Based on a level set model, a topology optimization method has been suggestedrecently. It uses a level set to express the moving structural boundary, which can flexibly handlecomplex topological changes. By combining ...Based on a level set model, a topology optimization method has been suggestedrecently. It uses a level set to express the moving structural boundary, which can flexibly handlecomplex topological changes. By combining vector level set models with gradient projectiontechnology, the level set method for topological optimization is extended to a topologicaloptimization problem with multi-constraints, multi-materials and multi-load cases. Meanwhile, anappropriate nonlinear speed, mapping is established in the tangential space of the activeconstraints for a fast convergence. Then the method is applied to structure designs, mechanism andmaterial designs by a number of benchmark examples. Finally, in order to further improvecomputational efficiency and overcome the difficulty that the level set method cannot generate newmaterial interfaces during the optimization process, the topological derivative analysis isincorporated into the level set method for topological optimization, and a topological derivativeand level set algorithm for topological optimization is proposed.展开更多
As global efforts to achieve carbon neutrality accelerate,understanding how digital economy development contributes to urban carbon reduction is crucial for achieving sustainable development.This study examines the im...As global efforts to achieve carbon neutrality accelerate,understanding how digital economy development contributes to urban carbon reduction is crucial for achieving sustainable development.This study examines the impact of digital economy expansion on carbon emission intensity in the Yangtze River Delta urban agglomeration,a key economic hub in China.Using panel data from 41 cities(2011–2021)and a moderated mediation model,we analyze how industrial upgrading and Green Total Factor Productivity(GTFP)mediate this relationship.Our findings confirm that the digital economy significantly reduces carbon intensity both directly and indirectly through these two pathways.In addition,government investment in science and technology positively moderates this effect by strengthening the carbon reduction impact via industrial transformation.Spatial heterogeneity analysis reveals that these effects are more pronounced in cities within the“one core,five circles,and four belts”framework and in non-resource-based cities,highlighting regional disparities.These results underscore the need for targeted policy measures,including enhanced digital infrastructure,green finance mechanisms,and regional collaboration to maximize the decarbonization benefits of digitalization.By integrating digital and low-carbon strategies,policymakers can drive high-quality,green urban transformation.展开更多
基金This project is supported by National Natural Science Foundation of China(No.598005001, No.10332010) and Key Science and Technology Research Project of Ministry of Education (No.104060).
文摘Based on a level set model, a topology optimization method has been suggestedrecently. It uses a level set to express the moving structural boundary, which can flexibly handlecomplex topological changes. By combining vector level set models with gradient projectiontechnology, the level set method for topological optimization is extended to a topologicaloptimization problem with multi-constraints, multi-materials and multi-load cases. Meanwhile, anappropriate nonlinear speed, mapping is established in the tangential space of the activeconstraints for a fast convergence. Then the method is applied to structure designs, mechanism andmaterial designs by a number of benchmark examples. Finally, in order to further improvecomputational efficiency and overcome the difficulty that the level set method cannot generate newmaterial interfaces during the optimization process, the topological derivative analysis isincorporated into the level set method for topological optimization, and a topological derivativeand level set algorithm for topological optimization is proposed.
基金The National Social Science Fund of China(23BGL222)The Key Project of Anhui Provincial Scientific Research Planning(2022AH051882)The Key Project of Anhui Provincial Scientific Research Planning(2024AH050632)。
文摘As global efforts to achieve carbon neutrality accelerate,understanding how digital economy development contributes to urban carbon reduction is crucial for achieving sustainable development.This study examines the impact of digital economy expansion on carbon emission intensity in the Yangtze River Delta urban agglomeration,a key economic hub in China.Using panel data from 41 cities(2011–2021)and a moderated mediation model,we analyze how industrial upgrading and Green Total Factor Productivity(GTFP)mediate this relationship.Our findings confirm that the digital economy significantly reduces carbon intensity both directly and indirectly through these two pathways.In addition,government investment in science and technology positively moderates this effect by strengthening the carbon reduction impact via industrial transformation.Spatial heterogeneity analysis reveals that these effects are more pronounced in cities within the“one core,five circles,and four belts”framework and in non-resource-based cities,highlighting regional disparities.These results underscore the need for targeted policy measures,including enhanced digital infrastructure,green finance mechanisms,and regional collaboration to maximize the decarbonization benefits of digitalization.By integrating digital and low-carbon strategies,policymakers can drive high-quality,green urban transformation.
