Qarhan Salt Lake is located in the eastern part of the Qaidam Basin,which is first discovered the large potash deposit in the late 1950s.The Bieletan section is located in the west of Qarhan Salt Lake,where saline sed...Qarhan Salt Lake is located in the eastern part of the Qaidam Basin,which is first discovered the large potash deposit in the late 1950s.The Bieletan section is located in the west of Qarhan Salt Lake,where saline sediment展开更多
Fluidization characteristics of quartz particles with different sizes are experimentally investigated in a fluidized bed with an inner diameter of 300 mm and height of 8250 mm.Results show that the average solid holdu...Fluidization characteristics of quartz particles with different sizes are experimentally investigated in a fluidized bed with an inner diameter of 300 mm and height of 8250 mm.Results show that the average solid holdup increases with the increase in superficial gas velocity and the decrease in initial solid holdup in the dense zone of the fluidized bed.The average cross-sectional solid holdup decreases with increasing bed height and superficial gas velocity.The bed expansion coefficient increases with the increase in superficial gas velocity and the decrease in solid holdup.Correlations of average solid holdup,average cross-sectional solid holdup and bed expansion coefficient are also established and discussed.These correlations can provide guidelines for better understanding of the fluidization characteristics.展开更多
Radar cross section (RCS) reduction technologies are very important in survivability of the military naval vessels. Ship appearance shaping as an effective countermeasure of RCS reduction redirects the scattered energ...Radar cross section (RCS) reduction technologies are very important in survivability of the military naval vessels. Ship appearance shaping as an effective countermeasure of RCS reduction redirects the scattered energy from one angular region of interest in space to another region of little interest. To decrease the scattering electromagnetic signals from ship scientifically, optimization methods should be introduced in shaping design. Based on the assumption of the characteristic section design method, mathematical formulations for optimal shaping design were established. Because of the computation-intensive analysis and singularity in shaping optimization, the response surface method (RSM) combined genetic algorithm (GA) was proposed. The poly-nomial response surface method was adopted in model approximation. Then genetic algorithms were employed to solve the surrogate optimization problem. By comparison RCS of the conventional and the optimal design, the superiority and effectiveness of proposed design methodology were verified.展开更多
文摘Qarhan Salt Lake is located in the eastern part of the Qaidam Basin,which is first discovered the large potash deposit in the late 1950s.The Bieletan section is located in the west of Qarhan Salt Lake,where saline sediment
文摘Fluidization characteristics of quartz particles with different sizes are experimentally investigated in a fluidized bed with an inner diameter of 300 mm and height of 8250 mm.Results show that the average solid holdup increases with the increase in superficial gas velocity and the decrease in initial solid holdup in the dense zone of the fluidized bed.The average cross-sectional solid holdup decreases with increasing bed height and superficial gas velocity.The bed expansion coefficient increases with the increase in superficial gas velocity and the decrease in solid holdup.Correlations of average solid holdup,average cross-sectional solid holdup and bed expansion coefficient are also established and discussed.These correlations can provide guidelines for better understanding of the fluidization characteristics.
基金the National Natural Science Founda-tion of China (No. 10672100)
文摘Radar cross section (RCS) reduction technologies are very important in survivability of the military naval vessels. Ship appearance shaping as an effective countermeasure of RCS reduction redirects the scattered energy from one angular region of interest in space to another region of little interest. To decrease the scattering electromagnetic signals from ship scientifically, optimization methods should be introduced in shaping design. Based on the assumption of the characteristic section design method, mathematical formulations for optimal shaping design were established. Because of the computation-intensive analysis and singularity in shaping optimization, the response surface method (RSM) combined genetic algorithm (GA) was proposed. The poly-nomial response surface method was adopted in model approximation. Then genetic algorithms were employed to solve the surrogate optimization problem. By comparison RCS of the conventional and the optimal design, the superiority and effectiveness of proposed design methodology were verified.
