Journal of Applied Mathematics
Volume 2012 (2012), Article ID 528719, 13 pages
http://dx.doi.org/10.1155/2012/528719
Research Article

Positive Solutions for Nonlinear Differential Equations with Periodic Boundary Condition

Shengjun Li,1 Li Liang,1 and Zonghu Xiu2

1College of Information Sciences and Technology, Hainan University, Haikou 570228, China
2College of Science and Information Science, Qingdao Agricultural University, Qingdao 266109, China

Received 22 February 2012; Accepted 23 March 2012

Academic Editor: Yeong-Cheng Liou

Copyright © 2012 Shengjun Li et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We study the existence of positive solutions for second-order nonlinear differential equations with nonseparated boundary conditions. Our nonlinearity may be singular in its dependent variable. The proof of the main result relies on a nonlinear alternative principle of Leray-Schauder. Recent results in the literature are generalized and significantly improved.