The connection efficiency of composite pre-tightened multi-tooth joint is low because of uneven load distribution and single load transmission path.In this paper,based on the principle of bio-tooth(suture)structure,co...The connection efficiency of composite pre-tightened multi-tooth joint is low because of uneven load distribution and single load transmission path.In this paper,based on the principle of bio-tooth(suture)structure,combining soft material with fractal,a composite pre-tightened multi-hierarchy tooth joint is proposed,and the bearing performance and failure process of the joint through experiments and finite element method under tensile load.First,the ultimate bearing capacity,load distribution ratio,and failure process of different hierarchies of teeth joints are studied through experiments.Then,the progressive damage models of different hierarchies of tooth joints are established,and experiments verify the validity of the finite element model.Finally,the effects of soft material and increasing tooth hierarchy on the failure process and bearing capacity of composite pre-tightened tooth joints are analyzed by the finite element method.The following conclusions can be drawn:(1)The embedding of soft materials changed the failure process of the joint.Increasing the tooth hierarchy can give the joint more load transfer paths,but the failure process of the joint is complicated.(2)Embedding soft materials and increasing the tooth hierarchy simultaneously can effectively improve the bearing capacity of composite pre-tightened tooth joints,which is 87.8%higher than that of traditional three-tooth joints.展开更多
Under the new energy resource structure,electrocatalysts are key materials for the development of proton membrane fuel cells,electrolysis of aquatic hydrogen devices,and carbon dioxide reduction equipment,to address e...Under the new energy resource structure,electrocatalysts are key materials for the development of proton membrane fuel cells,electrolysis of aquatic hydrogen devices,and carbon dioxide reduction equipment,to address energy shortages and even environmental pollution issues.Although controlling the morphology or doping with heteroatoms for catalyst active centers have accelerated the reaction rate,it is difficult to solve the problems of multiple by-products,and poor stability of catalytic sites.From this,it will be seen that single regulation of metal active centers is difficult to comprehensively solve application problems.Orderly assembly and coordination of catalyst multi-hierarchy structures at the mesoscale above the nanometer level probably be more reasonable strategies,and numerous studies in thermal catalysis have supported this viewpoint.This article reviews the multi-hierarchy design of electrocatalyst active centers,high-energy supports,and peripheral structures in recent years,providing unconventional inspiration about electrocatalyst creation,which perhaps serves as a simple tutorial of electrocatalysis exploration for abecedarian.展开更多
In order to evaluate stock quality scientifically, a synthetic evaluation system of stock quality is proposed on the basis of fuzzy set theory and grey multi-hierarchy decision method. Then the evaluation system is ap...In order to evaluate stock quality scientifically, a synthetic evaluation system of stock quality is proposed on the basis of fuzzy set theory and grey multi-hierarchy decision method. Then the evaluation system is applied to an example. The results show that the evaluation system can overcome the errors of expert＇s subjective judgment.展开更多
The multi-hierarchy simulation model for magnetic reconnection is developed,where both micro andmacro hierarchies are expressed consistently and simultaneously.Two hierarchies are connected smoothly by shake-hand sche...The multi-hierarchy simulation model for magnetic reconnection is developed,where both micro andmacro hierarchies are expressed consistently and simultaneously.Two hierarchies are connected smoothly by shake-hand scheme.As a numerical test,propagation of one-dimensional Alfv´en wave is examined using the multihierarchy simulation model.It is found that waves smoothly pass through frommacro to micro hierarchies and vice versa.展开更多
A multi-hierarchy simulation model aiming magnetic reconnection studies is developed and improved in which macroscopic and microscopic physics are computed consistently and simultaneously.Macroscopic physics is solved...A multi-hierarchy simulation model aiming magnetic reconnection studies is developed and improved in which macroscopic and microscopic physics are computed consistently and simultaneously.Macroscopic physics is solved by magnetohydrodynamics(MHD)algorithm,while microscopic dynamics is expressed by particle-in-cell(PIC)algorithm.The multi-hierarchy model relies on the domain decomposition method,and macro-and micro-hierarchies are interlocked smoothly by hand-shake scheme.As examination,plasma flow injection is simulated in the multihierarchy model.It is observed that plasmas flow from a macro-hierarchy to a microhierarchy across the magnetic field smoothly and continuously.展开更多
The grey quasi-preferred analysis (GQPA) is one of important methods for realizing system analysis to conquer the limitations of the existing GQPA model, without any considerations to the difference of the different b...The grey quasi-preferred analysis (GQPA) is one of important methods for realizing system analysis to conquer the limitations of the existing GQPA model, without any considerations to the difference of the different behavioral factor′s importance. It could not be used to analyze the complex system with multi-hierarchy correlation factors, the weighted synthetic method for calculating abstract incidence degrees between the system beha-vioral characteristics and correlative factors in different hierarchies is given out,and the hierarchic grey quasi-preferred analysis (HGQPA) model is established. The effectiveness of the HGQPA model is tested by the scientific-technical system of Jiangsu Province. The depth and the range of the application of GQPA are developed, and the HGQPA model is regarded as a new approach to systemically analyze the complex systems with multi-hierarchy correlation factors.展开更多
基金funded by the National Natural Science Foundation of China(52478138).
