Luobi Cave Luobi Cave Luobi Cave () is a karst cave under the west face of Yin Ridge (印岭) located north east of Lizhigou Town (荔枝沟镇), from Sanya City, Hainan Province, People's Republic of China. The entrance to the cave is approximately high and wide. Inside the apex reaches a height of with a floor area of about Two large stalactites hang down from the roof like large pens, hence the cave's name. A number of inscriptions carved into the walls of the cave are believed to date to the Yuan Dynasty (1271–1368). One of these refers to the precise date of
Calcium perchlorate increased due to the development of highly specific fluorescence indicators. Perchlorate salts are the product of a base and perchloric acid. Calcium perchlorate can be prepared through the heating of a mixture of calcium carbonate and ammonium perchlorate. Ammonium carbonate forms in the gaseous state, leaving behind a calcium perchlorate solid. Being very hygroscopic, calcium perchlorate is commonly seen in the presence of four water molecules, referred to as calcium perchlorate tetrahydrate. A hybrid organic-inorganic molecule is formed using dioxazaphosphocanes, eight-membered cyclic hydrogenphosphonates and calcium. Calcium from the calcium perchlorate contributes to the structural integrity of the oligomeric molecule; the