... s motivated by the work of Erbe and Tang [3, 4, 5]andisbased on the shooting method and the Sturm comparison theorem. The rest of the paperis organized as follows. In Section 2, we state and ... Normal University, Lanzhou 730070, ChinaE-mail address: mary@maths.uq.edu.auYulian An: Physical Software & Engineering, Lanzhou Jiaotong University, Lanzhou 730070,Gansu, ChinaE-mail address: ... J. Y. Wang and J. Jiang, The existence of positive solutions to a singular nonlinear boundary valueproblem, J. Math. Anal. Appl. 176 (1993), no. 2, 322–329.Ruyun Ma: Department of Mathematics,...