A vulcanized rubber layer is usually used on the head of an axisymmetric body to keep it streamlined and watertight.The elastic boundary condition is considered when the flow noise of an axisymmetric body is calculate...A vulcanized rubber layer is usually used on the head of an axisymmetric body to keep it streamlined and watertight.The elastic boundary condition is considered when the flow noise of an axisymmetric body is calculated,and we employ the mutual coupling method between the vulcanized rubber layer and the How around to solve the flow-noise field for an axisymmetric body in water.The results show that the deformation of the vulcanized rubber layer is reduced with the increase in Young's modulus.The Young's modulus of the rubber material should be large enough to keep it streamlined,and the noise power levels in the peak of the axisymmetric body are smaller than the other positions,which provides us with important theoretical support for laying acoustic arrays on the head of the body.展开更多
合成气制乙二醇路线的重要步骤为CO与亚硝酸甲酯(MN)偶联生成草酸二甲酯(DMO)中间体,同时副产碳酸二甲酯(DMC)和甲酸甲酯(MF)。在管式固定床反应器中采用商用Pd/α-Al_(2)O_(3)催化剂,考察了原料气体积分数、配比、温度、空速(SV)和NO...合成气制乙二醇路线的重要步骤为CO与亚硝酸甲酯(MN)偶联生成草酸二甲酯(DMO)中间体,同时副产碳酸二甲酯(DMC)和甲酸甲酯(MF)。在管式固定床反应器中采用商用Pd/α-Al_(2)O_(3)催化剂,考察了原料气体积分数、配比、温度、空速(SV)和NO体积分数对主、副反应的影响。结果表明,在130℃、10000~20000 mL/(h·g)条件下,MN转化率85%~90%,DMO选择性大于95%;高温、低空速、低反应物体积分数和低V(CO)/V(MN)比有利于DMC的生成,当CO与MN进料体积分数均为2.5%,空速20000 m L/(h·g)时,DMC选择性可达8.6%。进一步根据实验数据提出了反应动力学模型,模型表明CO、MN和NO具有较明显的阻尼吸附作用,与实验结果相符。展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11174235the Science and Technology Development Project of Shaanxi Province(No 2010KJXX-02)+1 种基金the Program for New Century Excellent Talents in University(No NCET-08-0455)the Excellent Doctorate Foundation of Northwestern Polytechnical University.
文摘A vulcanized rubber layer is usually used on the head of an axisymmetric body to keep it streamlined and watertight.The elastic boundary condition is considered when the flow noise of an axisymmetric body is calculated,and we employ the mutual coupling method between the vulcanized rubber layer and the How around to solve the flow-noise field for an axisymmetric body in water.The results show that the deformation of the vulcanized rubber layer is reduced with the increase in Young's modulus.The Young's modulus of the rubber material should be large enough to keep it streamlined,and the noise power levels in the peak of the axisymmetric body are smaller than the other positions,which provides us with important theoretical support for laying acoustic arrays on the head of the body.
文摘合成气制乙二醇路线的重要步骤为CO与亚硝酸甲酯(MN)偶联生成草酸二甲酯(DMO)中间体,同时副产碳酸二甲酯(DMC)和甲酸甲酯(MF)。在管式固定床反应器中采用商用Pd/α-Al_(2)O_(3)催化剂,考察了原料气体积分数、配比、温度、空速(SV)和NO体积分数对主、副反应的影响。结果表明,在130℃、10000~20000 mL/(h·g)条件下,MN转化率85%~90%,DMO选择性大于95%;高温、低空速、低反应物体积分数和低V(CO)/V(MN)比有利于DMC的生成,当CO与MN进料体积分数均为2.5%,空速20000 m L/(h·g)时,DMC选择性可达8.6%。进一步根据实验数据提出了反应动力学模型,模型表明CO、MN和NO具有较明显的阻尼吸附作用,与实验结果相符。