Compared to currently commercialized lithium-ion batteries,which use flammable organic liquid electrolytes and low-energy-density graphite anodes,solid-state lithium-metal batteries(SSLMBs)offer enhanced energy densit...Compared to currently commercialized lithium-ion batteries,which use flammable organic liquid electrolytes and low-energy-density graphite anodes,solid-state lithium-metal batteries(SSLMBs)offer enhanced energy density and improved safety,making them promising alternatives for next-generation rechargeable batteries[1].As a crucial component of these batteries,solid-state electrolytes—divided into inorganic solid ceramic electrolytes(SCEs)and organic solid polymer electrolytes(SPEs)—are vital for lithium-ion transport and inhibiting lithium dendrite growth.Among them,SCEs exhibit high ionic conductivity,excellent mechanical properties,and outstanding electrochemical and thermal stability.Nevertheless,their brittleness,interfacial challenges with electrodes,and the requirement for high stacking pressure during battery operation significantly hinder their scalable application.In comparison,SPEs are more favourable for manufacturing due to their flexibility and good interfacial compatibility with electrodes[2].Despite these advantages,SPEs still face significant challenges in achieving practical application.Firstly,typical SPEs,such as poly(ethylene oxide)(PEO),poly(vinylidene fluoride)(PVDF),and poly(ethylene glycol)diacrylate(PEGDA),are characterized by high crystallinity,which causes polymer chains to be tightly packed and rigid.This restricts the segmental motion within the SPEs,resulting in low ionic conductivity.Secondly,compared to lithium ions,anions with large ionic radii and low charge density typically form weaker interactions with the polymer chains,which facilitates their mobility and results in a low lithium-ion transference number(tt).Thirdly,the weak interactions between polymer chains in typical SPEs lead to a low elastic modulus,which in turn compromises their poor mechanical strength.展开更多
The numerical analysis for the matching of the core driven compression system in a double bypass variable cycle engine was presented in this paper.The system consists of a one-stage-core driven fan stage(CDFS),an inne...The numerical analysis for the matching of the core driven compression system in a double bypass variable cycle engine was presented in this paper.The system consists of a one-stage-core driven fan stage(CDFS),an inner bypass duct and a five-stage high pressure compressor(HPC),providing two basic operating modes: the single bypass mode and the double bypass mode.Variable vanes are necessary to realize the mode switch of the system.The correct matching in the double bypass mode requires a proper combination of the mass flow,total pressure ratio and blade speed.The work capacity of the system decreases in the double bypass mode and the pressure ratio tends to decrease more for the CDFS and the front stages of the HPC.The overall system efficiency is higher in the double bypass mode.The radial distributions of aerodynamic parameters are similar in different modes.The notable redistribution of mass flow downstream the CDFS in the single bypass mode leads to strong radial flows and additional mixing losses.The absolute flow angles into the inner bypass increase for the inner span and decrease for the outer span when the system is switched from the single bypass mode to the double bypass mode.展开更多
Many design engineers in cross-domain industries have attended training classes of TRIZ to improve their innovative abilities in China. Most of them are successful, but others are not. So the latest target of the trai...Many design engineers in cross-domain industries have attended training classes of TRIZ to improve their innovative abilities in China. Most of them are successful, but others are not. So the latest target of the trainers is to improve the training process used now in industry in China and to make the engineers to understand the basic principles of TRIZ better. Based on the mass-engineer-oriented training model(MEOTM) and mechanical engineers’ design cases, a relationship between managing activities about the opportunities for innovation and the training process is set up. It is shown that the inventive problems come first from opportunity searching for engineers. A training and gate system for evaluation is developed to involve the managing activities of the companies in the training process. Then comparison between the general analogous process and the application of TRIZ is made, which shows the advantages and depth principles of TRIZ for the engineers to apply them confidently. Lastly a new process is formed in which opportunity searching, engineers training, inventive problems identifying and solving,and three redesign paths are connected seamlessly. The research proposes an opportunity-driven redesign path that cooperates the training and opportunity searching, which will be applied in future training classes to make more and more engineers to follow.展开更多
Model-Driven Engineering (MDE) by reframing software development as the transformation of high-level models, promises lots of gains to Software Engineering in terms of productivity, quality and reusability. Although a...Model-Driven Engineering (MDE) by reframing software development as the transformation of high-level models, promises lots of gains to Software Engineering in terms of productivity, quality and reusability. Although a number of empirical studies have established the reality of these gains, there are still lots of reluctances toward the adoption of MDE in practice. This resistance can be explained by several technological and social factors among which a natural scepticism toward novel approaches. In this paper we attempt to provide arguments to help alleviate this scepticism by conducting an assessment of a MDE approach. Our goal is to show that although this MDE is novel, it retains similarities with the conventional Software Engineering approach while automating aspects of it.展开更多
