a new type of magnetically-recoverable catalyst was synthesized by the immobilization of h3pw12o40 on the surface of silica-encapsulated -fe2o3 nanoparticles. a series of novel 1,3,5-triaryl pyrazoline derivatives has been synthesized by the reaction of chalcone and phenylhydrazine in the presence of the -fe2o3@sio2-pw12nanoparticles, in high yields. the structures of compounds obtained were...