# Blow-up of Solutions for a Class of Nonlinear Parabolic Equations

### Zhang Lingling

Taiyuan University of Technology, China

## Abstract

In this paper, the blow up of solutions for a class of nonlinear parabolic equations

$u_t(x,t)=\nabla _{x}(a(u(x,t))b(x)c(t)\nabla _{x}u(x,t))+g(x,|\nabla _{x}u(x,t) |^2,t)f(u(x,t))$

with mixed boundary conditions is studied. By constructing an auxiliary function and using Hopf's maximum principles, an existence theorem of blow-up solutions, upper bound of ``blow-up time" and upper estimates of ``blow-up rate" are given under suitable assumptions on $a, b,c, f, g$, initial data and suitable mixed boundary conditions. The obtained result is illustrated through an example in which $a, b,c, f, g$ are power functions or exponential functions.