Complex engineered systems are often difficult to analyze and design due to the tangled interdependencies among their subsystems and components. Conventional design methods often need exact modeling or accurate struct...Complex engineered systems are often difficult to analyze and design due to the tangled interdependencies among their subsystems and components. Conventional design methods often need exact modeling or accurate structure decomposition, which limits their practical application. The rapid expansion of data makes utilizing data to guide and improve system design indispensable in practical engineering. In this paper, a data driven uncertainty evaluation approach is proposed to support the design of complex engineered systems. The core of the approach is a data-mining based uncertainty evaluation method that predicts the uncertainty level of a specific system design by means of analyzing association relations along different system attributes and synthesizing the information entropy of the covered attribute areas, and a quantitative measure of system uncertainty can be obtained accordingly. Monte Carlo simulation is introduced to get the uncertainty extrema, and the possible data distributions under different situations is discussed in detail The uncertainty values can be normalized using the simulation results and the values can be used to evaluate different system designs. A prototype system is established, and two case studies have been carded out. The case of an inverted pendulum system validates the effectiveness of the proposed method, and the case of an oil sump design shows the practicability when two or more design plans need to be compared. This research can be used to evaluate the uncertainty of complex engineered systems completely relying on data, and is ideally suited for plan selection and performance analysis in system design.展开更多
Additive manufacturing(AM)technology has revolutionized engineering field by enabling the creation of intricate,high-performance structures that were once difficult or impossible to fabricate.This transformative techn...Additive manufacturing(AM)technology has revolutionized engineering field by enabling the creation of intricate,high-performance structures that were once difficult or impossible to fabricate.This transformative technology has particularly advanced the development of metamaterials-engineered materials whose unique properties arise from their structure rather than composition-unlocking immense potential in fields ranging from aerospace to biomedical engineering.展开更多
Using electric motors instead of diesel engines as the driving system for mining excavators can reduce the energy consumption and operating costs.However,pure electric-driven mining excavators are prone to unexpected ...Using electric motors instead of diesel engines as the driving system for mining excavators can reduce the energy consumption and operating costs.However,pure electric-driven mining excavators are prone to unexpected power outages in mines because of drastic changes in load power,leading to significant fluctuations in the power demand of the grid,which in turn affects production.To solve the above problem,a pure electric-driven mining hydraulic excavator based on electric-motor-driven swing platform and hydraulic pumps was used as the research object.Moreover,supercapacitors and DC/DC converter,as the energy storage system(ESS)adjust the output power of the grid and recover the braking kinetic energy of the swing platform.Subsequently,a novel integrated energy management strategy for a DC bus voltage predictive controller based on the power feedforward of fuzzy rules is proposed to run mining excavators efficiently and reliably.Specifically,the working modes of the ESS are determined by the DC bus voltage and state of charge(SOC)of the supercapacitor.Next,the output power of the supercapacitor and the DC bus voltage were controlled by adjusting the charging and discharging currents of the DC/DC converter using a predictive controller and fuzzy rules.In addition,a digital prototype of the excavator was verified using an original machine test.The performance of the different strategies and driven systems were analyzed using digital prototypes.The results showed that,compared with traditional excavators with diesel engines,the operational cost of the developed excavators was reduced by 54.02%.Compared to pure electric-driven excavators without an ESS,the peak power of the grid for the developed excavators was reduced by 10%.This study designed an integrated energy management strategy for a pure electric mining excavator that can regulate the power output of the grid and maintain the stability of the bus voltage and SOC of the ESS.展开更多
Although the Model-Driven paradigm is being accepted in the research environment as a very useful and powerful option for effective software development, its real application in the enterprise context is still a chall...Although the Model-Driven paradigm is being accepted in the research environment as a very useful and powerful option for effective software development, its real application in the enterprise context is still a challenge for software engineering. Several causes can be stacked out, but one of them can be the lack of tool support for the efficient application of this paradigm. This paper presents a set of tools, grouped in a suite named NDT-Suite, which under the Model-Driven paradigm offer a suitable solution for software development. These tools explore different options that this paradigm can improve such as, development, quality assurance or requirement treatment. Besides, this paper analyses how they are being successfully applied in the industry.展开更多
