This book is the outcome of several courses and seminar talks held at the Instituto de Matematica Pura e Aplicada (IMPA) over the years.It is a greatly modified version of a previous work by the authors,Equacoes Diferenciais Parciais, Uma lntroducao, (Projeto Euclides, IMPA,1978). It has a twofold purpose, namely to introduce the student to the basic concepts of Fourier analysis and provide illustrations of recent applications where these concepts were used to study various properties of the solutions of some important nonlinear evolution equations.

　　本书为英文版。