摘要：We try to design the lattice with 2 super periods and 4-DBA structure in order to provide more drifts for the future development of the TTX source. Due to the space limitation in the lab, the 4-DBA lattice is *** the paper,we present the lattice design with a 4-DBA structure mainly for the pulse mode of the compact laser-electron storage ring （LESR）. Element parameters of the lattice are optimized with the help of the professional software and beam dynamics such as intra-beam scattering （IBS） and Compton scattering （CS） are calculated. Besides, the fringe field effect is analyzed with the numerical method.

摘要：Highly active and low-cost catalysts for electrochemical reactions such as the hydrogen evolution reaction （HER） are crucial for the development of efficient energy conversion and storage technologies. Theoretical simulations have been instrumental in revealing the correlations between the electronic structure of materials and their catalytic activity, and guide the prediction and development of improved catalysts. However, difficulties in accurately engineering the desired atomic sites lead to challenges in making direct comparisons between experi- mental and theoretical results. In MoS2, the Mo-edge has been demonstrated to be active for HER whereas the S-edge is inert. Using a computational descriptor- based approach, we predict that by incorporating transition metal atoms （Fe, Co, Ni, or Cu） the S-edge site should also become HER active. Vertically standing, edge-terminated MoS2 nanofilms provide a well-defined model system for verifying these predictions. The transition metal doped MoS2 nanofilms show an increase in exchange current densities by at least two-fold, in agreement with the theoretical calculations. This work opens up further opportunities for improving electrochemical catalysts by incorporating promoters into particular atomic sites, and for using well-defined systems in order to understand the origin of the promotion effects.