Fractional differential equations(FDEs)provide a powerful tool for modeling systems with memory and non-local effects,but understanding their underlying structure remains a significant challenge.While numerous numeric...Fractional differential equations(FDEs)provide a powerful tool for modeling systems with memory and non-local effects,but understanding their underlying structure remains a significant challenge.While numerous numerical and semi-analytical methods exist to find solutions,new approaches are needed to analyze the intrinsic properties of the FDEs themselves.This paper introduces a novel computational framework for the structural analysis of FDEs involving iterated Caputo derivatives.The methodology is based on a transformation that recasts the original FDE into an equivalent higher-order form,represented as the sum of a closed-form,integer-order component G(y)and a residual fractional power seriesΨ(x).This transformed FDE is subsequently reduced to a first-order ordinary differential equation(ODE).The primary novelty of the proposed methodology lies in treating the structure of the integer-order component G(y)not as fixed,but as a parameterizable polynomial whose coefficients can be determined via global optimization.Using particle swarm optimization,the framework identifies an optimal ODE architecture by minimizing a dual objective that balances solution accuracy against a high-fidelity reference and the magnitude of the truncated residual series.The effectiveness of the approach is demonstrated on both a linear FDE and a nonlinear fractional Riccati equation.Results demonstrate that the framework successfully identifies an optimal,low-degree polynomial ODE architecture that is not necessarily identical to the forcing function of the original FDE.This work provides a new tool for analyzing the underlying structure of FDEs and gaining deeper insights into the interplay between local and non-local dynamics in fractional systems.展开更多
In the new phase of sustainable development,agriculture is seeking sustainable management of the water-land-energy-economy-environment-food nexus.At present,there are few studies on optimizing crop planting structure ...In the new phase of sustainable development,agriculture is seeking sustainable management of the water-land-energy-economy-environment-food nexus.At present,there are few studies on optimizing crop planting structure and analyzing its spatial layout with consideration of natural and socio-economic factors.Herein,we proposed a framework for addressing this issue.In this framework,the NSGA-II algorithm was used to construct the multi-objective optimization model of crop planting structures with consideration of water and energy consumption,greenhouse gas(GHG)emissions,economic benefits,as well as food,land,and water security constraints,while the model for planting spatial layout optimization was established with consideration of crop suitability using the MaxEnt model and the improved Hungarian algorithm.This framework was further applied in the Black Soil Region of Northeast China(BSRNC)for analyzing optimized crop planting structures and spatial layouts of three main crops(rice,maize,and soybean)under various scenarios.This study showed that the sown area of rice in the BSRNC decreased by up to 40.73%and 35.30%in the environmental priority scenario and economic-environmental balance scenario,respectively,whereas that of soybean increased by up to 112.44%and 63.31%,respectively.In the economic priority scenario,the sown area of rice increased by up to 93.98%.Expanding the sown area of soybean was effective in reducing GHG emissions.On the contrary,rice production led to greater environmental costs though it provided higher economic returns.Among the three crops,maize exhibited an advantage in balancing environmental and economic benefits.Hegang-Jixi area in the northeast of the BSRNC was identified as the key area with the most intense crop planting transfer among different scenarios.Overall,this framework provides a new methodology for optimizing crop planting structures and spatial layouts with con-sideration of the nexus of various factors.Moreover,the case study demonstrates the applicability and expansion potential of the framework in the fields of sustainable agricultural development and food security assurance.展开更多
The optimization of civil engineering structures is critical for enhancing structural performance and material efficiency in engineering applications.Structural optimization approaches seek to determine the optimal de...The optimization of civil engineering structures is critical for enhancing structural performance and material efficiency in engineering applications.Structural optimization approaches seek to determine the optimal design,by considering material performance,cost,and structural safety.The design approaches aim to reduce the built environment’s energy use and carbon emissions.This comprehensive review examines optimization techniques,including size,shape,topology,and multi-objective approaches,by integrating these methodologies.The trends and advancements that contribute to developing more efficient,cost-effective,and reliable structural designs were identified.The review also discusses emerging technologies,such as machine learning applications with different optimization techniques.Optimization of truss,frame,tensegrity,reinforced concrete,origami,pantographic,and adaptive structures are covered and discussed.Optimization techniques are explained,including metaheuristics,genetic algorithm,particle swarm,ant-colony,harmony search algorithm,and their applications with mentioned structure types.Linear and non-linear structures,including geometric and material nonlinearity,are distinguished.The role of optimization in active structures,structural design,seismic design,form-finding,and structural control is taken into account,and the most recent techniques and advancements are mentioned.展开更多
The beam pumping unit(BPU)remains the most stable and reliable equipment for crude oil lifting.Despite its simple four-link mechanism,the structural design of the BPU presents a constrained single-objective optimizati...The beam pumping unit(BPU)remains the most stable and reliable equipment for crude oil lifting.Despite its simple four-link mechanism,the structural design of the BPU presents a constrained single-objective optimization problem.Currently,a comprehensive framework for the structural design and optimization of compound balanced BPUs is lacking.Therefore,this study proposes a novel structural design scheme for BPUs,aiming to meet the practical needs of designers and operators by sequentially optimizing both the dynamic characteristics and balance properties of the BPUs.A dynamic model of compound balanced BPU was established based on D'Alembert's principle.The constraints for structural dimensions were formulated based on the actual operational requirements and design experience with BPUs.To optimize the structure,three algorithms were employed:the particle swarm optimization(PSO)algorithm,the genetic algorithm(GA),and the gray wolf optimization(GWO)algorithm.Each newly generated individuals are regulated by constraints to ensure the rationality of the outcomes.Furthermore,the integration of three algorithms ensures the increased likelihood of attaining the global optimal solution.The polished rod acceleration of the optimized structure is significantly reduced,and the dynamic characteristics of the up and down strokes are essentially symmetrical.Additionally,these three algorithms are also applied to the balance optimization of BPUs based on the measured dynamometer card.The calculation results demonstrate that the GWO-based optimization method exhibits excellent robustness in terms of structural optimization by enhancing the operational smoothness of the BPU,as well as in balance optimization by achieving energy conservation.By applying the optimization scheme proposed in this paper,the CYJW7-3-23HF type of BPU was designed,achieving a maximum polished rod acceleration of±0.675 m/s^(2) when operating at a stroke of 6 min^(−1).When deployed in two wells,the root-mean-square(RMS)torque was minimized,reaching values of 7.539 kN·m and 12.921 kN·m,respectively.The proposed design method not only contributes to the personalized customization but also improves the design efficiency of compound balanced BPUs.展开更多
