Southern rootworm (Diabrotica undecimpunctata howardi) affects several plants such as soybean, sorghum, wheat, cucumber, alfalfa, cucurbits and it is most damaging to corn and peanuts. The pheromone based “attract an...Southern rootworm (Diabrotica undecimpunctata howardi) affects several plants such as soybean, sorghum, wheat, cucumber, alfalfa, cucurbits and it is most damaging to corn and peanuts. The pheromone based “attract and kill” strategy is one of the powerful ways to control pest population. To address our key objective of the practical utility of the synthetic pheromone, we have developed a simple synthetic strategy to produce gram scale southern corn rootworm pheromone in nine simple steps starting from S-Citronellol. The present strategy takes advantage of the existing chiral center of commercially available S-Citronellol. To get the basic carbon skeleton of the pheromone, the main step in the synthetic strategy is coupling of aliphatic units through Wittig reaction. The phosphonium salt from a non-functionalized aliphatic bromide followed by Wittig reaction improved the overall yield in the multistep synthesis of this pheromone. The large-scale production of pheromone enabled us to test it in the field.展开更多
As autonomous underwater vehicles(AUVs)merely adopt the inductive obstacle avoidance mechanism to avoid collisions with underwater obstacles,path planners for underwater robots should consider the poor search efficien...As autonomous underwater vehicles(AUVs)merely adopt the inductive obstacle avoidance mechanism to avoid collisions with underwater obstacles,path planners for underwater robots should consider the poor search efficiency and inadequate collision-avoidance ability.To overcome these problems,a specific two-player path planner based on an improved algorithm is designed.First,by combing the artificial attractive field(AAF)of artificial potential field(APF)approach with the random rapidly exploring tree(RRT)algorithm,an improved AAF-RRT algorithm with a changing attractive force proportional to the Euler distance between the point to be extended and the goal point is proposed.Second,a twolayer path planner is designed with path smoothing,which combines global planning and local planning.Finally,as verified by the simulations,the improved AAF-RRT algorithm has the strongest searching ability and the ability to cross the narrow passage among the studied three algorithms,which are the basic RRT algorithm,the common AAF-RRT algorithm,and the improved AAF-RRT algorithm.Moreover,the two-layer path planner can plan a global and optimal path for AUVs if a sudden obstacle is added to the simulation environment.展开更多
文摘Southern rootworm (Diabrotica undecimpunctata howardi) affects several plants such as soybean, sorghum, wheat, cucumber, alfalfa, cucurbits and it is most damaging to corn and peanuts. The pheromone based “attract and kill” strategy is one of the powerful ways to control pest population. To address our key objective of the practical utility of the synthetic pheromone, we have developed a simple synthetic strategy to produce gram scale southern corn rootworm pheromone in nine simple steps starting from S-Citronellol. The present strategy takes advantage of the existing chiral center of commercially available S-Citronellol. To get the basic carbon skeleton of the pheromone, the main step in the synthetic strategy is coupling of aliphatic units through Wittig reaction. The phosphonium salt from a non-functionalized aliphatic bromide followed by Wittig reaction improved the overall yield in the multistep synthesis of this pheromone. The large-scale production of pheromone enabled us to test it in the field.
基金Supported by Zhejiang Key R&D Program 558 No.2021C03157the“Construction of a Leading Innovation Team”project by the Hangzhou Munic-559 ipal government,the Startup funding of New-joined PI of Westlake University with Grant No.560(041030150118)the funding support from the Westlake University and Bright Dream Joint In-561 stitute for Intelligent Robotics.
文摘As autonomous underwater vehicles(AUVs)merely adopt the inductive obstacle avoidance mechanism to avoid collisions with underwater obstacles,path planners for underwater robots should consider the poor search efficiency and inadequate collision-avoidance ability.To overcome these problems,a specific two-player path planner based on an improved algorithm is designed.First,by combing the artificial attractive field(AAF)of artificial potential field(APF)approach with the random rapidly exploring tree(RRT)algorithm,an improved AAF-RRT algorithm with a changing attractive force proportional to the Euler distance between the point to be extended and the goal point is proposed.Second,a twolayer path planner is designed with path smoothing,which combines global planning and local planning.Finally,as verified by the simulations,the improved AAF-RRT algorithm has the strongest searching ability and the ability to cross the narrow passage among the studied three algorithms,which are the basic RRT algorithm,the common AAF-RRT algorithm,and the improved AAF-RRT algorithm.Moreover,the two-layer path planner can plan a global and optimal path for AUVs if a sudden obstacle is added to the simulation environment.