文摘The connection efficiency of composite pre-tightened multi-tooth joint is low because of uneven load distribution and single load transmission path.In this paper,based on the principle of bio-tooth(suture)structure,combining soft material with fractal,a composite pre-tightened multi-hierarchy tooth joint is proposed,and the bearing performance and failure process of the joint through experiments and finite element method under tensile load.First,the ultimate bearing capacity,load distribution ratio,and failure process of different hierarchies of teeth joints are studied through experiments.Then,the progressive damage models of different hierarchies of tooth joints are established,and experiments verify the validity of the finite element model.Finally,the effects of soft material and increasing tooth hierarchy on the failure process and bearing capacity of composite pre-tightened tooth joints are analyzed by the finite element method.The following conclusions can be drawn:(1)The embedding of soft materials changed the failure process of the joint.Increasing the tooth hierarchy can give the joint more load transfer paths,but the failure process of the joint is complicated.(2)Embedding soft materials and increasing the tooth hierarchy simultaneously can effectively improve the bearing capacity of composite pre-tightened tooth joints,which is 87.8%higher than that of traditional three-tooth joints.
基金supported by the National Natural Science Foundation of China(91963206,21932004,21872067,22172072)the Ministry of Science and Technology of China(2021YFA1500301)。
文摘Under the new energy resource structure,electrocatalysts are key materials for the development of proton membrane fuel cells,electrolysis of aquatic hydrogen devices,and carbon dioxide reduction equipment,to address energy shortages and even environmental pollution issues.Although controlling the morphology or doping with heteroatoms for catalyst active centers have accelerated the reaction rate,it is difficult to solve the problems of multiple by-products,and poor stability of catalytic sites.From this,it will be seen that single regulation of metal active centers is difficult to comprehensively solve application problems.Orderly assembly and coordination of catalyst multi-hierarchy structures at the mesoscale above the nanometer level probably be more reasonable strategies,and numerous studies in thermal catalysis have supported this viewpoint.This article reviews the multi-hierarchy design of electrocatalyst active centers,high-energy supports,and peripheral structures in recent years,providing unconventional inspiration about electrocatalyst creation,which perhaps serves as a simple tutorial of electrocatalysis exploration for abecedarian.
基金The National Natural Science Foundationof China (No.70272033)
文摘In order to evaluate stock quality scientifically, a synthetic evaluation system of stock quality is proposed on the basis of fuzzy set theory and grey multi-hierarchy decision method. Then the evaluation system is applied to an example. The results show that the evaluation system can overcome the errors of expert＇s subjective judgment.
基金This work was partially supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science(No.18340188)the Research Cooperation Program on’Hierarchy and Holism in Natural Sciences 2’at National Institutes of Natu-ral Sciences,and General Coordinated Research at National Institute for Fusion Science(NIFS06KTAT037,NIFS07KNXN095).
文摘The multi-hierarchy simulation model for magnetic reconnection is developed,where both micro andmacro hierarchies are expressed consistently and simultaneously.Two hierarchies are connected smoothly by shake-hand scheme.As a numerical test,propagation of one-dimensional Alfv´en wave is examined using the multihierarchy simulation model.It is found that waves smoothly pass through frommacro to micro hierarchies and vice versa.
基金This work was partially supported by the Research Cooperation Program on Hierarchy and Holism in Natural Sciences 2 at the National Institutes of Natural Sciences and the General Coordinated Research at the National Institute for Fusion Science(NIFS09KNXN174,NIFS10KTAS003).
文摘A multi-hierarchy simulation model aiming magnetic reconnection studies is developed and improved in which macroscopic and microscopic physics are computed consistently and simultaneously.Macroscopic physics is solved by magnetohydrodynamics(MHD)algorithm,while microscopic dynamics is expressed by particle-in-cell(PIC)algorithm.The multi-hierarchy model relies on the domain decomposition method,and macro-and micro-hierarchies are interlocked smoothly by hand-shake scheme.As examination,plasma flow injection is simulated in the multihierarchy model.It is observed that plasmas flow from a macro-hierarchy to a microhierarchy across the magnetic field smoothly and continuously.
文摘The grey quasi-preferred analysis (GQPA) is one of important methods for realizing system analysis to conquer the limitations of the existing GQPA model, without any considerations to the difference of the different behavioral factor′s importance. It could not be used to analyze the complex system with multi-hierarchy correlation factors, the weighted synthetic method for calculating abstract incidence degrees between the system beha-vioral characteristics and correlative factors in different hierarchies is given out,and the hierarchic grey quasi-preferred analysis (HGQPA) model is established. The effectiveness of the HGQPA model is tested by the scientific-technical system of Jiangsu Province. The depth and the range of the application of GQPA are developed, and the HGQPA model is regarded as a new approach to systemically analyze the complex systems with multi-hierarchy correlation factors.