As a key storage facility, the structural safety of large oil tanks is directly related to the stable operation of the energy system. The static pressure caused by the change of liquid level is one of the main loads i...As a key storage facility, the structural safety of large oil tanks is directly related to the stable operation of the energy system. The static pressure caused by the change of liquid level is one of the main loads in the service process of storage tanks, which determines the structural deformation and damage risk. To explore the structural deformation properties under the change of liquid levels and provide a theoretical basis for the prevention and control of damage risk, this paper systematically analyzes the mechanical response of storage tanks under the pressures induced by different liquid levels based on the shell theory. Combined with the finite element software COMSOL, the radial displacement and stress-strain distribution under different liquid levels are simulated to verify the accuracy and effectiveness of the proposed theoretical model. The increase in liquid level and radius aggravates the radial deformation and makes the risk point move up, while the increase in wall thickness can effectively reduce the deformation response. Suggestions on the monitoring zone and damage risk prevention measures have also been given to instruct the safe operation of oil tanks. The research provides theoretical support for the optimization design of storage tank structures, the construction of advanced structural health monitoring system and the prevention and control of damage risk.展开更多
Purpose–This paper aims to provide a comprehensive analysis of the strategic adjustments in China’s transportation structure,with a particular focus on the pivotal role of railway freight and its integration into th...Purpose–This paper aims to provide a comprehensive analysis of the strategic adjustments in China’s transportation structure,with a particular focus on the pivotal role of railway freight and its integration into the modern logistics system.It seeks to address the need for a more nuanced understanding of the“road to rail”policy,emphasizing the importance of intermodal collaboration and service of fragmented market demands.Design/methodology/approach–The study employs a transport economics perspective to evaluate the achievements and shortcomings of China’s transportation structure optimization.It bases its assessment of the current state of railway freight logistics,multi-modal transportation and the broader implications for the transportation service market on data analysis.The methodology includes a review of existing policies,an examination of industry practices and a comparative analysis with global trends in railway logistics.Findings–The research underscores the importance of focusing on the development of non-bulk materials,noting the insufficiency in the development of China’s rail multi-modal transportation and highlighting the instructive value of successful cases in open-top container road-rail intermodal transportation.The study posits that the railway sector must enhance cooperation with other market entities,aligning with the lead enterprises in the logistics chain that are characterized by speed,high value and strong coordination capabilities,in order to better serve the transportation market.This approach moves away from a reliance on the railway’s own capabilities alone.Originality/value–This paper offers original insights into the transformation of railway freight in China,contributing to the body of knowledge on transportation economics and logistics.It provides valuable recommendations for policymakers and industry practitioners,emphasizing the strategic importance of railway logistics in the context of China’s economic development and intense competition in the supply chain.The value of the article lies in its comprehensive understanding of the complexities involved in the adjustment of transportation structures,providing direction for the market-oriented reform of China’s railway freight sector.展开更多
Idiopathic pulmonary fibrosis(IPF)is a progressive lung disease and its incidence rate is rapidly rising.However,effective therapies for the treatment of IPF are still lacking.Phosphodiesterase 4(PDE4)inhibitors were ...Idiopathic pulmonary fibrosis(IPF)is a progressive lung disease and its incidence rate is rapidly rising.However,effective therapies for the treatment of IPF are still lacking.Phosphodiesterase 4(PDE4)inhibitors were reported to be potential anti-fibrotic agents.Herein,structure-based hit-to-lead optimization of natural isoaurostatin(8.98μmol/L)resulted in several potent inhibitors of PDE4 with half maximal inhibitory concentration(IC_(50))values ranging from 35 nmol/L to 126 nmol/L.Co-crystal structures revealed that isoaurostatin compounds exhibited different binding patterns from the classic PDE4 inhibitor rolipram and the analogues would favor to be Z configurations other than the corresponding E isomers.Finally,lead 2–9 showed remarkable in vitro/in vivo anti-fibrotic effects indicating its potential as a novel anti-IPF agent.展开更多
Magnesium alloy,as a new material for vascular stents,possesses excellent mechanical properties,biocompatibility,and biodegradability.However,the mechanical properties of magnesium alloy stents exhibit relatively infe...Magnesium alloy,as a new material for vascular stents,possesses excellent mechanical properties,biocompatibility,and biodegradability.However,the mechanical properties of magnesium alloy stents exhibit relatively inferior performance compared to traditional metal stents with identical structural characteristics.Therefore,improving their mechanical properties is a key issue in the development of biodegradable magnesium alloy stents.In this study,three new stent structures(i.e.,stent A,stent B,and stent C)were designed based on the typical structure of biodegradable stents.The changes made included altering the angle and arrangement of the support rings to create a support ring structure with alternating large and small angles,as well as modifying the position and shape of the link.Using finite element analysis,the compressive performance,expansion performance,bending flexibility performance,damage to blood vessels,and hemodynamic changes of the stent were used as evaluation indexes.The results of these comprehensive evaluations were utilized as the primary criteria for selecting the most suitable stent design.The results demonstrated that compared to the traditional stent,stents A,B,and C exhibited improvements in radial stiffness of 16.9%,15.1%,and 37.8%,respectively;reductions in bending stiffness of 27.3%,7.6%,and 38.1%,respectively;decreases in dog-boning rate of 5.1%,93.9%,and 31.3%,respectively;as well as declines in the low wall shear stress region by 50.1%,43.8%,and 36.2%,respectively.In comparison to traditional stents,a reduction in radial recoiling was observed for stents A and C,with decreases of 9.3% and 7.4%,respectively.Although there was a slight increase in vessel damage for stents A,B,and C compared to traditional stents,this difference was not significant to have an impact.The changes in intravascular blood flow rate were essentially the same after implantation of the four stents.A comparison of the four stents revealed that stents A and C exhibited superior overall mechanical properties and they have greater potential for clinical application.This study provides a reference for designing clinical stent structures.展开更多
