TY - GEN Y1 - 2022/// AV - public CY - Szeged A1 - Zhang Guowei UR - http://acta.bibl.u-szeged.hu/75826/ TI - Positive solutions to three classes of non-local fourth-order problems with derivative-dependent nonlinearities EP - 27 ID - acta75826 KW - Differenciálegyenlet SN - 1417-3875 N2 - In the article, we investigate three classes of fourth-order boundary value problems with dependence on all derivatives in nonlinearities under the boundary conditions involving Stieltjes integrals. A Gronwall-type inequality is employed to get an a priori bound on the third-order derivative term, and the theory of fixed-point index is used on suitable open sets to obtain the existence of positive solutions. The nonlinearities have quadratic growth in the third-order derivative term. Previous results in the literature are not applicable in our case, as shown by our examples. N1 - Bibliogr.: p. 25-27. ; összefoglalás angol nyelven ER -