To compensate for the limitations of previous studies,a complex network-based method is developed for determining importance measures,which combines the functional roles of the components of a mechatronic system and t...To compensate for the limitations of previous studies,a complex network-based method is developed for determining importance measures,which combines the functional roles of the components of a mechatronic system and their topological positions.First,the dependencies among the components are well-represented and well-calculated.Second,a mechatronic system is modeled as a weighted and directional functional dependency network(FDN),in which the node weights are determined by the functional roles of components in the system and their topological positions in the complex network whereas the edge weights are represented by dependency strengths.Third,given that the PageRank algorithm cannot calculate the dependency strengths among components,an improved PageRank importance measure(IPIM)algorithm is proposed,which combines the node weights and edge weights of complex networks.IPIM also considers the importance of neighboring components.Finally,a case study is conducted to investigate the accuracy of the proposed method.Results show that the method can effectively determine the importance measures of components.展开更多
Using a large, unique county-level panel dataset for China from 1998 to 2006, this paper investigates the relationship between local governments ＇fiscal pressure and their preference for developing polluting industr...Using a large, unique county-level panel dataset for China from 1998 to 2006, this paper investigates the relationship between local governments ＇fiscal pressure and their preference for developing polluting industries. The results show that there exist fiscal pressure effects; namely, a positive link between the fiscal pressure faced by a county and its industrial tax dependence on polluting industries. We also investigate the heterogeneity of the fiscal pressure effects and find that fiscal pressure effects are significant only when local fiscal pressure is sufficiently high up to a certain point, and when there are more earmarked transfers. In contrast to the situation in east China, fiscal pressure effects in central and west China are more pronounced Therefore, when dealing with environmental problems, policy-makers need to take local governments＇ fiscal conditions into account.展开更多
The conformational change of biological macromolecule is investigated from the point of quantum transition.A quantum theory on protein folding is proposed.Compared with other dynamical variables such as mobile electro...The conformational change of biological macromolecule is investigated from the point of quantum transition.A quantum theory on protein folding is proposed.Compared with other dynamical variables such as mobile electrons,chemical bonds and stretching-bending vibrations the molecular torsion has the lowest energy and can be looked as the slow variable of the system.Simultaneously,from the multi-minima property of torsion potential the local conformational states are well defined.Following the idea that the slow variables slave the fast ones and using the nonadiabaticity operator method we deduce the Hamiltonian describing conformational change.It is shown that the influence of fast variables on the macromolecule can fully be taken into account through a phase transformation of slow variable wave function.Starting from the conformation-transition Hamiltonian the nonradiative matrix element was calculated and a general formulas for protein folding rate was deduced.The analytical form of the formula was utilized to study the temperature dependence of protein folding rate and the curious non-Arrhenius temperature relation was interpreted.By using temperature dependence data the multi-torsion correlation was studied.The decoherence time of quantum torsion state is estimated.The proposed folding rate formula gives a unifying approach for the study of a large class problems of biological conformational change.展开更多
基金The National Natural Science Foundation of China(No.51875429)General Program of Shenzhen Natural Science Foundation(No.JCYJ20190809142805521)Wenzhou Major Program of Scientific and Technological Innovation(No.ZG2021021).
文摘To compensate for the limitations of previous studies,a complex network-based method is developed for determining importance measures,which combines the functional roles of the components of a mechatronic system and their topological positions.First,the dependencies among the components are well-represented and well-calculated.Second,a mechatronic system is modeled as a weighted and directional functional dependency network(FDN),in which the node weights are determined by the functional roles of components in the system and their topological positions in the complex network whereas the edge weights are represented by dependency strengths.Third,given that the PageRank algorithm cannot calculate the dependency strengths among components,an improved PageRank importance measure(IPIM)algorithm is proposed,which combines the node weights and edge weights of complex networks.IPIM also considers the importance of neighboring components.Finally,a case study is conducted to investigate the accuracy of the proposed method.Results show that the method can effectively determine the importance measures of components.
文摘Using a large, unique county-level panel dataset for China from 1998 to 2006, this paper investigates the relationship between local governments ＇fiscal pressure and their preference for developing polluting industries. The results show that there exist fiscal pressure effects; namely, a positive link between the fiscal pressure faced by a county and its industrial tax dependence on polluting industries. We also investigate the heterogeneity of the fiscal pressure effects and find that fiscal pressure effects are significant only when local fiscal pressure is sufficiently high up to a certain point, and when there are more earmarked transfers. In contrast to the situation in east China, fiscal pressure effects in central and west China are more pronounced Therefore, when dealing with environmental problems, policy-makers need to take local governments＇ fiscal conditions into account.
文摘The conformational change of biological macromolecule is investigated from the point of quantum transition.A quantum theory on protein folding is proposed.Compared with other dynamical variables such as mobile electrons,chemical bonds and stretching-bending vibrations the molecular torsion has the lowest energy and can be looked as the slow variable of the system.Simultaneously,from the multi-minima property of torsion potential the local conformational states are well defined.Following the idea that the slow variables slave the fast ones and using the nonadiabaticity operator method we deduce the Hamiltonian describing conformational change.It is shown that the influence of fast variables on the macromolecule can fully be taken into account through a phase transformation of slow variable wave function.Starting from the conformation-transition Hamiltonian the nonradiative matrix element was calculated and a general formulas for protein folding rate was deduced.The analytical form of the formula was utilized to study the temperature dependence of protein folding rate and the curious non-Arrhenius temperature relation was interpreted.By using temperature dependence data the multi-torsion correlation was studied.The decoherence time of quantum torsion state is estimated.The proposed folding rate formula gives a unifying approach for the study of a large class problems of biological conformational change.