Flow velocity uniformity of the microchannel plate is a major factor affecting the performance of microchannel devices.In order to improve the velocity distribution uniformity of the microchannel plate,we designed two...Flow velocity uniformity of the microchannel plate is a major factor affecting the performance of microchannel devices.In order to improve the velocity distribution uniformity of the microchannel plate,we designed two new microchannel structures:V-type and A-type.The effects of various structural parameters of the manifolds on the velocity distribution are reported.The V-type and A-type microchannel plates had a more uniform velocity distribution compared to the Z-type microchannel plate.The final result showed that it is beneficial for the V-type microchannel plate to obtain a more uniform velocity distribution when the manifold structure parameters are X_(in)=-1,X_(out)=0,Y_(in)=10,Y_(out)=6,Hin=4,H_(out)=1,and R=0.5.展开更多
In this paper,the front axle of a certain model is taken as the research object,and the stress and deformation of the frontaxle under three typical working conditions are analyzed by finite element technology.Based on...In this paper,the front axle of a certain model is taken as the research object,and the stress and deformation of the frontaxle under three typical working conditions are analyzed by finite element technology.Based on the simulation results,the 3D model of the front axle was optimized,and the finite element analysis of the optimized structure of the front axle under three typical working conditions was carried out to verify the correctness of the model.Finally,the fatigue tool module of ANSYS Workbench was used to analyze the fatigue life of the front axle under the optimized emergency conditions,and the feasibility of the model was verified.The analysis data shows that the design of the front axle components still has a lot of potential for lightweighting,and the weight of the front axle can be reduced by 6.73%through optimization,and the performance of the front axle can also meet the needs of use.The research conclusionhas a certain reference value for the lightweight design of automobile front axle.展开更多
Green finance,as an important policy to promote high-quality economic development,has become a focus of attention in the academic and policy circles for its promotion of industrial structure optimization.Based on the ...Green finance,as an important policy to promote high-quality economic development,has become a focus of attention in the academic and policy circles for its promotion of industrial structure optimization.Based on the data of six provinces in Central China from 2010 to 2023,this paper constructs a comprehensive index of green finance development by using entropy value method and empirically analyses the impact of green finance on industrial structure optimization.The results show that the level of green finance development has a significant contribution to the optimization of the industrial structure in the central region.Accordingly,this study provides suggestions for deepening green finance reform and accelerating industrial transformation and upgrading.展开更多
Under the background of this era,green finance and the upgrading and optimization of industrial structure have become a hot research topic.The article focuses on Jiangsu Province,carefully explores the impact of green...Under the background of this era,green finance and the upgrading and optimization of industrial structure have become a hot research topic.The article focuses on Jiangsu Province,carefully explores the impact of green financial development on the upgrading and optimization of industrial structure and the real effect,collates and summarizes the theories of green finance and industrial structure at home and abroad,and carefully analyzes the development of green finance in Jiangsu Province,such as the gradual expansion of green credit scale,the characteristics of industrial structure,the change of the proportion of three industries,the development situation of emerging industries and so on.By means of econometrics,an empirical model covering Green Financial Development Indicators and industrial structure optimization indicators is established to do multiple linear regression analysis and stability test.The empirical results show that the development of green finance in Jiangsu plays an obvious positive role in the optimization and upgrading of industrial structure.Green finance is environmental protection,new energy and other green industries are given important financial support,which drives their scale expansion and technological innovation,and makes the industrial structure develop towards a higher level and a more reasonable direction.From this point of view,corresponding proposals are put forward to improve the policy incentive system,add green financial products,and strengthen the construction of green financial market.The purpose is to give better play to the advantages of green finance,accelerate the optimization and upgrading of industrial structure in Jiangsu,and provide theoretical basis and practical guidance for achieving green economic transformation and sustainable development.展开更多
It is known that structural optimization may lead to designs of structures having low stability and sometimes even kinematically unstable designs. This paper presents a robust design method for improving the stability...It is known that structural optimization may lead to designs of structures having low stability and sometimes even kinematically unstable designs. This paper presents a robust design method for improving the stability of opti mized structures. A new approach is proposed, in which cer tain perturbation loads are introduced and the corresponding compliance is added to the objective function as a penaliza tion. The stability of the optimized structures can thus be improved substantially by considering structural responses to the original and the introduced loads. Numerical exam ples show the simplicity and effectiveness of the proposed method.展开更多
The vacuum vessel of the HT-7U superconducting tokamak will be a fully-welded structure with a double-wall. The space between the double-wall will be filled with borated water for neutron shielding. Non-circular cross...The vacuum vessel of the HT-7U superconducting tokamak will be a fully-welded structure with a double-wall. The space between the double-wall will be filled with borated water for neutron shielding. Non-circular cross-section is designed for plasma elongating. Horizontal and vertical ports are designed for diagnosing, vacuum pumping, plasma heating and plasma current driving, etc. The vacuum vessel consists of 16 segments. It will be baked out at 250℃ to obtain a clean wall. When the machine is in operation, both the hot wall (the wall temperature is around 100℃) and the cold wall (wall temperature is in normal equilibrium) are considered. The stress caused by thermal deformation and the electromagnetic (EM) loads caused by 1.5 MA plasma disruption in 3.5 T magnetic field have to be taken into account in the design of the HT-7U vacuum vessel Finite element method was employed for structure analysis of the vacuum vessel.展开更多
