在建立了实封闭域F上复元素域C与四元素体H后得到了:(1)全阵代数F2n中有子代数同构于C,全阵代数F4n中有子代数同构于H;(2)F上代数扩张体只有F、C和H;(3)设F是域K里上维数有限的真子域,则F是实封闭的K是代数闭域且K=F((-1)～(1/2));(4)设...在建立了实封闭域F上复元素域C与四元素体H后得到了:(1)全阵代数F2n中有子代数同构于C,全阵代数F4n中有子代数同构于H;(2)F上代数扩张体只有F、C和H;(3)设F是域K里上维数有限的真子域,则F是实封闭的K是代数闭域且K=F((-1)～(1/2));(4)设A是F上的有限维代数,①若A是可除代数,则A同构于F、C或H,②若A是中心可除代数,则A同构于F或H,③若A是单代数,则A同构于全阵代数Fn、Cn与Hn中之一,④若A是中心单代数,则A同构于全阵代数Fn或Hn,⑤若A没有非零幂零理想,则A=sum Mni from i=1 to l,其中Mni∈{Fni,Cni,Hni},i=1,2,…,l。展开更多
The most complicated component in cavitating flow and pressure distribution is the flow in the cavity closure line. The cavitating flow and pressure distribution provide critical aspects of flow field details in the r...The most complicated component in cavitating flow and pressure distribution is the flow in the cavity closure line. The cavitating flow and pressure distribution provide critical aspects of flow field details in the region. The integral of pressure results of the hydrodynamic forces, indicate domination in the design of a supercavitating vehicle. An experiment was performed in a water tunnel to investigate the pressure characteristics of the cavity closure region. Ventilation methods were employed to generate artificial cavity, and the ventilation rate was adjusted accordingly to obtain the desired cavity length. An array of pressure transducers was laid down the cavity closure line to capture pressure distribution in this region. The experimental results show that there is a pressure peak in the cavity closure region, and the rise rate of pressure in space tends to be higher in the upwind side when the flow is non-axisymmetric. The transient pressure variations during the cavity formation procedure were also present. The method of measurement in this paper can be referenced by engineers. The result helps to study the flow pattern of cavity closure region, and it can also be used to analyze the formation of supercavitating vehicle hydrodynamics.展开更多
文摘在建立了实封闭域F上复元素域C与四元素体H后得到了:(1)全阵代数F2n中有子代数同构于C,全阵代数F4n中有子代数同构于H;(2)F上代数扩张体只有F、C和H;(3)设F是域K里上维数有限的真子域,则F是实封闭的K是代数闭域且K=F((-1)～(1/2));(4)设A是F上的有限维代数,①若A是可除代数,则A同构于F、C或H,②若A是中心可除代数,则A同构于F或H,③若A是单代数,则A同构于全阵代数Fn、Cn与Hn中之一,④若A是中心单代数,则A同构于全阵代数Fn或Hn,⑤若A没有非零幂零理想,则A=sum Mni from i=1 to l,其中Mni∈{Fni,Cni,Hni},i=1,2,…,l。
基金Foundation item： Supported by the National Natural Science Foundation of China （11172241）, and Northwestern Polytechnical University Foundation for Fundamental Research. （NPU-FFR- 1015）
文摘The most complicated component in cavitating flow and pressure distribution is the flow in the cavity closure line. The cavitating flow and pressure distribution provide critical aspects of flow field details in the region. The integral of pressure results of the hydrodynamic forces, indicate domination in the design of a supercavitating vehicle. An experiment was performed in a water tunnel to investigate the pressure characteristics of the cavity closure region. Ventilation methods were employed to generate artificial cavity, and the ventilation rate was adjusted accordingly to obtain the desired cavity length. An array of pressure transducers was laid down the cavity closure line to capture pressure distribution in this region. The experimental results show that there is a pressure peak in the cavity closure region, and the rise rate of pressure in space tends to be higher in the upwind side when the flow is non-axisymmetric. The transient pressure variations during the cavity formation procedure were also present. The method of measurement in this paper can be referenced by engineers. The result helps to study the flow pattern of cavity closure region, and it can also be used to analyze the formation of supercavitating vehicle hydrodynamics.
