Flow visualization and hot-wire measurement techniques were combined to investigate the influence of the size and number of tabs on jet flow field and vortex structure generation mechanism. Streamwise vortices generat...Flow visualization and hot-wire measurement techniques were combined to investigate the influence of the size and number of tabs on jet flow field and vortex structure generation mechanism. Streamwise vortices generated by the tabs of different sizes and numbers were observed from the flow visualization images. Combined with flow visualization, hot-wire measurement gave a quantitative insight of the effect of various tabbed jet flows. Instantaneous two-component velocity signals (longitudinal and transverse velocity components) at different cross sections along radius direction and streamwise direction with different tabbed jet nozzles were measured using hot-wire anemometer. Average flow field parameters of tabbed jet flow such as mean velocity, tur-bulence intensity, vorticity were analyzed and the effects of tabs with different sizes and numbers were compared with that of circular no-tab jet flow. It is revealed that the generation of a series of counter-rotating quasi-streamwise vortices, azimuthal vortices and double-row azi-muthal vortex are the reasons for mixing enhancement of tabbed turbulent jet flow.展开更多
目的比较和分析Rpl32和Rpl13作为单内参基因与两者作为双内参基因,用于检测大鼠挫伤肌肉组织中TAB2 m RNA表达量的结果。方法 78只SD大鼠,随机分为正常对照组(1组)和肌肉损伤组(12组)。采用自由落体法制作大鼠肌肉挫伤模型,分别于4h^48...目的比较和分析Rpl32和Rpl13作为单内参基因与两者作为双内参基因,用于检测大鼠挫伤肌肉组织中TAB2 m RNA表达量的结果。方法 78只SD大鼠,随机分为正常对照组(1组)和肌肉损伤组(12组)。采用自由落体法制作大鼠肌肉挫伤模型,分别于4h^48h之间12个时间点取肌肉组织,提取总RNA、合成c DNA、采用real-time q PCR法,以Rpl32和Rpl13作为单独内参基因和二者作为双内参基因检测大鼠肌肉挫伤组织中TAB2 m RNA相对表达量,并计算检测结果的变异系数。结果以Rpl32或Rpl13单独作为内参基因或作为双内参基因,TAB2 m RNA表达随损伤时间总体均呈现降低的变化规律,但使用单内参基因在24h和32h出现极高值,而用双内参基因计算未出现极值,且各结果的变异系数均较小。结论 Rpl32和Rpl13作为双内参基因用于计算TAB2 m RNA相对表达量,可提高分析结果的准确性,在相关实验中建议选择使用。展开更多
基金National Natural Science Foundation of China (No.10472081)Program for New Century Excellent Talents in Universities of Minis-try of Education of China and Plan of Tianjin Science and Technology Development (No.06TXTJJC13800)
文摘Flow visualization and hot-wire measurement techniques were combined to investigate the influence of the size and number of tabs on jet flow field and vortex structure generation mechanism. Streamwise vortices generated by the tabs of different sizes and numbers were observed from the flow visualization images. Combined with flow visualization, hot-wire measurement gave a quantitative insight of the effect of various tabbed jet flows. Instantaneous two-component velocity signals (longitudinal and transverse velocity components) at different cross sections along radius direction and streamwise direction with different tabbed jet nozzles were measured using hot-wire anemometer. Average flow field parameters of tabbed jet flow such as mean velocity, tur-bulence intensity, vorticity were analyzed and the effects of tabs with different sizes and numbers were compared with that of circular no-tab jet flow. It is revealed that the generation of a series of counter-rotating quasi-streamwise vortices, azimuthal vortices and double-row azi-muthal vortex are the reasons for mixing enhancement of tabbed turbulent jet flow.
文摘目的比较和分析Rpl32和Rpl13作为单内参基因与两者作为双内参基因,用于检测大鼠挫伤肌肉组织中TAB2 m RNA表达量的结果。方法 78只SD大鼠,随机分为正常对照组(1组)和肌肉损伤组(12组)。采用自由落体法制作大鼠肌肉挫伤模型,分别于4h^48h之间12个时间点取肌肉组织,提取总RNA、合成c DNA、采用real-time q PCR法,以Rpl32和Rpl13作为单独内参基因和二者作为双内参基因检测大鼠肌肉挫伤组织中TAB2 m RNA相对表达量,并计算检测结果的变异系数。结果以Rpl32或Rpl13单独作为内参基因或作为双内参基因,TAB2 m RNA表达随损伤时间总体均呈现降低的变化规律,但使用单内参基因在24h和32h出现极高值,而用双内参基因计算未出现极值,且各结果的变异系数均较小。结论 Rpl32和Rpl13作为双内参基因用于计算TAB2 m RNA相对表达量,可提高分析结果的准确性,在相关实验中建议选择使用。
