This paper collected and arranged competitive scientific research projects undertaken by Tropical Crops Genetic Resources Institute of Chinese Academy of Tropical Agricultural Sciences in 2003-2014. Through statistica...This paper collected and arranged competitive scientific research projects undertaken by Tropical Crops Genetic Resources Institute of Chinese Academy of Tropical Agricultural Sciences in 2003-2014. Through statistical analysis on quantity of projects,funded amount,age of person responsible,professional title of person responsible,academic degree of person responsible,research object,it discussed relevant characteristics and rules. Finally,it came up with pertinent measures and recommendations,in the hope of providing services for decision-making and scientific and technological management.展开更多
Transport of a Brownian particle moving in a periodic potential is investigated in the presence of an asymmetric unbiased external force. The asymmetry of the external force and the asymmetry of the potentlal are the ...Transport of a Brownian particle moving in a periodic potential is investigated in the presence of an asymmetric unbiased external force. The asymmetry of the external force and the asymmetry of the potentlal are the two ways of inducing a net current. It is found that the competition of the spatial asymmetry of potential with the temporal asymmetry of the external force leads to the phenomena like current reversal The competition between the two opposite driving factors is a necessary but not a sufficient condition for current reversals.展开更多
The permanent magnet eddy current coupler(PMEC)solves the problem of flexible connection and speed regulation between the motor and the load and is widely used in electrical transmission systems.It provides torque to ...The permanent magnet eddy current coupler(PMEC)solves the problem of flexible connection and speed regulation between the motor and the load and is widely used in electrical transmission systems.It provides torque to the load and generates heat and losses,reducing its energy transfer efficiency.This issue has become an obstacle for PMEC to develop toward a higher power.This paper aims to improve the overall performance of PMEC through multi-objective optimization methods.Firstly,a PMEC modeling method based on the Levenberg-Marquardt back propagation(LMBP)neural network is proposed,aiming at the characteristics of the complex input-output relationship and the strong nonlinearity of PMEC.Then,a novel competition mechanism-based multi-objective particle swarm optimization algorithm(NCMOPSO)is proposed to find the optimal structural parameters of PMEC.Chaotic search and mutation strategies are used to improve the original algorithm,which improves the shortcomings of multi-objective particle swarm optimization(MOPSO),which is too fast to converge into a global optimum,and balances the convergence and diversity of the algorithm.In order to verify the superiority and applicability of the proposed algorithm,it is compared with several popular multi-objective optimization algorithms.Applying them to the optimization model of PMEC,the results show that the proposed algorithm has better comprehensive performance.Finally,a finite element simulation model is established using the optimal structural parameters obtained by the proposed algorithm to verify the optimization results.Compared with the prototype,the optimized PMEC has reduced eddy current losses by 1.7812 kW,increased output torque by 658.5 N·m,and decreased costs by 13%,improving energy transfer efficiency.展开更多
Sodium is an important light non-ferrous metal with special properties and is widely applied in various fields of pharmaceutical intermediates,airbags metallurgy and nuclear coolants.However,the high energy consumptio...Sodium is an important light non-ferrous metal with special properties and is widely applied in various fields of pharmaceutical intermediates,airbags metallurgy and nuclear coolants.However,the high energy consumption,low current efficiency of the sodium industry,coupled with the substantial sodium slag byproduct and inefficient sodium slag recovery technology,have greatly hindered the further development of the metallic sodium industry.Although many research papers and new patents continue to emerge,there are very few reviews on the preparation of metallic sodium and the disposal of sodium slag which affects the exchange and development of new technologies in the sodium industry.Herein,this review summarizes the progress in sodium production technology and sodium slag recovery.Based on the ion migration mechanism and the competition discharge mechanism of different cations,constructing suitable electrolyte components containing sodium and selecting appropriate membrane materials can significantly improve current efficiency and reduce the reduction of impurity metals,while sodium slag recovery methods like mechanical separation,solvent leaching,and melting substitution have been developed,enabling the recycling of valuable components.Furthermore,this review explores sodium applications in energy storage,inorganic/organic synthesis,metal smelting,and nuclear reactors.It emphasizes the need for further technological advancements to address energy efficiency,slag recovery,and chlorine gas utilization challenges in sodium production.展开更多
基金Supported by Special Project for Reform of Non-profit Scientific Research Institution"Study on Whole Process Management of Agricultural Scientific and Technological Projects"
文摘This paper collected and arranged competitive scientific research projects undertaken by Tropical Crops Genetic Resources Institute of Chinese Academy of Tropical Agricultural Sciences in 2003-2014. Through statistical analysis on quantity of projects,funded amount,age of person responsible,professional title of person responsible,academic degree of person responsible,research object,it discussed relevant characteristics and rules. Finally,it came up with pertinent measures and recommendations,in the hope of providing services for decision-making and scientific and technological management.
