摘要:In this paper, we analyze the boundary value problem of a class of multi-order fractional differential equations involving the standard Caputo fractional derivative with the general periodic boundary conditions: { L ( D ) u ( t ) = f ( t , u ( t ) ) , t ∈ [ 0 , T ] , T > 0 , u ( 0 ) = u ( T ) > 0 , u ′ ( 0 ) = u ′ ( T ) > 0 , $$ \textstyle\begin{cases} L(D)u(t) = f(t,u(t)),\quad t\in[0,T], T>0, \\ u(0) = u(T)>0,\qquad u'(0)=u'(T)>0, \end{cases} $$ where L ( D ) = ∑ i = 0 n a i D S i $L(D)=\sum^{n}_{i=0}a_{i}D^{S_{i}}$ , 1 ≤ S 0 < ⋯ < S n − 1 < S n < 2 $1\leq S_(<\cdots