The explicit expression of Helmholtz free energy has been obtained from the equation of state from effiective field approach.From the Helmholtz free energy,four characteristic temperatures describing a first-order fer...The explicit expression of Helmholtz free energy has been obtained from the equation of state from effiective field approach.From the Helmholtz free energy,four characteristic temperatures describing a first-order ferroelectric phase transitions have been determined.The physical meaning of coe±cients in Landau-type free energy has been revealed by comparison with the expanding Helmholtz function.Temperature dependence of polarization under different bias,and hysteresis loops at different temperatures are presented and discussed.These results provide the basic understandings of the static properties of first-order ferroelectric phase transitions.展开更多
In this paper, a novel approach for service substitutions based on the service type in terms of its interface type and behavior semantics is proposed. In order to analyze and verify behavior-consistent service substit...In this paper, a novel approach for service substitutions based on the service type in terms of its interface type and behavior semantics is proposed. In order to analyze and verify behavior-consistent service substitutions in dynamic environments, we first present a formal language to describe services from control-flow perspective, then introduce a type and effect system to infer conservative approximations of all possible behaviors of these services. The service behaviors are represented by concurrent behavior expressions （CBEs）. Built upon the interpretation of CBEs, behavior-consistent service substitutions are defined and analyzed by subtyping technology. The correctness of the analysis approach is guaranteed by type safety theorem, which is mechanically proved in the Coq proof assistant. Finally, applications in web services show that our method is effective and feasible.展开更多
基金The authors gratefully acknowledge to MICINN of Spain for supporting the project FIS2008-00715National Natural Science Foundation of China under Grant Nos.51172129,51172128 and 51102153.
文摘The explicit expression of Helmholtz free energy has been obtained from the equation of state from effiective field approach.From the Helmholtz free energy,four characteristic temperatures describing a first-order ferroelectric phase transitions have been determined.The physical meaning of coe±cients in Landau-type free energy has been revealed by comparison with the expanding Helmholtz function.Temperature dependence of polarization under different bias,and hysteresis loops at different temperatures are presented and discussed.These results provide the basic understandings of the static properties of first-order ferroelectric phase transitions.
基金the National Natural Science Foundation of China(Nos.61232007 and 91118004)the Innovation Program of Shanghai Municipal Education Commission(No.13ZZ023)
文摘In this paper, a novel approach for service substitutions based on the service type in terms of its interface type and behavior semantics is proposed. In order to analyze and verify behavior-consistent service substitutions in dynamic environments, we first present a formal language to describe services from control-flow perspective, then introduce a type and effect system to infer conservative approximations of all possible behaviors of these services. The service behaviors are represented by concurrent behavior expressions （CBEs）. Built upon the interpretation of CBEs, behavior-consistent service substitutions are defined and analyzed by subtyping technology. The correctness of the analysis approach is guaranteed by type safety theorem, which is mechanically proved in the Coq proof assistant. Finally, applications in web services show that our method is effective and feasible.
