Incidence of defects in MoSi2 rods prepared by con- tinuous extrusion is dependent on the viscosity of binder. Generally, low viscosity results in surface defects while high viscosity is responsible for inner defects....Incidence of defects in MoSi2 rods prepared by con- tinuous extrusion is dependent on the viscosity of binder. Generally, low viscosity results in surface defects while high viscosity is responsible for inner defects. Cross-section observations indicated that the typical inner defects in sintered MoSi2 rods were large fissure cavity, multiple small holes and single small cavity, of which the characteristic ultrasonic reflection patterns have been experimentally established. Formation of the inner defects is attributed to the inhomogeneous feedstock moving behav- ior in die, which is aggravated with increasing viscosity of binder. Defect free MoSi2 rods were prepared successfully via con. tinuous extrusion by carefully controlling the viscosity of binder.展开更多
This study tests the influence of environmental risks associated with floods, hurricanes, and hazardous material releases on human migration behavior. With close attention to a function of environmental risk factors, ...This study tests the influence of environmental risks associated with floods, hurricanes, and hazardous material releases on human migration behavior. With close attention to a function of environmental risk factors, socio-demographic attributes, hazard risk and locational attributes were measured and correlated to the standardized number of recent arrivals and long term residents at the census tract level. Two groups (i.e., recent arrivals and long-term residents) were created to compare their moving behavior. The results indicate that flood risk showed little relationship to either recent arrivals or long-term residents. These results are consistent with past research which suggests that people tend to ignore their vulnerability to natural hazards. However, both groups had negative relationships to the risk from hurricanes and hazardous material releases. This counter-intuitive result suggests that other factors, such as proximity to employment opportunities or property tax advantages, need to be examined. In particular, the recent arrivals were negatively related to chemical risk while long-term residents were positively related to chemical risks, indicating that people that just arrived and old residents are somewhat different in perceiving environmental risks. In addition, the results of this study suggest that people are objective about environmental risks in selecting their habitat. However, once the habitat is settled, people’s perception of the risks may be interfered or reduced by other factors.展开更多
The downward moving behavior of pellets in a 8 m2 pellet shaft furnace with an internal vertical air channel and a drying bed was studied by means of a visualized model(1-15) and a top model(1-1).The visualized model ...The downward moving behavior of pellets in a 8 m2 pellet shaft furnace with an internal vertical air channel and a drying bed was studied by means of a visualized model(1-15) and a top model(1-1).The visualized model experiment shows that the downward movement of pellets can be regarded as plug flow approximately inside the furnace except for the lower region of cooling zone due to the influence of the drained hopper.The top model experiment reveals that the pellet sizes increase along the moving direction because of the percolation phenomenon,which results in a decrease of the resistance coefficient and an increase of the gas flow rate from the furnace wall toward the furnace center.展开更多
文摘Incidence of defects in MoSi2 rods prepared by con- tinuous extrusion is dependent on the viscosity of binder. Generally, low viscosity results in surface defects while high viscosity is responsible for inner defects. Cross-section observations indicated that the typical inner defects in sintered MoSi2 rods were large fissure cavity, multiple small holes and single small cavity, of which the characteristic ultrasonic reflection patterns have been experimentally established. Formation of the inner defects is attributed to the inhomogeneous feedstock moving behav- ior in die, which is aggravated with increasing viscosity of binder. Defect free MoSi2 rods were prepared successfully via con. tinuous extrusion by carefully controlling the viscosity of binder.
文摘This study tests the influence of environmental risks associated with floods, hurricanes, and hazardous material releases on human migration behavior. With close attention to a function of environmental risk factors, socio-demographic attributes, hazard risk and locational attributes were measured and correlated to the standardized number of recent arrivals and long term residents at the census tract level. Two groups (i.e., recent arrivals and long-term residents) were created to compare their moving behavior. The results indicate that flood risk showed little relationship to either recent arrivals or long-term residents. These results are consistent with past research which suggests that people tend to ignore their vulnerability to natural hazards. However, both groups had negative relationships to the risk from hurricanes and hazardous material releases. This counter-intuitive result suggests that other factors, such as proximity to employment opportunities or property tax advantages, need to be examined. In particular, the recent arrivals were negatively related to chemical risk while long-term residents were positively related to chemical risks, indicating that people that just arrived and old residents are somewhat different in perceiving environmental risks. In addition, the results of this study suggest that people are objective about environmental risks in selecting their habitat. However, once the habitat is settled, people’s perception of the risks may be interfered or reduced by other factors.
基金Projects(59374166,58974155) supported by the National Natural Science Foundation of China
文摘The downward moving behavior of pellets in a 8 m2 pellet shaft furnace with an internal vertical air channel and a drying bed was studied by means of a visualized model(1-15) and a top model(1-1).The visualized model experiment shows that the downward movement of pellets can be regarded as plug flow approximately inside the furnace except for the lower region of cooling zone due to the influence of the drained hopper.The top model experiment reveals that the pellet sizes increase along the moving direction because of the percolation phenomenon,which results in a decrease of the resistance coefficient and an increase of the gas flow rate from the furnace wall toward the furnace center.
