随着我国轨道交通行业的飞速发展,车体减重对于节省能源意义重大。采用CMT冷金属过渡焊接技术对4-0.8 mm SUS301L-MT不锈钢搭接接头进行了工艺研究,获得最优工艺参数;同时,对焊接接头进行了宏观形貌、微观组织观察、力学性能以及变形测...随着我国轨道交通行业的飞速发展,车体减重对于节省能源意义重大。采用CMT冷金属过渡焊接技术对4-0.8 mm SUS301L-MT不锈钢搭接接头进行了工艺研究,获得最优工艺参数;同时,对焊接接头进行了宏观形貌、微观组织观察、力学性能以及变形测量。结果表明,在最优工艺参数下,焊缝成形美观,无明显缺陷,焊缝区组织主要为奥氏体柱状晶和枝晶状铁素体;焊接接头拉伸剪切最大力达到了22 234.42 N,硬度测试最小值均出现在焊缝区;焊后试板呈现波浪变形,最大Z方向变形量出现在试板边缘。展开更多
Objective To evaluate trends of overweight and obesity prevalence between 1996 and 2007 in Yi farmers and Yi migrants.Methods An Yi migrant study was conducted in Liangshan Yi Autonomous Prefecture,Sichuan Province,Ch...Objective To evaluate trends of overweight and obesity prevalence between 1996 and 2007 in Yi farmers and Yi migrants.Methods An Yi migrant study was conducted in Liangshan Yi Autonomous Prefecture,Sichuan Province,China from 1996 to 2007.Data were collected with identical methods,including standardized questionnaire and body measurements.Results Age‐ and sex‐specific body mass index （BMI） significantly increased from 20.02 in 1996 to 22.36 in 2007,among Yi farmers,which was significantly different from those among Yi migrants （23.67 in 2007 and 20.90 in 1996） （P0.05）.Prevalence of obesity rose from 1.21 % in 1996 to 4.55 % in 2007 （OR=1.15,P0.001） in Yi migrants,while that in Yi farmers from none in 1996 to 0.12 % in 2007 （P0.05）.Prevalence of overweight rose significantly to 26.24 %in 2007 from 17.24 % in 1996 （OR=1.06,P0.001） in Yi migrants,while that in Yi farmers from 1.29 % in 1996 to 4.45 % in 2007 （OR=1.14,P0.001）.Yi migrants appeared to have a 5.52‐fold higher risk ondeveloping overweight and obesity than Yi farmers have.Conclusion The Yi migrants had a steeper increase of overweight with year and consequently caused more obesity.Change in lifestyle may contribute most likely to higher prevalence of overweight and obesity in Yi migrants.展开更多
文摘随着我国轨道交通行业的飞速发展,车体减重对于节省能源意义重大。采用CMT冷金属过渡焊接技术对4-0.8 mm SUS301L-MT不锈钢搭接接头进行了工艺研究,获得最优工艺参数;同时,对焊接接头进行了宏观形貌、微观组织观察、力学性能以及变形测量。结果表明,在最优工艺参数下,焊缝成形美观,无明显缺陷,焊缝区组织主要为奥氏体柱状晶和枝晶状铁素体;焊接接头拉伸剪切最大力达到了22 234.42 N,硬度测试最小值均出现在焊缝区;焊后试板呈现波浪变形,最大Z方向变形量出现在试板边缘。
基金supported by a grant (No 30671811) from the national natural science foundation of China
文摘Objective To evaluate trends of overweight and obesity prevalence between 1996 and 2007 in Yi farmers and Yi migrants.Methods An Yi migrant study was conducted in Liangshan Yi Autonomous Prefecture,Sichuan Province,China from 1996 to 2007.Data were collected with identical methods,including standardized questionnaire and body measurements.Results Age‐ and sex‐specific body mass index （BMI） significantly increased from 20.02 in 1996 to 22.36 in 2007,among Yi farmers,which was significantly different from those among Yi migrants （23.67 in 2007 and 20.90 in 1996） （P0.05）.Prevalence of obesity rose from 1.21 % in 1996 to 4.55 % in 2007 （OR=1.15,P0.001） in Yi migrants,while that in Yi farmers from none in 1996 to 0.12 % in 2007 （P0.05）.Prevalence of overweight rose significantly to 26.24 %in 2007 from 17.24 % in 1996 （OR=1.06,P0.001） in Yi migrants,while that in Yi farmers from 1.29 % in 1996 to 4.45 % in 2007 （OR=1.14,P0.001）.Yi migrants appeared to have a 5.52‐fold higher risk ondeveloping overweight and obesity than Yi farmers have.Conclusion The Yi migrants had a steeper increase of overweight with year and consequently caused more obesity.Change in lifestyle may contribute most likely to higher prevalence of overweight and obesity in Yi migrants.
