中文摘要：

针对由一个制造商和一个零售商组成的闭环供应链，在随机市场需求下，假设制造商风险中性，零售商风险偏好，采用补偿策略和回购契约可以实现闭环供应链的协调。然而突发事件发生造成零售商面临的需求分布变化时，闭环供应链的销售活动将受到影响，闭环供应链的协调将被打破；但是闭环供应链的废旧品回收活动却不受突发事件的影响。为此，给出了闭环供应链对突发事件的最优应对策略，并调整了原来的回购契约使其能协调应对突发事件。最后，运用数值实验对模型进行了验证。

英文摘要：

For a closed-loop supply chain consisting of one manufacturer and one retailer who faces stochastic market demand, it can be coordinated with return policy and buy back contract when manufacturer is risk neutral and retailer is risk chasing under some setting. But this coordination may be broken off by an emergent event, which maybe makes the demand disruptions, i. c. , it makes the demand distribution different from the assumption needed to achieve original closed-loop supply chain＇s coordination. But the taking back of used products is not affected by the emergent event. In this paper, an optimal strategy for closed-loop supply chain to the disruptions is given and, as optimal response for the closed-loop supply chain to the disruptions, an adjusted buy back contract which can coordinate the closed-loop supply chain under disruption is proposed, And some managerial insights are provided. Finally, a numerical example is given to validate the findings.