Confined water in the Ordovician limestone is one of the hidden troubles that threaten safe production of mines in north China. A numerical model of the key strata was developed. It included the structural characteris...Confined water in the Ordovician limestone is one of the hidden troubles that threaten safe production of mines in north China. A numerical model of the key strata was developed. It included the structural characteristics and mechanical properties of the floor rock at the working face of a particular coal mine. The model was used to predict failure modes and to help establish rules for safe mining above the aquifer. The distribution of deformation, failure and seepage was simulated by using Dilian Mechsoft's Real- istic Failure Process Analysis (RFPA2D) program. The stress distribution, the deformation and the flow vectors were also obtained. The results indicate that: 1) The original balance of the stress and seepage fields is disturbed due to coal mining; and 2) As the working face advances different deformation, or failure, appears in the surrounding rocks, the water-resisting strata in floor may be destroyed and the passage of water from the aquifer into the mine may occur. The combined action of mining stress and water pressure ultimately lead to water inrush from the floor.展开更多
From the organization of animal flocks to the emergence of swarming behaviors in bacterial suspension,populations of motile organisms at all scales display coherent collective motion.Recent studies showed that the ani...From the organization of animal flocks to the emergence of swarming behaviors in bacterial suspension,populations of motile organisms at all scales display coherent collective motion.Recent studies showed that the anisotropic interaction between active particles plays a key role in the phase behaviors.Here we investigate the collective behaviors of based-active Janus particles that experience an anisotropic interaction of which the orientation is opposite to the direction of active force by using Langevin dynamics simulations in two dimensional space.Interestingly,the system shows emergence of collective swarming states upon increasing the total area fraction of particles,which is not observed in systems without anisotropic interaction or activity.The threshold for emergence of swarming states decreases as particle activity or interaction strength increases.We have also performed basic kinetic analysis to reproduce the essential features of the simulation results.Our results demonstrate that anisotropic interactions at the individual level are sufficient to set homogeneous active particles into stable directed motion.展开更多
基金Projects 504902750634050 supported by the National Natural Science Foundation of China+1 种基金2007CB209400 by the National Basic Research Programof China2006A038 by SR Foundation of China University of Mining & Technology
文摘Confined water in the Ordovician limestone is one of the hidden troubles that threaten safe production of mines in north China. A numerical model of the key strata was developed. It included the structural characteristics and mechanical properties of the floor rock at the working face of a particular coal mine. The model was used to predict failure modes and to help establish rules for safe mining above the aquifer. The distribution of deformation, failure and seepage was simulated by using Dilian Mechsoft's Real- istic Failure Process Analysis (RFPA2D) program. The stress distribution, the deformation and the flow vectors were also obtained. The results indicate that: 1) The original balance of the stress and seepage fields is disturbed due to coal mining; and 2) As the working face advances different deformation, or failure, appears in the surrounding rocks, the water-resisting strata in floor may be destroyed and the passage of water from the aquifer into the mine may occur. The combined action of mining stress and water pressure ultimately lead to water inrush from the floor.
基金supported by the Ministry of Science and Technology(2016YFA0400904 and 2018YFA0208702)the National Natural Foundation of China(No.21973085,No.21833007,No.21790350,No.21673212,No.21521001,and No.21473165)+1 种基金the Fundamental Research Funds for the Central Universities(No.WK2340000074)Anhui Initiative in Quantum Information Technologies(No.AHY090200).
文摘From the organization of animal flocks to the emergence of swarming behaviors in bacterial suspension,populations of motile organisms at all scales display coherent collective motion.Recent studies showed that the anisotropic interaction between active particles plays a key role in the phase behaviors.Here we investigate the collective behaviors of based-active Janus particles that experience an anisotropic interaction of which the orientation is opposite to the direction of active force by using Langevin dynamics simulations in two dimensional space.Interestingly,the system shows emergence of collective swarming states upon increasing the total area fraction of particles,which is not observed in systems without anisotropic interaction or activity.The threshold for emergence of swarming states decreases as particle activity or interaction strength increases.We have also performed basic kinetic analysis to reproduce the essential features of the simulation results.Our results demonstrate that anisotropic interactions at the individual level are sufficient to set homogeneous active particles into stable directed motion.
