5Pach L, Duncans R. Effects of a magnetic field on the precipitation of calcium carbonate[J]. Journal of Materials Science letters, 1996, (15) :613- 615.
6Deren E. Le teatitement des depots Calcaires clans V ear par Leprocdel CEPIL' Eau, L' Intustrie[J]. Les Nuisances, 1985, (91) :49 - 52.
6X. GAO, D. XU ,Y. WANG. Study and Design of Novel Wall Cleaning Robot System [ J ]. Hight Technology Letters ,2004, 14(4) :39 -44.
7Jordi Palacin,Jose Antonio Salse,Xavi Clua. Building a Mo- bile Robot for a Floor-cleaning Operation in Domestic Envi- ronments [ J ]. 1EEE Tran-Sactions On Instrumentation And Measurement ,2004,53 ( 5 ) : 1418 - 1424.