondary ossification center and the metaphysis corresponding histologically to zone of provisional calcification of secondary ossification center, physis of the secondary ossification center, epiphyseal cartilage, main physis and main zone of provisional calcification. Both T2 and T1 values in the physeal cartilage were much longer than those in the epiphyseal cartilage (P<0.05). Conclusion: MRI findings differentiate the different zones of growth cartilage and correlate with histologic findings. T2 and T1 are longer in physeal cartilage than in epiphyseal cartilage, perhaps reflecting differences in water binding by proteoglycan. 展开更多
关键词 生长软骨 小猪 MRI 典型特征 组织学 T1 T2 测量法 张驰时间 软骨部分
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