The performance and variability patterns in the wood element’s dimensions, specific gravity and growth parameters namely ramet height and GBH were evaluated in 16 clones of parents, F1 and F2 hybrids of Populus delto...The performance and variability patterns in the wood element’s dimensions, specific gravity and growth parameters namely ramet height and GBH were evaluated in 16 clones of parents, F1 and F2 hybrids of Populus deltoides Bartr. ex Marsh. Ramet radial variations were nonsignificant, while inter-clonal variations due to interaction of clone/replication were significant for all the wood traits except vessel element length. Inter-clonal variations were significant only for fiber length and fiber wall thickness. Fiber length and specific gravity were significantly higher in female, while wall thickness and vessel element length were higher in male clones. Female parents （G48 and S7C8） showed higher fiber length and specific gravity than of the male parent （G3）, while vessel diameter and wall thickness were higher in male par- ent （G3）. There is not much difference in fiber length and vessel element’s dimensions among the parents, F1 and F2 generation hybrid clones. Specific gravity did not showed any trend for parents, F1 and F2 generations. Generally female clones showed higher growth rate. Broad sense heritability for wood traits ranged from 0.143 （fiber length） to 0.505 （fiber wall thickness）, while for growth traits it was 0.374 （GBH） and 0.418 （height）. Genetic gain for all the wood and growth traits was positive for most of the wood traits. The highly divergent male clone （78） and female clones （S7C8, G48, W/A 49） in number of combinations could be used for developing new hybrids of desired wood traits to develop new clones.展开更多
The present paper provides both experimental and DEM analyses of the filling and discharge of pea grains from a 3D flat-bottomed bin. In the DEM model, the fixed mean values of the experimentally determined single par...The present paper provides both experimental and DEM analyses of the filling and discharge of pea grains from a 3D flat-bottomed bin. In the DEM model, the fixed mean values of the experimentally determined single particle data, such as the particle density, Young＇s modulus, Poisson＇s ratio as well as the sliding and rolling friction coefficients were incorporated to analyse their effects on the macroscale indicators, such as the wall pressure, discharge velocities and material outflow parameters. The effect of rolling friction was studied based on the experimentally measured single particle rolling friction coefficient. This analysis is aimed at the quantitative prediction of flow parameters as related to the identification of material parameters.展开更多
Axial segreganon or a bidisperse mixture of particles in a long rotating drum is studied using the discrete element method. Simulation results show that particle interaction is responsible for axial segregation, the p...Axial segreganon or a bidisperse mixture of particles in a long rotating drum is studied using the discrete element method. Simulation results show that particle interaction is responsible for axial segregation, the patterns of which are influenced by the end wall effect. Axial segregation patterns transform under competing influences of the end walls and the particle interaction forces. The two influential factors vary with various rotational speeds and end wall friction levels. The result is the transition of different axial segregation patterns： two large-particle bands at both ends, two small-particle bands at both ends, or a random segregation pattern where either a large-particle band or small-particle band may appear at either end.展开更多
文摘The performance and variability patterns in the wood element’s dimensions, specific gravity and growth parameters namely ramet height and GBH were evaluated in 16 clones of parents, F1 and F2 hybrids of Populus deltoides Bartr. ex Marsh. Ramet radial variations were nonsignificant, while inter-clonal variations due to interaction of clone/replication were significant for all the wood traits except vessel element length. Inter-clonal variations were significant only for fiber length and fiber wall thickness. Fiber length and specific gravity were significantly higher in female, while wall thickness and vessel element length were higher in male clones. Female parents （G48 and S7C8） showed higher fiber length and specific gravity than of the male parent （G3）, while vessel diameter and wall thickness were higher in male par- ent （G3）. There is not much difference in fiber length and vessel element’s dimensions among the parents, F1 and F2 generation hybrid clones. Specific gravity did not showed any trend for parents, F1 and F2 generations. Generally female clones showed higher growth rate. Broad sense heritability for wood traits ranged from 0.143 （fiber length） to 0.505 （fiber wall thickness）, while for growth traits it was 0.374 （GBH） and 0.418 （height）. Genetic gain for all the wood and growth traits was positive for most of the wood traits. The highly divergent male clone （78） and female clones （S7C8, G48, W/A 49） in number of combinations could be used for developing new hybrids of desired wood traits to develop new clones.
文摘The present paper provides both experimental and DEM analyses of the filling and discharge of pea grains from a 3D flat-bottomed bin. In the DEM model, the fixed mean values of the experimentally determined single particle data, such as the particle density, Young＇s modulus, Poisson＇s ratio as well as the sliding and rolling friction coefficients were incorporated to analyse their effects on the macroscale indicators, such as the wall pressure, discharge velocities and material outflow parameters. The effect of rolling friction was studied based on the experimentally measured single particle rolling friction coefficient. This analysis is aimed at the quantitative prediction of flow parameters as related to the identification of material parameters.
基金supported by the Key Science and Technology Innovation Team of Zhejiang Province(2010R50001-3)
文摘Axial segreganon or a bidisperse mixture of particles in a long rotating drum is studied using the discrete element method. Simulation results show that particle interaction is responsible for axial segregation, the patterns of which are influenced by the end wall effect. Axial segregation patterns transform under competing influences of the end walls and the particle interaction forces. The two influential factors vary with various rotational speeds and end wall friction levels. The result is the transition of different axial segregation patterns： two large-particle bands at both ends, two small-particle bands at both ends, or a random segregation pattern where either a large-particle band or small-particle band may appear at either end.
