Lifetime isone of the important indicators of automotive proton exchange membrane fuel cells. People used to evaluate the lifetime of vehicular fuel cells by laboratory tests or road tests that usually take thousands ...Lifetime isone of the important indicators of automotive proton exchange membrane fuel cells. People used to evaluate the lifetime of vehicular fuel cells by laboratory tests or road tests that usually take thousands hours even years. In order to achieve a rapid evaluation technique and to seek lifetime extension methods, a lifetime calculation formation was drawn out in consideration of the vehicle driving cycle and the working condition factors. Bench experiments were individually carried out on two fuel-cell stacks same as ones applied on vehicle, and the performance decay rates of the two stacks were obtained under four operation conditions of changing load cycle, start-stop cycle, idling and heavy load. As a result, the predicted lifetimes rather conform to the actual running status in road test. And the research on the fuel cell performance decay rates under different load conditions was also done. Consequently, an unexpected finding was discovered that operating under micro-current has an effect on recovering fuel cell performance. The vehicle fuel cell rapid assessment method only requires four laboratory tests of driving cycle, load cycle, idle operating conditions and heavy load conditions, and the whole process merely lasts less than 250 h. These experimental results can be used to predict the vehicular fuel cell lifetimes on various utility models or driving cycles, therefore to optimize the application model to prolong the fuel cell lifetime. Actually in the experiment, it has already been proved successfully that the fuel cell lifetime could be extended from 1 100 h to 2 600 h by optimizing operating mode. The quick evaluation method is helpful to develop extended life fuel cell and to deplete fuel cell for a longer time.展开更多
Reclamations of dumps in the Most Basin that is located in the North Bohemia consist of restoration of extremely unfavourable properties of rocks that are poured down onto the dump body. These rocks come from the surf...Reclamations of dumps in the Most Basin that is located in the North Bohemia consist of restoration of extremely unfavourable properties of rocks that are poured down onto the dump body. These rocks come from the surface layer and the layer where coal bed is present. Sands, clay sands and kaolin (illitic clays) are the main components that occur in the material. Other components are predominantly organic (coal) mass, siderite and pyrite. This report briefly summarizes the history and present of ore, non-metallic and coal mining in the region and addresses in detail the issue of moderating the consequences of mining, which is one of the principal activities of the Research Institute for Brown Coal, j.s.c. in Most. The concept of landscape reclamation in the largest dumps after mining ends, the technical reclamation methodology and the well considered use of fertilizable soil are main results presented in this article.展开更多
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2007AA05Z125)
文摘Lifetime isone of the important indicators of automotive proton exchange membrane fuel cells. People used to evaluate the lifetime of vehicular fuel cells by laboratory tests or road tests that usually take thousands hours even years. In order to achieve a rapid evaluation technique and to seek lifetime extension methods, a lifetime calculation formation was drawn out in consideration of the vehicle driving cycle and the working condition factors. Bench experiments were individually carried out on two fuel-cell stacks same as ones applied on vehicle, and the performance decay rates of the two stacks were obtained under four operation conditions of changing load cycle, start-stop cycle, idling and heavy load. As a result, the predicted lifetimes rather conform to the actual running status in road test. And the research on the fuel cell performance decay rates under different load conditions was also done. Consequently, an unexpected finding was discovered that operating under micro-current has an effect on recovering fuel cell performance. The vehicle fuel cell rapid assessment method only requires four laboratory tests of driving cycle, load cycle, idle operating conditions and heavy load conditions, and the whole process merely lasts less than 250 h. These experimental results can be used to predict the vehicular fuel cell lifetimes on various utility models or driving cycles, therefore to optimize the application model to prolong the fuel cell lifetime. Actually in the experiment, it has already been proved successfully that the fuel cell lifetime could be extended from 1 100 h to 2 600 h by optimizing operating mode. The quick evaluation method is helpful to develop extended life fuel cell and to deplete fuel cell for a longer time.
基金supported by project QJ1520307 entitled“Sustainable Forms of Management in an Anthropogenically Burdened Region.”financial support from state budget resources through the KUS program,Ministry of Agriculture of the Czech Republic.
文摘Reclamations of dumps in the Most Basin that is located in the North Bohemia consist of restoration of extremely unfavourable properties of rocks that are poured down onto the dump body. These rocks come from the surface layer and the layer where coal bed is present. Sands, clay sands and kaolin (illitic clays) are the main components that occur in the material. Other components are predominantly organic (coal) mass, siderite and pyrite. This report briefly summarizes the history and present of ore, non-metallic and coal mining in the region and addresses in detail the issue of moderating the consequences of mining, which is one of the principal activities of the Research Institute for Brown Coal, j.s.c. in Most. The concept of landscape reclamation in the largest dumps after mining ends, the technical reclamation methodology and the well considered use of fertilizable soil are main results presented in this article.
