Mao Ye

Inversion of particle-size distribution from angular light-scattering data with genetic algorithms

A stochastic inverse technique based on a genetic algorithm (GA) to invert particle-size distribution from angular light-scattering data is developed. This inverse technique is independent of any given a priori information of particle-size distribution. Numerical tests show that this technique can be successfully applied to inverse problems with high stability in the presence of random noise and low susceptibility to the shape of distributions. It has also been shown that the GA-based inverse technique is more efficient in use of computing time than the inverse Monte Carlo method recently developed by Ligon et al. [Appl. Opt. 35, 4297 (1996)].

Characteristics of Coke Deposition Over a SAPO-34 Catalyst in the Methanol-to-Olefins Reaction

The deactivation of SAPO-34 catalyst in the methanol-to-olefins process has been studied at temperatures of 400 to 475°C. The catalyst activity keeps stable before a rapid deactivation occurs at a critical coke content. The analysis of retained coke species showed that methylbenzenes were the most abundant species at lower temperatures (400°C and 425°C), while polycyclic aromatics became the dominant species at 475°C. The growth in the retained coke species with increasing temperature comes from the enhanced reactivity of methylbenzenes and methylnaphthalenes at high reaction temperature, where methylnaphthalenes may function as another active reaction centers.

An inverse technique devised from modification of annealing-evolution algorithm for particle sizing by light scattering

An inverse technique devised from the modification of annealing-evolution algorithm has been developed for particle sizing by light scattering. Numerical tests have been performed. The results show that the technique is more effective and has attractive advantages such as high stability against random noise and low sensitivity to the shape of the distributions.

A novel PIV technique using one frame of image

Summary form only given. A novel technique for measuring two-dimensional flow field has been developed. It cans measure the vector field by capturing only one frame of picture of flow field and by using the cross-correlation method. The technique employer rather simple equipment compare with common PIV techniques, which normally needs pulse lasers to capture two frame of pictures. The experimental apparatus (1 mW He-Ne laser and common CCD camera) as shown in this paper is currently suitable to measure a certain range of velocity of flow. The range of measured velocity is from 0.007 to 3 m/s, and measured area 16/spl times/12 mm, which could be expanded while using more power of laser.