Taking into account the interaction between electrons and phonons, in the case without-rotating-wave aproximation, we study the entangling property between the mesoscopic circuit and environment at coherent state or e...Taking into account the interaction between electrons and phonons, in the case without-rotating-wave aproximation, we study the entangling property between the mesoscopic circuit and environment at coherent state or equilibrium state. The result indicates that, in long time limit t →∞, the averages of charge and current in the circuit only depend on the average of the system at the initial state when the environment is initially at thermal equilibrimn. However, when the environment is initially at coherent state, the average of charge and current in the circuit is determined by the specific coherent state ensemble. Generally speaking, the entanglement between the circuit and environment will lead to the quantum state purity declining of the circuit, then the circuit emerges decoherent phenomenon, and so a mixed sta.te appears. Purity changes are related to the initial quantum state of environment and circuit. With the further evolution of time, coherence will be gradually restored, but cannot return to 1.展开更多
The dynamic theory of die swell deduced in a previous paper was extensively applied to study the extrudate swelling behaviors of two entangled polymeric liquids （HDPE and PBD） in a simple shear flow at steady shear ...The dynamic theory of die swell deduced in a previous paper was extensively applied to study the extrudate swelling behaviors of two entangled polymeric liquids （HDPE and PBD） in a simple shear flow at steady shear stress. The mechanism and dynamics for the recoils and the recoveries of viscoelastic strains in the extrudate were investigated under the free recovery and dynamic states. It was found that in the course of recovery the free recoil and the growth of die swell in the extrudate may be divided into two recovery regions （instantaneous and delayed regions） and three growth stages （instantaneous, delayed, and ultimate extrudate swelling stages）. The free recoil and the extrudate swelling behaviors may be expressed as a function of shear stress. The correlations of instantaneous, delayed, total and ultimate extrudate swell effects to the molecular parameters and the operational variables in the simple shear flow at steady shear stress were derived from the dynamic theory of die swell. Also, two sets of new universal equations on the total extrudate swelling effect （TESE） and ultimate extrudate swelling effect （UESE） were deduced. The first is the universal equation of the logarithmic correlation between the TESE and the growth time under the free and dynamic states; the second is the universal equation of the logarithmic correlation between the UESE and the operational variables under the free and equilibrium states. The first equation was verified by experimental data of PBD with different molecular weights at different operational variables. The second equation was verified by experimental data of HDPE at two temperatures and different operational variables. An excellent agreement result was obtained. The excellent agreement shows that the two universal equations can be used directly to predict the correlations of the TESE and UESE to the growth time, the molecular parameters, and the operational variables under the dynamic and equilibrium states.展开更多
基金the Natural Science Foundation of Jiangxi Province of China under Grant No.2007GZW0187
文摘Taking into account the interaction between electrons and phonons, in the case without-rotating-wave aproximation, we study the entangling property between the mesoscopic circuit and environment at coherent state or equilibrium state. The result indicates that, in long time limit t →∞, the averages of charge and current in the circuit only depend on the average of the system at the initial state when the environment is initially at thermal equilibrimn. However, when the environment is initially at coherent state, the average of charge and current in the circuit is determined by the specific coherent state ensemble. Generally speaking, the entanglement between the circuit and environment will lead to the quantum state purity declining of the circuit, then the circuit emerges decoherent phenomenon, and so a mixed sta.te appears. Purity changes are related to the initial quantum state of environment and circuit. With the further evolution of time, coherence will be gradually restored, but cannot return to 1.
文摘The dynamic theory of die swell deduced in a previous paper was extensively applied to study the extrudate swelling behaviors of two entangled polymeric liquids （HDPE and PBD） in a simple shear flow at steady shear stress. The mechanism and dynamics for the recoils and the recoveries of viscoelastic strains in the extrudate were investigated under the free recovery and dynamic states. It was found that in the course of recovery the free recoil and the growth of die swell in the extrudate may be divided into two recovery regions （instantaneous and delayed regions） and three growth stages （instantaneous, delayed, and ultimate extrudate swelling stages）. The free recoil and the extrudate swelling behaviors may be expressed as a function of shear stress. The correlations of instantaneous, delayed, total and ultimate extrudate swell effects to the molecular parameters and the operational variables in the simple shear flow at steady shear stress were derived from the dynamic theory of die swell. Also, two sets of new universal equations on the total extrudate swelling effect （TESE） and ultimate extrudate swelling effect （UESE） were deduced. The first is the universal equation of the logarithmic correlation between the TESE and the growth time under the free and dynamic states; the second is the universal equation of the logarithmic correlation between the UESE and the operational variables under the free and equilibrium states. The first equation was verified by experimental data of PBD with different molecular weights at different operational variables. The second equation was verified by experimental data of HDPE at two temperatures and different operational variables. An excellent agreement result was obtained. The excellent agreement shows that the two universal equations can be used directly to predict the correlations of the TESE and UESE to the growth time, the molecular parameters, and the operational variables under the dynamic and equilibrium states.
