Social imbalance and obsolescence of the built environment has emerged in large sized housing estates in metropolises. In particular, the requirement of such planned housing areas has not matched public service provid...Social imbalance and obsolescence of the built environment has emerged in large sized housing estates in metropolises. In particular, the requirement of such planned housing areas has not matched public service provided by the infrastructure. On not only physical but also social aspect of local communities of this kind of housing area have a lot of problems while it also has a lot of good characteristics. A representative one is that age of the tenants is rising very swiftly and it makes the local community imbalanced. Nowadays many countries including Japan have tackled problems concerning housing estates constructed during the mass housing era and try to search for ways to reactivate so-called new town areas by utilisation of existing environmental resources such as building stock and ample green open space. In Japan many elemental technologies have been developed in order to utilise existing building stock. However, how to combine these technologies and new holistic methods for reactivation are still underdeveloped. Therefore, it is very important to fred these ways and to make a comprehensive plan for rehabilitation of these areas. The first purpose of our study is to develop and clarify how to organise and integrate many kinds of elemental techniques and the holistic measures for the improvement of both social and physical environment in suburban mass housing estates. Subsequently we try to reorganise proper relations between human settlements and the various service provision for those regions. Our last focus is put on searching for new ways to raise the value of existing housing environment. Our conclusion intends to indicate important of the master plan and its execution, where mass housing estates progress for the physical and social improvement.展开更多
The squeeze casting method with local pressure compensation was proposed to form a flywheel housing component with a weight of 35 kg.The numerical simulation,microstructure observation and phase characterization were ...The squeeze casting method with local pressure compensation was proposed to form a flywheel housing component with a weight of 35 kg.The numerical simulation,microstructure observation and phase characterization were performed,and the influence of local pressure compensation on feeding of thick-wall position,microstructure and mechanical properties of the formed components were discussed.Results show that the molten metal keeps a good fluidity and the filling is complete during the filling process.Although the solidification at thick-wall positions of the mounting ports is slow,the local pressure compensation effectively realizes the local forced feeding,significantly eliminating the shrinkage cavity defects.In the microstructure of AlSi9Mg alloy,α-Al primarily consists of fragmented dendrites and rosette grains,while eutectic Si predominantly comprises needles and short rods.The impact of local pressure compensation on strength is relatively minimal,yet its influence on elongation is considerable.Following local pressure compensation,the average elongation at the compensated areas is 9.18%,which represents a 44.90%higher than that before compensation.The average tensile strength is 209.1 MPa,and the average yield strength is 100.6 MPa.The local pressure compensation can significantly reduce or even eliminate the internal defects in the 35 kg large-weight components formed by squeeze casting.展开更多
文摘Social imbalance and obsolescence of the built environment has emerged in large sized housing estates in metropolises. In particular, the requirement of such planned housing areas has not matched public service provided by the infrastructure. On not only physical but also social aspect of local communities of this kind of housing area have a lot of problems while it also has a lot of good characteristics. A representative one is that age of the tenants is rising very swiftly and it makes the local community imbalanced. Nowadays many countries including Japan have tackled problems concerning housing estates constructed during the mass housing era and try to search for ways to reactivate so-called new town areas by utilisation of existing environmental resources such as building stock and ample green open space. In Japan many elemental technologies have been developed in order to utilise existing building stock. However, how to combine these technologies and new holistic methods for reactivation are still underdeveloped. Therefore, it is very important to fred these ways and to make a comprehensive plan for rehabilitation of these areas. The first purpose of our study is to develop and clarify how to organise and integrate many kinds of elemental techniques and the holistic measures for the improvement of both social and physical environment in suburban mass housing estates. Subsequently we try to reorganise proper relations between human settlements and the various service provision for those regions. Our last focus is put on searching for new ways to raise the value of existing housing environment. Our conclusion intends to indicate important of the master plan and its execution, where mass housing estates progress for the physical and social improvement.
基金supported by the National Key R&D Program of China(No.2022YFB3404204)the National Natural Science Foundation of China(NSFC)under Grant Nos.U2241232,U2341253 and 52375317.
文摘The squeeze casting method with local pressure compensation was proposed to form a flywheel housing component with a weight of 35 kg.The numerical simulation,microstructure observation and phase characterization were performed,and the influence of local pressure compensation on feeding of thick-wall position,microstructure and mechanical properties of the formed components were discussed.Results show that the molten metal keeps a good fluidity and the filling is complete during the filling process.Although the solidification at thick-wall positions of the mounting ports is slow,the local pressure compensation effectively realizes the local forced feeding,significantly eliminating the shrinkage cavity defects.In the microstructure of AlSi9Mg alloy,α-Al primarily consists of fragmented dendrites and rosette grains,while eutectic Si predominantly comprises needles and short rods.The impact of local pressure compensation on strength is relatively minimal,yet its influence on elongation is considerable.Following local pressure compensation,the average elongation at the compensated areas is 9.18%,which represents a 44.90%higher than that before compensation.The average tensile strength is 209.1 MPa,and the average yield strength is 100.6 MPa.The local pressure compensation can significantly reduce or even eliminate the internal defects in the 35 kg large-weight components formed by squeeze casting.
