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The quaternary alloys La0.8-xCexMg0.2Ni3.8 (x=0, 0.1,0.3,0.5) were prepared by induction melting, and the effects of partial substitution of Ce for La on the phase structure and electrochemical performances of super lattice La4MgNi19 negative materials were investigated. Results show that La4MgNi19 alloys contain LaNi5 phase, (La,Mg)2Ni7(3R-Ce2Ni7 and 2H-Gd2Co7) phase, (La,Mg)5Ni19 (3R-Ce5Co19) phase. The 2H-Pr5Co19 type phase appears while (La,Mg)2Ni7 phase disappears, after partial substitution of Ce for La. The increase of Ce element substitution has led to an obvious increase of the abundance of A5B19 phase and decrease of AB5 phase accordingly. Ce contributes to the formation of A5B19 phase, especially 2H-Pr5Co19 type phase. With the increase of Ce content from 0 to 0.5, the maximum discharge capacity of alloy electroded increases firstly and then decreased. The x=0.1 alloy exhibits a maximum discharge capacity of 380.36 mAh/g. It is also found that this substitution has caused a significant increase in the activation number, the cyclic stability, high-rate discharge ability. The well performance demonstrates that it is the hydrogen diffusion in the alloy that controls the high rate discharge.

Mg2Ni-Ni-5%RExOy(CeO2, Nd2O3, Tb4O7) composites were synthesized via ball milling method. The microstructure and hydrogen storage properties of the materials were analyzed systematically by XRD, SEM, EDS, the electrochemical and kinetic measurements. The results show that the crystallinities of the composites with rare earth oxides decrease, and the distribution of the rare earth oxide catalysts on the surface of alloys is uniform. The maximum discharge capacities of the composites with rare earth oxides rise evidently,the discharge capacity of the sample containing Tb4O7 reaches to 871mAh·g-1 at room temperature, and the composites can also keep higher cycling stability. The CeO2 and Tb4O7 catalysts can enhance the abilities of charge transfer on the surface of alloys, and improve the transmission rate of H atoms in the bulk of Mg2Ni alloy obviously. The rare earth oxides catalysts can also increase the gaseous hydrogen absorption capacity. The hydrogen storage capacity of the sample with Tb4O7 reaches to 2.02%(mass fraction) at 250℃, which is the maximum hydrogen absorption capacity among these samples, but the hydriding rate is relatively slow at lower temperature. The catalytic effect of the rare earth oxides is mainly related to the changeable valences of the rare earth ions, that is, the more likely of the valences change of the ions, the better the catalytic activities exhibit. The catalytic activities in descending order are Tb4O7, CeO2 and Nd2O3.

The quaternary alloys La0.8-xCexMg0.2Ni3.8 (x=0, 0.1,0.3,0.5) were prepared by induction melting, and the effects of partial substitution of Ce for La on the phase structure and electrochemical performances of super lattice La4MgNi19 negative materials were investigated. Results show that La4MgNi19 alloys contain LaNi5 phase, (La,Mg)2Ni7(3R-Ce2Ni7 and 2H-Gd2Co7) phase, (La,Mg)5Ni19 (3R-Ce5Co19) phase. The 2H-Pr5Co19 type phase appears while (La,Mg)2Ni7 phase disappears, after partial substitution of Ce for La. The increase of Ce element substitution has led to an obvious increase of the abundance of A5B19 phase and decrease of AB5 phase accordingly. Ce contributes to the formation of A5B19 phase, especially 2H-Pr5Co19 type phase. With the increase of Ce content from 0 to 0.5, the maximum discharge capacity of alloy electroded increases firstly and then decreased. The x=0.1 alloy exhibits a maximum discharge capacity of 380.36 mAh/g. It is also found that this substitution has caused a significant increase in the activation number, the cyclic stability, high-rate discharge ability. The well performance demonstrates that it is the hydrogen diffusion in the alloy that controls the high rate discharge.

Nanosized CuO particles were synthesized via precipitation method, and the crystalline sizes were controlled by adjusting different calcinations temperature. XRD result shows that the obtained samples exhibit CuO single phase structure, the crystalline sizes are 7.5, 14.4nm and 23.4nm respectively. Then Mg2Ni-Ni-5%CuO composites were obtained through ball milling technique, the electrochemical hydrogen storage properties, kinetic performances and the activation energies of hydrogen desorption were tested and analyzed. The results show that the maximum discharge capacities and the electrocatalytic activity on the surface and the diffusivities of H in the bulk of the Mg-based composites electrodes are improved by adding the nanosized CuO catalysts. DSC measurement shows that the nanosized CuO catalyst leads to decrease in hydrogen desorption temperature by about 50K than that of composites without CuO. The activation energies of the composites of Mg2Ni-Ni and Mg2Ni-Ni -5% CuO600,which are calculated by Kissinger formula, are 86.9kJ/mol and 89.3kJ/mol respectively.

The Ni-5%RExOy (CeO2, La2O3, Eu2O3) as composite additives, Mg2Ni-Ni-5%RExOy composites were prepared by the ball milling method. The effects of different additives on the structure, morphology, electrochemistry and kinetic properties of Mg2Ni alloy were studied systematically. The results show that composite additives can improve the proportion of amorphous and nanocrystalline structure of Mg2Ni alloy. The particle size is homogeneous but the agglomeration is observed in the sample with Ni-5%CeO2 additives. The composites with additives show higher maximum discharge capacity and better cycle stabilities. All of these three kinds of composite additives can improve the kinetic properties of the composites effectively, including optimizing the charge-transfer ability, the reversibility of the electrochemical reaction on the alloy surface, and enhancing the diffusion coefficients of H atoms in the bulk of alloy. Among these three kinds of additives, Ni-5%CeO2 additive shows the best catalysis effect on promoting the kinetic properties of the composites.

We analyzed culturable endophytic bacteria from Moso bamboo (Phyllostachys edulis) using traditional bacterial isolation and culture methods and then studied the colony characteristics and diversity with a 16S rDNA sequence analysis. We isolated 82 endophytic bacteria strains belonging to 47 species in 26 genera from the root, rhizome, stem and leaves of Moso bamboo species from populations on Wuyi Mountain, and in the Jiangle and Changting regions. There were significant differences in the composition of the culturable endophytic bacteria isolated from the different areas and from different tissues. The dominant bacteria strains from the Wuyi Mountain samples were Arthrobacter, Staphylococcus, Bacillus and Enterobacter, while the dominant bacteria from the Jiangle samples were Bacillus, Staphylococcus and Curtobacterium, and the dominant bacteria in the Changting samples were Alcaligenes, Pseudomonas, Staphylococcus and Bacillus. Our results demonstrate the abundant diversity of endophytic bacteria in Moso bamboo.