Above-Threshold Ionization of Xenon by Chirped Intense Laser Pulses

We experimentally investigate above-threshold ionization of xenon subject to chirped intense laser pulses. While for few-cycle laser pulses free of chirp, the Freeman resonance narrow peaks in the photoelectron spectra become strongly suppressed, they will re-emerge for laser pulses with a certain chirp. Moreover, the position of the resonant peaks exhibits a strong dependence on the direction of the chirp. The experimental features can be understood by a two-step ionization process; that is, a multi-photon excitation plus subsequent ionization process.     

气相色谱法测定润肤膏霜中肌醇的含量

肌醇分子式为C6H12O6,化学名称为环已六醇,别名肌糖、筋肉醇、纤维醇、环六甲烷醇等,是生物体内的一种必需的营养因子。其作为营养加强剂,已在食品、保健品、饲料中得到了广泛应用。由于其具有促进细胞生长和防止老化、抑制黑色素产生、防止雀斑生成、防止脱发、促进毛发再生的作用,近年来,肌醇开始应用于日用化妆品领域,已成为制造高级化妆品的重要原料之一[1]。目前,化妆品行业已实施的全成分标识进一步表明部分化妆品中添加了肌