A new contact model of traveling wave ultrasonic motor （TWUSM） with a visco-elastic stator frictional layer was presented. In this model, the initial boundaries were revised, and the rotor revolution speed could he ...A new contact model of traveling wave ultrasonic motor （TWUSM） with a visco-elastic stator frictional layer was presented. In this model, the initial boundaries were revised, and the rotor revolution speed could he calculated iteratively. This model was compared with compliant slider and rigid stator model. The results of motor characteristics simulations showed that the motors based on this model would gain bigger stall torque. Then the friction and wear characteristics of two models were analyzed. The motors based on this model had lower coefficient of friction and better wear resistance.展开更多
According to the critical size ratio for the characteristic particle size to film thickness between grinding wheel and work, the machining mechanisms in abrasive jet precision finishing with grinding wheel as restrain...According to the critical size ratio for the characteristic particle size to film thickness between grinding wheel and work, the machining mechanisms in abrasive jet precision finishing with grinding wheel as restraint can be categorized into four states, namely, two-body lapping, three-body polishing, abrasive jet machining and fluid hydrodynamic shear stress machining. The critical transition condition of two-body lapping to three-body polishing was analyzed. The single abrasive material removal models of two-body lapping, three-body polishing, abrasive jet finishing and fluid hydrodynamic shear stress machining were proposed. Experiments were performed in the refited plane grinding machine for theoretical modes verification. It was found that experimental results agreed with academic modes and the modes validity was verified.展开更多
The background of research was conditions of settlement in slum area at Tallo which are most apprehensive; lack of facilities, the houses made of flammable materials, and some criminal action occurred in the density s...The background of research was conditions of settlement in slum area at Tallo which are most apprehensive; lack of facilities, the houses made of flammable materials, and some criminal action occurred in the density settlement. Upgrading Programs has been twice implemented in this area. However, those have the same aim, to improve street and drainage condition around the area. The different between of them is the using of material which are the first program used asphalt as street cover material and the second one used paving blok. Although the upgrading programs had done, the condition of the settlement did not improve significantly. The problems in settlement were not only leak in infrastructure condition and needs, but also lake of community welfare, unemployment, housing conditions, and the existence of the warehouses in the settlement. The flood problems also appeared in this area which closed with the water channel to the city disposal channel so when rainy season, the area is always flooded and enter into the entrance of the houses. The objective of this research was to find the root of the problems and find good solutions for the environment and how to meet the major needs of the settlement upgrading program into the local community point of view. Field research and questioners was conducted as research method to the research objectivities in the needs of community for good environment. Furthermore, the data from the field research was analyzed by making synchronization with the theory of environmental sustainability. Results from this research showed the comparison study between first and the last condition of the settlement area which had the upgrading program implementation. These findings could provide a new guideline for the government in policy related to slum upgrading.展开更多
基金Sponsored by the Natural Sciences Foundation of China (Grant No 50575055)the National 973 Key Development Project in Fundamental Science Research (Grant No2007CB607602)
文摘A new contact model of traveling wave ultrasonic motor （TWUSM） with a visco-elastic stator frictional layer was presented. In this model, the initial boundaries were revised, and the rotor revolution speed could he calculated iteratively. This model was compared with compliant slider and rigid stator model. The results of motor characteristics simulations showed that the motors based on this model would gain bigger stall torque. Then the friction and wear characteristics of two models were analyzed. The motors based on this model had lower coefficient of friction and better wear resistance.
基金Sponsored by the National Natural Science Foundation of China (Grant No 50475052)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No 20040145001)
文摘According to the critical size ratio for the characteristic particle size to film thickness between grinding wheel and work, the machining mechanisms in abrasive jet precision finishing with grinding wheel as restraint can be categorized into four states, namely, two-body lapping, three-body polishing, abrasive jet machining and fluid hydrodynamic shear stress machining. The critical transition condition of two-body lapping to three-body polishing was analyzed. The single abrasive material removal models of two-body lapping, three-body polishing, abrasive jet finishing and fluid hydrodynamic shear stress machining were proposed. Experiments were performed in the refited plane grinding machine for theoretical modes verification. It was found that experimental results agreed with academic modes and the modes validity was verified.
文摘The background of research was conditions of settlement in slum area at Tallo which are most apprehensive; lack of facilities, the houses made of flammable materials, and some criminal action occurred in the density settlement. Upgrading Programs has been twice implemented in this area. However, those have the same aim, to improve street and drainage condition around the area. The different between of them is the using of material which are the first program used asphalt as street cover material and the second one used paving blok. Although the upgrading programs had done, the condition of the settlement did not improve significantly. The problems in settlement were not only leak in infrastructure condition and needs, but also lake of community welfare, unemployment, housing conditions, and the existence of the warehouses in the settlement. The flood problems also appeared in this area which closed with the water channel to the city disposal channel so when rainy season, the area is always flooded and enter into the entrance of the houses. The objective of this research was to find the root of the problems and find good solutions for the environment and how to meet the major needs of the settlement upgrading program into the local community point of view. Field research and questioners was conducted as research method to the research objectivities in the needs of community for good environment. Furthermore, the data from the field research was analyzed by making synchronization with the theory of environmental sustainability. Results from this research showed the comparison study between first and the last condition of the settlement area which had the upgrading program implementation. These findings could provide a new guideline for the government in policy related to slum upgrading.
