In this paper,the leader–follower consensus of feedforward nonlinear multi-agent systems is achieved by designing the distributed output feedback controllers with a time-varying gain.The agents dynamics are assumed t...In this paper,the leader–follower consensus of feedforward nonlinear multi-agent systems is achieved by designing the distributed output feedback controllers with a time-varying gain.The agents dynamics are assumed to be in upper triangular structure and satisfy Lipschitz conditions with an unknown constant multiplied by a time-varying function.A time-varying gain,which increases monotonously and tends to infinity,is proposed to construct a compensator for each follower agent.Based on a directed communication topology,the distributed output feedback controller with a time-varying gain is designed for each follower agent by only using the output information of the follower and its neighbors.It is proved by the Lyapunov theorem that the leader–follower consensus of the multi-agent system is achieved by the proposed consensus protocol.The effectiveness of the proposed time-varying gain method is demonstrated by a circuit system.展开更多
[Objectives] This study was conducted to find water-soluble fertilizers( WSFs) suitable for watermelon cultivation in Hainan area.[Methods] The effects of three WSFs on watermelon yield and quality were studied.[Resul...[Objectives] This study was conducted to find water-soluble fertilizers( WSFs) suitable for watermelon cultivation in Hainan area.[Methods] The effects of three WSFs on watermelon yield and quality were studied.[Results]Fahai·Jiabao WSF improved watermelon yield by 7.87% compared with the CK,and showed a net increase of income of 538.4 yuan/667 m^2.And it could significantly improve soluble sugar,Vc and protein contents,and could effectively reduce nitrate content.[Conclusions]Fahai·Jiabao WSF is the optimal WSF for integration of water and fertilizer,and has the market prospect of large-area application and extension.展开更多
The repair of critical-sized bone defects remains a significant challenge in regenerative medicine.Using guided bone regeneration(GBR)membranes has emerged as a promising treatment strategy.In this study,we fabricate ...The repair of critical-sized bone defects remains a significant challenge in regenerative medicine.Using guided bone regeneration(GBR)membranes has emerged as a promising treatment strategy.In this study,we fabricate a novel multilayer density-gradient electrospun nanofiber membrane comprising bone morphogenetic protein-2(BMP-2)combined with nano-hydroxyapatite(nHA)and vascular endothelial growth factor(VEGF)embedded in a polylactic acid(PLA)and type I collagen(COL)nanofiber matrix,denoted as BMP-2@nHA/VEGF@(PLA/COL).The gradient density structure of membranes is engineered to mimic the periosteum tissue,thereby creating an optimal microenvironment for bone regeneration while preventing soft tissue invasion.The membrane exhibits commendable mechanical properties and favorable degradation characteristics.Drug release experiments reveal that the membrane enables an early-phase release of VEGF,coupled with a prolonged release of BMP-2,advantageous for fostering early vascularization and long-term osteogenesis.In vitro studies confirm that the membrane effectively maintains barrier function while enhancing the coordinated advancement of both vascularization and osteogenesis.Furthermore,experiments with a rat cranial bone defect model demonstrate that the membrane substantially accelerates bone regeneration.Consequently,the bionic membrane developed in this research shows considerable potential for clinical applications in GBR therapies.展开更多
基金the National Natural Science Foundation of China(Nos.61973189,62073190)the Research Fund for the Taishan Scholar Project of Shandong Province of China(No.ts20190905)the Natural Science Foundation of Shandong Province of China(No.ZR2020ZD25).
文摘In this paper,the leader–follower consensus of feedforward nonlinear multi-agent systems is achieved by designing the distributed output feedback controllers with a time-varying gain.The agents dynamics are assumed to be in upper triangular structure and satisfy Lipschitz conditions with an unknown constant multiplied by a time-varying function.A time-varying gain,which increases monotonously and tends to infinity,is proposed to construct a compensator for each follower agent.Based on a directed communication topology,the distributed output feedback controller with a time-varying gain is designed for each follower agent by only using the output information of the follower and its neighbors.It is proved by the Lyapunov theorem that the leader–follower consensus of the multi-agent system is achieved by the proposed consensus protocol.The effectiveness of the proposed time-varying gain method is demonstrated by a circuit system.
基金Supported by Special Fund for Cultivated Land Improvement in Hainan Province(No.HNGDxf201501)
文摘[Objectives] This study was conducted to find water-soluble fertilizers( WSFs) suitable for watermelon cultivation in Hainan area.[Methods] The effects of three WSFs on watermelon yield and quality were studied.[Results]Fahai·Jiabao WSF improved watermelon yield by 7.87% compared with the CK,and showed a net increase of income of 538.4 yuan/667 m^2.And it could significantly improve soluble sugar,Vc and protein contents,and could effectively reduce nitrate content.[Conclusions]Fahai·Jiabao WSF is the optimal WSF for integration of water and fertilizer,and has the market prospect of large-area application and extension.
基金The first author was partially supported by NSF grants DMS-0900938 and DMS-1162309The second author was partially supported by NSF grant DMS-1001625.
文摘We undertake a local analysis of combinatorial independence as it connects to topological entropy within the framework of actions of sofic groups.
基金supported by National Natural Science Foundation of China(82401173)National Key Research&Development Program of China(2022YFE0106000)Jilin Province and Chinese Academy of Sciences Science and Technology Cooperation High-technology Industrialization Special Fund Project(Grant No.2023SYHZ0006).
文摘The repair of critical-sized bone defects remains a significant challenge in regenerative medicine.Using guided bone regeneration(GBR)membranes has emerged as a promising treatment strategy.In this study,we fabricate a novel multilayer density-gradient electrospun nanofiber membrane comprising bone morphogenetic protein-2(BMP-2)combined with nano-hydroxyapatite(nHA)and vascular endothelial growth factor(VEGF)embedded in a polylactic acid(PLA)and type I collagen(COL)nanofiber matrix,denoted as BMP-2@nHA/VEGF@(PLA/COL).The gradient density structure of membranes is engineered to mimic the periosteum tissue,thereby creating an optimal microenvironment for bone regeneration while preventing soft tissue invasion.The membrane exhibits commendable mechanical properties and favorable degradation characteristics.Drug release experiments reveal that the membrane enables an early-phase release of VEGF,coupled with a prolonged release of BMP-2,advantageous for fostering early vascularization and long-term osteogenesis.In vitro studies confirm that the membrane effectively maintains barrier function while enhancing the coordinated advancement of both vascularization and osteogenesis.Furthermore,experiments with a rat cranial bone defect model demonstrate that the membrane substantially accelerates bone regeneration.Consequently,the bionic membrane developed in this research shows considerable potential for clinical applications in GBR therapies.
