【摘要】 本文给出了一类边值问题的唯一性及解集的结构 ,同时 ,对 PBVP和 BVP,证明了当右端函数 f关于 u单调不减时 ,上、下解的存在性等价于解的存在性 ,其主要结果改进和推广了V.L aks,E.Liz和 J.J.Nieto等人的相应结果。更多还原

【Abstract】 This paper gives uniqueness and structure of the set of solutions for boundary value problems.Meanwhile we showed that the existence of upper and lower solutions is equivalent to assuming the existence of solutions when f is nondecreasing in u for PBVP and BVP.The main results in this paper improved and extended the results of V.Laks.,E.Liz and J.J.Nirto.更多还原