Model transformation is one of the prominent features and the rising research area of Model Driven Engineering (MDE). MDE promotes models to primary artifacts that drive the whole development process. This paper prese...Model transformation is one of the prominent features and the rising research area of Model Driven Engineering (MDE). MDE promotes models to primary artifacts that drive the whole development process. This paper presents the model transformation approach for textual model oriented programs Umple (UML Programming Language) to generate android applications (apps). The proposed approach improved the generation of android source code by using Drools transformation rules and introducing new concern in model driven mobile engineering. The major objective of proposed transformation approach intends to address consistency between source and target model and also intends to handle productivity issues in model driven software development. The main results of model transformation approach are Java class for model layer, XML file for view layer and android activity class for controller layer. Results show that proposed approach achieves high consistency between source and target model and also improves model transformation productivity.展开更多
The success of system modernization depends on the existence of technical frameworks for information integration and tool interoperation like the Model Driven Architecture （MDA）. Reverse engineering techniques play ...The success of system modernization depends on the existence of technical frameworks for information integration and tool interoperation like the Model Driven Architecture （MDA）. Reverse engineering techniques play a crucial role in system modernization. This paper describes how to reverse engineering activity diagrams from object oriented code in the MDA context focusing on transformations at model and metamodel levels. A framework to reverse engineering MDA models from object oriented code that distinguishes three different abstraction levels linked to models, metamodels and formal specifications, is described. At model level, transformations are based on static and dynamic analysis. At metamodel level, transformations are specified as 0CL （Object Constraint Language） contracts between M0F （Meta Object Facility） metamodels which control the consistency of these transformations. The level of formal specification includes algebraic specifications of MOF metamodels and metamodel-based transformations. This paper analyzes a recovery process of activity diagrams from Java code by applying static and dynamic analysis and shows a formalization of this process in terms of MOF metamodels. The authors validate their approach by using Eclipse Modeling Framework, Ecore metamodels and ATL （Atlas Transformation Language）.展开更多
According to formula we can simulate their driven force and acceleration.The mechanical formula is used to obtain dynamics is used to simulate.The driven force increases when torque increases and tire diameter decreas...According to formula we can simulate their driven force and acceleration.The mechanical formula is used to obtain dynamics is used to simulate.The driven force increases when torque increases and tire diameter decreases.We need torque to increase so this is our plan.Acceleration raises when torque raises and it reduces when its weight raises.With the decreasing of radius of road the centripetal acceleration is increasing in the condition of light vehicle.It is that it decreases sluggishly before 0.35m/s2 then it maintains a steep decline to 0.62m/s2 and at last becomes sluggish again.It is valued that the economical efficiency about consumed fuel under different power.In the time of 0.2hr the fuel inflamer inclines sharply first then turns stable.It is the smallest value.Beyond it the fuel maintains a high value all the time.The discharged pollution gas decreases with the decreasing initial temperature.The low initial temperature is good to fuel gas.Meantime the smallest incline range is 300~350K which explains that it is the most save one.展开更多
基金supported by the University of Wollongong,Wollongong,Australiafinancial support from the National Natural Science Foundation of China(22272086)Natural Science Foundation of Sichuan Province(2023NSFSC0009).
文摘Compared to currently commercialized lithium-ion batteries,which use flammable organic liquid electrolytes and low-energy-density graphite anodes,solid-state lithium-metal batteries(SSLMBs)offer enhanced energy density and improved safety,making them promising alternatives for next-generation rechargeable batteries[1].As a crucial component of these batteries,solid-state electrolytes—divided into inorganic solid ceramic electrolytes(SCEs)and organic solid polymer electrolytes(SPEs)—are vital for lithium-ion transport and inhibiting lithium dendrite growth.Among them,SCEs exhibit high ionic conductivity,excellent mechanical properties,and outstanding electrochemical and thermal stability.Nevertheless,their brittleness,interfacial challenges with electrodes,and the requirement for high stacking pressure during battery operation significantly hinder their scalable application.In comparison,SPEs are more favourable for manufacturing due to their flexibility and good interfacial compatibility with electrodes[2].Despite these advantages,SPEs still face significant challenges in achieving practical application.Firstly,typical SPEs,such as poly(ethylene oxide)(PEO),poly(vinylidene fluoride)(PVDF),and poly(ethylene glycol)diacrylate(PEGDA),are characterized by high crystallinity,which causes polymer chains to be tightly packed and rigid.This restricts the segmental motion within the SPEs,resulting in low ionic conductivity.Secondly,compared to lithium ions,anions with large ionic radii and low charge density typically form weaker interactions with the polymer chains,which facilitates their mobility and results in a low lithium-ion transference number(tt).Thirdly,the weak interactions between polymer chains in typical SPEs lead to a low elastic modulus,which in turn compromises their poor mechanical strength.
