We study the solvability of following infinite systems of fractional boundary
value problem {cD?ui(t) = fi(t, ui(t))), ? ? (n ? 1, n), 0 < t
< +?, ui(0) = 0, uq i (0) = 0, cD??1ui(?) = ?m?2,j=1 ?jui(?j). The purpose
of this work is to present a new family of measures of noncompactness in the
regulated function spaces R(R+,R?) on unbounded interval and a fixed point
theorem of Darbo type. Finally, we give an example to show the effectiveness
of the obtained result.