Mg-based hydrogen storage alloys are considered as a promising candidate for hydrogen system because of its lightweight, high storage capacity, low price and rich mineral resources. In detail, we reviewed the preparat...Mg-based hydrogen storage alloys are considered as a promising candidate for hydrogen system because of its lightweight, high storage capacity, low price and rich mineral resources. In detail, we reviewed the preparation and properties of Mg-Ni-based hydrogen storage alloys. All kinds of attempts have been done to improve the hydriding and dehydriding behaviors. It is found that the partial substitution of foreign elements can decrease the hydrogen absorption temperature, especially the substitution of a more electronegative element, such as AI and Mn. Mechanical alloying (MA) and mechanical grinding (MG) are the most effective methods to improve the hydriding/dehydriding kinetics and electrochemical capacity, and decrease the desorption temperature. but the corrosion resistance is so poor that the 80% of maximum capacity is lost within ten cycles. Microencapsulation is a useful measurement for improving the corrosion resistance and electrocatalytic activity. fn order to improve the properties of the alloys for practical application, the alloys should have a large number of defects, which give activated sites, subsequently, MA, MG and electroless plating should be used to improve the hydriding/dehydriding kinetics and protect the surface of alloys, respectively. The new composite Mg-based alloys give a new way for the hydrogen storage material to practical application. Furthermore we put forward several problems which will be discussed in future.展开更多
Subject Code:B01With the support by the National Natural Science Foundation of China,a creative study by the research group led by Prof.Chen Qianwang(陈乾旺)from the University of Science and Technology of China and H...Subject Code:B01With the support by the National Natural Science Foundation of China,a creative study by the research group led by Prof.Chen Qianwang(陈乾旺)from the University of Science and Technology of China and High Magnetic Field Laboratory,Hefei Institutes of Physical Science,Chinese Academy of展开更多
Objective To explore the effects of a potential anti-oxidative plant,Erigeron multiradiatus(Asteraceae) ,plant materials from naturally distributed high-altitude populations at different stages of life cycle were coll...Objective To explore the effects of a potential anti-oxidative plant,Erigeron multiradiatus(Asteraceae) ,plant materials from naturally distributed high-altitude populations at different stages of life cycle were collected.Methods Fifteen extracts obtained from the Ganzi region(Sichuan,China) were studied to assess their radical-scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals and reducing power ability.Moreover,considering that anti-oxidants and free radical scavengers can also exert protective effect on endothelial cells from oxidative injury,these extracts were also evaluated for their anti-oxidative activity against cellular injury in the cultured human endothelial cell line(ECV304) induced by hydrogen peroxide(H2O2) .Results All the extracts had radical-scavenging and/or reducing power ability,and the most active extract was found during flowering whereas the lowest appeared during vegetative growth period.The accumulation of anti-oxidative compounds was found to be affected by the altitude of growth environment.Total flavonoid content assay was also performed to support this outcome.Furthermore,these extracts also exhibited different effects on attenuating H2O2-induced cytotoxicity and inhibiting lipid peroxidation and LDH leakage from endothelial cells.Conclusion E.multiradiatus may be an important natural anti-oxidant and this property may contribute to verifying the utilization of this plant in Tibet folk medicine.展开更多
基金The work is subsidized by the Special Funds for Major state Basic Research Projects and Project 59781001 of the National Natural Science Foundation of China.
文摘Mg-based hydrogen storage alloys are considered as a promising candidate for hydrogen system because of its lightweight, high storage capacity, low price and rich mineral resources. In detail, we reviewed the preparation and properties of Mg-Ni-based hydrogen storage alloys. All kinds of attempts have been done to improve the hydriding and dehydriding behaviors. It is found that the partial substitution of foreign elements can decrease the hydrogen absorption temperature, especially the substitution of a more electronegative element, such as AI and Mn. Mechanical alloying (MA) and mechanical grinding (MG) are the most effective methods to improve the hydriding/dehydriding kinetics and electrochemical capacity, and decrease the desorption temperature. but the corrosion resistance is so poor that the 80% of maximum capacity is lost within ten cycles. Microencapsulation is a useful measurement for improving the corrosion resistance and electrocatalytic activity. fn order to improve the properties of the alloys for practical application, the alloys should have a large number of defects, which give activated sites, subsequently, MA, MG and electroless plating should be used to improve the hydriding/dehydriding kinetics and protect the surface of alloys, respectively. The new composite Mg-based alloys give a new way for the hydrogen storage material to practical application. Furthermore we put forward several problems which will be discussed in future.
文摘Subject Code:B01With the support by the National Natural Science Foundation of China,a creative study by the research group led by Prof.Chen Qianwang(陈乾旺)from the University of Science and Technology of China and High Magnetic Field Laboratory,Hefei Institutes of Physical Science,Chinese Academy of
基金Applied Fundamental Research Scheme of the Bureau of Science and Technology of Sichuan Province, China (2009JY0017)the Fundamental Research Funds for the Central Universities, Southwest University for Nationalities (09NZYZJ01)
文摘Objective To explore the effects of a potential anti-oxidative plant,Erigeron multiradiatus(Asteraceae) ,plant materials from naturally distributed high-altitude populations at different stages of life cycle were collected.Methods Fifteen extracts obtained from the Ganzi region(Sichuan,China) were studied to assess their radical-scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals and reducing power ability.Moreover,considering that anti-oxidants and free radical scavengers can also exert protective effect on endothelial cells from oxidative injury,these extracts were also evaluated for their anti-oxidative activity against cellular injury in the cultured human endothelial cell line(ECV304) induced by hydrogen peroxide(H2O2) .Results All the extracts had radical-scavenging and/or reducing power ability,and the most active extract was found during flowering whereas the lowest appeared during vegetative growth period.The accumulation of anti-oxidative compounds was found to be affected by the altitude of growth environment.Total flavonoid content assay was also performed to support this outcome.Furthermore,these extracts also exhibited different effects on attenuating H2O2-induced cytotoxicity and inhibiting lipid peroxidation and LDH leakage from endothelial cells.Conclusion E.multiradiatus may be an important natural anti-oxidant and this property may contribute to verifying the utilization of this plant in Tibet folk medicine.