文摘The numerical analysis for the matching of the core driven compression system in a double bypass variable cycle engine was presented in this paper.The system consists of a one-stage-core driven fan stage(CDFS),an inner bypass duct and a five-stage high pressure compressor(HPC),providing two basic operating modes: the single bypass mode and the double bypass mode.Variable vanes are necessary to realize the mode switch of the system.The correct matching in the double bypass mode requires a proper combination of the mass flow,total pressure ratio and blade speed.The work capacity of the system decreases in the double bypass mode and the pressure ratio tends to decrease more for the CDFS and the front stages of the HPC.The overall system efficiency is higher in the double bypass mode.The radial distributions of aerodynamic parameters are similar in different modes.The notable redistribution of mass flow downstream the CDFS in the single bypass mode leads to strong radial flows and additional mixing losses.The absolute flow angles into the inner bypass increase for the inner span and decrease for the outer span when the system is switched from the single bypass mode to the double bypass mode.
基金Supported by National Natural Science Foundation of China(Grant Nos.51675159,51305123)
文摘Many design engineers in cross-domain industries have attended training classes of TRIZ to improve their innovative abilities in China. Most of them are successful, but others are not. So the latest target of the trainers is to improve the training process used now in industry in China and to make the engineers to understand the basic principles of TRIZ better. Based on the mass-engineer-oriented training model(MEOTM) and mechanical engineers’ design cases, a relationship between managing activities about the opportunities for innovation and the training process is set up. It is shown that the inventive problems come first from opportunity searching for engineers. A training and gate system for evaluation is developed to involve the managing activities of the companies in the training process. Then comparison between the general analogous process and the application of TRIZ is made, which shows the advantages and depth principles of TRIZ for the engineers to apply them confidently. Lastly a new process is formed in which opportunity searching, engineers training, inventive problems identifying and solving,and three redesign paths are connected seamlessly. The research proposes an opportunity-driven redesign path that cooperates the training and opportunity searching, which will be applied in future training classes to make more and more engineers to follow.
文摘Model-Driven Engineering (MDE) by reframing software development as the transformation of high-level models, promises lots of gains to Software Engineering in terms of productivity, quality and reusability. Although a number of empirical studies have established the reality of these gains, there are still lots of reluctances toward the adoption of MDE in practice. This resistance can be explained by several technological and social factors among which a natural scepticism toward novel approaches. In this paper we attempt to provide arguments to help alleviate this scepticism by conducting an assessment of a MDE approach. Our goal is to show that although this MDE is novel, it retains similarities with the conventional Software Engineering approach while automating aspects of it.
基金Supported by National Hi-tech Research and Development Program of China(863 Program,Grant No.2015AA042101)
文摘Complex engineered systems are often difficult to analyze and design due to the tangled interdependencies among their subsystems and components. Conventional design methods often need exact modeling or accurate structure decomposition, which limits their practical application. The rapid expansion of data makes utilizing data to guide and improve system design indispensable in practical engineering. In this paper, a data driven uncertainty evaluation approach is proposed to support the design of complex engineered systems. The core of the approach is a data-mining based uncertainty evaluation method that predicts the uncertainty level of a specific system design by means of analyzing association relations along different system attributes and synthesizing the information entropy of the covered attribute areas, and a quantitative measure of system uncertainty can be obtained accordingly. Monte Carlo simulation is introduced to get the uncertainty extrema, and the possible data distributions under different situations is discussed in detail The uncertainty values can be normalized using the simulation results and the values can be used to evaluate different system designs. A prototype system is established, and two case studies have been carded out. The case of an inverted pendulum system validates the effectiveness of the proposed method, and the case of an oil sump design shows the practicability when two or more design plans need to be compared. This research can be used to evaluate the uncertainty of complex engineered systems completely relying on data, and is ideally suited for plan selection and performance analysis in system design.
文摘Additive manufacturing(AM)technology has revolutionized engineering field by enabling the creation of intricate,high-performance structures that were once difficult or impossible to fabricate.This transformative technology has particularly advanced the development of metamaterials-engineered materials whose unique properties arise from their structure rather than composition-unlocking immense potential in fields ranging from aerospace to biomedical engineering.
