A low density cement slurry of zero thickening transition period which was appropriate to low temperature and shallow flow cementing operation in deepwater was introduced.
According to forecast, water flow shall be low during dry period of 2006-2007 and water supply in the Pearl River Delta shall be threatened by salty tide again.
High gene flow via spore dispersal in an earlier period when C. thalictroides was widely distributed in China is a plausible reason for the low genetic differentiation among populations.