A new method based on adjoint system and minus system to compute unstable equilibrium points on the stability boundary of power system classical model is proposed.

In this paper,the existence of sign-changing solutions to a class of nonlinear second order equation with three-point boundary value problems is discussed.

We study the existence and multiplicity of sign-changing solutions for six-order nonlinear boundary value problems by using fixed point index theory and anti-symmetrical extension method.

We show existence results for multiple sign-changing solution for third-order two- point boundary value problems by using the fixed point index and the topologic degree theory.

Global existence and blow-up of sign-changing solutions to semilinear parabolic equations;