分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: Strong-field ionization of polar molecules contains rich dynamical processes such as tunneling, excitation, and Stark shift. These processes occur on a sub-cycle time scale and are difficult to distinguish in ultrafast measurements. Here, with a developed strong-field model considering effects of both Coulomb and permanent dipole, we show that photoelectron momentum distributions (PMDs) in orthogonal two-color laser fields can be utilized to resolve these processes with attosecond-scale resolution. A feature quantity related to the asymmetry in PMDs is obtained, with which the complex electron dynamics of polar molecules in each half laser cycle is characterized and the subtle time difference when electrons escaping from different sides of the polar molecule is identified.
分类: 核科学技术 >> 核材料与工艺技术 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: A novel extractant, N,N-dimethyl-N,N-didecyl-3-oxa-diglycolamide (DMDDDGA), was designed and synthesized for extraction of lanthanides in the nuclear fuel reprocessing. The extraction behaviors of Gd, Dy, Er and Ho from nitric acid solution were investigated using DMDDDGA in chloroform. The effects of nitric acid concentration, extractant concentration, and temperature on the extraction were investigated. The distribution ratio of lanthanides increases with concentrations of the extractant and nitric acid, but decreases with increasing temperature, which indicates that the extraction process is exothermic. FT-IR spectra indicated that the C=O in DMDDDGA is coordinated with metal ion in the extracted species and the stoichiometries of lanthanides(III) complex are Gd(NO3)33DMDDDGA, Dy(NO3)34DMDDDGA, Er(NO3)34DMDDDGA, and Ho(NO3)34DMDDDGA.