In this paper,to present a lightweight-developed front underrun protection device(FUPD)for heavy-duty trucks,plain weave carbon fiber reinforced plastic(CFRP)is used instead of the original high-strength steel.First,t...In this paper,to present a lightweight-developed front underrun protection device(FUPD)for heavy-duty trucks,plain weave carbon fiber reinforced plastic(CFRP)is used instead of the original high-strength steel.First,the mechanical and structural properties of plain carbon fiber composite anti-collision beams are comparatively analyzed from a multi-scale perspective.For studying the design capability of carbon fiber composite materials,we investigate the effects of TC-33 carbon fiber diameter(D),fiber yarn width(W)and height(H),and fiber yarn density(N)on the front underrun protective beam of carbon fiber compositematerials.Based on the investigation,a material-structure matching strategy suitable for the front underrun protective beam of heavy-duty trucks is proposed.Next,the composite material structure is optimized by applying size optimization and stack sequence optimization methods to obtain the higher performance carbon fiber composite front underrun protection beam of commercial vehicles.The results show that the fiber yarn height(H)has the greatest influence on the protective beam,and theH1matching scheme for the front underrun protective beamwith a carbon fiber composite structure exhibits superior performance.The proposed method achieves a weight reduction of 55.21% while still meeting regulatory requirements,which demonstrates its remarkable weight reduction effect.展开更多
Objective To study the changing characteristics and trend of medical income structure in the government-run hospitals of traditional Chinese medicine(TCM),evaluate the effects of relevant reform measures,and to put fo...Objective To study the changing characteristics and trend of medical income structure in the government-run hospitals of traditional Chinese medicine(TCM),evaluate the effects of relevant reform measures,and to put forward corresponding suggestions for further optimizing their income structure.Methods The data related to the average medical income of government-run hospitals of TCM from 2012 to 2021 were sorted out.Then,descriptive analysis method was used to analyze the changes of related indicators.Besides,structural change method was applied to investigate the changes of outpatient income and inpatient income.Results and Conclusion From 2012 to 2021,the growth of medical income in government-run hospitals of TCM tended to be stable,and the proportion of medical service income increased from 22.62%(2012)to 29.38%(2021),but the average annual growth rate was only 0.68%.The main items that caused the change of outpatient income structure were medicine revenue,laboratory tests,diagnosis and treatment,and the cumulative contribution rate was 89.15%.The main items that caused the change of inpatient income structure were medicine revenue,sanitary materials,and auxiliary examinations income,with a cumulative contribution rate of 80.04%.However,the contribution rate of registration,diagnosis,treatment,surgery and nursing income reflecting the value of medical personnel’s technical labor was relatively small.The medical income structure of government-run hospitals of TCM underwent great changes and gradually became reasonable,but the medical service income increased slowly,and not all indicators achieved the expectations.To promote the sustainable development of public hospitals of TCM and enable them to provide high-quality and efficient TCM medical and health services,it is necessary to further improve the relevant policy mechanism.展开更多
Build-up panels for the commercial aircraft fuselage subjected to the axial compression load are studied by both experimental and theoretical methods.An integral panel is designed with the same overall size and weight...Build-up panels for the commercial aircraft fuselage subjected to the axial compression load are studied by both experimental and theoretical methods.An integral panel is designed with the same overall size and weight as the build-up structure,and finite element models（FEMs）of these two panels are established.Experimental results of build-up panels agree well with the FEM results with the nonliearity and the large deformation,so FEMs are validated.FEM calculation results of these two panels indicate that the failure mode of the integral panel is different from that of the build-up panel,and the failure load increases by 18.4% up to post-buckling.Furthermore,the integral structure is optimized by using the multi-island genetic algorithm and the sequential quadratic programming.Compared with the initial design,the optimal mass is reduced by 8.7% and the strength is unchanged.展开更多
The GBA’s Outline Development Plan targets new energy development as an essential requirement going forward.OPTIMIZING the energy structure of the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)and building a clean,l...The GBA’s Outline Development Plan targets new energy development as an essential requirement going forward.OPTIMIZING the energy structure of the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)and building a clean,low-carbon,safe,and efficient energy supply system is a priority set in the GBA’s Outline Development Plan.展开更多
Zinc-based batteries have attracted widespread attention due to their inherent safety,notable cost-effectiveness and consistent performance,etc.However,the advancement of zinc-based battery technology encounters signi...Zinc-based batteries have attracted widespread attention due to their inherent safety,notable cost-effectiveness and consistent performance,etc.However,the advancement of zinc-based battery technology encounters significant challenges,including the formation of zinc dendrites and irreversible side reactions.Separators are vital in batteries due to their role in preventing electrode contact and facilitating rapid movement of ions within the electrolyte.The incorporation of cellulose in batteries enables uniform ion transport and a stable electricfield,attributed to its excellent hydrophilicity,strong mechanical strength,and abundant active sites.Herein,the latest research progress of cellulose-based separators on various zinc-based batteries is systematically summarized.To begin with,the accomplishments and inherent limitations of traditional sep-arators are clarified.Next,it underscores the advantages of cellulose-based materials in battery technology,thoroughly examining their utilization and merits as separators in zinc-based batteries.Lastly,the review offers prospective insights into the future trajectory of cellulose-based separators in zinc-based batteries.Through a comprehensive analysis of the present landscape,the review establishes a framework for the future design and enhancement of cellulose-based separators,thereby fostering the progression of associated industries.展开更多
This paper introduces dynamic boundary updating-surrogate model-based(DBU-SMB),a novel evolutionary framework for global optimization that integrates dynamic boundary updating(DBU)within a surrogate model-based(SMB)ap...This paper introduces dynamic boundary updating-surrogate model-based(DBU-SMB),a novel evolutionary framework for global optimization that integrates dynamic boundary updating(DBU)within a surrogate model-based(SMB)approach.The method operates in three progressive stages:adaptive sampling,DBU,and refinement.In the first stage,adaptive sampling strategically explores the design space to gather critical information for improving the surrogate model.The second stage incorporates DBU to guide the optimization toward promising regions in the parameter space,enhancing consistency and efficiency.Finally,the refinement stage iteratively improves the optimization results,ensuring a comprehensive exploration of the design space.The proposed DBU-SMB framework is algorithm-agnostic,meaning it does not rely on any specific machine learning model or meta-heuristic algorithm.To demonstrate its effectiveness,we applied DBU-SMB to four highly nonlinear and non-convex optimization problems.The results show a reduction of over 90%in the number of function evaluations compared to traditional methods,while avoiding entrapment in local optima and discovering superior solutions.These findings highlight the efficiency and robustness of DBU-SMB in achieving optimal designs,particularly for large-scale and complex optimization problems.展开更多
基金Research Council of Lithuania(LMTLT),agreement No.S-PD-24-120Research Council of Lithuania(LMTLT),agreement No.S-PD-24-120funded by the Research Council of Lithuania.
