Please tell me What is 331 Model

[ndung200790]

Please tell me what is SU(3)cXSU(3)LXU(1)X model, and how to quantize electric charge, because I hear that they can do this quantization based on 331 model. Please help me, I am eagerly to know it.
With my best wishes and regard.

 

[ndung200790]

Please help me:three generation problem

I hear that some model example: SU(5), SU(10) solve many puzzle as quantization of charge
,proton decay, But I wonder whether those beyond standard model can solve the problem of
three quark-lepton generations or not.
Thanks very much for your help.