Influence of Rare Earth Oxide on the Performance of Secondary Zinc Electrodes

应用阴极极化法在锌电极上覆盖一层稀土氢氧化物膜La(OH)3或Ce(OH)3,并用循环伏安、动电位极化、定电位阴极极化实验研究其电化学性能.结果表明,La(OH)3或Ce(OH)3膜能抑制锌酸根离子的迁移,提高析氢过电位,降低腐蚀电流密度并能抑制枝晶生长.SEM观测显示,稀土氧化物La2O3或CeO2改变了锌沉积形态,进而提高了锌酸钙电极的充放电循环性能.Influence of La(OH)_(3 )or Ce(OH)_3in secondary zinc electrode was investigated by the cyclic voltammetry, potentiodynamic polarizationand potentiostatic polarization tests and influence of La_2O_3or CeO_2in the charge/discharge performance of Zn/Ni battery was studied by galvanostatic charge/discharge experiment. The results showed that the film of rare earth hydroxide prevented the zincate species from transferring toward solution, enhanced hydrogen overpotential and decreased thecorrosion current density (i_(corr)), and therefore inhibited zinc corrosion. The potentiostatic polarization results at100mV overpotential showed thatLa(OH)_3or Ce(OH)_3coated on the zinc electrode effectively suppressed the zinc dendrite growth. The La_2O_(3 )or CeO_2addition to the calcium zincate electrode improved the cycle performance of Zn/Ni battery.作者联系地址：南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所 天津300071 ,天津300071 ,天津300071 ,天津300071Author's Address: Institute of New Energy Material Chemistry, Nankai University, Tianjin 300071,Chin

Cloning and Expression of FcBMP-7 Gene in Chinese Shrimp Fenneropenaeus chinensis

In order to analyze the expression of bone morphogenetic protein-7 (BMP-7) gene,a member of transforming growth factor beta (TGF-beta) superfamily, in the muscle growth and development of Chinese shrimp Fenneropenaeus chinensis,the BMP-7 (FcBMP-7) was cloned by through Rapid Amplification of cDNA Ends (RACE) technology. The full-length cDNA of FcBMP-7 was 2003 bp, containing 466 bp of 5' untranslated region(UTR),295 bp of 3' UTR and 1242 bp of open reading frame(ORF),encoding 413 amino acids. Using real-time PCR technology to analyze the expression pattern of FcBMP-7 in the muscle tissues of Chinese shrimp larvae at five different developmental stages (gastrulation stage,nauplius stage, zoea stage,mysis stage,and postlarval stage). The results showed that the gene was expressed in all stages of larval development,with the minimal expression in the gastrula stage,the significant increase in expression level from the nauplius stage (P<0.05), and the maximal expression level in the mysis stage; indicating that FcBMP-7 was involved in the development of shrimp muscle. Expression pattern of FcBMP-7 in 8 tissues of two sizes of Chinese shrimp revealed that FcBMP-7 had extensive tissue expression. There were significantly different in the expression levels in most tissues between the two groups (P<0.05),especially in the heart,intestine,muscle,periopod and pleopod (P<0.01). The findings suggested that FcBMP-7 gene played a certain role in the muscle growth and development of Chinese shrimp,which would lay a theoretical foundation for further analysis of the molecular mechanism of muscle development in Chinese shrimp