No abstract

A catalyst based on Fe/active carbon (Fe/AC) and H2O2 as oxidant for the catalytic wet hydrogen peroxide oxidation of phenol in aqueous solution was investigated. The results indicate that the degradation rate of phenol(20mg/L) reach 90.5% in the presence of Fe/AC(2g/L) and hydrogen peroxide (0.5 %) at pH value 7 after 5 hours under normal temperature and atmospheric pressure. Kinetic studies of the degradation reaction show that the degradation rate of phenol nearly follows the first-order reaction. The reaction rate constant and activity energy are 0.4162 min-1 and 23.64 kJ/mol at 25°C, respectively.

Pd-based catalysts modified with BaO as a promoter was prepared by impregnation method. The catalyst was characterized by H2-temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). The catalytic activity towards methanol showed that the BaO modification promoted the conversion of methanol. The light-off temperature (T50), complete conversion temperature (T90) and ΔT (T90-T50) for methanol oxidation are 100°C, 125°C and 25°C, respectively. The H2-TPR results showed that the addition of BaO increased palladium highly dispersed and promoted the reductive ability. It also enhanced the metal-support interaction and increased the electronic surroundings of Pd and Ce sites, which maintained Pd in a higher oxidized state and Ce4+ in Ce3+ state, consequently increased the activity for methanol oxidation according to XPS measurements.

The three-level converter based on A-NPC topology can improve waveform quality of the output voltage, decrease the switch voltage and reduce the loss of the inductor, thus it has broad application prospects in the electrical power storage domain. This paper built the semi-physical real-time simulation platform of A-NPC three-level battery power storage system by designing the control system and the main circuit of the A-NPC topology converter, and researched the control mechanism of the power storage converter control algorithm with digital simulation platform. The experimental results of the prototype machine show that the A-NPC three-level battery power storage system built in this paper was fine, compared with the most common two-level topology, three-level converter has characteristics of lower output current waveform distortion factor, lower current harmonics and higher efficiency. Three-level converter used in the power storage system is able to gain access to low THD during steady-state operation and fine dynamic characteristics.

X-ray Fluorescence was used to determine the content of 25 inorganic elements in Chengdu dust in this article, and enrichment factor was used to analyze its distribution characteristics and source apportionment. The results showed that Cr was the extremely severe pollutant, with its average concentration of 64.57μg/g, the average enrichment factor coefficient of 477.79, which was more than 10 times higher than background value, suggested it was significantly contributed by the anthropogenic sources. Ca was the heavily polluted element, with its concentration of 7.71μg/g in average, and the average enrichment factor coefficient being 12.26, which was more than 10 times of the background value, showed it was also affected by the anthropogenic sources. The enrichment factor coefficient of Na, As, Co, Cu, Mn, Ni, Pb, Se, V, Zn, K, Mg, Br, Cs was about 1 in average, illustrated that they were not obviously affected by the man-made pollution.