The temperature distribution under shear with a high strain rate and the cooling rate of the shear bands of Al, Cu and 0.06C steel have been calculated using a computer. The results show that the temperature of shear ...The temperature distribution under shear with a high strain rate and the cooling rate of the shear bands of Al, Cu and 0.06C steel have been calculated using a computer. The results show that the temperature of shear band increases with the increase of the average strain rate (_o). When _o is in the range 8×10~5 to 10~6 1/s, the structure of the adiabatic shear band in a 0.06C steel is martensite but it becomes metallic glass if _o=10~6 1/s. As to A1 and Cu, the structure of the adiabatic shear bands can also be of metallic glass if _o is greater than 1.8×10~6 and 5.5×10~7 1/s respectively. It explains that Cu tends most difficultly to form adiabatic shear band, while 0.06C steel most readily among the three metals.展开更多
A laboratory experiment was carried out to determine the effect of different constant temperatures on germination and early seedling establishment and to study the variation among parameters of thermal time model para...A laboratory experiment was carried out to determine the effect of different constant temperatures on germination and early seedling establishment and to study the variation among parameters of thermal time model parameters for two contrasting chickpea cultivars . Seeds were subjected to six constant temperatures from 10 o C to 35 o C . A complete randomized design was used with four replication. Analysis of variance showed significant differences among treatments for all characters studied. The final germination percentage significantly increased with increasing temperature up to 25 ° C, and thereafter there was a sharp decrease in final germination at 30 ° and 35 ° C. Desi type cultivar (small seeded) “Jabel Marra” significantly exhibited higher final germination percentage and lower germination rate compared with the kabui type cultivar “Shendi” at all temperatures. The median (θ T(50) ) of the thermal time was significantly differ between the two chickpea cultivars. The large seeded cultivars (shendi) recorded significantly higher median thermal time than the small seeded cultivars (Jabel Marra). The results also revealed a significant differences between the two cultivars in all thermal time model parameters. The small seeded cultivar (Jabel Marra) scored lower total dry matter and temperature tolerance index (TTI) compared to the large seeded cultivar (Shendi) at all temperatures studied.展开更多
文摘The temperature distribution under shear with a high strain rate and the cooling rate of the shear bands of Al, Cu and 0.06C steel have been calculated using a computer. The results show that the temperature of shear band increases with the increase of the average strain rate (_o). When _o is in the range 8×10~5 to 10~6 1/s, the structure of the adiabatic shear band in a 0.06C steel is martensite but it becomes metallic glass if _o=10~6 1/s. As to A1 and Cu, the structure of the adiabatic shear bands can also be of metallic glass if _o is greater than 1.8×10~6 and 5.5×10~7 1/s respectively. It explains that Cu tends most difficultly to form adiabatic shear band, while 0.06C steel most readily among the three metals.
文摘A laboratory experiment was carried out to determine the effect of different constant temperatures on germination and early seedling establishment and to study the variation among parameters of thermal time model parameters for two contrasting chickpea cultivars . Seeds were subjected to six constant temperatures from 10 o C to 35 o C . A complete randomized design was used with four replication. Analysis of variance showed significant differences among treatments for all characters studied. The final germination percentage significantly increased with increasing temperature up to 25 ° C, and thereafter there was a sharp decrease in final germination at 30 ° and 35 ° C. Desi type cultivar (small seeded) “Jabel Marra” significantly exhibited higher final germination percentage and lower germination rate compared with the kabui type cultivar “Shendi” at all temperatures. The median (θ T(50) ) of the thermal time was significantly differ between the two chickpea cultivars. The large seeded cultivars (shendi) recorded significantly higher median thermal time than the small seeded cultivars (Jabel Marra). The results also revealed a significant differences between the two cultivars in all thermal time model parameters. The small seeded cultivar (Jabel Marra) scored lower total dry matter and temperature tolerance index (TTI) compared to the large seeded cultivar (Shendi) at all temperatures studied.