文摘Transport of a Brownian particle moving in a periodic potential is investigated in the presence of an asymmetric unbiased external force. The asymmetry of the external force and the asymmetry of the potentlal are the two ways of inducing a net current. It is found that the competition of the spatial asymmetry of potential with the temporal asymmetry of the external force leads to the phenomena like current reversal The competition between the two opposite driving factors is a necessary but not a sufficient condition for current reversals.
基金supported by the National Natural Science Foundation of China under Grant 52077027.
文摘The permanent magnet eddy current coupler(PMEC)solves the problem of flexible connection and speed regulation between the motor and the load and is widely used in electrical transmission systems.It provides torque to the load and generates heat and losses,reducing its energy transfer efficiency.This issue has become an obstacle for PMEC to develop toward a higher power.This paper aims to improve the overall performance of PMEC through multi-objective optimization methods.Firstly,a PMEC modeling method based on the Levenberg-Marquardt back propagation(LMBP)neural network is proposed,aiming at the characteristics of the complex input-output relationship and the strong nonlinearity of PMEC.Then,a novel competition mechanism-based multi-objective particle swarm optimization algorithm(NCMOPSO)is proposed to find the optimal structural parameters of PMEC.Chaotic search and mutation strategies are used to improve the original algorithm,which improves the shortcomings of multi-objective particle swarm optimization(MOPSO),which is too fast to converge into a global optimum,and balances the convergence and diversity of the algorithm.In order to verify the superiority and applicability of the proposed algorithm,it is compared with several popular multi-objective optimization algorithms.Applying them to the optimization model of PMEC,the results show that the proposed algorithm has better comprehensive performance.Finally,a finite element simulation model is established using the optimal structural parameters obtained by the proposed algorithm to verify the optimization results.Compared with the prototype,the optimized PMEC has reduced eddy current losses by 1.7812 kW,increased output torque by 658.5 N·m,and decreased costs by 13%,improving energy transfer efficiency.
基金financially supported by the National Key Research and Development Program of China(2023YFC3903500)the National Natural Science Foundation of China(21676022&21706004)+1 种基金the Fundamental Research Funds for the Central Universities(ONYC232301)Inner Mongolia Rui Xin Chemical Co.,Ltd.for providing support on data support and financial support。
文摘Sodium is an important light non-ferrous metal with special properties and is widely applied in various fields of pharmaceutical intermediates,airbags metallurgy and nuclear coolants.However,the high energy consumption,low current efficiency of the sodium industry,coupled with the substantial sodium slag byproduct and inefficient sodium slag recovery technology,have greatly hindered the further development of the metallic sodium industry.Although many research papers and new patents continue to emerge,there are very few reviews on the preparation of metallic sodium and the disposal of sodium slag which affects the exchange and development of new technologies in the sodium industry.Herein,this review summarizes the progress in sodium production technology and sodium slag recovery.Based on the ion migration mechanism and the competition discharge mechanism of different cations,constructing suitable electrolyte components containing sodium and selecting appropriate membrane materials can significantly improve current efficiency and reduce the reduction of impurity metals,while sodium slag recovery methods like mechanical separation,solvent leaching,and melting substitution have been developed,enabling the recycling of valuable components.Furthermore,this review explores sodium applications in energy storage,inorganic/organic synthesis,metal smelting,and nuclear reactors.It emphasizes the need for further technological advancements to address energy efficiency,slag recovery,and chlorine gas utilization challenges in sodium production.
