The electrocarboxylation reaction is an attractive means to convert CO_(2) into valuable chemicals under ambient conditions,while it still suffers from low efficiency due to the high stability of CO_(2).In this work,w...The electrocarboxylation reaction is an attractive means to convert CO_(2) into valuable chemicals under ambient conditions,while it still suffers from low efficiency due to the high stability of CO_(2).In this work,we report a double activation strategy for simultaneously activating CO_(2) and acetophenone by silver-doped CeO_(2)(Ag-CeO_(2)) nanowires,featuring as an effective electrocatalyst for electrocarboxylation of acetophenone with CO_(2).Compared to the Ag foil,Ag nanoparticles and CeO_(2) nanowires,the Ag-CeO_(2)nanowire catalyst allowed to reduce the onset potential difference between CO_(2) and acetophenone activation,thus enabling efficient electrocarboxylation to form 2-phenyllactic acid.The Faradaic efficiency for producing 2-phenyllactic acid reached 91%at−1.8 V versus Ag/AgI.This double activation strategy of activating both CO_(2)and organic substrate molecules can benefit the catalyst design to improve activities and selectivities in upgrading CO_(2)fixation for higher-value electrocarboxylation.展开更多
MXene,with metallic conductivity,strong hydrophilicity,and rich chemistries,has been widely used as electrode material for energy storage.However,the notorious issues of aggregation and oxidation for MXene significant...MXene,with metallic conductivity,strong hydrophilicity,and rich chemistries,has been widely used as electrode material for energy storage.However,the notorious issues of aggregation and oxidation for MXene significantly inhibit its electrochemical performance and further wide application.Herein,a physicochemical double protection strategy is proposed to stabilize MXene in the hydrothermal process effectively.Polyvinylpyrrolidone(PVP),with the structure of a long chain and abundant O/N function groups,provides physical protection against agglomeration(steric effect)and chemical protection against oxidation(electron transfer)at the same time,contributing to the synthesis of MXene-based hybrids with high conductivity and fully exposed active sites.As proof of the concept,2D MXene/Co_(9)S_(8) nanohybrids with a scaly surface are fabricated and present impressive performance,especially rate performance for hybrid supercapacitor(HSC)with MoS_(2) as the counter electrode.The HSC demonstrates a high energy density of 111 Wh kg^(-1) at 845 W kg^(-1) and an excellent rate performance of 61 Wh kg^(-1) at 16.9 kW kg^(-1).展开更多
Solving the path planning problem of Autonomous Underwater Vehicles(AUVs)is crucial for reducing energy waste and improving operational efficiency.However,two main challenges hinder further development:Firstly,existin...Solving the path planning problem of Autonomous Underwater Vehicles(AUVs)is crucial for reducing energy waste and improving operational efficiency.However,two main challenges hinder further development:Firstly,existing algorithms often treat this as a single-objective optimization problem,whereas in reality,it should be multi-objective,considering factors such as distance,safety,and smoothness simultaneously.Secondly,the limited availability of optimization results arises due to they are single-path,which fail to meet real-world conditions.To address these challenges,first of all,an improved AUV path planning model is proposed,in which the collisions of path and obstacles are classified more specifically.Subsequently,a novel Altruistic Nurturing Algorithm(ANA)inspired by natural altruism is introduced.In the algorithm,nurturing cost considering Pareto rank and crowd distance is introduced as guidance of evolution to avoid futile calculation,abandonment threshold is self-adaptive with descendant situation to help individuals escape from local optima and double selection strategy combining crowd and k-nearest neighbors selection helps to get a better-distributed Pareto front.Experimental results comparing ANA with existing algorithms in AUV path planning demonstrate its superiority.Finally,a user-friendly interface,the Multi-Objective AUV Path Planner,is designed to provide users with a group of paths for informed decisionmaking.展开更多
Motivated by recent advances made in the study of dividend control and risk management problems involving the U.S.bankruptcy code,in this paper we follow[44]to revisit the De Finetti dividend control problem under the...Motivated by recent advances made in the study of dividend control and risk management problems involving the U.S.bankruptcy code,in this paper we follow[44]to revisit the De Finetti dividend control problem under the reorganization process and the regulator's intervention documented in U.S.Chapter 11 bankruptcy.We do this by further accommodating the fixed transaction costs on dividends to imitate the real-world procedure of dividend payments.Incorporating the fixed transaction costs transforms the targeting optimal dividend problem into an impulse control problem rather than a singular control problem,and hence computations and proofs that are distinct from[44]are needed.To account for the financial stress that is due to the more subtle concept of Chapter 11 bankruptcy,the surplus process after dividends is driven by a piece-wise spectrally negative Lévy process with endogenous regime switching.Some explicit expressions of the expected net present values under a double barrier dividend strategy,new to the literature,are established in terms of scale functions.With the help of these expressions,we are able to characterize the optimal strategy among the set of admissible double barrier dividend strategies.When the tail of the Lévy measure is log-convex,this optimal double barrier dividend strategy is then verified as the optimal dividend strategy,solving our optimal impulse control problem.展开更多
文摘The electrocarboxylation reaction is an attractive means to convert CO_(2) into valuable chemicals under ambient conditions,while it still suffers from low efficiency due to the high stability of CO_(2).In this work,we report a double activation strategy for simultaneously activating CO_(2) and acetophenone by silver-doped CeO_(2)(Ag-CeO_(2)) nanowires,featuring as an effective electrocatalyst for electrocarboxylation of acetophenone with CO_(2).Compared to the Ag foil,Ag nanoparticles and CeO_(2) nanowires,the Ag-CeO_(2)nanowire catalyst allowed to reduce the onset potential difference between CO_(2) and acetophenone activation,thus enabling efficient electrocarboxylation to form 2-phenyllactic acid.The Faradaic efficiency for producing 2-phenyllactic acid reached 91%at−1.8 V versus Ag/AgI.This double activation strategy of activating both CO_(2)and organic substrate molecules can benefit the catalyst design to improve activities and selectivities in upgrading CO_(2)fixation for higher-value electrocarboxylation.
