Double diffusion convection in a cavity with a hot square obstacle inside is simulated using the lattice Boltzmann method. The results are presented for the Rayleigh numbers 104,105 and 106, the Lewis numbers 0.1, 2 a...Double diffusion convection in a cavity with a hot square obstacle inside is simulated using the lattice Boltzmann method. The results are presented for the Rayleigh numbers 104,105 and 106, the Lewis numbers 0.1, 2 and 10 and aspect ratio A(obstacle height/cavity height) of 0.2, 0.4 and 0.6 for a range of buoyancy number N = 0 to- 4 with the effect of opposing flow. The results indicate that for |N| b 1, the Nusselt and Sherwood numbers decrease as buoyancy ratio increases, while for |N| N 1, they increase with |N|. As the Lewis number increases, higher buoyancy ratio is required to overcome the thermal effects and the minimum value of the Nusselt and Sherwood numbers occur at higher buoyancy ratios. The increase in the Rayleigh or Lewis number results in the formation of the multi-cell flow in the enclosure and the vortices will vanish as |N| increases.展开更多
The effect of grid shape on the properties of transparent conductive films(TCFs) is theoretically analyzed and experimentally verified. The light transmittance by three types of grid shapes: triangle, square and hexag...The effect of grid shape on the properties of transparent conductive films(TCFs) is theoretically analyzed and experimentally verified. The light transmittance by three types of grid shapes: triangle, square and hexagon have been theoretically calculated and simulated. It was found that hexagonal grid unit has the highest light transmittance limit under the practical lattice parameters and its decrease in light transmittance caused by the increase of line width in printing process is the least. The grid of three different shapes with same theoretical transmittance is fabricated through flexographic printing. The result shows that the actual light transmittance of the printed TCFs is lower than its theoretical value because of the inevitable width increase of printed grid lines, with slight difference between the three shapes. However, it is greatly different in terms of conductivity, leading to variation in the quality factor Q(defined as the ratio of light transmittance to total resistance) which represents the performance of TCFs. The Q of hexagonal grid(6.04) is the highest, which is 21% higher than that of the square grid.展开更多
A hybrid quantum architecture was proposed to engineer a localization-delocalization phase transition of light in a two-dimension square lattices of superconducting coplanar waveguide resonators,which are interconnect...A hybrid quantum architecture was proposed to engineer a localization-delocalization phase transition of light in a two-dimension square lattices of superconducting coplanar waveguide resonators,which are interconnected by current-biased Josephson junction phase qubits.We find that the competition between the on-site repulsion and the nonlocal photonic hopping leads to the Mott insulator-superfluid transition.By using the mean-field approach and the quantum master equation,the phase boundary between these two different phases could be obtained when the dissipative effects of superconducting resonators and phase qubit are considered.The good tunability of the effective on-site repulsion and photon-hopping strengths enable quantum simulation on condensed matter physics and many-body models using such a superconducting resonator lattice system.The experimental feasibility is discussed using the currently available technology in the circuit QED.展开更多
文摘Double diffusion convection in a cavity with a hot square obstacle inside is simulated using the lattice Boltzmann method. The results are presented for the Rayleigh numbers 104,105 and 106, the Lewis numbers 0.1, 2 and 10 and aspect ratio A(obstacle height/cavity height) of 0.2, 0.4 and 0.6 for a range of buoyancy number N = 0 to- 4 with the effect of opposing flow. The results indicate that for |N| b 1, the Nusselt and Sherwood numbers decrease as buoyancy ratio increases, while for |N| N 1, they increase with |N|. As the Lewis number increases, higher buoyancy ratio is required to overcome the thermal effects and the minimum value of the Nusselt and Sherwood numbers occur at higher buoyancy ratios. The increase in the Rayleigh or Lewis number results in the formation of the multi-cell flow in the enclosure and the vortices will vanish as |N| increases.
基金supported by the Beijing Municipal Commission of Education Foundation for School Innovation Ability Promotion Plan(Grant No.TJSHG201310015016)the Key Project of Beijing Institute of Graphic Communication(Grant No.Ea201501)the Creative Groups of Materials and Technology of Printed Electronics(Grant No.23190113100)
文摘The effect of grid shape on the properties of transparent conductive films(TCFs) is theoretically analyzed and experimentally verified. The light transmittance by three types of grid shapes: triangle, square and hexagon have been theoretically calculated and simulated. It was found that hexagonal grid unit has the highest light transmittance limit under the practical lattice parameters and its decrease in light transmittance caused by the increase of line width in printing process is the least. The grid of three different shapes with same theoretical transmittance is fabricated through flexographic printing. The result shows that the actual light transmittance of the printed TCFs is lower than its theoretical value because of the inevitable width increase of printed grid lines, with slight difference between the three shapes. However, it is greatly different in terms of conductivity, leading to variation in the quality factor Q(defined as the ratio of light transmittance to total resistance) which represents the performance of TCFs. The Q of hexagonal grid(6.04) is the highest, which is 21% higher than that of the square grid.
基金supported by the National Science Foundation of China(Grant Nos.11372122,10874122 and 11074070)the Program for Excellent Talents at the University of Guangdong Province(Guangdong Teacher Letter[1010]No.79)
文摘A hybrid quantum architecture was proposed to engineer a localization-delocalization phase transition of light in a two-dimension square lattices of superconducting coplanar waveguide resonators,which are interconnected by current-biased Josephson junction phase qubits.We find that the competition between the on-site repulsion and the nonlocal photonic hopping leads to the Mott insulator-superfluid transition.By using the mean-field approach and the quantum master equation,the phase boundary between these two different phases could be obtained when the dissipative effects of superconducting resonators and phase qubit are considered.The good tunability of the effective on-site repulsion and photon-hopping strengths enable quantum simulation on condensed matter physics and many-body models using such a superconducting resonator lattice system.The experimental feasibility is discussed using the currently available technology in the circuit QED.
