To predict the flow evolution of fish swimming problems,a flow solver based on the immersed boundary lattice Boltzmann method is developed.A flexible iterative algorithm based on the framework of implicit boundary for...To predict the flow evolution of fish swimming problems,a flow solver based on the immersed boundary lattice Boltzmann method is developed.A flexible iterative algorithm based on the framework of implicit boundary force correction is used to save the computational cost and memory,and the momentum forcing is described by a simple direct force formula without complicated integral calculation when the velocity correction at the boundary node is determined.With the presented flow solver,the hydrodynamic interaction between the fish-induced dynamic stall vortices and the incoming vortices in unsteady flow is analyzed.Numerical simulation results unveil the mechanism of fish exploiting vortices to enhance their own hydrodynamic performances.The superior swimming performances originate from the relative movement between the“merged vortex”and the locomotion of the fishtail,which is controlled by the phase difference.Formation conditions of the“merged vortex”become the key factor for fish to exploit vortices to improve their swimming performance.We further discuss the effect of the principal components of locomotion.From the results,we conclude that lateral translation plays a crucial role in propulsion while body undulation in tandem with rotation and head motion reduce the locomotor cost.展开更多
In this paper,we solve the Dirac equation under spin symmetry limit for attractive radial potential including a Coulomb-like tensor interaction.By using the parametric generalization of the Nikiforov-Uvarov method,the...In this paper,we solve the Dirac equation under spin symmetry limit for attractive radial potential including a Coulomb-like tensor interaction.By using the parametric generalization of the Nikiforov-Uvarov method,the energy eigenvalues equation and the corresponding wave functions have been obtained in closed forms.Some numerical results are given too.展开更多
A Mechanism-Inferring method of networks exploited from machine learning theory caneffectively evaluate the predicting performance of a network model.The existing method for inferringnetwork mechanisms based on a cens...A Mechanism-Inferring method of networks exploited from machine learning theory caneffectively evaluate the predicting performance of a network model.The existing method for inferringnetwork mechanisms based on a census of subgraph numbers has some drawbacks,especially the needfor a runtime increasing strongly with network size and network density.In this paper,an improvedmethod has been proposed by introducing a census algorithm of subgraph concentrations.Networkmechanism can be quickly inferred by the new method even though the network has large scale andhigh density.Therefore,the application perspective of mechanism-inferring method has been extendedinto the wider fields of large-scale complex networks.By applying the new method to a case of proteininteraction network,the authors obtain the same inferring result as the existing method,which approvesthe effectiveness of the method.展开更多
The bond dilution effects are investigated for the spin-1 Blume-Capel model on the Bethe lattice by using the exact recursion relations. The bilinear interaction parameter is either turned on ferromagnetically with pr...The bond dilution effects are investigated for the spin-1 Blume-Capel model on the Bethe lattice by using the exact recursion relations. The bilinear interaction parameter is either turned on ferromagnetically with probability p or turned off with probability 1 - p between the nearest-neighbor spins. The thermal variations of the order-parameters are studied in detail to obtain the phase diagrams on the possible planes spanned by the temperature （T）, probability （p） and crystal field （D） for the coordination numbers q = 3, 4, and 6. The lines of the second-order phase transitions, To-lines, combined with the first-order ones, Tt-lines, at the tricritical points （TCP） are always found for any p and q on the （T, D）-planes. It is also found that the model gives only Tc-lines, To-lines combined with the Tt-lines at the TCP＇s and only Tt-lines with the consecutively decreasing values of D on the （T, p）-planes for aJ1 q.展开更多
"Active" components can be introduced into a passive system to completely change its physical behavior from its typical behavior at thermodynamic equilibrium. To reveal the interaction mechanisms between ind..."Active" components can be introduced into a passive system to completely change its physical behavior from its typical behavior at thermodynamic equilibrium. To reveal the interaction mechanisms between individuals, researchers have designed unique self-propelled particles to mimic the collective behavior of biological systems. This review focuses on recent theoretical and experimental advances in the study of self-propelled particle systems and their individual and collective behaviors. The potential applications of active particles in chemical, biological and environmental sensing and single particle imaging are discussed.展开更多
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘To predict the flow evolution of fish swimming problems,a flow solver based on the immersed boundary lattice Boltzmann method is developed.A flexible iterative algorithm based on the framework of implicit boundary force correction is used to save the computational cost and memory,and the momentum forcing is described by a simple direct force formula without complicated integral calculation when the velocity correction at the boundary node is determined.With the presented flow solver,the hydrodynamic interaction between the fish-induced dynamic stall vortices and the incoming vortices in unsteady flow is analyzed.Numerical simulation results unveil the mechanism of fish exploiting vortices to enhance their own hydrodynamic performances.The superior swimming performances originate from the relative movement between the“merged vortex”and the locomotion of the fishtail,which is controlled by the phase difference.Formation conditions of the“merged vortex”become the key factor for fish to exploit vortices to improve their swimming performance.We further discuss the effect of the principal components of locomotion.From the results,we conclude that lateral translation plays a crucial role in propulsion while body undulation in tandem with rotation and head motion reduce the locomotor cost.
文摘In this paper,we solve the Dirac equation under spin symmetry limit for attractive radial potential including a Coulomb-like tensor interaction.By using the parametric generalization of the Nikiforov-Uvarov method,the energy eigenvalues equation and the corresponding wave functions have been obtained in closed forms.Some numerical results are given too.
基金supported by the National Natural Science Foundation of China under Grant No. 70401019
文摘A Mechanism-Inferring method of networks exploited from machine learning theory caneffectively evaluate the predicting performance of a network model.The existing method for inferringnetwork mechanisms based on a census of subgraph numbers has some drawbacks,especially the needfor a runtime increasing strongly with network size and network density.In this paper,an improvedmethod has been proposed by introducing a census algorithm of subgraph concentrations.Networkmechanism can be quickly inferred by the new method even though the network has large scale andhigh density.Therefore,the application perspective of mechanism-inferring method has been extendedinto the wider fields of large-scale complex networks.By applying the new method to a case of proteininteraction network,the authors obtain the same inferring result as the existing method,which approvesthe effectiveness of the method.
文摘The bond dilution effects are investigated for the spin-1 Blume-Capel model on the Bethe lattice by using the exact recursion relations. The bilinear interaction parameter is either turned on ferromagnetically with probability p or turned off with probability 1 - p between the nearest-neighbor spins. The thermal variations of the order-parameters are studied in detail to obtain the phase diagrams on the possible planes spanned by the temperature （T）, probability （p） and crystal field （D） for the coordination numbers q = 3, 4, and 6. The lines of the second-order phase transitions, To-lines, combined with the first-order ones, Tt-lines, at the tricritical points （TCP） are always found for any p and q on the （T, D）-planes. It is also found that the model gives only Tc-lines, To-lines combined with the Tt-lines at the TCP＇s and only Tt-lines with the consecutively decreasing values of D on the （T, p）-planes for aJ1 q.
基金supported by the National Natural Science Foundation of China (21425519)the Tsinghua University Startup Fund
文摘"Active" components can be introduced into a passive system to completely change its physical behavior from its typical behavior at thermodynamic equilibrium. To reveal the interaction mechanisms between individuals, researchers have designed unique self-propelled particles to mimic the collective behavior of biological systems. This review focuses on recent theoretical and experimental advances in the study of self-propelled particle systems and their individual and collective behaviors. The potential applications of active particles in chemical, biological and environmental sensing and single particle imaging are discussed.
