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This paper aims to investigate the influence of different speed at the end of the constant power section of the traction characteristic curve (TCC) on the vehicle dynamic performance and evaluate the TCC. A dynamics co-simulation model is developed in SIMPACK and MATLAB for dynamic analysis of the urban rail vehicle (URV) under different traction characteristics. Then it is used to investigate how acceleration distance and vehicle dynamic performance varies with the speed at the end of the constant power section of the TCC under different starting torques. Moreover, the entropy weight TOPSIS method which is widely used to solve the multi-objective decision-making problem is chosen to evaluate the traction characteristics based on various dynamic performance indexes over 25 test sections and acceleration distance. The results show that under traction conditions, the starting torque has effects on the lateral and vertical accelerations of car body, lateral and vertical wheel-rail contact forces, derailment coefficient and wheel unloading factor. The higher the torque, the greater the value of each index, that means the poorer the vehicle ride characteristics and running safety. For a given starting torque, the dynamic performance indexes increase with the increase of the speed at the end of the constant power section from 50 km/h to 80 km/h during the vehicle speed-up process. The maximum growth rate of the lateral and vertical accelerations of car body, lateral and vertical wheel-rail contact forces are 17%, 8%, 8% and 2%, respectively, when the speed at the end of the constant power section increases from 50 km/h to 80 km/h. Last, the comprehensive evaluation of traction characteristics using entropy-weight TOPSIS method reveals when the starting torque is 800 N · m , 1000 N · m , 1200 N · m and 1400 N · m , the corresponding optimal speed at the end of the constant power section is 80 km/h, 80 km/h, 70 km/h and 50 km/h, respectively. The result of the study can provide theoretical support for traction characteristic design and traction control for URVs. [ABSTRACT FROM AUTHOR]

China is the advocator and builder of the thought of a community with a shared future for mankind. The international dissemination of its discourse requires more solid theoretical supporting research. Hence, the thought of a community with a shared future for mankind is China's intelligent contribution to the world and has been instrumental in solving major regional and global problems. Consequently, the Chinese academic community has the responsibility and obligation to convey the thought of a community with a shared future for mankind to the world in an understandable, objective, and authentic discourse. Further, it is responsible for continuously enhancing the scientific aspect and feasibility of the thought through academic achievements and excellence, thus establishing a leading research system. Currently, COVID-19 jeopardizes global public health security, including in political, economic, and social arenas. However, countries across the world are already in a state of close ties and destiny. Amid global public security incidents, the thought of a community with a shared future for mankind is connected by common interests, values, and responsibilities. Through the value resonance of its theoretical connotation, contacts and cooperation between countries are promptly promoted to form a close community of interests, health, destiny, and responsibilities to jointly respond to global crises and disasters. Therefore, amid the critical global fight against COVID-19, society urgently needs to forge an international consensus for fighting against this virus and maintaining global public health and safety with the thought of a community of a shared future for mankind. Accordingly, based on the perspectives of geopolitics and community, this paper first attempts to explore a theoretical analysis of the thought of a community with a shared future for mankind regarding scientific connotation, historical evolution, and contemporary values. Then, we examine specific cases to explain the practical applications of the thought of a community with a shared future for mankind in the fight against COVID-19 from the perspective of domestic practice, the Chinese program, and Western practice. Further, in doing so, we aim to demonstrate its dual value in spread and practice as well as its plight. Finally, we propose that governance and responsibility in the post-COVID-19 era, based on the thought of a community with a shared future for mankind, should be implemented by countries globally. Doing so involves playing a significant role in promoting global cooperation, maintaining world public health security, preventing a global recession, eliminating secondary disasters arising from COVID-19, transforming global governance, and reshaping international geopolitical relations. Therefore, this article may contribute to human society in fully and objectively understanding the thought of a community with a shared future for mankind, thus leading it to play a greater role in solving major global issues such as public health emergencies.

Promoting the social integration of ecological migrants and identifying the key constraints to their integration are significant issues for social governance and transformation. Most previous studies have not systematically analyzed the level of social integration of migrants from the perspective of spatial ternary dialectics or systematically analyzed physical, social, and spiritual spaces. Based on space production theory, this study used principal component analyses to evaluate the ternary spatial integration level of physical, social, and spiritual spaces of ecological migrants in a specific resettlement area in Yinchuan City, China, and the Tobit regression model was used to identify the key constraint factors. The results demonstrate that the overall socio-spatial integration levels of ecological migrants in Yinchuan City are lower than that of the overall migrant population nationwide, and the levels of their spatial adaptation and spatial practice integration lag behind that of spatial belonging and spatial identity integration. Meanwhile, length of residency, occupation type, monthly income, and household type have facilitating effects on the ecological migrants’ social integration, while gender, age, ethnicity, and education levels have insignificant effects. In particular, occupation type is a key factor in promoting social integration and improving employment among ecological migrants. It is concluded that upgrading production skills and raising employment for ecological migrants can foster sustainable social space production patterns, facilitate virtuous cycles, and eliminate inhibiting factors such as lagging spatial practices, regional cultural differences, and socio-spatial deprivation.