This paper presents a software for simulating the thermal performance of solar water heating systems. The implemented model computes the energy balance in the hot water storage tank in each time step along a simulatio...This paper presents a software for simulating the thermal performance of solar water heating systems. The implemented model computes the energy balance in the hot water storage tank in each time step along a simulation interval. Its input data are values from a typical meteorological year of a chosen location and the hot water load. The system components are the hot water storage tank and the solar collector. Firstly, the validation of the model is presented and then four solar water heating systems are simulated in four different cities along one year. The storage tank water hourly temperatures were obtained for a typical meteorological year and those values were compared with the values obtained by the widespread TRNSYS simulation software. The results obtained from this comparison were satisfactory.展开更多
In this paper, we study the persistence of invariant tori of integrable Hamiltonian systems satisfying Rssmann's non-degeneracy condition when symplectic integrators are applied to them. Meanwhile, we give an esti...In this paper, we study the persistence of invariant tori of integrable Hamiltonian systems satisfying Rssmann's non-degeneracy condition when symplectic integrators are applied to them. Meanwhile, we give an estimate of the measure of the set occupied by the invariant tori in the phase space. On an invariant torus,numerical solutions are quasi-periodic with a diophantine frequency vector of time step size dependence. These results generalize Shang's previous ones(1999, 2000), where the non-degeneracy condition is assumed in the sense of Kolmogorov.展开更多
We investigate the Landau damping of the collective mode in a quasi-one-dimensional repulsive Bose-Einstein condensate by using the self-consistent time-dependent Hartree-Fock-Bogoliubov approximation.We put forward a...We investigate the Landau damping of the collective mode in a quasi-one-dimensional repulsive Bose-Einstein condensate by using the self-consistent time-dependent Hartree-Fock-Bogoliubov approximation.We put forward a new method to calculate the Landau damping rate of the collective mode in the condensate and discuss the dependence of the Landau damping on temperature,on transverse trapping frequency,on atom number in the condensate,and on length of the system.Different from the usual calculation method for the three dimension system,our new calculation method is an interactive one by considering the practical relaxation of the elementary excitation.With little approximation,our theoretical calculation results agree with the experimental ones.Comparing with the usual calculation method,our theory is helpful to deduce the inter-particle interactions in damping phenomenon.展开更多
文摘This paper presents a software for simulating the thermal performance of solar water heating systems. The implemented model computes the energy balance in the hot water storage tank in each time step along a simulation interval. Its input data are values from a typical meteorological year of a chosen location and the hot water load. The system components are the hot water storage tank and the solar collector. Firstly, the validation of the model is presented and then four solar water heating systems are simulated in four different cities along one year. The storage tank water hourly temperatures were obtained for a typical meteorological year and those values were compared with the values obtained by the widespread TRNSYS simulation software. The results obtained from this comparison were satisfactory.
基金supported by National Natural Science Foundation of China(Grant No.11671392)
文摘In this paper, we study the persistence of invariant tori of integrable Hamiltonian systems satisfying Rssmann's non-degeneracy condition when symplectic integrators are applied to them. Meanwhile, we give an estimate of the measure of the set occupied by the invariant tori in the phase space. On an invariant torus,numerical solutions are quasi-periodic with a diophantine frequency vector of time step size dependence. These results generalize Shang's previous ones(1999, 2000), where the non-degeneracy condition is assumed in the sense of Kolmogorov.
基金Supported by National Natural Science Foundation of China under Grant No.10864006the Key Research Project of Xinjiang Higher Education,China under Grant No.XJED2010141the Key Discipline of Theoretical Physics of Xinjiang,China and the Postgraduate Scientific and Technological Innovation Project of Xinjiang Normal University,China under Grant No.20111202
文摘We investigate the Landau damping of the collective mode in a quasi-one-dimensional repulsive Bose-Einstein condensate by using the self-consistent time-dependent Hartree-Fock-Bogoliubov approximation.We put forward a new method to calculate the Landau damping rate of the collective mode in the condensate and discuss the dependence of the Landau damping on temperature,on transverse trapping frequency,on atom number in the condensate,and on length of the system.Different from the usual calculation method for the three dimension system,our new calculation method is an interactive one by considering the practical relaxation of the elementary excitation.With little approximation,our theoretical calculation results agree with the experimental ones.Comparing with the usual calculation method,our theory is helpful to deduce the inter-particle interactions in damping phenomenon.
