Shrinkage porosity defect is often found in an air cooled jumbo steel ingot, which will influence the quality of the final rolled plates. In practical production, some rolled plates are frequently rejected due to the ...Shrinkage porosity defect is often found in an air cooled jumbo steel ingot, which will influence the quality of the final rolled plates. In practical production, some rolled plates are frequently rejected due to the serious shrinkage porosity of the ingot. To improve the quality of the ingot, a new cooling method, gradient cooling process （in which the upper part of the ingot is air cooled and the lower part is spray cooled） was put forward in this study. The solidification behaviors for a 60 t jumbo slab ingot under gradient cooling condition were simulated using the ProCast software, and the results were compared with those of an ingot by air cooling condition. The solidifying tendency, temperature field and distribution of shrinkage porosities in the ingot under different cooling conditions were analyzed. Simulation results show that under gradient cooling condition the solidification of the slab ingot progresses in an upward manner along the vertical z axis and in a centripetal manner along the horizontal x and y axes. Gradient cooling can efficiently reduce shrinkage porosity of the jumbo slab ingot by optimizing the solidification sequence, and making the position of shrinkage porosity move from near the middle height of the ingot （under air cooling condition） towards the head of the ingot; and the secondary shrinkage is eliminated. In addition, the solidification time of the ingot under gradient cooling is 7.3 h in this simulation, which is 2.7 h faster than that under air cooling. A 60 t jumbo slab ingot was successfully produced under gradient cooling condition. The ingot was rolled to a plate with a thickness of 100 mm and length of 18,000 mm, and ultrasonic flaw detection was performed. Some porosity was found along the axis of the plate at 4,900 position of the defect is moved towards the head with the simulated result. - 6,000 mm from the head of the plate, indicating that the of the ingot. This distribution trend of the defect is consistent展开更多
目的:观察全功能动态矫正衣对痉挛型脑性瘫痪(简称脑瘫)患儿的临床疗效。方法:将符合纳入标准的痉挛型脑瘫患随机分为2组,每组30例,对照组采用运动学分析评估及康复训练方法,治疗组在运动学分析评估及康复训练方法基础上增加全功能动态...目的:观察全功能动态矫正衣对痉挛型脑性瘫痪(简称脑瘫)患儿的临床疗效。方法:将符合纳入标准的痉挛型脑瘫患随机分为2组,每组30例,对照组采用运动学分析评估及康复训练方法,治疗组在运动学分析评估及康复训练方法基础上增加全功能动态矫正衣。在康复治疗2个月前后,采用Berg平衡量表(Berg Balance Scale,BBS)、粗大运动功能测试量表(Gross Motor Function Measure,GMFM)分别评定平衡能力和粗大运动能力。结果:治疗前2组的BBS,GMFM,精细运动功能评估量表(Fine Motor Function Measure Scale,FMFM)评分差异均无统计学意义(P>0.05)。治疗后,治疗组BBS评分为12.28±2.26,GMFM评分为68.16±16.6,FMFM评分为113.57±19.06,较对照组显著提高,差异有统计学意义(P<0.05)。结论:运动学分析评估及康复训练方法配合全功能动态矫正衣能提高痉挛型脑瘫患儿平衡能力与粗大运动功能。展开更多
基金supported by the Science and Technology Projects of Ministry of Education of P. R. China (The study on heat conducting and initial solidification shell of jumbo slab ingot under gradient cooling, Grant No. 20112120120003)
文摘Shrinkage porosity defect is often found in an air cooled jumbo steel ingot, which will influence the quality of the final rolled plates. In practical production, some rolled plates are frequently rejected due to the serious shrinkage porosity of the ingot. To improve the quality of the ingot, a new cooling method, gradient cooling process （in which the upper part of the ingot is air cooled and the lower part is spray cooled） was put forward in this study. The solidification behaviors for a 60 t jumbo slab ingot under gradient cooling condition were simulated using the ProCast software, and the results were compared with those of an ingot by air cooling condition. The solidifying tendency, temperature field and distribution of shrinkage porosities in the ingot under different cooling conditions were analyzed. Simulation results show that under gradient cooling condition the solidification of the slab ingot progresses in an upward manner along the vertical z axis and in a centripetal manner along the horizontal x and y axes. Gradient cooling can efficiently reduce shrinkage porosity of the jumbo slab ingot by optimizing the solidification sequence, and making the position of shrinkage porosity move from near the middle height of the ingot （under air cooling condition） towards the head of the ingot; and the secondary shrinkage is eliminated. In addition, the solidification time of the ingot under gradient cooling is 7.3 h in this simulation, which is 2.7 h faster than that under air cooling. A 60 t jumbo slab ingot was successfully produced under gradient cooling condition. The ingot was rolled to a plate with a thickness of 100 mm and length of 18,000 mm, and ultrasonic flaw detection was performed. Some porosity was found along the axis of the plate at 4,900 position of the defect is moved towards the head with the simulated result. - 6,000 mm from the head of the plate, indicating that the of the ingot. This distribution trend of the defect is consistent
文摘目的:观察全功能动态矫正衣对痉挛型脑性瘫痪(简称脑瘫)患儿的临床疗效。方法:将符合纳入标准的痉挛型脑瘫患随机分为2组,每组30例,对照组采用运动学分析评估及康复训练方法,治疗组在运动学分析评估及康复训练方法基础上增加全功能动态矫正衣。在康复治疗2个月前后,采用Berg平衡量表(Berg Balance Scale,BBS)、粗大运动功能测试量表(Gross Motor Function Measure,GMFM)分别评定平衡能力和粗大运动能力。结果:治疗前2组的BBS,GMFM,精细运动功能评估量表(Fine Motor Function Measure Scale,FMFM)评分差异均无统计学意义(P>0.05)。治疗后,治疗组BBS评分为12.28±2.26,GMFM评分为68.16±16.6,FMFM评分为113.57±19.06,较对照组显著提高,差异有统计学意义(P<0.05)。结论:运动学分析评估及康复训练方法配合全功能动态矫正衣能提高痉挛型脑瘫患儿平衡能力与粗大运动功能。
