The extended LEPS constructed by 5-MP (the 5-parameter Morse potential) is performed. At low coverage, O2 prefers to dissociate on the Pd(100) and (110) surfaces; however, at high coverage, it can stably adsorb in the H−B−H site on the Pd(111) surface and more molecular states are found. The calculation results agree well with the experimental results, especially, the results of O2 on Pd(111) explain well the three precursor states (the superoxo-like state, the peroxo-like and second peroxo-like state) of HREELS and EELS results. Simultaneously, the conceptions of the molecular dissociation limit and the surface dissociation distance are brought forward first, which illuminate the dissociation mechanism of the O2 on the low-index surfaces and offer the answer to the question why is it more difficult for O2 to dissociate on the (111) surface than on the (100) and (110) surfaces?

The accurate remote estimation of the Secchi disk depth (ZSD) in turbid waters is essential in the monitoring the ecological environment of lakes. Using the field measured ZSD and the remote sensing reflectance (Rrs(λ)) data, a new semi-analytical algorithm (denoted as ZSDZ) for retrieving ZSD was developed from Rrs(λ), and it was applied to Geostationary Ocean Color Imager (GOCI) images in extremely turbid waters. Our results are as follows: (1) the ZSDZ performs well in estimating ZSD in turbid water bodies (0.15 m < ZSD < 2.5 m). By validating with the field measured data that were collected in four turbid inland lakes, the determination coefficient (R2) is determined to be 0.89, with a mean absolute square percentage error (MAPE) of 22.39%, and root mean square error (RMSE) of 0.24 m. (2) The ZSDZ improved the retrieval accuracy of ZSD in turbid waters and outperformed the existing semi-analytical schemes. (3) The developed algorithm and GOCI data are in order to map the hourly variation of ZSD in turbid inland waters, the GOCI-derived results reveal a significant spatiotemporal variation in our study region, which are significantly driven by wind forcing. This study can provide a new approach for estimating water transparency in turbid waters, offering important support for the management of inland waters.

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The 5-parameter Morse potential (for short 5-MP) of the interaction between C, 0 atom and Rh surface and the extended LEPS potential have been constructed, and the adsorption and diffusion of CO molecules on Rh low index surfaces and open rough Rh(331) stepped surface are investigated. This work puts forward the concept of vibration dactylogram property for molecular adsorption states. The calculation results and the analysis of vibration dactylogram show that there exists the commonness in the adsorption on Rh low index surfaces and Rh(331) stepped surface: with the increasing coverage, the top, bridge sites are adsorbed in perpendicularly in sequence, and the top sites are the steady adsorption sites and the bridge sites are the next. On (100) surface, CO molecules obtain the eigenvibration of 2009, 1946 cm-1 on the top and bridge sites respectively and the difference between the binding energy of above two sites is 0.09 eV; on (110) surface, CO molecules obtain the eigenvibration of 2019, 1961 cm-1 respectively; on (111) surface, CO molecules on the top, bridge and hollow sites produce the eigenvibration of 2000, 1912, 1894 cm-1 respectively, the binding energies of the three sites decrease in tum and the discrepancy between the top and bridge sites is 0.03 eV; on (331) surface, top and bridge sites between two equivalent top sites are adsorbed in, and then obtain the eigenvibration of2018, 1987 cm-\ 1969, 1927 cm-1 respectively.

An analytical model of secondary electron (SE) emission (SEE) from metal surface with regular structure is presented. In this model, the quantitative relationship between the SE emission yield (SEY) and surface topography is examined. Using the idea of multi-generation for SE emission, the first-generation of SEs is considered as being dominant in total SEs. The shielding effect of the surface structures on the SE is found to be the main factor influencing final SEY. On the basis of the cosine distribution of secondary electrons emission direction, the quantitative relationship between the SEY and surface topography parameters is revealed. Then taking the rectangular and triangular grooves for example, the analytical formulas of first-generation SEY are derived for both normal and oblique incidence. The analytical results are then verified with the Monte Carlo simulation results and experimental data. The results show that a rectangular groove with a bigger depth-to-width ratio can suppress the SEE more efficiently. For a triangular groove, owing to having both enhancing and suppressing effects on SEE, a small groove angle is required for effective SEE suppression. The present analytical model gives an insight into the relationship between the SEY and the surface topography parameters and is helpful for the structure design to modify SEY.