The diffusible hydrogen contents in precharged (Co,Fe) 3V alloy were measured. It is found that atomic ordering can not promote hydrogen penetration in the (Co,Fe) 3V alloy. The ultimate tensile strength (UTS) and duc...The diffusible hydrogen contents in precharged (Co,Fe) 3V alloy were measured. It is found that atomic ordering can not promote hydrogen penetration in the (Co,Fe) 3V alloy. The ultimate tensile strength (UTS) and ductilities in various condition were also investigated. The results show that the UTS and elongation of disordered alloy are higher than that of ordered one with fixed diffusible hydrogen content and (Co,Fe) 3V alloy with ordered structure is highly susceptible to the embrittlement in hydrogen gas. The factor which may affect the susceptibility to the embrittlement of (Co,Fe) 3V alloy in hydrogen gas is mainly due to that the atomic ordering may accelerate the kinetics of the catalytic reaction for the dissociation of molecular hydrogen into atomic hydrogen. However, it can not be roled out that atomic ordering intensifies planar slip and restricts cross slip at the grain boundaries and enhances the susceptibility of the alloy to hydrogen embrittlement.展开更多
Dry valleys are a striking geographic landscape in Hengduan Mountains Region and are characterized by low rainfall, desert type of vegetation and fragile environment. Past efforts and resources have been concentrated ...Dry valleys are a striking geographic landscape in Hengduan Mountains Region and are characterized by low rainfall, desert type of vegetation and fragile environment. Past efforts and resources have been concentrated mainly on rehabilitation of degraded ecosystem and fragile environment, particularly reforestation, while socio-economic development has been largely overlooked. Despite successes in pocket areas, the overall trend of unsustainability and environmental deterioration are continuing. It is important to understand that uplift of the Tibetan Plateau is the root cause of development of dry valleys, and development and formation of dry valleys is a natural process. Human intervention has played a secondary role in development of dry valleys and degradation of dry valleys though human intervention in many cases has speeded up environmental degradation of the dry valleys. It is important to understand that dry valleys are climatic enclaves and an integrated approach that combines rehabilitation of degraded ecosystems and socio-economic development should be adopted if the overall goal of sustainable development of dry valleys is to be achieved. Promotion of niche-based cash crops, rural energy including hydropower, solar energy, biogas and fuelwood plantation is recommended as the priority activities.展开更多
文摘The diffusible hydrogen contents in precharged (Co,Fe) 3V alloy were measured. It is found that atomic ordering can not promote hydrogen penetration in the (Co,Fe) 3V alloy. The ultimate tensile strength (UTS) and ductilities in various condition were also investigated. The results show that the UTS and elongation of disordered alloy are higher than that of ordered one with fixed diffusible hydrogen content and (Co,Fe) 3V alloy with ordered structure is highly susceptible to the embrittlement in hydrogen gas. The factor which may affect the susceptibility to the embrittlement of (Co,Fe) 3V alloy in hydrogen gas is mainly due to that the atomic ordering may accelerate the kinetics of the catalytic reaction for the dissociation of molecular hydrogen into atomic hydrogen. However, it can not be roled out that atomic ordering intensifies planar slip and restricts cross slip at the grain boundaries and enhances the susceptibility of the alloy to hydrogen embrittlement.
基金supported jointly by the National Key Project for Basic Research on Tibetan Plateau(G1998040800)Promotion Plan of the Ministry of Education and President Foundation of the Chinese Academy of Sciences.
文摘Dry valleys are a striking geographic landscape in Hengduan Mountains Region and are characterized by low rainfall, desert type of vegetation and fragile environment. Past efforts and resources have been concentrated mainly on rehabilitation of degraded ecosystem and fragile environment, particularly reforestation, while socio-economic development has been largely overlooked. Despite successes in pocket areas, the overall trend of unsustainability and environmental deterioration are continuing. It is important to understand that uplift of the Tibetan Plateau is the root cause of development of dry valleys, and development and formation of dry valleys is a natural process. Human intervention has played a secondary role in development of dry valleys and degradation of dry valleys though human intervention in many cases has speeded up environmental degradation of the dry valleys. It is important to understand that dry valleys are climatic enclaves and an integrated approach that combines rehabilitation of degraded ecosystems and socio-economic development should be adopted if the overall goal of sustainable development of dry valleys is to be achieved. Promotion of niche-based cash crops, rural energy including hydropower, solar energy, biogas and fuelwood plantation is recommended as the priority activities.
