Biomedical subjects
Publications and source records attributed to Wan Zhang.
We propose a novel approach to similarity assessment for graphic symbols. Symbols are represented as 2D kernel densities and their similarity is measured by the Kullback-Leibler divergence. Symbol orientation is found by gradient-based angle searching or independent component analysis. Experimental results show the outstanding performance of this approach in various situations.
The influence of the synthesis conditions (method and sequence of adding reagents, reaction temperature, stirring rate) on the luminescence performance of the rare earth ternary complex compound europium-salicylic acid-(1,10-phenanthroline) [Eu(Sal)(3)Phen] was studied. We show that the method and sequence of adding reagents greatly affects the luminescence properties of the products. Within the range of synthesis temperatures (30-70 degrees C), the complex has a better luminescence performance at the lower temperature. However, performance decreased when the temperature decreased to 20 degrees C. Increase of stirring rate led to better performance in the range 200-700 r.p.m. Infrared (IR) spectroscopy, scanning electron microscopy (SEM) and wide-angle X-ray diffraction (WAXD) were utilized to characterize the structure and morphology of Eu(Sal)(3)Phen. The studies demonstrate that the crystallization of the product increased with increasing luminescence of the product. Therefore, it is proposed that increasing the crystallization of the product will enhance its luminescence performance.