基金financially supported by the Beijing Natural Science Founding(No.2202050)the National Natural Science Foundation of China(No.21111120074).
文摘MXene,with metallic conductivity,strong hydrophilicity,and rich chemistries,has been widely used as electrode material for energy storage.However,the notorious issues of aggregation and oxidation for MXene significantly inhibit its electrochemical performance and further wide application.Herein,a physicochemical double protection strategy is proposed to stabilize MXene in the hydrothermal process effectively.Polyvinylpyrrolidone(PVP),with the structure of a long chain and abundant O/N function groups,provides physical protection against agglomeration(steric effect)and chemical protection against oxidation(electron transfer)at the same time,contributing to the synthesis of MXene-based hybrids with high conductivity and fully exposed active sites.As proof of the concept,2D MXene/Co_(9)S_(8) nanohybrids with a scaly surface are fabricated and present impressive performance,especially rate performance for hybrid supercapacitor(HSC)with MoS_(2) as the counter electrode.The HSC demonstrates a high energy density of 111 Wh kg^(-1) at 845 W kg^(-1) and an excellent rate performance of 61 Wh kg^(-1) at 16.9 kW kg^(-1).
基金supported by the Guangzhou City School Joint Found Project(SL2022A03J01009)the National Nature Science Foundation of China(Grant No.51975135)the Natural Science Foundation of Guangdong Province(2018A030310063).
文摘Solving the path planning problem of Autonomous Underwater Vehicles(AUVs)is crucial for reducing energy waste and improving operational efficiency.However,two main challenges hinder further development:Firstly,existing algorithms often treat this as a single-objective optimization problem,whereas in reality,it should be multi-objective,considering factors such as distance,safety,and smoothness simultaneously.Secondly,the limited availability of optimization results arises due to they are single-path,which fail to meet real-world conditions.To address these challenges,first of all,an improved AUV path planning model is proposed,in which the collisions of path and obstacles are classified more specifically.Subsequently,a novel Altruistic Nurturing Algorithm(ANA)inspired by natural altruism is introduced.In the algorithm,nurturing cost considering Pareto rank and crowd distance is introduced as guidance of evolution to avoid futile calculation,abandonment threshold is self-adaptive with descendant situation to help individuals escape from local optima and double selection strategy combining crowd and k-nearest neighbors selection helps to get a better-distributed Pareto front.Experimental results comparing ANA with existing algorithms in AUV path planning demonstrate its superiority.Finally,a user-friendly interface,the Multi-Objective AUV Path Planner,is designed to provide users with a group of paths for informed decisionmaking.
基金the financial support from the National Natural Science Foundation of China(12171405 and 11661074)the Program for New Century Excellent Talents in Fujian Province University+2 种基金the financial support from the Characteristic&Preponderant Discipline of Key Construction Universities in Zhejiang Province(Zhejiang Gongshang University-Statistics)Collaborative Innovation Center of Statistical Data Engineering Technology&ApplicationDigital+Discipline Construction Project(SZJ2022B004)。
文摘Motivated by recent advances made in the study of dividend control and risk management problems involving the U.S.bankruptcy code,in this paper we follow[44]to revisit the De Finetti dividend control problem under the reorganization process and the regulator's intervention documented in U.S.Chapter 11 bankruptcy.We do this by further accommodating the fixed transaction costs on dividends to imitate the real-world procedure of dividend payments.Incorporating the fixed transaction costs transforms the targeting optimal dividend problem into an impulse control problem rather than a singular control problem,and hence computations and proofs that are distinct from[44]are needed.To account for the financial stress that is due to the more subtle concept of Chapter 11 bankruptcy,the surplus process after dividends is driven by a piece-wise spectrally negative Lévy process with endogenous regime switching.Some explicit expressions of the expected net present values under a double barrier dividend strategy,new to the literature,are established in terms of scale functions.With the help of these expressions,we are able to characterize the optimal strategy among the set of admissible double barrier dividend strategies.When the tail of the Lévy measure is log-convex,this optimal double barrier dividend strategy is then verified as the optimal dividend strategy,solving our optimal impulse control problem.
