Alleviation Effects of Rare Earth on Cd Stress to Rape

Using rapes as test materials, the fastness expression and alleviation effect of rapes were studied under Cd stress condition, as the rapeseeds were dipped in the single element( La, Ce, Nd, Pr)and mixed rare earth (RE). The results indicate that, under Cd stress, the dry and fresh weight are increased by both the single element and mixed rare earth treatment, and the fastness of rape is improved. The single element of rare earth decreases the Cd content in rape roots and transmits Cd to the edible parts above the ground in which the alleviation effect of Ce is most significant. La treatment takes the second place, so that the poisonous effect of heavy metal Cd is eased. The mixed rare earth doesnt alleviate the assimilation of Cd in rape roots, but accelerates the transfer of Cd to the parts above the ground. The research puts forward that the alleviation of rare earth on Cd stress has connection with the decrease of Ca content.     

基于网络平台的英语自主写作教学探究

英语写作是高职学生英语学习的薄弱环节.本文针对英语写作现状,对基于网络平台的英语自主写作教学的特点及可行性进行了分析,并提出了实施过程中需注意的问题.