倍频YAG泵浦脉冲钛宝石激光器设计与激光运转

用10ns倍频YAG激光泵浦实现了Ti~(3+):Al_2O_3激光运转,最大输出能量可达37mJ,能量转换效率40%,斜率效率59%,量子效率80%,泵浦阈值0.5～1.2J/cm~2,在662～938nm波长范围内实现了连续调谐.     

铜(410)表面乙烯吸附与脱氢的理论研究

Adsorption and dehydrogenation of ethylene on Cu(410) surface are investigated with firstprinciples calculations and micro-kinetics analysis. Ethylene dehydrogenation is found to start from the most stable π-bonded state instead of the previously proposed di-σ-bonded state. Our vibrational frequencies calculations verify the π-bonded adsorption at step sites at low coverage and low surface temperature and di-σ-bonded ethylene on C-C dimer (C₂H₄-CC) is proposed to be the species contributing to the vibrational peaks experimentally observed at high coverage at 193 K. The presence of C₂H₄-CC indicates that the dehydrogenation of ethylene on Cu(410) can proceed at temperature as low as 193 K.