Effects of humus fractions (fulvic acid, brown humic acid and grey humic acid) on the leachability and transferring activity of five types of mineral-bound Hg were investigated. Under the acid leaching condition: fulv...Effects of humus fractions (fulvic acid, brown humic acid and grey humic acid) on the leachability and transferring activity of five types of mineral-bound Hg were investigated. Under the acid leaching condition: fulvic acid could promote leachability and vertical transference of all the mineral-bound Hg. Brown humic acid could retard the leaching and transferring processes of CaCO3-Hg, Fe2O3-Hg, MnO2-Hg and kaolinite Hg but not bentonite-Hg. Grey humic acid could greatly enhance residing ability of the mineral-bound Hg in the soil column and restrain them from vertical transferring. The effect of humus on leachability and transferring activity on the mineral-bound Hg was closely related to its ability to convert the mineral-bound Hg into organic-bound form and the transferability of the latter in the soil column. The characteristics of the mineral-bound Hg in speciation were the internal factors that determined the extent and rate of the influence of the humus.展开更多
Reading English newspapers and magazines is an effective way to help the students get the latest information worldwide and improve English levels. The present article first analyzes the features of the English newspap...Reading English newspapers and magazines is an effective way to help the students get the latest information worldwide and improve English levels. The present article first analyzes the features of the English newspapers and magazines and then proposes making good use of them through such classroom activities as discussing the hot issue and role-playing to provide more authentic situations in which the students can have chances to practice four English skills, achieving the ideal teaching result.展开更多
基金Project (No. 970601) supported by the State Education Commission, China.
文摘Effects of humus fractions (fulvic acid, brown humic acid and grey humic acid) on the leachability and transferring activity of five types of mineral-bound Hg were investigated. Under the acid leaching condition: fulvic acid could promote leachability and vertical transference of all the mineral-bound Hg. Brown humic acid could retard the leaching and transferring processes of CaCO3-Hg, Fe2O3-Hg, MnO2-Hg and kaolinite Hg but not bentonite-Hg. Grey humic acid could greatly enhance residing ability of the mineral-bound Hg in the soil column and restrain them from vertical transferring. The effect of humus on leachability and transferring activity on the mineral-bound Hg was closely related to its ability to convert the mineral-bound Hg into organic-bound form and the transferability of the latter in the soil column. The characteristics of the mineral-bound Hg in speciation were the internal factors that determined the extent and rate of the influence of the humus.
文摘Reading English newspapers and magazines is an effective way to help the students get the latest information worldwide and improve English levels. The present article first analyzes the features of the English newspapers and magazines and then proposes making good use of them through such classroom activities as discussing the hot issue and role-playing to provide more authentic situations in which the students can have chances to practice four English skills, achieving the ideal teaching result.