文摘Fractional differential equations(FDEs)provide a powerful tool for modeling systems with memory and non-local effects,but understanding their underlying structure remains a significant challenge.While numerous numerical and semi-analytical methods exist to find solutions,new approaches are needed to analyze the intrinsic properties of the FDEs themselves.This paper introduces a novel computational framework for the structural analysis of FDEs involving iterated Caputo derivatives.The methodology is based on a transformation that recasts the original FDE into an equivalent higher-order form,represented as the sum of a closed-form,integer-order component G(y)and a residual fractional power seriesΨ(x).This transformed FDE is subsequently reduced to a first-order ordinary differential equation(ODE).The primary novelty of the proposed methodology lies in treating the structure of the integer-order component G(y)not as fixed,but as a parameterizable polynomial whose coefficients can be determined via global optimization.Using particle swarm optimization,the framework identifies an optimal ODE architecture by minimizing a dual objective that balances solution accuracy against a high-fidelity reference and the magnitude of the truncated residual series.The effectiveness of the approach is demonstrated on both a linear FDE and a nonlinear fractional Riccati equation.Results demonstrate that the framework successfully identifies an optimal,low-degree polynomial ODE architecture that is not necessarily identical to the forcing function of the original FDE.This work provides a new tool for analyzing the underlying structure of FDEs and gaining deeper insights into the interplay between local and non-local dynamics in fractional systems.
基金funded by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.72221002)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA28060200)National Natural Science Foundation of Youth Project(Grant No.72303087).
文摘In the new phase of sustainable development,agriculture is seeking sustainable management of the water-land-energy-economy-environment-food nexus.At present,there are few studies on optimizing crop planting structure and analyzing its spatial layout with consideration of natural and socio-economic factors.Herein,we proposed a framework for addressing this issue.In this framework,the NSGA-II algorithm was used to construct the multi-objective optimization model of crop planting structures with consideration of water and energy consumption,greenhouse gas(GHG)emissions,economic benefits,as well as food,land,and water security constraints,while the model for planting spatial layout optimization was established with consideration of crop suitability using the MaxEnt model and the improved Hungarian algorithm.This framework was further applied in the Black Soil Region of Northeast China(BSRNC)for analyzing optimized crop planting structures and spatial layouts of three main crops(rice,maize,and soybean)under various scenarios.This study showed that the sown area of rice in the BSRNC decreased by up to 40.73%and 35.30%in the environmental priority scenario and economic-environmental balance scenario,respectively,whereas that of soybean increased by up to 112.44%and 63.31%,respectively.In the economic priority scenario,the sown area of rice increased by up to 93.98%.Expanding the sown area of soybean was effective in reducing GHG emissions.On the contrary,rice production led to greater environmental costs though it provided higher economic returns.Among the three crops,maize exhibited an advantage in balancing environmental and economic benefits.Hegang-Jixi area in the northeast of the BSRNC was identified as the key area with the most intense crop planting transfer among different scenarios.Overall,this framework provides a new methodology for optimizing crop planting structures and spatial layouts with con-sideration of the nexus of various factors.Moreover,the case study demonstrates the applicability and expansion potential of the framework in the fields of sustainable agricultural development and food security assurance.
文摘The optimization of civil engineering structures is critical for enhancing structural performance and material efficiency in engineering applications.Structural optimization approaches seek to determine the optimal design,by considering material performance,cost,and structural safety.The design approaches aim to reduce the built environment’s energy use and carbon emissions.This comprehensive review examines optimization techniques,including size,shape,topology,and multi-objective approaches,by integrating these methodologies.The trends and advancements that contribute to developing more efficient,cost-effective,and reliable structural designs were identified.The review also discusses emerging technologies,such as machine learning applications with different optimization techniques.Optimization of truss,frame,tensegrity,reinforced concrete,origami,pantographic,and adaptive structures are covered and discussed.Optimization techniques are explained,including metaheuristics,genetic algorithm,particle swarm,ant-colony,harmony search algorithm,and their applications with mentioned structure types.Linear and non-linear structures,including geometric and material nonlinearity,are distinguished.The role of optimization in active structures,structural design,seismic design,form-finding,and structural control is taken into account,and the most recent techniques and advancements are mentioned.
基金supported by the Key Laboratory of Petroleum and Natural Gas Equipment,Ministry of Education(No.OGE202303-08)Engineering Technology Research Center for Industrial Internet of Things and Intelligent Sensing,Hubei Province(No.KXZ 202203).
文摘The beam pumping unit(BPU)remains the most stable and reliable equipment for crude oil lifting.Despite its simple four-link mechanism,the structural design of the BPU presents a constrained single-objective optimization problem.Currently,a comprehensive framework for the structural design and optimization of compound balanced BPUs is lacking.Therefore,this study proposes a novel structural design scheme for BPUs,aiming to meet the practical needs of designers and operators by sequentially optimizing both the dynamic characteristics and balance properties of the BPUs.A dynamic model of compound balanced BPU was established based on D'Alembert's principle.The constraints for structural dimensions were formulated based on the actual operational requirements and design experience with BPUs.To optimize the structure,three algorithms were employed:the particle swarm optimization(PSO)algorithm,the genetic algorithm(GA),and the gray wolf optimization(GWO)algorithm.Each newly generated individuals are regulated by constraints to ensure the rationality of the outcomes.Furthermore,the integration of three algorithms ensures the increased likelihood of attaining the global optimal solution.The polished rod acceleration of the optimized structure is significantly reduced,and the dynamic characteristics of the up and down strokes are essentially symmetrical.Additionally,these three algorithms are also applied to the balance optimization of BPUs based on the measured dynamometer card.The calculation results demonstrate that the GWO-based optimization method exhibits excellent robustness in terms of structural optimization by enhancing the operational smoothness of the BPU,as well as in balance optimization by achieving energy conservation.By applying the optimization scheme proposed in this paper,the CYJW7-3-23HF type of BPU was designed,achieving a maximum polished rod acceleration of±0.675 m/s^(2) when operating at a stroke of 6 min^(−1).When deployed in two wells,the root-mean-square(RMS)torque was minimized,reaching values of 7.539 kN·m and 12.921 kN·m,respectively.The proposed design method not only contributes to the personalized customization but also improves the design efficiency of compound balanced BPUs.
