文献:Elmore, Steven W.; Cooper, Curt S.; Schultz, Colleen C.; Hutchinson, Douglas K.; Donner, Pamela L.; Green, Brian E.; Anderson, David D.; Xie, Qinghua; Dinges, Jurgen; Lynch, Linda M.; Pratt, John K. Patent: US2002/49223 A1, 2002 ; US 20020049223 A1