基金Supported by National Natural Science Foundation of ChinaShanxi Coalbased Low-Carbon Joint Fund(Grant No.U1910211)。
文摘Using electric motors instead of diesel engines as the driving system for mining excavators can reduce the energy consumption and operating costs.However,pure electric-driven mining excavators are prone to unexpected power outages in mines because of drastic changes in load power,leading to significant fluctuations in the power demand of the grid,which in turn affects production.To solve the above problem,a pure electric-driven mining hydraulic excavator based on electric-motor-driven swing platform and hydraulic pumps was used as the research object.Moreover,supercapacitors and DC/DC converter,as the energy storage system(ESS)adjust the output power of the grid and recover the braking kinetic energy of the swing platform.Subsequently,a novel integrated energy management strategy for a DC bus voltage predictive controller based on the power feedforward of fuzzy rules is proposed to run mining excavators efficiently and reliably.Specifically,the working modes of the ESS are determined by the DC bus voltage and state of charge(SOC)of the supercapacitor.Next,the output power of the supercapacitor and the DC bus voltage were controlled by adjusting the charging and discharging currents of the DC/DC converter using a predictive controller and fuzzy rules.In addition,a digital prototype of the excavator was verified using an original machine test.The performance of the different strategies and driven systems were analyzed using digital prototypes.The results showed that,compared with traditional excavators with diesel engines,the operational cost of the developed excavators was reduced by 54.02%.Compared to pure electric-driven excavators without an ESS,the peak power of the grid for the developed excavators was reduced by 10%.This study designed an integrated energy management strategy for a pure electric mining excavator that can regulate the power output of the grid and maintain the stability of the bus voltage and SOC of the ESS.
文摘Although the Model-Driven paradigm is being accepted in the research environment as a very useful and powerful option for effective software development, its real application in the enterprise context is still a challenge for software engineering. Several causes can be stacked out, but one of them can be the lack of tool support for the efficient application of this paradigm. This paper presents a set of tools, grouped in a suite named NDT-Suite, which under the Model-Driven paradigm offer a suitable solution for software development. These tools explore different options that this paradigm can improve such as, development, quality assurance or requirement treatment. Besides, this paper analyses how they are being successfully applied in the industry.
文摘Model transformation is one of the prominent features and the rising research area of Model Driven Engineering (MDE). MDE promotes models to primary artifacts that drive the whole development process. This paper presents the model transformation approach for textual model oriented programs Umple (UML Programming Language) to generate android applications (apps). The proposed approach improved the generation of android source code by using Drools transformation rules and introducing new concern in model driven mobile engineering. The major objective of proposed transformation approach intends to address consistency between source and target model and also intends to handle productivity issues in model driven software development. The main results of model transformation approach are Java class for model layer, XML file for view layer and android activity class for controller layer. Results show that proposed approach achieves high consistency between source and target model and also improves model transformation productivity.
文摘The success of system modernization depends on the existence of technical frameworks for information integration and tool interoperation like the Model Driven Architecture （MDA）. Reverse engineering techniques play a crucial role in system modernization. This paper describes how to reverse engineering activity diagrams from object oriented code in the MDA context focusing on transformations at model and metamodel levels. A framework to reverse engineering MDA models from object oriented code that distinguishes three different abstraction levels linked to models, metamodels and formal specifications, is described. At model level, transformations are based on static and dynamic analysis. At metamodel level, transformations are specified as 0CL （Object Constraint Language） contracts between M0F （Meta Object Facility） metamodels which control the consistency of these transformations. The level of formal specification includes algebraic specifications of MOF metamodels and metamodel-based transformations. This paper analyzes a recovery process of activity diagrams from Java code by applying static and dynamic analysis and shows a formalization of this process in terms of MOF metamodels. The authors validate their approach by using Eclipse Modeling Framework, Ecore metamodels and ATL （Atlas Transformation Language）.
文摘According to formula we can simulate their driven force and acceleration.The mechanical formula is used to obtain dynamics is used to simulate.The driven force increases when torque increases and tire diameter decreases.We need torque to increase so this is our plan.Acceleration raises when torque raises and it reduces when its weight raises.With the decreasing of radius of road the centripetal acceleration is increasing in the condition of light vehicle.It is that it decreases sluggishly before 0.35m/s2 then it maintains a steep decline to 0.62m/s2 and at last becomes sluggish again.It is valued that the economical efficiency about consumed fuel under different power.In the time of 0.2hr the fuel inflamer inclines sharply first then turns stable.It is the smallest value.Beyond it the fuel maintains a high value all the time.The discharged pollution gas decreases with the decreasing initial temperature.The low initial temperature is good to fuel gas.Meantime the smallest incline range is 300~350K which explains that it is the most save one.
