清华大学硕士论文博士论文格式及范文(6)

清华大学硕士论文博士论文格式及范文

英 文 摘 要

Abstract

Electronic excited state is one of the common forms in which atoms, molecules and ions exist in the nature. Study on the characters and dynamics behaviors of the molecular excited states, such as energy levels, lifetimes, predissociation and auto-ionization, as well as on their electronic structures, is not only a significant topic related to chemical reactions and chemical dynamics, but also one of the frontiers in the field of atomic and molecular physics.

In present dissertation, experimental studies of the predissociated Rydberg states of CaCl by using the resonance enhanced multiphoton ionization (REMPI) and ion-dip detection spectroscopy were carried out. Five core-penetrating Rydberg states of CaCl in the intermediate effective principle quantum number region, n*=5~7, were observed for the first time. Theoretical analysis confirmed the predissociation mechanism which supposed these Rydberg states were led by an interaction with a

2+

continuum state. A potential energy curve of this 2 + continuum state in the

energy region of 45000~47500cm-1 was fitted based on the observed predissociation linewidths. Some Rydberg levels with anomalously small rotational constants were also observed. They might be the fragments of the core-nonpenetrating Rydberg states. All these results provide rich information for understanding the mechanism of dissociation of molecules with highly polar core and some correlative dynamical processes.

……………………………………………………………………………………

Key words: molecular excited state, rydberg state, predissociation, Na2, CaCl

- I -