The present study aims to investigate the interaction between the free surface and a semi/shallowly submerged underwater vehicle,especially when the submergence depth h is smaller than 0.75D(D:submarine maximum diamet...The present study aims to investigate the interaction between the free surface and a semi/shallowly submerged underwater vehicle,especially when the submergence depth h is smaller than 0.75D(D:submarine maximum diameter).In this respect,the straight-ahead simulations of the generic SUBOFF underwater vehicle geometry are conducted with constant forward velocities using the Unsteady Reynolds-Averaged Navier-Stokes(URANS)equations with a Shear-Stress Transport(SST)k-ωturbulence model in commercial code Fluent,at submergence depths and Froude numbers ranging from h=0 to h=3.3D and from Fn=0.205 to Fn=0.512,respectively.The numerical models are verified against the existing experimental data.The analysis of the obtained results indicates that in the case of the semi and shallowly submerged underwater vehicle(UV),both the submergence depth and forward velocity have a great effect on the behaviors of hydrodynamic forces acting on the UV.The magnitude of maximum total resistance may reach almost five times the value of resistance exerted on the totally submerged hull.Both the forces acting on the UV and the generated waves when the submergence depth h is smaller than 0.75D are significantly different from those whenr h is larger than 0.75D.The conclusions can be used as reference for future research on near free surface motions of underwater vehicles and the design of small water-plane area twin hull.展开更多
为研究白藜芦醇(RES)对胰岛素抵抗小鼠的糖脂代谢影响及心肌的保护作用。将雄性c57bl/6小鼠随机分对照组(NC)、高脂组(H)、高脂+溶媒(C)、高脂+溶媒+RES干预组(R),分别给予相应饲料喂养14周后给予相应灌胃干预处理。8周后检测小鼠血脂...为研究白藜芦醇(RES)对胰岛素抵抗小鼠的糖脂代谢影响及心肌的保护作用。将雄性c57bl/6小鼠随机分对照组(NC)、高脂组(H)、高脂+溶媒(C)、高脂+溶媒+RES干预组(R),分别给予相应饲料喂养14周后给予相应灌胃干预处理。8周后检测小鼠血脂、血糖、血清脂肪因子;检测心肌羟脯氨酸;采用蛋白质印迹法(western blotting,WB)检测心肌Ⅰ、Ⅲ型胶原的蛋白表达;实时荧光定量PCR、WB检测小鼠的心肌PPARγ(过氧化物酶增殖物激活受体γ)、ADPN(脂联素)、TNF-α(肿瘤坏死因子α)的mRNA及蛋白表达情况。结果表明:与NC组相比,H组与C组总胆固醇(total cholesteral,TC)、低密度脂蛋白(low density lipoprotein,LDL)升高(P<0.01);血清瘦素、抵抗素水平升高;心肌中羟脯氨酸、胶原、TNF-α升高(P<0.01或P<0.05);PPARγ、ADPN表达下降(P<0.01);而R组较H组TC、LDL降低(P<0.05);血清瘦素、抵抗素水平下降;心肌中胶原、TNF-α降低(P<0.01或P<0.05);PPARγ、ADPN的表达升高(P<0.01)。RES可能是通过激动PPARγ调节ADPN、TNF-α改善胰岛素抵抗小鼠糖脂代谢紊乱、心肌肥厚、纤维化。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52372356).
文摘The present study aims to investigate the interaction between the free surface and a semi/shallowly submerged underwater vehicle,especially when the submergence depth h is smaller than 0.75D(D:submarine maximum diameter).In this respect,the straight-ahead simulations of the generic SUBOFF underwater vehicle geometry are conducted with constant forward velocities using the Unsteady Reynolds-Averaged Navier-Stokes(URANS)equations with a Shear-Stress Transport(SST)k-ωturbulence model in commercial code Fluent,at submergence depths and Froude numbers ranging from h=0 to h=3.3D and from Fn=0.205 to Fn=0.512,respectively.The numerical models are verified against the existing experimental data.The analysis of the obtained results indicates that in the case of the semi and shallowly submerged underwater vehicle(UV),both the submergence depth and forward velocity have a great effect on the behaviors of hydrodynamic forces acting on the UV.The magnitude of maximum total resistance may reach almost five times the value of resistance exerted on the totally submerged hull.Both the forces acting on the UV and the generated waves when the submergence depth h is smaller than 0.75D are significantly different from those whenr h is larger than 0.75D.The conclusions can be used as reference for future research on near free surface motions of underwater vehicles and the design of small water-plane area twin hull.
文摘为研究白藜芦醇(RES)对胰岛素抵抗小鼠的糖脂代谢影响及心肌的保护作用。将雄性c57bl/6小鼠随机分对照组(NC)、高脂组(H)、高脂+溶媒(C)、高脂+溶媒+RES干预组(R),分别给予相应饲料喂养14周后给予相应灌胃干预处理。8周后检测小鼠血脂、血糖、血清脂肪因子;检测心肌羟脯氨酸;采用蛋白质印迹法(western blotting,WB)检测心肌Ⅰ、Ⅲ型胶原的蛋白表达;实时荧光定量PCR、WB检测小鼠的心肌PPARγ(过氧化物酶增殖物激活受体γ)、ADPN(脂联素)、TNF-α(肿瘤坏死因子α)的mRNA及蛋白表达情况。结果表明:与NC组相比,H组与C组总胆固醇(total cholesteral,TC)、低密度脂蛋白(low density lipoprotein,LDL)升高(P<0.01);血清瘦素、抵抗素水平升高;心肌中羟脯氨酸、胶原、TNF-α升高(P<0.01或P<0.05);PPARγ、ADPN表达下降(P<0.01);而R组较H组TC、LDL降低(P<0.05);血清瘦素、抵抗素水平下降;心肌中胶原、TNF-α降低(P<0.01或P<0.05);PPARγ、ADPN的表达升高(P<0.01)。RES可能是通过激动PPARγ调节ADPN、TNF-α改善胰岛素抵抗小鼠糖脂代谢紊乱、心肌肥厚、纤维化。
