摘要
Very recently, we have found that the method used in our recent paper （appeared in 2005） could be extended to obtain two general series-transformation formulas for formal power series defined over the complex number field. As usual, △, △k, D, and Dk denote, respectively, the difference and differential operators with △f（t） = f（t ＋ 1） - f（t）, Dr（t） = （d/dr）f （t） and △^0 = D0 = 1 （the identity operator）. What we have obtained are the following two general transformation formulas （formal expansion formulas） ∞∑k=0 f（k）φ^（k）（0）t^k/k!=∞∑k=0△^kf（0）φ^（k）（0）t^k/k! （1） ∞∑k=0 f（k）φ^（k）（0）t^k/k!=∞∑k=01/k!f（0）φ^（k）（0）t^k/k! （2）
利用Krasnoselskii-Zabreiko不动点定理获得了非线性三点边值问题解的一个新的存在定理.
基金
the Natural Science Foundation of Gansu Province of China
