A centrifugal fan with the high speed and compact dimensions is studied numerically and experimentally. The centrifugal fan consists of a shrouded impeller rotating at 34 000 r/min with a small tip clearance 0.7 mm to...A centrifugal fan with the high speed and compact dimensions is studied numerically and experimentally. The centrifugal fan consists of a shrouded impeller rotating at 34 000 r/min with a small tip clearance 0.7 mm to the fixed outer casing. Computational models with/without the tip clearance are built and the κ-ω shear stress transport (SST) turbulence model and the unstructured mesh are applied to the numerical simulation for unsteady solutions. The overall performance is measured on a standard experimental bench and the major flow feature of each component inside the centrifugal fan is numerically investigated. In the presence of the tip clearance due to the difference of static pressure between leading and trailing edges of the clearance, i. e. , leading and trailing edges of the impeller, a strong return flow exists inside the clearance passage and re-circulates the main stream inside the impeller passage, and produces the strong flow interaction, thus changing the flow field and influencing the overall performance.展开更多
Objective To determine the spatio-temporal expression of p70S6k activation in hippocampus in mesial temporal lobe epilepsy. Methods Temporal lobe epilepsy model was established by stereotaxically unilateral and intrah...Objective To determine the spatio-temporal expression of p70S6k activation in hippocampus in mesial temporal lobe epilepsy. Methods Temporal lobe epilepsy model was established by stereotaxically unilateral and intrahip-pocampal injection of kainite acid (KA) in adult male C57BL/6 mice. Latent and chronic epileptogenesis were represented by mice 5 days after KA injection (n=5) and mice 5 weeks after KA injection (n=8), respectively. Control mice (n=5) were injected with saline. Immunohistochemical assays were performed on brain sections of the mice. Results Hippocampus both ipsilateral and contralateral to the KA injection displayed significantly up-regulated pS6 immunoreactivity in dispersed granule cells in 5-day and 5-week model mice. Conclusion The activation of p70S6k is mainly located in the dentate gyrus in KA-induced mouse model of temporal lobe epilepsy, indicating that the activation may be related with the disperse degree and hypertrophy of granule cells.展开更多
文摘A centrifugal fan with the high speed and compact dimensions is studied numerically and experimentally. The centrifugal fan consists of a shrouded impeller rotating at 34 000 r/min with a small tip clearance 0.7 mm to the fixed outer casing. Computational models with/without the tip clearance are built and the κ-ω shear stress transport (SST) turbulence model and the unstructured mesh are applied to the numerical simulation for unsteady solutions. The overall performance is measured on a standard experimental bench and the major flow feature of each component inside the centrifugal fan is numerically investigated. In the presence of the tip clearance due to the difference of static pressure between leading and trailing edges of the clearance, i. e. , leading and trailing edges of the impeller, a strong return flow exists inside the clearance passage and re-circulates the main stream inside the impeller passage, and produces the strong flow interaction, thus changing the flow field and influencing the overall performance.
基金Supported by National Natural Science Foundation of China (31021091, 30971001)Beijing Natural Science Foundation (7102109)Fok Ying Tong Education Foundation (121024)
文摘Objective To determine the spatio-temporal expression of p70S6k activation in hippocampus in mesial temporal lobe epilepsy. Methods Temporal lobe epilepsy model was established by stereotaxically unilateral and intrahip-pocampal injection of kainite acid (KA) in adult male C57BL/6 mice. Latent and chronic epileptogenesis were represented by mice 5 days after KA injection (n=5) and mice 5 weeks after KA injection (n=8), respectively. Control mice (n=5) were injected with saline. Immunohistochemical assays were performed on brain sections of the mice. Results Hippocampus both ipsilateral and contralateral to the KA injection displayed significantly up-regulated pS6 immunoreactivity in dispersed granule cells in 5-day and 5-week model mice. Conclusion The activation of p70S6k is mainly located in the dentate gyrus in KA-induced mouse model of temporal lobe epilepsy, indicating that the activation may be related with the disperse degree and hypertrophy of granule cells.