Laser surface cladding was applied on a TC4 Ti alloy to improve its surface properties. Mixed TiC and Ti powders with a TiC-to-Ti mass ratio of 1：3 were put onto the TC4 Ti alloy and subsequently treated by laser bea...Laser surface cladding was applied on a TC4 Ti alloy to improve its surface properties. Mixed TiC and Ti powders with a TiC-to-Ti mass ratio of 1：3 were put onto the TC4 Ti alloy and subsequently treated by laser beam. The microstructure and composition modifications in the surfaee layer were carefully investigated by using SEM, EDX and XRD. Due to melting, liquid state mixing followed by rapid solidification and cooling, a layer with graded microstructures and compositions formed. The TiC powders were completely dissolved into the melted layer during melting and segregated as fine dendrites when solidified. The inter-dendritic areas were filled with fine a＇ phase lamellae enrich in A1. Mainly due to the reduced TiC volume fraction with increasing depth, the hardness decreases with increasing depth in the laser clad layer with a maximum value of HV1400, about 4.5 times of the initial one.展开更多
Social capital has been recognised as a factor affecting sustainable development in every discipline. A network or a partnership is identified as a ＂structural＂ form of social capital and a tool to empower participa...Social capital has been recognised as a factor affecting sustainable development in every discipline. A network or a partnership is identified as a ＂structural＂ form of social capital and a tool to empower participants in the networks. There is a belief that social networks can be initiated or created at every level of social capital, from micro to macro. However, the concept of community is the key component of social capital, creating both physical ties （geographical locality） and normative behaviours （sense of belonging）. Therefore, this study is intended to enhance social capital at the community or micro-level, in order to sustain tourism development in those areas, and networking is initiated to enhance social capital. Participatory Action Research （PAR） was applied to tourism development in Kon Kaen Province. Tools and techniques used during this study included： observations, preliminary meetings, community meetings, tourism audits, workshops, and network meetings. Eleven districts in Khon Kaen were actively involved in the planning process.展开更多
基金Project(J51402) supported by the Leading Academic Discipline Project of Shanghai Education Commission,ChinaProject(gjd08004) supported by the Foundation for Excellent Youth Scholar of China+2 种基金 Project(08QA14035) supported by the Shanghai Science and Technology Development Foundation, China Project(0852nm01400) supported by the Special Foundation of Shanghai Education Commission for Nano-Materials Research, China Project(08520513400) supported by Crucial Project of the Shanghai Science and Technology Commission,China
文摘Laser surface cladding was applied on a TC4 Ti alloy to improve its surface properties. Mixed TiC and Ti powders with a TiC-to-Ti mass ratio of 1：3 were put onto the TC4 Ti alloy and subsequently treated by laser beam. The microstructure and composition modifications in the surfaee layer were carefully investigated by using SEM, EDX and XRD. Due to melting, liquid state mixing followed by rapid solidification and cooling, a layer with graded microstructures and compositions formed. The TiC powders were completely dissolved into the melted layer during melting and segregated as fine dendrites when solidified. The inter-dendritic areas were filled with fine a＇ phase lamellae enrich in A1. Mainly due to the reduced TiC volume fraction with increasing depth, the hardness decreases with increasing depth in the laser clad layer with a maximum value of HV1400, about 4.5 times of the initial one.
文摘Social capital has been recognised as a factor affecting sustainable development in every discipline. A network or a partnership is identified as a ＂structural＂ form of social capital and a tool to empower participants in the networks. There is a belief that social networks can be initiated or created at every level of social capital, from micro to macro. However, the concept of community is the key component of social capital, creating both physical ties （geographical locality） and normative behaviours （sense of belonging）. Therefore, this study is intended to enhance social capital at the community or micro-level, in order to sustain tourism development in those areas, and networking is initiated to enhance social capital. Participatory Action Research （PAR） was applied to tourism development in Kon Kaen Province. Tools and techniques used during this study included： observations, preliminary meetings, community meetings, tourism audits, workshops, and network meetings. Eleven districts in Khon Kaen were actively involved in the planning process.
