Automatic width control is a key issue in hot strip rolling process. The edge rolling has been widely used in the roughing stand of hot strip mill to control the width of the slab. However, the edge rolling and conseq...Automatic width control is a key issue in hot strip rolling process. The edge rolling has been widely used in the roughing stand of hot strip mill to control the width of the slab. However, the edge rolling and consequent hori- zontal rolling will cause a significant width change in the head part and tail part of the slab, which have to be trimmed before the finishing stands. Based on the width reduction deformation curve of the head and tail along the longitudinal direction of slab, the short stroke control （SSC） technology has been developed to overcome this problem. The finite element method has been used to simulate the unsteady edge rolling process. Three short stroke control curves have been compared in order to obtain the best width control result. The optimized short stroke control curve has been ap- plied to the automatic width control system of industrial hot rolling mill, and good performance is obtained.展开更多
The precision width control is vital for product quality and production economy in plate width control process, so short stroke control method was used in plate rolling by opening or closing edger gap so as to avoid h...The precision width control is vital for product quality and production economy in plate width control process, so short stroke control method was used in plate rolling by opening or closing edger gap so as to avoid head end necking. Head end necking on different broadening ratio was analyzed, and sections of different elongations at edger roiling was calculated; based on the law of volume constancy, the adjustment functions were described by parabolic functions. Control curves were developed with three Gaussian curves by means of additional combining; SSC control curve was changed with different weights of those curves, w1 effect one-third of SSC length, w2 effect two-third of SSC length, w3 effect all three parts of SSC length. In order to adjust the amount of weights for precise quantification, PSO algorithm was used to build sufficiency function so as to obtain best rectangular degree by global optimization. Practical applications showed that the method proposed is available to improve the product rolling yields by 1.0% -2. 0% and worthy to apply to plate rolling.展开更多
According to technological requirement of hot charge rolling and hot direct rolling,in this paper,we investigated the technology of the width control rolling in the rougher mills of hot strip continuous rolling mill t...According to technological requirement of hot charge rolling and hot direct rolling,in this paper,we investigated the technology of the width control rolling in the rougher mills of hot strip continuous rolling mill train.On the basis of improving width range of continuous casting of slab,we obtained a good result of greatly increasing the yield of slab→coil is achieved.展开更多
目的:观察缺血性中风患者中医体质状态与短期预后的相关性。方法:采集2021年9月―2023年4月在北京中医医院延庆医院住院的200例急性缺血性中风患者包含基本信息、基线病情在内的一般信息,运用中医体质辨识系统进行中医体质辨识,以患者发...目的:观察缺血性中风患者中医体质状态与短期预后的相关性。方法:采集2021年9月―2023年4月在北京中医医院延庆医院住院的200例急性缺血性中风患者包含基本信息、基线病情在内的一般信息,运用中医体质辨识系统进行中医体质辨识,以患者发病1个月时的日常生活活动能力量表(Barthel Index,BI)评分作为患者短期预后的判定依据,运用Logistic回归分析筛选影响缺血性中风短期预后的因素。结果:单因素分析结果显示,缺血性中风患者短期预后与年龄、美国国立卫生研究院卒中量表(National Institute of Health Stroke Scale,NIHSS)评分、阴虚质、痰湿质、血瘀质有关,差异有统计学意义(P<0.05);logistic回归模型进行多因素分析结果显示,年龄[β=0.049,比值比(OR)=1.050,95%置信区间(CI)(1.020,1.082)],NIHSS评分[β=0.279,OR=1.321,95%CI(1.174,1.487)],阴虚质[β=1.657,OR=5.245,95%CI(2.441,11.268)],痰湿质[β=1.661,OR=5.266,95%CI(2.301,12.053)]是缺血性中风短期预后的独立危险因素(P<0.05)。结论:中医体质状态是影响缺血性中风患者短期预后的重要因素,其中阴虚质、痰湿质是缺血性中风患者短期预后不良的独立危险因素。展开更多
基金Item Sponsored by National Science and Technology Support Programfor 11th Five-Year Plan of China (2006BAE03A13)International Cooperation Research Project of Shanxi Province (2009081013)
文摘Automatic width control is a key issue in hot strip rolling process. The edge rolling has been widely used in the roughing stand of hot strip mill to control the width of the slab. However, the edge rolling and consequent hori- zontal rolling will cause a significant width change in the head part and tail part of the slab, which have to be trimmed before the finishing stands. Based on the width reduction deformation curve of the head and tail along the longitudinal direction of slab, the short stroke control （SSC） technology has been developed to overcome this problem. The finite element method has been used to simulate the unsteady edge rolling process. Three short stroke control curves have been compared in order to obtain the best width control result. The optimized short stroke control curve has been ap- plied to the automatic width control system of industrial hot rolling mill, and good performance is obtained.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51001023)the Fundamental Research Funds for the Central Universities(Grant No.N100307004)
文摘The precision width control is vital for product quality and production economy in plate width control process, so short stroke control method was used in plate rolling by opening or closing edger gap so as to avoid head end necking. Head end necking on different broadening ratio was analyzed, and sections of different elongations at edger roiling was calculated; based on the law of volume constancy, the adjustment functions were described by parabolic functions. Control curves were developed with three Gaussian curves by means of additional combining; SSC control curve was changed with different weights of those curves, w1 effect one-third of SSC length, w2 effect two-third of SSC length, w3 effect all three parts of SSC length. In order to adjust the amount of weights for precise quantification, PSO algorithm was used to build sufficiency function so as to obtain best rectangular degree by global optimization. Practical applications showed that the method proposed is available to improve the product rolling yields by 1.0% -2. 0% and worthy to apply to plate rolling.
文摘According to technological requirement of hot charge rolling and hot direct rolling,in this paper,we investigated the technology of the width control rolling in the rougher mills of hot strip continuous rolling mill train.On the basis of improving width range of continuous casting of slab,we obtained a good result of greatly increasing the yield of slab→coil is achieved.
文摘目的:观察缺血性中风患者中医体质状态与短期预后的相关性。方法:采集2021年9月―2023年4月在北京中医医院延庆医院住院的200例急性缺血性中风患者包含基本信息、基线病情在内的一般信息,运用中医体质辨识系统进行中医体质辨识,以患者发病1个月时的日常生活活动能力量表(Barthel Index,BI)评分作为患者短期预后的判定依据,运用Logistic回归分析筛选影响缺血性中风短期预后的因素。结果:单因素分析结果显示,缺血性中风患者短期预后与年龄、美国国立卫生研究院卒中量表(National Institute of Health Stroke Scale,NIHSS)评分、阴虚质、痰湿质、血瘀质有关,差异有统计学意义(P<0.05);logistic回归模型进行多因素分析结果显示,年龄[β=0.049,比值比(OR)=1.050,95%置信区间(CI)(1.020,1.082)],NIHSS评分[β=0.279,OR=1.321,95%CI(1.174,1.487)],阴虚质[β=1.657,OR=5.245,95%CI(2.441,11.268)],痰湿质[β=1.661,OR=5.266,95%CI(2.301,12.053)]是缺血性中风短期预后的独立危险因素(P<0.05)。结论:中医体质状态是影响缺血性中风患者短期预后的重要因素,其中阴虚质、痰湿质是缺血性中风患者短期预后不良的独立危险因素。
