- 作者: 蔡政憲 ; 徐子正 ; 牟中原
- 作者服務機構: 台灣大學化學系
- 中文摘要: We have developed a videomicroscopic computer imaging system for observing meso-scale nonequilibrium physicochemical structures. Charged-coupled device (CCD) in optical detection, and computer-enhancement of digitized image, have greatly improved the resolution, sensitivity, and dynamical range of this technique. We apply this system to the observation of various complex crystallization patterns from suberic acid melts and camphene condensation. These patterns are of the scale one to 100 micrometers. They are resulted from nonlinear dynamical instabilities of a growing crystal fronts. The following patterns are observed; dendrites, destabilization of flat surface, cellular solidification, tip-splitting, and dense branches. A computer simulation based on diffusion-limited aggregates(DLA) model is performed to show this instability. The DLA model with surface tension effect is able to result in fractal-like, dendrite, and needle-like growth pattern.
- 英文摘要: --
- 中文關鍵字: Nonequilibrium Pattern; Diffusion Limited Aggregates; Crystal Growth; Videomicroscopy
- 英文關鍵字: 非平衡模式;晶體成長;影像顯微術