| 4 | A joint optimization framework for wheat harvesting and transportation considering fragmental farmlands显示文摘Crop harvesting and transportation should be considered as an integrated system to be optimized aiming to reduce the total operational costs.However,current studies mainly focused on how to reduce operational cost for a link,not from integrated perspective.In this paper,a joint problem which consists of harvesting and transportation problem is implemented and optimized to meet the better schedule with less operational costs.The harvesting and transportation problems could respectively be considered as a vehicle routing problem with multiple trips and a transportation problem,.These two problems should be optimized jointly because combine-harvesters and transporters should be synchronized at fragmental farmlands.A mixed integer programming is employed considering all constraints arising in the joint optimized framework.Furthermore,a hybrid algorithm is presented to find an optimum solution for this problem.Five different cases are used to verify the performance of the hybrid algorithm.Besides,our real cases are used to prove that there is a significant improvement if the integrated wheat harvesting and transportation policy is adopted.The results indicate that the model and algorithm is an effective approach to help farmers to decrease reaping costs. | P.He J.Li | 2021 | Information Processing in Agriculture2021，8，1： | 0 |
| 5 | 基于背景噪声的龙门山断裂带10年地震波速变化研究显示文摘本研究利用龙门山断裂带附近20个宽频带地震台站2007~2017年10年期间的连续波形资料,通过三分量地震背景噪声干涉测量技术,得到了4个不同周期的相对地震波速变化,重点研究了2008年汶川M W7.9地震和2013年芦山M W6.6地震对波速变化的影响。结果显示,在1~3s和3~8s周期,汶川地震均造成了断层区附近急剧的同震波速降低,降幅在0.04%~0.06%之间;在地震发生后的9年,波速的恢复幅度仅为同震波速降低值的1/4,即约3/4的波速降低未得到恢复。对于6~15s周期,我们观测到在汶川主震后约100天时出现了微小的波速下降,降幅约为0.0066%。本研究还发现芦山地震造成了1~3s周期的微小但较为可靠的波速降低,幅度约为0.01%。我们推断波速变化的物理机制可能包括:地震导致的浅层地壳(小于3km)破坏、断层区深部(约10km)的介质破坏,以及断裂带深部(约20km)的震后余滑。汶川地震后龙门山断裂区域波速恢复非常缓慢,这可能是由于区域应力加载速率较慢使得龙门山断裂带在汶川震后的缓慢愈合导致的。 | Z.K.Liu J.L.Huang P.He J.J.Qi 齐娟娟 | 2020 | 世界地震译丛2020，51，2： | 0 |
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