基金supported by Fundamental Research Funds for the Central Universities(No.lzujbky-2024-05)Innovation Foundation of Provincial Education Department of Gansu(2024B-005)+1 种基金Scientific Department of Gansu(24CXGA083,24CXGA024,JK2024-28,JK2024-32,23CXJA0007)Industrial Support Plan Project of Provincial Education Department of Gansu(2025CYZC-003 and CYZC-2024-10).
文摘As a key storage facility, the structural safety of large oil tanks is directly related to the stable operation of the energy system. The static pressure caused by the change of liquid level is one of the main loads in the service process of storage tanks, which determines the structural deformation and damage risk. To explore the structural deformation properties under the change of liquid levels and provide a theoretical basis for the prevention and control of damage risk, this paper systematically analyzes the mechanical response of storage tanks under the pressures induced by different liquid levels based on the shell theory. Combined with the finite element software COMSOL, the radial displacement and stress-strain distribution under different liquid levels are simulated to verify the accuracy and effectiveness of the proposed theoretical model. The increase in liquid level and radius aggravates the radial deformation and makes the risk point move up, while the increase in wall thickness can effectively reduce the deformation response. Suggestions on the monitoring zone and damage risk prevention measures have also been given to instruct the safe operation of oil tanks. The research provides theoretical support for the optimization design of storage tank structures, the construction of advanced structural health monitoring system and the prevention and control of damage risk.
基金supported by the Yuxiu Innovation Project of NCUT(Grant No.2024NCUTYXCX211).
文摘Purpose–This paper aims to provide a comprehensive analysis of the strategic adjustments in China’s transportation structure,with a particular focus on the pivotal role of railway freight and its integration into the modern logistics system.It seeks to address the need for a more nuanced understanding of the“road to rail”policy,emphasizing the importance of intermodal collaboration and service of fragmented market demands.Design/methodology/approach–The study employs a transport economics perspective to evaluate the achievements and shortcomings of China’s transportation structure optimization.It bases its assessment of the current state of railway freight logistics,multi-modal transportation and the broader implications for the transportation service market on data analysis.The methodology includes a review of existing policies,an examination of industry practices and a comparative analysis with global trends in railway logistics.Findings–The research underscores the importance of focusing on the development of non-bulk materials,noting the insufficiency in the development of China’s rail multi-modal transportation and highlighting the instructive value of successful cases in open-top container road-rail intermodal transportation.The study posits that the railway sector must enhance cooperation with other market entities,aligning with the lead enterprises in the logistics chain that are characterized by speed,high value and strong coordination capabilities,in order to better serve the transportation market.This approach moves away from a reliance on the railway’s own capabilities alone.Originality/value–This paper offers original insights into the transformation of railway freight in China,contributing to the body of knowledge on transportation economics and logistics.It provides valuable recommendations for policymakers and industry practitioners,emphasizing the strategic importance of railway logistics in the context of China’s economic development and intense competition in the supply chain.The value of the article lies in its comprehensive understanding of the complexities involved in the adjustment of transportation structures,providing direction for the market-oriented reform of China’s railway freight sector.
基金supported by the Natural Science Foundation of China(Nos.22277019,82150204,22307031,22377023,22077143,and 82003594)Key Project of Guangdong Natural Science Foundation(No.2016A030311033)+2 种基金Fundamental Research Funds for Hainan University(Nos.KYQD(ZR)-21031,KYQD(ZR)-21108,KYQD(ZR)-23003,and XTCX2022JKA01)Guangdong Provincial Key Laboratory of Construction Foundation(No.2023B1212060022)Science Foundation of Hainan Province(Nos.KJRC2023B10,824YXQN420,and 324MS018)。
文摘Idiopathic pulmonary fibrosis(IPF)is a progressive lung disease and its incidence rate is rapidly rising.However,effective therapies for the treatment of IPF are still lacking.Phosphodiesterase 4(PDE4)inhibitors were reported to be potential anti-fibrotic agents.Herein,structure-based hit-to-lead optimization of natural isoaurostatin(8.98μmol/L)resulted in several potent inhibitors of PDE4 with half maximal inhibitory concentration(IC_(50))values ranging from 35 nmol/L to 126 nmol/L.Co-crystal structures revealed that isoaurostatin compounds exhibited different binding patterns from the classic PDE4 inhibitor rolipram and the analogues would favor to be Z configurations other than the corresponding E isomers.Finally,lead 2–9 showed remarkable in vitro/in vivo anti-fibrotic effects indicating its potential as a novel anti-IPF agent.
基金supported by the National Natural Science Foundation of China(Grant Nos.12272250 and 12372310)China Postdoctoral Science Foundation(Grant No.2020M680913)+1 种基金Shanxi Scholarship Council of China(Grant No.2022-081)Shanxi Postgraduate Innovation Project and Shanxi Huajin Orthopaedic Public Foundation.
文摘Magnesium alloy,as a new material for vascular stents,possesses excellent mechanical properties,biocompatibility,and biodegradability.However,the mechanical properties of magnesium alloy stents exhibit relatively inferior performance compared to traditional metal stents with identical structural characteristics.Therefore,improving their mechanical properties is a key issue in the development of biodegradable magnesium alloy stents.In this study,three new stent structures(i.e.,stent A,stent B,and stent C)were designed based on the typical structure of biodegradable stents.The changes made included altering the angle and arrangement of the support rings to create a support ring structure with alternating large and small angles,as well as modifying the position and shape of the link.Using finite element analysis,the compressive performance,expansion performance,bending flexibility performance,damage to blood vessels,and hemodynamic changes of the stent were used as evaluation indexes.The results of these comprehensive evaluations were utilized as the primary criteria for selecting the most suitable stent design.The results demonstrated that compared to the traditional stent,stents A,B,and C exhibited improvements in radial stiffness of 16.9%,15.1%,and 37.8%,respectively;reductions in bending stiffness of 27.3%,7.6%,and 38.1%,respectively;decreases in dog-boning rate of 5.1%,93.9%,and 31.3%,respectively;as well as declines in the low wall shear stress region by 50.1%,43.8%,and 36.2%,respectively.In comparison to traditional stents,a reduction in radial recoiling was observed for stents A and C,with decreases of 9.3% and 7.4%,respectively.Although there was a slight increase in vessel damage for stents A,B,and C compared to traditional stents,this difference was not significant to have an impact.The changes in intravascular blood flow rate were essentially the same after implantation of the four stents.A comparison of the four stents revealed that stents A and C exhibited superior overall mechanical properties and they have greater potential for clinical application.This study provides a reference for designing clinical stent structures.
