Search

Copyright of CT Theory & Applications is the property of Editorial Department of CT Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dynamic soil behaviour at the contact interface during transplanting makes it difficult to ensure transplanting quality. To solve this problem, the Hertz-Mindlin with bonding contact model was used to calibrate the parameters of soils in Inner Mongolia. Based on the response surface design principle, four-factor and three level tests were performed using the repose angle as an evaluation index, and the following influence factors were considered: the soil-soil restoration coefficient, the soil-steel restoration coeficient, the soil-steel static friction coefficient and the soil-steel static friction coefficient. A regression model was analysed, and an optimization procedure yielded the following optimum combination of parameters: a soil-soil restoration coefficient of 0.45, a soil-steel restoration coefficient of 0.35, a soil-steel static friction coefficient of 0.85 and a soil-steel rolling friction coefficient of 0.13. This optimal combination was used to simulate the soil at the contact interface. The particle dynamic behaviour and soil particle mass flow were used to analyse the soil dynamic behaviour, showing that the average mass flow during the gradual opening of the duckbilled planter tends to increase over time; when the duckbilled planter gradually leaves soil, the contact interface of soil particles in the corner of the duckbilled planter unit causes a reduction in the fluctuation range of the soil mass flow, which exhibits a wave-like change. After the duckbilled planter has left soil, the contact interface of the soil changes tends to stabilize. The duckbilled planter-soil discrete element simulation model was verified. The results of this study provide a reference for the optimal design of a duckbilled planter structure. [ABSTRACT FROM AUTHOR]

In this paper, the entropy weight method is applied to quantitatively measure the energy security levels of 30 provinces in China from 2004 to 2017. Then, functional data analysis is used to investigate the changes in energy security from a dynamic perspective. Results show that the energy security level of Inner Mongolia (0.7080), Shanxi (0.6713), and Shaanxi (0.5878) ranked in the top three in 2017. From 2004 to 2017, China's energy security experienced five stages: Increasing—decreasing—increasing—decreasing—increasing. Until now, energy security is in the recovery period. According to the similarity of the energy security function curve, the 30 provinces can be divided into three categories: Leading area, Medium area, and Backward area. These findings have great significance in ensuring regional energy security. • China's energy security goes through five stages. • There are great differences in energy security level among 30 provinces. • The energy security of 30 provinces can be divided into three categories. • There are differences in potential conversion laws of energy security. • The top three provinces of energy security are Shanxi, Inner Mongolia and Xinjiang. [ABSTRACT FROM AUTHOR]