请教表面增强拉曼光谱的增强因子怎么求解

基本的等式EF=(I-SERS/N-SERS)/(I-bulk/N-bulk)
Isurf : 吸附在基底上探针分子的特征峰的积分面积
Nsurf : 活性基底上激光所照射到的探针分子数
Ibulk : 溶液中探针分子特征峰的积分面积
Nbulk : 溶液中激光能照射到的有效探针分子数
以上各个参量的详细计算见文献：(1) Investigation of surface-enhanced Raman scattering from platinum electrodes using a confocal Raman microscope: dependence of surface roughening pretreatment，W.B. Cai, B. Ren, X.Q. Li, C.X. She, F.M. Liu, X.W. Cai, Z.Q. Tian，Surface Science 406 (1998) 9–22

(2) Preparation of silver nanoparticles by photo-reduction for surface-enhanced
Raman scattering,Huiying Jia, Jiangbo Zeng, Wei Song, Jing An, Bing Zhao, Thin Solid Films 496 (2006) 281 – 287