Department of Fundamental Courses, Academy of Armored Force Engineering, Beijing, China.
This paper is devoted to the study of second-order Duffing
equation 
with singularity at
the origin, where 
tends to positive
infinity as 
, and the primitive function 
as 
. By applying the phase-plane analysis methods and
Poincaré-Bohl theorem, we obtain the existence of harmonic solutions of the
given equation under a kind of nonresonance condition for the time map.
Xia, J. , Zheng, S. , Lv, B. and Shan, C. (2014) Harmonic Solutions of Duffing Equation with Singularity via Time Map. Applied Mathematics, 5, 1528-1534. doi: 10.4236/am.2014.510146.
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