The adsorption, vibration, and diffusion of O atoms on Rh(100), Rh(111), Rh(110), and Rh(711) surfaces were studied using the 5-parameter Morse potential (5-MP) of interaction between an adatom and a metal surface cluster. Our theoretical calculations provide information about adsorption sites, adsorption geometry, binding energy, and eigenvibration. Our results agreed very well with experimental results. Four major results follow. First, the theoretical calculation showed that on the Rh(100) surface the 4-fold hollow site is the only adsorption site. Second, on the O-Rh(111) system, the 3-fold hollow site is the stable adsorption site. Third, on the Rh(110) surface at low coverage, the O atom is adsorbed preferably on the pseudo-3-fold site, while with increasing coverage, the O atom is adsorbed not only on the pseudo-3-fold site but also on the long bridge site. Last, as for the Rh(711) stepped surface, the 3-fold site on the (111) step is metastable, whereas the 4-fold sites on the (100) terrace are stable, which enables the O atoms to diffuse easily from the 3-fold to the 4-fold site at low coverage. Therefore, the O atoms are adsorbed preferrably on the stable 4-fold sites of the (100) terrace and then later as coverage increases on the metastable 3-fold site of the (110) step.

A novel type of L-serine and chitosan modified glassy carbon electrode (L-Ser/CS-GCE) as a electrochemical sensor for determination of paracetamol was fabricated. With potassium ferricyanide as the probe, electrochemical properties of this sensor were characterized via electrochemical impedance spectroscopy(EIS) and measured EIS data were fitted with an equivalent circuit to investigate the detailed information about the electrode/solution interface. The electrochemical behavior of paracetamol on L-Ser/CS-GCE was studied via Cyclic voltammetry(CV). This electrochemical sensor showed an excellent electrocatalytic activity for the oxidation of paracetamol in pH4.9 acetate buffer solution and accelerated electron transfer between the electrode and paracetamol. Linear scan voltammetry (LSV) was used for determination of paracetamol. Peak current increased linearly with increasing paracetamol concentration in the range of 2.0×10-6～1.0×10 -3mol/L and the detection limit was found to be 8.3×10-7mol/L. The electrochemical sensor showed good stability and reproducibility. The practical application of the electrochemical sensor was successfully applied for determining the concentration of paracetamol in commercial acetaminophen tablets.

The high nitrogen austenitic stainless steel is a kind of difficult-to-machine material. On the basis of material properties analysis, and through comparison test of tool wear resistance, this article made a study on the typical wear & breakage patterns and wears mechanism of insert during the cutting process, and made an analysis on the affection of the mechanical properties of tool materials of various brands to the cutting technological parameters. The results show that the tool wear and breakage are mainly expressed as adhesive wear of rake face and micro chipping of end cutting edge. Compared with the other inserts, YG8 has the best property and a longest life span within the 50~75 m /min cutting speed range.