5Blouin M,Rindt W,Moore O. Sulfur-coated fertilizers from controlled release: pilot plant production[J]. J Agric Food Chem, 1971,19:801 --809.
6Scheffe H. Experiments with mixtures[J]. J Roy Stat Soc B,1958,20:344--360.
7Tremble M E. Improving fertilizer use efficiency--Controlled-release and stabilized fertilizers in agriculture[M]. Paris:International Fertilizer Industry Association, 1997. 11-- 12.
8Ender M T,Peppsa N A. Transport of ionizable drugs and protein in Crosslinked poly (acrylicacid) and polycarrylic acid-cohydroxyethyl methacrylate hydrogels .II. Diffusion and release studies[J]. Journal of Controlled Release, 1997,48:47--56.