The entanglement properties of a three-spin X X Z Heisenberg chain with three-spin interaction are studied by means of concurrence of pairwise entanglement. We show that ground-state pairwise entanglement, pairwise th...The entanglement properties of a three-spin X X Z Heisenberg chain with three-spin interaction are studied by means of concurrence of pairwise entanglement. We show that ground-state pairwise entanglement, pairwise thermal entanglement, or quantum phase transition is not present in antiferromagnetic spin chain. For the ferromagnetic case, quantum phase transition takes place at A = 1 for anisotropic interaction and at some values of three-spin coupling strength, and pairwise thermal entanglement increases when the value of J/T increases and with anisotropic interaction and three-spin interaction decrease. In addition, we find that increasing the anisotropic interaction and the three-spin interaction will decrease critical temperature.展开更多
Aedes aegypti is known as the responsible vector in transmitting dengue flavivirus. Unavailability of medication to cure the transmission in human blood becomes a global health issue in recent decades. World epidemiol...Aedes aegypti is known as the responsible vector in transmitting dengue flavivirus. Unavailability of medication to cure the transmission in human blood becomes a global health issue in recent decades. World epidemiologists are encouraged to focus on investigation toward an effective and inexpensive way to prevent dengue transmission, i.e. mosquito control. In this paper, we present a model depicting the dynamics of mosquito population based on indoor-outdoor life cycle classification. The basic mosquito offspring number is obtained and analysis of equilibria is shown. We bring along a discussion on application of optimal control model which engineers two simultaneous schemes. The first scheme is done by disseminating chemical like Temephos in spots where eggs and larvae develop, meanwhile the second scheme is done by conducting fumigation through areas where adult mosquitoes prevalently nest, indoor as well as outdoor. A version of gradient-based method is presented to set down a workflow in minimizing the objective functional with respect to control variable. Numerical results from analysis of the basic mosquito offspring number with constant control and from optimal control suggest that one has to enhance the usage of fumigation rather than Temephos. It is also suggested that applying both control schemes simultaneously gives the most significant reduction to the population.展开更多
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10447116 and 10325521 and the China Postdoctoral Science Foundation under Grant No. 2005038316
文摘The entanglement properties of a three-spin X X Z Heisenberg chain with three-spin interaction are studied by means of concurrence of pairwise entanglement. We show that ground-state pairwise entanglement, pairwise thermal entanglement, or quantum phase transition is not present in antiferromagnetic spin chain. For the ferromagnetic case, quantum phase transition takes place at A = 1 for anisotropic interaction and at some values of three-spin coupling strength, and pairwise thermal entanglement increases when the value of J/T increases and with anisotropic interaction and three-spin interaction decrease. In addition, we find that increasing the anisotropic interaction and the three-spin interaction will decrease critical temperature.
文摘Aedes aegypti is known as the responsible vector in transmitting dengue flavivirus. Unavailability of medication to cure the transmission in human blood becomes a global health issue in recent decades. World epidemiologists are encouraged to focus on investigation toward an effective and inexpensive way to prevent dengue transmission, i.e. mosquito control. In this paper, we present a model depicting the dynamics of mosquito population based on indoor-outdoor life cycle classification. The basic mosquito offspring number is obtained and analysis of equilibria is shown. We bring along a discussion on application of optimal control model which engineers two simultaneous schemes. The first scheme is done by disseminating chemical like Temephos in spots where eggs and larvae develop, meanwhile the second scheme is done by conducting fumigation through areas where adult mosquitoes prevalently nest, indoor as well as outdoor. A version of gradient-based method is presented to set down a workflow in minimizing the objective functional with respect to control variable. Numerical results from analysis of the basic mosquito offspring number with constant control and from optimal control suggest that one has to enhance the usage of fumigation rather than Temephos. It is also suggested that applying both control schemes simultaneously gives the most significant reduction to the population.