基金supported by Scientific Research Project of Guangdong Provincial Department of Education(2024KQNCX152).
文摘Flow velocity uniformity of the microchannel plate is a major factor affecting the performance of microchannel devices.In order to improve the velocity distribution uniformity of the microchannel plate,we designed two new microchannel structures:V-type and A-type.The effects of various structural parameters of the manifolds on the velocity distribution are reported.The V-type and A-type microchannel plates had a more uniform velocity distribution compared to the Z-type microchannel plate.The final result showed that it is beneficial for the V-type microchannel plate to obtain a more uniform velocity distribution when the manifold structure parameters are X_(in)=-1,X_(out)=0,Y_(in)=10,Y_(out)=6,Hin=4,H_(out)=1,and R=0.5.
文摘In this paper,the front axle of a certain model is taken as the research object,and the stress and deformation of the frontaxle under three typical working conditions are analyzed by finite element technology.Based on the simulation results,the 3D model of the front axle was optimized,and the finite element analysis of the optimized structure of the front axle under three typical working conditions was carried out to verify the correctness of the model.Finally,the fatigue tool module of ANSYS Workbench was used to analyze the fatigue life of the front axle under the optimized emergency conditions,and the feasibility of the model was verified.The analysis data shows that the design of the front axle components still has a lot of potential for lightweighting,and the weight of the front axle can be reduced by 6.73%through optimization,and the performance of the front axle can also meet the needs of use.The research conclusionhas a certain reference value for the lightweight design of automobile front axle.
基金Project of Hunan Federation of Social Sciences,“Research on the Coupling Coordination Relationship between Green Finance and Industrial Structure Optimization in Hunan Province”(Project No.:XSP2023GLC027)。
文摘Green finance,as an important policy to promote high-quality economic development,has become a focus of attention in the academic and policy circles for its promotion of industrial structure optimization.Based on the data of six provinces in Central China from 2010 to 2023,this paper constructs a comprehensive index of green finance development by using entropy value method and empirically analyses the impact of green finance on industrial structure optimization.The results show that the level of green finance development has a significant contribution to the optimization of the industrial structure in the central region.Accordingly,this study provides suggestions for deepening green finance reform and accelerating industrial transformation and upgrading.
基金The Impact of Digital Economy on Green Development Efficiency.2025 Nanjing University of Science and Technology Zijin College Campus Level Scientific Research Project(Project No.:2025ZXSK0401011)。
文摘Under the background of this era,green finance and the upgrading and optimization of industrial structure have become a hot research topic.The article focuses on Jiangsu Province,carefully explores the impact of green financial development on the upgrading and optimization of industrial structure and the real effect,collates and summarizes the theories of green finance and industrial structure at home and abroad,and carefully analyzes the development of green finance in Jiangsu Province,such as the gradual expansion of green credit scale,the characteristics of industrial structure,the change of the proportion of three industries,the development situation of emerging industries and so on.By means of econometrics,an empirical model covering Green Financial Development Indicators and industrial structure optimization indicators is established to do multiple linear regression analysis and stability test.The empirical results show that the development of green finance in Jiangsu plays an obvious positive role in the optimization and upgrading of industrial structure.Green finance is environmental protection,new energy and other green industries are given important financial support,which drives their scale expansion and technological innovation,and makes the industrial structure develop towards a higher level and a more reasonable direction.From this point of view,corresponding proposals are put forward to improve the policy incentive system,add green financial products,and strengthen the construction of green financial market.The purpose is to give better play to the advantages of green finance,accelerate the optimization and upgrading of industrial structure in Jiangsu,and provide theoretical basis and practical guidance for achieving green economic transformation and sustainable development.
基金supported by State Key Laboratory of Structural Analysis for Industrial Equipment,Dalian University of Technology,China(GZ1305)the National Natural Science Foundation of China(11002058 and 11372004)
文摘It is known that structural optimization may lead to designs of structures having low stability and sometimes even kinematically unstable designs. This paper presents a robust design method for improving the stability of opti mized structures. A new approach is proposed, in which cer tain perturbation loads are introduced and the corresponding compliance is added to the objective function as a penaliza tion. The stability of the optimized structures can thus be improved substantially by considering structural responses to the original and the introduced loads. Numerical exam ples show the simplicity and effectiveness of the proposed method.
文摘The vacuum vessel of the HT-7U superconducting tokamak will be a fully-welded structure with a double-wall. The space between the double-wall will be filled with borated water for neutron shielding. Non-circular cross-section is designed for plasma elongating. Horizontal and vertical ports are designed for diagnosing, vacuum pumping, plasma heating and plasma current driving, etc. The vacuum vessel consists of 16 segments. It will be baked out at 250℃ to obtain a clean wall. When the machine is in operation, both the hot wall (the wall temperature is around 100℃) and the cold wall (wall temperature is in normal equilibrium) are considered. The stress caused by thermal deformation and the electromagnetic (EM) loads caused by 1.5 MA plasma disruption in 3.5 T magnetic field have to be taken into account in the design of the HT-7U vacuum vessel Finite element method was employed for structure analysis of the vacuum vessel.
基金supported by the Guangxi Science and Technology Plan and Project(Grant Numbers 2021AC19131 and 2022AC21140)Guangxi University of Science and Technology Doctoral Fund Project(Grant Number 20Z40).
