The recession and revitalization of old industrial cities concerns urban industrial evolution and its characteristics. Based on the theory of evolutionary resilience, we developed an analytical framework for the indus...The recession and revitalization of old industrial cities concerns urban industrial evolution and its characteristics. Based on the theory of evolutionary resilience, we developed an analytical framework for the industrial structure evolution of old industrial cities, and applied the framework to a case study in Shenyang. The following conclusions are drawn. First, since 1978, Shenyang's industrial growth capacity has shown fluctuation between ‘contraction-expansion'. As the secondary industry has a much stronger expansionary and contractionary capacity for growth, this results in lacking stability leading to industrial structure transformation. Second, since 1999, the orientation towards a high-end manufacturing industry in Shenyang has weakened, and the evolution of the new and old growth path is characterized by low-end orientation. Third, since 2007, Shenyang's industrial innovation output capacity has dropped sharply which has been significantly affected by scientific and technological personnel and enterprise-owed science and technology institutions and to a less extent by R&D expenditure. We applied the resilience theory to study the industrial evolution of an old industrial city, explored new study perspectives on industrial evolution and verified the applicability of the resilience theory. This paper provides a scientific reference for understanding the recent deceleration in economic growth in the Northeast old industrial base, and for exploring new paths toward revitalization.展开更多
Diverse wrinkling patterns can occur on curved bilayer systems under differential growth or expansion.In such systems,stress anisotropy is frequently encountered,and the coupling effect of curvature and stress anisotr...Diverse wrinkling patterns can occur on curved bilayer systems under differential growth or expansion.In such systems,stress anisotropy is frequently encountered,and the coupling effect of curvature and stress anisotropy on the pattern evolution remains largely unexplored.In this study,we investigate the evolution of wrinkling patterns on a cylinder core-shell system with stress anisotropy leveraging both theoretical analysis and finite element simulations.Critical buckling analysis has identified three distinct critical buckling modes regulated by the stress anisotropy,i.e.,axial sinusoidal mode,checkerboard mode,and circumferential sinusoidal mode.Our finite element simulations,along with post-buckling analysis,reveal seven distinct evolutionary paths stemming from the three critical buckling modes.We present phase diagrams for both the critical buckling modes and their evolutionary paths,which are determined by dimensionless curvature and stress anisotropy.Our results not only expand the theoretical research on surface wrinkling of a core-shell soft cylinder but also introduce stress anisotropy as a significant parameter for regulating the wrinkling patterns and their evolutionary paths in curved bilayer systems.The revelation of a multitude of wrinkling patterns and their evolutionary pathways holds great potential for advancing applications that leverage tunable wrinkle surfaces.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41571152,41771179,41630749,41601124)the Key Deployment Projects of the Chinese Academy of Sciences(No.ZDBS-SSW-SQC)135 Planning and Featured Services Projects of IGA,Chinese Academy of Sciences(No.Y6H2091001)
文摘The recession and revitalization of old industrial cities concerns urban industrial evolution and its characteristics. Based on the theory of evolutionary resilience, we developed an analytical framework for the industrial structure evolution of old industrial cities, and applied the framework to a case study in Shenyang. The following conclusions are drawn. First, since 1978, Shenyang's industrial growth capacity has shown fluctuation between ‘contraction-expansion'. As the secondary industry has a much stronger expansionary and contractionary capacity for growth, this results in lacking stability leading to industrial structure transformation. Second, since 1999, the orientation towards a high-end manufacturing industry in Shenyang has weakened, and the evolution of the new and old growth path is characterized by low-end orientation. Third, since 2007, Shenyang's industrial innovation output capacity has dropped sharply which has been significantly affected by scientific and technological personnel and enterprise-owed science and technology institutions and to a less extent by R&D expenditure. We applied the resilience theory to study the industrial evolution of an old industrial city, explored new study perspectives on industrial evolution and verified the applicability of the resilience theory. This paper provides a scientific reference for understanding the recent deceleration in economic growth in the Northeast old industrial base, and for exploring new paths toward revitalization.
基金the support from the National Natural Science Foundation of China(Grant Nos.12272130,and 11902114)the support from the National Natural Science Foundation of China(Grant No.52235005)+1 种基金the Natural Science Foundation for Excellent Young Scholars of Hunan Province(Grant No.2022JJ20003)the support from“The Fundamental Research Funds for the Central Universities,Peking University”。
文摘Diverse wrinkling patterns can occur on curved bilayer systems under differential growth or expansion.In such systems,stress anisotropy is frequently encountered,and the coupling effect of curvature and stress anisotropy on the pattern evolution remains largely unexplored.In this study,we investigate the evolution of wrinkling patterns on a cylinder core-shell system with stress anisotropy leveraging both theoretical analysis and finite element simulations.Critical buckling analysis has identified three distinct critical buckling modes regulated by the stress anisotropy,i.e.,axial sinusoidal mode,checkerboard mode,and circumferential sinusoidal mode.Our finite element simulations,along with post-buckling analysis,reveal seven distinct evolutionary paths stemming from the three critical buckling modes.We present phase diagrams for both the critical buckling modes and their evolutionary paths,which are determined by dimensionless curvature and stress anisotropy.Our results not only expand the theoretical research on surface wrinkling of a core-shell soft cylinder but also introduce stress anisotropy as a significant parameter for regulating the wrinkling patterns and their evolutionary paths in curved bilayer systems.The revelation of a multitude of wrinkling patterns and their evolutionary pathways holds great potential for advancing applications that leverage tunable wrinkle surfaces.
