In this dissertation,we mainly use Nevanlinna theory and its difference analogues to survey the value distribution of difference polynomials,the existence and growth of mero-morphic solutions of difference equations.Moreover,we also consider the properties of entire solutions of a kind of the nonlinear differential-difference equation.The contents of this thesis are organized as follows:In the first chapter,we introduce some backgrounds and give the main results of present thesis.We also give some related definitions and lemmas.In the second chapter,we survey the value distribution of q-difiference polynomial f(qz)-a(f(z))n and f(q1z)f(q2z)...f(qmz)-a(f(z))n,here f(z)is a transcendental entire function with zero order.Furthermore,we also study the property of entire solutions of a certain q-difference equation.In the third chapter,we study the value distribution of q-difference product f(z)f(qz)and fn(z)(f(qz)-f(z)),here f(z)is a transcendental entire function with finite positive order,q ? 0,1.We also consider the property of entire solutions of a certain q-difference linear equation.In the fourth chapter,we investigate the existence and growth of solutions of the q-difference equation ?i=1n f=(qiz)=R(z,f(z)),where R(z,f(z))is an irreducible rational function in f(z).We also give an estimation of the growth of transcendental meromorphic solutions of the equation ?i=1n f(qiz)=f(z)m.In the fifth chapter,we investigate the deficiencies and growth of meromorphic solu-tions of difference equation An(z)f(z+n)+…+A1(z)f(z)+ A0(z)f(z)= F(z),where An(z),…,A0(z),F(z)are meromorphic functions with An(z)F(z)(?)0.In the sixth chapter,we study entire solutions of the nonlinear differential-difference equation of the form where p1(z),p2(z)are nonzero polynomials,q1(z),q2(z)are nonconstant polynomials,q(z),a(z)are nonzero entire functions of finite order,n ? 2 is an integer.For a special case,of n = 3,q1(z)=-q2(z),and p1(z),p2(z)are nonzero constants,we also obtain some results. |