Characters of Bi-peaked Tubercles on Rice Lemmas Printings from Broken Pottey Pieces Unearthed from 4 Excavation Sites in Liyang Flatlands, Hunan Preparation and Structural Characterization of Bamboo Charcoal Pottery Composites Research on Carbon/Pottery Adsorption Composite for Removing Fluoride Preparation and Characterization of Carbon/Pottery Composite with Physical Method