2QIN Xianli, FU Mingchao, SHEN Bin. Gas Wireless Monitoring System Based on Zigbee Technology [C]//国际安全科学与技术学术研讨会,沈阳,2010:219-223.
3GREGERSEN H, JENSEN C S. Temporal Entity- Relationship Models.. a Survey [J]. IEEE Transactions on Knowledge and Data Engineering, 1999,11 (3) .. 464- 497.