文摘In this paper,to present a lightweight-developed front underrun protection device(FUPD)for heavy-duty trucks,plain weave carbon fiber reinforced plastic(CFRP)is used instead of the original high-strength steel.First,the mechanical and structural properties of plain carbon fiber composite anti-collision beams are comparatively analyzed from a multi-scale perspective.For studying the design capability of carbon fiber composite materials,we investigate the effects of TC-33 carbon fiber diameter(D),fiber yarn width(W)and height(H),and fiber yarn density(N)on the front underrun protective beam of carbon fiber compositematerials.Based on the investigation,a material-structure matching strategy suitable for the front underrun protective beam of heavy-duty trucks is proposed.Next,the composite material structure is optimized by applying size optimization and stack sequence optimization methods to obtain the higher performance carbon fiber composite front underrun protection beam of commercial vehicles.The results show that the fiber yarn height(H)has the greatest influence on the protective beam,and theH1matching scheme for the front underrun protective beamwith a carbon fiber composite structure exhibits superior performance.The proposed method achieves a weight reduction of 55.21% while still meeting regulatory requirements,which demonstrates its remarkable weight reduction effect.
文摘Objective To study the changing characteristics and trend of medical income structure in the government-run hospitals of traditional Chinese medicine(TCM),evaluate the effects of relevant reform measures,and to put forward corresponding suggestions for further optimizing their income structure.Methods The data related to the average medical income of government-run hospitals of TCM from 2012 to 2021 were sorted out.Then,descriptive analysis method was used to analyze the changes of related indicators.Besides,structural change method was applied to investigate the changes of outpatient income and inpatient income.Results and Conclusion From 2012 to 2021,the growth of medical income in government-run hospitals of TCM tended to be stable,and the proportion of medical service income increased from 22.62%(2012)to 29.38%(2021),but the average annual growth rate was only 0.68%.The main items that caused the change of outpatient income structure were medicine revenue,laboratory tests,diagnosis and treatment,and the cumulative contribution rate was 89.15%.The main items that caused the change of inpatient income structure were medicine revenue,sanitary materials,and auxiliary examinations income,with a cumulative contribution rate of 80.04%.However,the contribution rate of registration,diagnosis,treatment,surgery and nursing income reflecting the value of medical personnel’s technical labor was relatively small.The medical income structure of government-run hospitals of TCM underwent great changes and gradually became reasonable,but the medical service income increased slowly,and not all indicators achieved the expectations.To promote the sustainable development of public hospitals of TCM and enable them to provide high-quality and efficient TCM medical and health services,it is necessary to further improve the relevant policy mechanism.
文摘Build-up panels for the commercial aircraft fuselage subjected to the axial compression load are studied by both experimental and theoretical methods.An integral panel is designed with the same overall size and weight as the build-up structure,and finite element models（FEMs）of these two panels are established.Experimental results of build-up panels agree well with the FEM results with the nonliearity and the large deformation,so FEMs are validated.FEM calculation results of these two panels indicate that the failure mode of the integral panel is different from that of the build-up panel,and the failure load increases by 18.4% up to post-buckling.Furthermore,the integral structure is optimized by using the multi-island genetic algorithm and the sequential quadratic programming.Compared with the initial design,the optimal mass is reduced by 8.7% and the strength is unchanged.
文摘The GBA’s Outline Development Plan targets new energy development as an essential requirement going forward.OPTIMIZING the energy structure of the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)and building a clean,low-carbon,safe,and efficient energy supply system is a priority set in the GBA’s Outline Development Plan.
基金financially supported by National Natural Science Foundation of China(No.22304055)Central Guiding Local Science and Technology Development Fund Project(No.236Z4409G)+3 种基金Natural Science Foundation of Hebei Province(No.D2023209012,B2022209026)Youth Talent Program of Hebei Province Education Department(No.BJ2025032)Science and Technology Planning Project of Tangshan City(No.22130227H)Youth Scholars Promotion Plan of North China University of Science and Technology(No.QNTJ202306).
文摘Zinc-based batteries have attracted widespread attention due to their inherent safety,notable cost-effectiveness and consistent performance,etc.However,the advancement of zinc-based battery technology encounters significant challenges,including the formation of zinc dendrites and irreversible side reactions.Separators are vital in batteries due to their role in preventing electrode contact and facilitating rapid movement of ions within the electrolyte.The incorporation of cellulose in batteries enables uniform ion transport and a stable electricfield,attributed to its excellent hydrophilicity,strong mechanical strength,and abundant active sites.Herein,the latest research progress of cellulose-based separators on various zinc-based batteries is systematically summarized.To begin with,the accomplishments and inherent limitations of traditional sep-arators are clarified.Next,it underscores the advantages of cellulose-based materials in battery technology,thoroughly examining their utilization and merits as separators in zinc-based batteries.Lastly,the review offers prospective insights into the future trajectory of cellulose-based separators in zinc-based batteries.Through a comprehensive analysis of the present landscape,the review establishes a framework for the future design and enhancement of cellulose-based separators,thereby fostering the progression of associated industries.
文摘This paper introduces dynamic boundary updating-surrogate model-based(DBU-SMB),a novel evolutionary framework for global optimization that integrates dynamic boundary updating(DBU)within a surrogate model-based(SMB)approach.The method operates in three progressive stages:adaptive sampling,DBU,and refinement.In the first stage,adaptive sampling strategically explores the design space to gather critical information for improving the surrogate model.The second stage incorporates DBU to guide the optimization toward promising regions in the parameter space,enhancing consistency and efficiency.Finally,the refinement stage iteratively improves the optimization results,ensuring a comprehensive exploration of the design space.The proposed DBU-SMB framework is algorithm-agnostic,meaning it does not rely on any specific machine learning model or meta-heuristic algorithm.To demonstrate its effectiveness,we applied DBU-SMB to four highly nonlinear and non-convex optimization problems.The results show a reduction of over 90%in the number of function evaluations compared to traditional methods,while avoiding entrapment in local optima and discovering superior solutions.These findings highlight the efficiency and robustness of DBU-SMB in achieving optimal designs,particularly for large-scale and complex optimization problems.
