Coupling evaluation for material removal and thermal control on precision milling machine tools

Machine tools are one of the most representative machining systems in manufacturing.The energy consumption of machine tools has been a research hotspot and frontier for green low-carbon manufacturing.However,previous research merely regarded the material removal(MR)energy as useful energy consumption and ignored the useful energy consumed by thermal control(TC)for maintaining internal thermal stability and machining accuracy.In pursuit of energy-efficient,high-precision machining,more attention should be paid to the energy consumption of TC and the coupling relationship between MR and TC.Hence,the cutting energy efficiency model considering the coupling relationship is established based on the law of conservation of energy.An index of energy consumption ratio of TC is proposed to characterize its effect on total energy usage.Furthermore,the heat characteristics are analyzed,which can be adopted to represent machining accuracy.Experimental study indicates that TC is the main energy-consuming process of the precision milling machine tool,which overwhelms the energy consumption of MR.The forced cooling mode of TC results in a 7%reduction in cutting energy efficiency.Regression analysis shows that heat dissipation positively contributes 54.1%to machining accuracy,whereas heat generation negatively contributes 45.9%.This paper reveals the coupling effect of MR and TC on energy efficiency and machining accuracy.It can provide a foundation for energyefficient,high-precision machining of machine tools.

International progress and evaluation on interactive coupling effects between urbanization and the eco-environment

Global urbanization is exerting severe stress and having far-reaching impacts on the eco-environment, and yet there exists a complex non-linear coupling relationship between the two. Research on the interactive coupling effect between urbanization and the eco-environment will be a popular area of study and frontier in international earth system science and sustainability science in the next 10 years, while also being a high-priority research topic of particular interest to international organizations. This paper systematically collates and summarizes the international progress made in research on interactive coupling theory, coupling relationships, coupling mechanisms, coupling laws, coupling thresholds, coupling models and coupling optimization decision support systems. The research shows that urbanization and eco-environment interactive coupling theories include the Kuznets curve theory, telecoupling theory, planetary boundaries theory, footprint family theory and urban metabolism theory; most research on interactive coupling relationships is concerned with single- element coupling relationships, such as those between urbanization and water, land, atmosphere, climate change, ecosystems and biodiversity; the majority of research on interactive coupling mechanisms and laws focuses on five research paradigms, including coupled human and nature systems, complex social-ecological systems, urban ecosystems, social-economic-natural complex ecosystems, and urbanization development and eco-environment constraint ring; the majority of interactive coupling simulations use STIRPAT models, coupling degree models, multi-agent system models and big data urban computer models; and research has been carried out on urbanization and eco-environment coupling thresholds, coercing risk and optimal decision support systems. An objective evaluation of progress in international research on interactive coupling between urbanization and the eco-environment suggests that there are six main research focal points and six areas lacking research： a lot of research exists on macroscopic coupling effects, with little research on urban agglomeration and scale coupling effects; considerable research exists on sin-gle-dimension coupling effects, with little on multiple-dimension coupling effects; a great deal exists on ＂one-to-one＂ dual- element coupling effects, with little on ＂many-to-many＂ multiple-element coupling effects; a lot exists on positive feedback coupling effects, and little on negative feedback coupling effects; a great deal exists on empirical coupling effects, and little on theoretical coupling effects; a great deal exists on the use of simple quantitative methods, and little on using integrated simulation methods. Future studies should focus on coupling effects between urbanization in urban agglomerations and the eco-environment, spatial scale coupling effects, multi-dimensional coupling effects, telecoupling effects, ＂one-to-many＂ and ＂many-to-many＂ element coupling effects, and positive and negative feedback coupling effects. There is also a need to strengthen the development and application of dynamic models for multi-element,-scale,-scenario,-module and-agent integrated spatiotemporal coupling systems and further improve theoretical innovations in coupling effect research and integrate and form complete and diverse coupling theoretical systems.

Numerical evaluation of radiation and optical coupling occurring in optical coupler

We present in this work a new mathematical model to analyze and evaluate optical phenomena occurring in the nonuniform optical waveguide used in integrated optics as an optical coupler. By introducing some modifications to the intrinsic integral, we perfectly assess the radiation field present in the adjacent medium of the waveguide and, thus, follow the evolution of the optical coupling from the taper thin film to the substrate and cladding until there is a total energy transfer. The new model that is introduced can be used to evaluate electromagnetic field distribution in three mediums that constitute any nonuniform optical couplers presenting great or low wedge angles.