Now there are many simulations on the nanoparticles, the first problem is about the modeling for nanoparticles. There are main two methods in DPD, the first one is the ref.[Phil. Trans. R. Soc. Lond. A (2004) 362, 1773-1781], the other is the ref.[J. Chem. Phys. (2004) 121, 10641]. Who can tell me how to model the nanoparticles like the two references in MS, especially the latter? Thank you very much for the reply!