In the present paper, the composition of humus and the charateHstics of humic acid from seven paddy soils were compared with those of upland (and / or natural) soils. Results show that :(1) in each group of the soil s...In the present paper, the composition of humus and the charateHstics of humic acid from seven paddy soils were compared with those of upland (and / or natural) soils. Results show that :(1) in each group of the soil samples for comparison the HA / FA ratio of the humus of a paddy soil, in most cases, was appreciably higher than that of adjacent upland (and / or natural) soil derived from the same parent material; (2) the humic acid extracted from the paddy soils was characterized by a higher C/ O ratio, a higher content of methoxyl groups, and a lower content of carboxyl groups than those from the corresponding upland (and / or natural) flooded soils, implying that the humic acid formed under rice cultivation is in a lower degree of humification than that formed under upland (and / or natural) conditions; and (3) the humic acid of paddy soils, however, was not always characterized by a lower aromaticity than that of the corresponding upland (and / or natural) soils.展开更多
In this paper,the detailed analysis of the influence of thermal and non-Newtonian aspects of lubricant(couple stress fluid)on EHL line contact as a function of slide-roll ratio is presented.The novel low complexity FA...In this paper,the detailed analysis of the influence of thermal and non-Newtonian aspects of lubricant(couple stress fluid)on EHL line contact as a function of slide-roll ratio is presented.The novel low complexity FAS(full approximation scheme),of the multigrid scheme,with Jacobi dipole and Gauss Seidel relaxation is used for the solution of coupled equations viz.modified Reynolds equation,film thickness equation and energy equation satisfying appropriate boundary conditions.The analysis reveals the combined influence of non-Newtonian,thermal and slide-roll ratio(of bearing moving with different speeds)on pressure,film thickness and pressure spike covering a wide range of physical parameters of interest.Results show that pressure spike is strongly influenced by thermal,slide-roll ratio and non-Newtonian character of lubricant with negligible effect on the overall pressure distribution.Also,the minimum film thickness is slightly altered and it increases with the increase in the couple stress parameter.These findings confirm the importance of non-Newtonian and thermal effects in the study of EHL.展开更多
文摘In the present paper, the composition of humus and the charateHstics of humic acid from seven paddy soils were compared with those of upland (and / or natural) soils. Results show that :(1) in each group of the soil samples for comparison the HA / FA ratio of the humus of a paddy soil, in most cases, was appreciably higher than that of adjacent upland (and / or natural) soil derived from the same parent material; (2) the humic acid extracted from the paddy soils was characterized by a higher C/ O ratio, a higher content of methoxyl groups, and a lower content of carboxyl groups than those from the corresponding upland (and / or natural) flooded soils, implying that the humic acid formed under rice cultivation is in a lower degree of humification than that formed under upland (and / or natural) conditions; and (3) the humic acid of paddy soils, however, was not always characterized by a lower aromaticity than that of the corresponding upland (and / or natural) soils.
文摘In this paper,the detailed analysis of the influence of thermal and non-Newtonian aspects of lubricant(couple stress fluid)on EHL line contact as a function of slide-roll ratio is presented.The novel low complexity FAS(full approximation scheme),of the multigrid scheme,with Jacobi dipole and Gauss Seidel relaxation is used for the solution of coupled equations viz.modified Reynolds equation,film thickness equation and energy equation satisfying appropriate boundary conditions.The analysis reveals the combined influence of non-Newtonian,thermal and slide-roll ratio(of bearing moving with different speeds)on pressure,film thickness and pressure spike covering a wide range of physical parameters of interest.Results show that pressure spike is strongly influenced by thermal,slide-roll ratio and non-Newtonian character of lubricant with negligible effect on the overall pressure distribution.Also,the minimum film thickness is slightly altered and it increases with the increase in the couple stress parameter.These findings confirm the importance of non-Newtonian and thermal effects in the study of EHL.
