How and When Factors of Agricultural Contribution Influence Urbanization: A Historical Analysis of Tibet

Abstract

Agriculture Powers Urbanization. How and when agriculture influences urbanization in underdeveloped regions remain poorly understood from an agricultural contribution perspective, specifically the food contribution (FDC), raw materials contribution (MLC), labor contribution (LRC), and market contribution (MTC). This study investigated this issue in the context of Tibet. A Granger causality test (GCT), the impulse response function (IRF), and variance decomposition (VD) were used. The GCT results demonstrated that agricultural contribution factors (ACFs), Granger-cause urbanization, and the IRF and VD results demonstrated that the influences of ACFs on urbanization were various and asynchronous. Both MTC and LRC quickly and positively respond to urbanization; however, LRC currently influences urbanization, whereas MTC influences urbanization currently and in the future. Both MLC and FDC negatively and slowly respond to urbanization; however, MLC currently influences urbanization, whereas FDC will influence urbanization in the future. This study’s findings depict changing trajectories of the role of ACFs in urbanization, elucidating urban–rural transformation.

Influence of particle characteristics on dynamic characteristics of tail beam under coal rock caving impact

“…Zhao et al (2020a) studied the effect of particle radius on roller load characteristics and coal fall during the simulation of the spiral drum cutting process by discrete element software, and the simulation results were closer to the theoretical values by using particles with a radius of 12 mm to build the coal wall, which provided a reference for the selection of particle radius in the simulation of coal mining machine cutting process using EDEM discrete element simulation software and laid the foundation for the study of the reliability of mining equipment (Zhao et al, 2020b), identification of coal gangue in the fully mechanized coal (Zhang et al, 2021), and adaptive height control of coal mining machine (Wang et al, 2021). Particle characteristics have an important influence on the accuracy of discrete element simulation tests and have been studied accordingly in the fields of medicine (Bharadwaj et al, 2010), agriculture (Liu et al, 2021;Zhang et al, 2022), and geotechnical engineering (Xinliang et al, 2021). Researchers at home and abroad use discrete element simulation software to study the key technologies and equipment of fully mechanized top-coal caving, but there is a lack of relevant research on the particle characteristics that affect the simulation results.…”