Effects of particle size （A：d50 = 336. 9 μm, B：d50 =123.5μm, C： d50=19.5 μm, D： dso=2.21μm） and content （1 wt% , 3 wt% , 5 wt% , 7 wt% ） of silicon powder on cold crushing strength （CCS） , pore size dis...Effects of particle size （A：d50 = 336. 9 μm, B：d50 =123.5μm, C： d50=19.5 μm, D： dso=2.21μm） and content （1 wt% , 3 wt% , 5 wt% , 7 wt% ） of silicon powder on cold crushing strength （CCS） , pore size distribution and microstructure of Al2O3 - ZrO2 - C refractories coked at high temperature had been investigated by means of mercury porosimeter, SEM, EDS, tic. The results indicated that particle size and content of silicon powder affected the cold crushing strength of coked specimens. It increased with the addition of silicon powder and its finer particle size. However, it decreased greatly when using too fine silicon powder. The particle size and content of silicon powder also impacted the phase evolution and microstructure of coked specimens, much more β-SiC whiskers constituted network structure and well distributed in specimens with reduction of their slenderness ratios when finer silicon powder was added, corresponding to that, the specimens＇ pore size distribution range became narrower with smaller pore diameter, but β-SiC whiskers were distributed sparsely and the specific pore volume of small pores increased when much finer powder was added. It was worthly mentioned that some nitride could form in specimens with addition of appropriate particle size and content of silicon powder.展开更多
The adsorption of NO on the M/c-ZrOu（110） （M = Ru, Rh） surface has been studied with periodic slab model by PWgl approach of GGA within the framework of density functional theory. The results of geometry optimizat...The adsorption of NO on the M/c-ZrOu（110） （M = Ru, Rh） surface has been studied with periodic slab model by PWgl approach of GGA within the framework of density functional theory. The results of geometry optimization indicated that the hollow site is energetically stable for Ru and Rh atoms＇ adsorption on the c-ZrO2（110） surface with adsorption energies of 207.4 and 106.3 kJ/mol, respectively. When NO is adsorbed on the M/ZrO2（110） surface, the N-down adsorption is the most stable. We also studied the adsorption of double NO on the M/c-ZrOu（110） surface. Complete linear synchronous transit and quadratic synchronous transit approaches were used to search the transition state for dissociation reaction. NO has two possible dissociation passways： （1） 2NO → N2 （g） ＋ 20 （ads）, （2） 2NO→ N20 （g） ＋ O （ads）, and the former is easier than the latter based on the calculation results.展开更多
文摘Effects of particle size （A：d50 = 336. 9 μm, B：d50 =123.5μm, C： d50=19.5 μm, D： dso=2.21μm） and content （1 wt% , 3 wt% , 5 wt% , 7 wt% ） of silicon powder on cold crushing strength （CCS） , pore size distribution and microstructure of Al2O3 - ZrO2 - C refractories coked at high temperature had been investigated by means of mercury porosimeter, SEM, EDS, tic. The results indicated that particle size and content of silicon powder affected the cold crushing strength of coked specimens. It increased with the addition of silicon powder and its finer particle size. However, it decreased greatly when using too fine silicon powder. The particle size and content of silicon powder also impacted the phase evolution and microstructure of coked specimens, much more β-SiC whiskers constituted network structure and well distributed in specimens with reduction of their slenderness ratios when finer silicon powder was added, corresponding to that, the specimens＇ pore size distribution range became narrower with smaller pore diameter, but β-SiC whiskers were distributed sparsely and the specific pore volume of small pores increased when much finer powder was added. It was worthly mentioned that some nitride could form in specimens with addition of appropriate particle size and content of silicon powder.
基金Supported by NNSFC(10676007,90922022)Foundation of State Key Laboratory of Coal Combustion(FSKLCC0814)+1 种基金NCETFJ(2006-HX-103,2006-HX-97) Foundation of Fuzhou University(2008-XQ-07,XRC-0732)
文摘The adsorption of NO on the M/c-ZrOu（110） （M = Ru, Rh） surface has been studied with periodic slab model by PWgl approach of GGA within the framework of density functional theory. The results of geometry optimization indicated that the hollow site is energetically stable for Ru and Rh atoms＇ adsorption on the c-ZrO2（110） surface with adsorption energies of 207.4 and 106.3 kJ/mol, respectively. When NO is adsorbed on the M/ZrO2（110） surface, the N-down adsorption is the most stable. We also studied the adsorption of double NO on the M/c-ZrOu（110） surface. Complete linear synchronous transit and quadratic synchronous transit approaches were used to search the transition state for dissociation reaction. NO has two possible dissociation passways： （1） 2NO → N2 （g） ＋ 20 （ads）, （2） 2NO→ N20 （g） ＋ O （ads）, and the former is easier than the latter based on the calculation results.
