Abstract
Effects of shear flow are investigated in melts of diblock copolymers in the homogeneous disordered phase near the microphase separation transition point. Simple approximate expressions are given for the anisotropic scattering intensity in nonlinear regimes under shear. A non-Newtonian effect and a normal stress effect are also examined, which are caused by deformations of the critical fluctuations in shear. An explicit expression is also found for the critical part of the complex shear modulus. This paper is a generalization of recent work by Fredrickson and Larson.