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
This paper presents a methodology which is very useful to design shape-preserving advection finite difference scheme on general E-grid horizontal arrangement of variables through introducing a two-step shape-preservin...This paper presents a methodology which is very useful to design shape-preserving advection finite difference scheme on general E-grid horizontal arrangement of variables through introducing a two-step shape-preserving positive definite advection scheme in the moisture equation of the LASG-REM (LASG regional E-grid eta-coordinate forecast model). By trial-forecasting six local heavy raincases, the efficiency of the shape-preserving advection scheme in practical application has been examined. The LASG-REM with the shape-preserving advection scheme has a good forecasting ability for local precipitation.展开更多
An Eulerian flux-form advection scheme, called the Two-step Shape-Preserving Advection Scheme （TSPAS）, was generalized and implemented on a spherical icosahedral hexagonal grid （also referred to as a geodesic grid...An Eulerian flux-form advection scheme, called the Two-step Shape-Preserving Advection Scheme （TSPAS）, was generalized and implemented on a spherical icosahedral hexagonal grid （also referred to as a geodesic grid） to solve the transport equation. The C grid discretization was used for the spatial discretization. To implement TSPAS on an unstructured grid, the original finite-difference scheme was further generalized. The two-step integration utilizes a combination of two separate schemes （a low-order monotone scheme and a high-order scheme that typically cannot ensure monotonicity） to calculate the fluxes at the cell walls （one scheme corresponds to one cell wall）. The choice between these two schemes for each edge depends on a pre-updated scalar value using slightly increased fluxes. After the determination of an appropriate scheme, the final integration at a target cell is achieved by summing the fluxes that are computed by the different schemes. The conservative and shape-preserving properties of the generalized scheme are demonstrated. Numerical experiments are conducted at several horizontal resolutions. TSPAS is compared with the Flux Corrected Transport （FCT） approach to demonstrate the differences between the two methods, and several transport tests are performed to examine the accuracy, efficiency and robustness of the two schemes.展开更多
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.
文摘This paper presents a methodology which is very useful to design shape-preserving advection finite difference scheme on general E-grid horizontal arrangement of variables through introducing a two-step shape-preserving positive definite advection scheme in the moisture equation of the LASG-REM (LASG regional E-grid eta-coordinate forecast model). By trial-forecasting six local heavy raincases, the efficiency of the shape-preserving advection scheme in practical application has been examined. The LASG-REM with the shape-preserving advection scheme has a good forecasting ability for local precipitation.
基金supported by the National Natural Science Foundation of China(Grant No.41505066)the Basic Scientific Research and Operation Foundation of Chinese Academy Meteorological Sciences(Grant Nos.2015Z002,2015Y005)the National Research and Development Key Program:Global Change and Mitigation Strategies(No.2016YFA0602101)
文摘An Eulerian flux-form advection scheme, called the Two-step Shape-Preserving Advection Scheme （TSPAS）, was generalized and implemented on a spherical icosahedral hexagonal grid （also referred to as a geodesic grid） to solve the transport equation. The C grid discretization was used for the spatial discretization. To implement TSPAS on an unstructured grid, the original finite-difference scheme was further generalized. The two-step integration utilizes a combination of two separate schemes （a low-order monotone scheme and a high-order scheme that typically cannot ensure monotonicity） to calculate the fluxes at the cell walls （one scheme corresponds to one cell wall）. The choice between these two schemes for each edge depends on a pre-updated scalar value using slightly increased fluxes. After the determination of an appropriate scheme, the final integration at a target cell is achieved by summing the fluxes that are computed by the different schemes. The conservative and shape-preserving properties of the generalized scheme are demonstrated. Numerical experiments are conducted at several horizontal resolutions. TSPAS is compared with the Flux Corrected Transport （FCT） approach to demonstrate the differences between the two methods, and several transport tests are performed to examine the accuracy, efficiency and robustness of the two schemes.
