In this work, we study approximations of supercritical or suction vortices in tornadic flows and their contribution to tornadogenesis and tornado maintenance using self-avoiding walks on a cubic lattice. We extend the...In this work, we study approximations of supercritical or suction vortices in tornadic flows and their contribution to tornadogenesis and tornado maintenance using self-avoiding walks on a cubic lattice. We extend the previous work on turbulence by A. Chorin and collaborators to approximate the statistical equilibrium quantities of vortex filaments on a cubic lattice when both an energy and a statistical temperature are involved. Our results confirm that supercritical (smooth, “straight”) vortices have the highest average energy and correspond to negative temperatures in this model. The lowest-energy configurations are folded up and “balled up” to a great extent. The results support A. Chorin’s findings that, in the context of supercritical vortices in a tornadic flow, when such high-energy vortices stretch, they need to fold and transfer energy to the surrounding flow, contributing to tornado maintenance or leading to its genesis. The computations are performed using a Markov Chain Monte Carlo approach with a simple sampling algorithm using local transformations that allow the results to be reliable over a wide range of statistical temperatures, unlike the originally used pivot algorithm that only performs well near infinite temperatures. Efficient ways to compute entropy are discussed and show that a system with supercritical vortices will increase entropy by having these vortices fold and transfer their energy to the surrounding flow.展开更多
Rock mass is fractured media. Its fracture is a nonlinear process. Theaccumulation of acoustic emission (AF) is closely related to the degree of damage. The dynamicsproblem is simply described based on the non-equilib...Rock mass is fractured media. Its fracture is a nonlinear process. Theaccumulation of acoustic emission (AF) is closely related to the degree of damage. The dynamicsproblem is simply described based on the non-equilibrium statistical theory of crack evolvement,trying to use the hybrid analysis of the statistical theory and scan electron microscopy (SEM), thecharacters of AE signals from rock damage in a mined-out area is synthetically analyzed andevaluated. These provide an evidence to reverse deduce and accurately infer the position of rockfracture for dynamical hazard control.展开更多
以International Business Machines Corporation(简称IBM)为研究样本,将非平衡统计理论及其朗之万方程运用到经济学领域,将企业看作经济学领域的非平衡系统,企业内部各种元素之间的相互作用看作是白噪声,企业外部因素对系统作用看作是...以International Business Machines Corporation(简称IBM)为研究样本,将非平衡统计理论及其朗之万方程运用到经济学领域,将企业看作经济学领域的非平衡系统,企业内部各种元素之间的相互作用看作是白噪声,企业外部因素对系统作用看作是色噪声,建立该领域的双噪声驱动下的广义朗之万方程。以该企业年报数据为原始数据,方程求解出企业研发投入与其绩效的统计关系。其统计关系表明企业绩效与研发投入呈非线性关系,并与企业绩效与研发投入的实际相吻合。展开更多
文摘In this work, we study approximations of supercritical or suction vortices in tornadic flows and their contribution to tornadogenesis and tornado maintenance using self-avoiding walks on a cubic lattice. We extend the previous work on turbulence by A. Chorin and collaborators to approximate the statistical equilibrium quantities of vortex filaments on a cubic lattice when both an energy and a statistical temperature are involved. Our results confirm that supercritical (smooth, “straight”) vortices have the highest average energy and correspond to negative temperatures in this model. The lowest-energy configurations are folded up and “balled up” to a great extent. The results support A. Chorin’s findings that, in the context of supercritical vortices in a tornadic flow, when such high-energy vortices stretch, they need to fold and transfer energy to the surrounding flow, contributing to tornado maintenance or leading to its genesis. The computations are performed using a Markov Chain Monte Carlo approach with a simple sampling algorithm using local transformations that allow the results to be reliable over a wide range of statistical temperatures, unlike the originally used pivot algorithm that only performs well near infinite temperatures. Efficient ways to compute entropy are discussed and show that a system with supercritical vortices will increase entropy by having these vortices fold and transfer their energy to the surrounding flow.
基金This work was financially supported by the Natural Science Foundation of Shannxi Province (No.2003E_213 )the Doctoral Foundation of the Ministry of Education of China (No.20020008021)the National Natural Science Foundation of China (No.50074002)
文摘Rock mass is fractured media. Its fracture is a nonlinear process. Theaccumulation of acoustic emission (AF) is closely related to the degree of damage. The dynamicsproblem is simply described based on the non-equilibrium statistical theory of crack evolvement,trying to use the hybrid analysis of the statistical theory and scan electron microscopy (SEM), thecharacters of AE signals from rock damage in a mined-out area is synthetically analyzed andevaluated. These provide an evidence to reverse deduce and accurately infer the position of rockfracture for dynamical hazard control.
文摘以International Business Machines Corporation(简称IBM)为研究样本,将非平衡统计理论及其朗之万方程运用到经济学领域,将企业看作经济学领域的非平衡系统,企业内部各种元素之间的相互作用看作是白噪声,企业外部因素对系统作用看作是色噪声,建立该领域的双噪声驱动下的广义朗之万方程。以该企业年报数据为原始数据,方程求解出企业研发投入与其绩效的统计关系。其统计关系表明企业绩效与研发投入呈非线性关系,并与企业绩效与研发投入的实际相吻合。
