RT Journal T1 Existence of optimal positive solutions for Neumann boundary value problems of second order differential equations A1 WANG Jing-jing, LU Yan-qiong PB JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) FD YR 2020 JF JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) JO JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) VO 55 IS 3 SP 113 DO 10.6040/j.issn.1671-9352.0.2019.208 K1 Neumann boundary value problem;positive solution;nonnegative Greens function;fixed point exponent LK {http://lxbwk.njournal.sdu.edu.cn/EN/article/article_3248.shtml}