Zirconium-based metallic glasses(Zr-MGs)are demonstrated to exhibit high mechanical strength,low elastic modulus and excellent biocompatibility,making them promising materials for endosseous implants.Meanwhile,tantalu...Zirconium-based metallic glasses(Zr-MGs)are demonstrated to exhibit high mechanical strength,low elastic modulus and excellent biocompatibility,making them promising materials for endosseous implants.Meanwhile,tantalum(Ta)is also well known for its ideal corrosion resistance and biological effects.However,the metal has an elastic modulus as high as 186 GPa which is not comparable to the natural bone(10–30 GPa),and it also has a relative high cost.Here,to fully exploit the advantages of Ta as endosseous implants,a small amount of Ta(as low as 3 at.%)was successfully added into a Zr-MG to generate an advanced functional endosseous implant,Zr58Cu25Al14Ta3 MG,with superior comprehensive properties.Upon carefully dissecting the atomic structure and surface chemistry,the results show that amorphization of Ta enables the uniform distribution in material surface,leading to a significantly improved chemical stability and extensive material-cell contact regulation.Systematical analyses on the immunological,angiogenesis and osteogenesis capability of the material are carried out utilizing the next-generation sequencing,revealing that Zr_(58)Cu_(25)Al_(14)Ta_(3)MG can regulate angiogenesis through VEGF signaling pathway and osteogenesis via BMP signaling pathway.Animal experiment further confirms a sound osseointegration of Zr_(58)Cu_(25)Al_(14)Ta_(3)MG in achieving better bone-implant-contact and inducing faster periimplant bone formation.展开更多
With the rapid development of warehouse robots in logistics and other industries,research on their path planning has become increasingly important.Based on the analysis of various conflicts that occur when the warehou...With the rapid development of warehouse robots in logistics and other industries,research on their path planning has become increasingly important.Based on the analysis of various conflicts that occur when the warehouse robot travels,this study proposes a two-level vehicle path planning model for multi-warehouse robots,which integrates static and dynamic planning to improve operational efficiency and reduce operating costs.In the static phase,the blockage factor is introduced to enhance the ant colony optimization(ACO)algorithm as a negative feedback mechanism to effectively avoid the blockage nodes during movement.In the dynamic stage,a dynamic priority mechanism is designed to adjust the routing strategy in real time and give the optimal path according to the real situation.To evaluate the model’s effectiveness,simulations were performed under different operating environments and application strategies based on an actual grid environment map.The simulation results confirm that the proposed model outperforms other methods in terms of average running distance,number of blocked nodes,percentage of replanned paths,and average running time,showing great potential in optimizing warehouse operations.展开更多
基金supported by the National Natural Science Foundation of China(52035001)National Key R&D Program of China(2019YFB1706904)+3 种基金Beijing Training Project for the Leading Talents in S&T(Z191100006119022)National Key Research and Development Plan(2018YFA0703603)National Science 535 Foundation of China(52192602)Youth Fund of the National Natural Science Foundation of China(82201125).
文摘Zirconium-based metallic glasses(Zr-MGs)are demonstrated to exhibit high mechanical strength,low elastic modulus and excellent biocompatibility,making them promising materials for endosseous implants.Meanwhile,tantalum(Ta)is also well known for its ideal corrosion resistance and biological effects.However,the metal has an elastic modulus as high as 186 GPa which is not comparable to the natural bone(10–30 GPa),and it also has a relative high cost.Here,to fully exploit the advantages of Ta as endosseous implants,a small amount of Ta(as low as 3 at.%)was successfully added into a Zr-MG to generate an advanced functional endosseous implant,Zr58Cu25Al14Ta3 MG,with superior comprehensive properties.Upon carefully dissecting the atomic structure and surface chemistry,the results show that amorphization of Ta enables the uniform distribution in material surface,leading to a significantly improved chemical stability and extensive material-cell contact regulation.Systematical analyses on the immunological,angiogenesis and osteogenesis capability of the material are carried out utilizing the next-generation sequencing,revealing that Zr_(58)Cu_(25)Al_(14)Ta_(3)MG can regulate angiogenesis through VEGF signaling pathway and osteogenesis via BMP signaling pathway.Animal experiment further confirms a sound osseointegration of Zr_(58)Cu_(25)Al_(14)Ta_(3)MG in achieving better bone-implant-contact and inducing faster periimplant bone formation.
基金funded by the Basic and Applied Research Foundation of Guangdong Province(2020A1515111024).
文摘With the rapid development of warehouse robots in logistics and other industries,research on their path planning has become increasingly important.Based on the analysis of various conflicts that occur when the warehouse robot travels,this study proposes a two-level vehicle path planning model for multi-warehouse robots,which integrates static and dynamic planning to improve operational efficiency and reduce operating costs.In the static phase,the blockage factor is introduced to enhance the ant colony optimization(ACO)algorithm as a negative feedback mechanism to effectively avoid the blockage nodes during movement.In the dynamic stage,a dynamic priority mechanism is designed to adjust the routing strategy in real time and give the optimal path according to the real situation.To evaluate the model’s effectiveness,simulations were performed under different operating environments and application strategies based on an actual grid environment map.The simulation results confirm that the proposed model outperforms other methods in terms of average running distance,number of blocked nodes,percentage of replanned paths,and average running time,showing great potential in optimizing warehouse operations.
