The most stable isomers of NanBm （m ＋ n = 6） clusters and their hydrogen storage properties are investigated by means of density functional theory with a 6-311＋G（d） basis set. To study the hydrogen storage prope...The most stable isomers of NanBm （m ＋ n = 6） clusters and their hydrogen storage properties are investigated by means of density functional theory with a 6-311＋G（d） basis set. To study the hydrogen storage properties, all of the stable structures of NanBmHx （m ＋ n =6） clusters have been optimized. It shows that boron atoms of NanBm are separated from the other boron atoms, and form satellite BHx （x = 3, 4） clusters around the centre, which attach to the system by a bridging bond of a hydrogen atom or an Na atom. Compared with the hydrogen storage capabilities, the Na3B3 has the highest hydrogen storage capacity among NanBm clusters. The binding energies, interaction energies of hydrogen atom with NanBm clusters and second difference in energy of Na3B3Hx clusters have been calculated. The results show that the stability of the NanBmHx clusters present an odd-even oscillatory effect, as the number of H atoms increases.展开更多
With its superior comprehensive properties, cold-rolled enameling steel is widely applied in many fields. However, its low yield stress greatly limits its application. This study aims to improve the yield stress of co...With its superior comprehensive properties, cold-rolled enameling steel is widely applied in many fields. However, its low yield stress greatly limits its application. This study aims to improve the yield stress of cold-rolled enameling steel under the premise of meeting formability and enameling properties by strengthening the ferrite matrix via solid strengthening of Mn. The grain size of ferrite before and after enameling,mechanical properties of annealed steel, and precipitation behavior of second-phase precipitates are obtained through studying the microstructure and properties of enameling steel at different stages. The microstructure of the steel investigated at room temperature is found to contain equiaxial ferrite and bunchy cementite particles;the ferrite grains have grown to some extent after enameling. The fine dispersed TiC particles and cementite particles contained in the annealed steel are the main factors improving the hydrogen storage capability. Finally, the result of a falling-ball impact test shows that the steel has achieved excellent adherence.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 10965002 and 30960031)the Science Foundation of Education Committee of Jiangxi Province,China (Grant No. GJJ10540)the Doctoral Startup Fund of Jinggangshan University
文摘The most stable isomers of NanBm （m ＋ n = 6） clusters and their hydrogen storage properties are investigated by means of density functional theory with a 6-311＋G（d） basis set. To study the hydrogen storage properties, all of the stable structures of NanBmHx （m ＋ n =6） clusters have been optimized. It shows that boron atoms of NanBm are separated from the other boron atoms, and form satellite BHx （x = 3, 4） clusters around the centre, which attach to the system by a bridging bond of a hydrogen atom or an Na atom. Compared with the hydrogen storage capabilities, the Na3B3 has the highest hydrogen storage capacity among NanBm clusters. The binding energies, interaction energies of hydrogen atom with NanBm clusters and second difference in energy of Na3B3Hx clusters have been calculated. The results show that the stability of the NanBmHx clusters present an odd-even oscillatory effect, as the number of H atoms increases.
文摘With its superior comprehensive properties, cold-rolled enameling steel is widely applied in many fields. However, its low yield stress greatly limits its application. This study aims to improve the yield stress of cold-rolled enameling steel under the premise of meeting formability and enameling properties by strengthening the ferrite matrix via solid strengthening of Mn. The grain size of ferrite before and after enameling,mechanical properties of annealed steel, and precipitation behavior of second-phase precipitates are obtained through studying the microstructure and properties of enameling steel at different stages. The microstructure of the steel investigated at room temperature is found to contain equiaxial ferrite and bunchy cementite particles;the ferrite grains have grown to some extent after enameling. The fine dispersed TiC particles and cementite particles contained in the annealed steel are the main factors improving the hydrogen storage capability. Finally, the result of a falling-ball impact test shows that the steel has achieved excellent adherence.
