摘要
We consider a nonlinear time-dependent point power reactor problem with delayed temperature feedback on reactivity. By using the method of upper and lower solutions coupled with the monotone iterative techniques, two monotone sequences are constructed and shown to converge monotonically from above and below to the unique solution of the problem. The monotone convergence leads to an existence-comparison theorem in terms of upper and lower solutions. Through the construction of suitable upper and lower solutions, the existence-comparison theorem is used to investigate the explicit relationship among reactor parameters so that we can determine the subcriticality and supercriticality of reactor power from a time-dependent system point of view. © 1990.