这里就有英文论文http://www.docin.com/p-686478455.html这里有技巧http://wenku.baidu.com/link?url=V8dkFcI3sd0Lti2Z8xW-P7v7O8hKqOn0vR8_GO0-GBFsdbYMt3sOXhu64gzvhLCZUyoPO2hadyTFJk6UV-ZFGpWpeoKJj69iqNhJ_VE-EHC
