volume diffusion
1.The specific reaction-rate constant k, and temperature follow theordinary Arrhenius relationship, and can be represented as the following formula: k=Aexp(-153, 000/RT)The activation energy, 153 Kcal/mole, can be explained as that required for thegrowth of α-Al_2O_3 in δ-Al_2O_3, with the volume diffusion of aluminum ion as thepossible rate-determining factor.
2. Results Maximum ventilatory volume(MVV), residual volume/total lung capacity(RV/TLC), forced expiratory volume in 1 second (FEV 1), peak expiratory flow(PEF), velocity at 75% vital volume(V 75 ) and diffusion capacity of the lung for carbon monoxide in respiratory failure group was significantly worse than those of control group( P<0.01) .
4.A Control-volume-based Numerical Method for the Convection-diffusion Problem in the Environment
8.When the catalysts pore volume are plugged up by the high boiling point products (whether the pore to be micro or macro), the rate becomes an internal diffusion controlling one, and the effectiveness of the catalytic surface changed into 0.082. The calculated coefficient of diffusion is of 2.4 10~(-5) cm~2/sec, which is in agreement with the magnitude of liquid-phase diffusion.
10.The separation factor of hydrogen to nitrogen measured at a pressure of 0. IMPa was 3.03. It was showed that the gas diffusion through the membrane is governed by Knudsen diffusion mechanism. The most probable pore diameter of an unsupported membrane after calcination at 600℃ was less than 3 nm, its specific surface area reached 294.85m2/g and . the total pore volume was 0. 2778mL/g.
