Early drinking is considered to result in making tolerant of alcohol consumption and a higher prevalence of alcohol related disorders in the later. We focused generational impacts on drinking rate among high school st...Early drinking is considered to result in making tolerant of alcohol consumption and a higher prevalence of alcohol related disorders in the later. We focused generational impacts on drinking rate among high school students based on multiple nationwide data. The surveys were nationwide, cross-sectional random sampling surveys given every 4 years from the Japanese Youth Tobacco and Alcohol Surveys, 1996 to 2008. Participants were male 53,925 high school students from 7th grade to 11th grade. We divided to the three follow-up groups every 4 years from 1996 to 2004 for male junior high school students in 7th grades and the end periods were 4 years later in 11th grades. Outcome measures in this study were life time drinking, current drinking within 30 days and weekly drinking. All drinking rates decreased each at 7th and at 11th grade. The increments in these drinking rates from 7th grade to 11th grade in males decreased gradually in recent follow-up groups. Generational impacts should be considered by using follow-up groups to study drinking behaviors among students.展开更多
Wake structures and vortex induced vibration （VIV） of a spring-supported wide-D-section cylinder were experimentally investigated using an X-wire, a novel phase-locked particle image velocimetry （PIV）, and an acce...Wake structures and vortex induced vibration （VIV） of a spring-supported wide-D-section cylinder were experimentally investigated using an X-wire, a novel phase-locked particle image velocimetry （PIV）, and an acceleration sensor at a low speed wind tunnel. Compared with the fixed case, the 2P （two pair） vortex mode as defined by Govardhan and Williamson （2000） rather than S （single vortex） mode exists in the wake. The velocity deficit behind the cylinder is much larger than that of fixed case. The mean drag coefficient increases from 1.42 for the fixed case to 1.64 for the vibrating case. The Reynolds stress presents even distribution and small with increased distance of X/D = -2 to X/D = -10. The power spectra density based on accelerator and hot wire data presents a highlight identical. It shows that after a strong interaction the cylinder vibration and the vortex shedding come to a stable state. The vortex sheddin~ is totally locked on and controlled by the cylinder vihratinn.展开更多
为研究内置开孔钢板(PBL)加劲肋的宽肢钢管混凝土组合柱(W-LCFST)的轴压性能,以L形双板连接钢管混凝土组合柱(LCFST-D)的轴压试验为基础,开展了W-LCFST柱参数化分析。结果表明:添加PBL加劲肋可增强混凝土和钢板之间的相互作用,与未添加...为研究内置开孔钢板(PBL)加劲肋的宽肢钢管混凝土组合柱(W-LCFST)的轴压性能,以L形双板连接钢管混凝土组合柱(LCFST-D)的轴压试验为基础,开展了W-LCFST柱参数化分析。结果表明:添加PBL加劲肋可增强混凝土和钢板之间的相互作用,与未添加PBL加劲肋的试件相比,添加1组PBL加劲肋,承载力提高了3.8%~5%,延性系数提高了14.3%~25.7%;添加2组PBL加劲肋,承载力提高了7.9%,延性系数提高了29.2%。最后,基于Mander理论,提出了预测W-LCFST柱截面承载力的计算公式,并将预测公式计算结果、日本规范Recommendations for design and construction of concrete filled steel tubular structures(AIJ-CFT(1997))、美国规范Load and resistance factor design specification for structural steel buildings(AISC-LRFD(1999))、《矩形钢管混凝土结构技术规程》(CECS159:2004)分别与有限元结果进行了对比。结果表明:上述公式计算结果均较为保守,但所提出的预测公式计算结果更加准确,平均误差为7%。展开更多
文摘Early drinking is considered to result in making tolerant of alcohol consumption and a higher prevalence of alcohol related disorders in the later. We focused generational impacts on drinking rate among high school students based on multiple nationwide data. The surveys were nationwide, cross-sectional random sampling surveys given every 4 years from the Japanese Youth Tobacco and Alcohol Surveys, 1996 to 2008. Participants were male 53,925 high school students from 7th grade to 11th grade. We divided to the three follow-up groups every 4 years from 1996 to 2004 for male junior high school students in 7th grades and the end periods were 4 years later in 11th grades. Outcome measures in this study were life time drinking, current drinking within 30 days and weekly drinking. All drinking rates decreased each at 7th and at 11th grade. The increments in these drinking rates from 7th grade to 11th grade in males decreased gradually in recent follow-up groups. Generational impacts should be considered by using follow-up groups to study drinking behaviors among students.
基金supported by the National Natural Science Foundation of China(11472158)
文摘Wake structures and vortex induced vibration （VIV） of a spring-supported wide-D-section cylinder were experimentally investigated using an X-wire, a novel phase-locked particle image velocimetry （PIV）, and an acceleration sensor at a low speed wind tunnel. Compared with the fixed case, the 2P （two pair） vortex mode as defined by Govardhan and Williamson （2000） rather than S （single vortex） mode exists in the wake. The velocity deficit behind the cylinder is much larger than that of fixed case. The mean drag coefficient increases from 1.42 for the fixed case to 1.64 for the vibrating case. The Reynolds stress presents even distribution and small with increased distance of X/D = -2 to X/D = -10. The power spectra density based on accelerator and hot wire data presents a highlight identical. It shows that after a strong interaction the cylinder vibration and the vortex shedding come to a stable state. The vortex sheddin~ is totally locked on and controlled by the cylinder vihratinn.
文摘为研究内置开孔钢板(PBL)加劲肋的宽肢钢管混凝土组合柱(W-LCFST)的轴压性能,以L形双板连接钢管混凝土组合柱(LCFST-D)的轴压试验为基础,开展了W-LCFST柱参数化分析。结果表明:添加PBL加劲肋可增强混凝土和钢板之间的相互作用,与未添加PBL加劲肋的试件相比,添加1组PBL加劲肋,承载力提高了3.8%~5%,延性系数提高了14.3%~25.7%;添加2组PBL加劲肋,承载力提高了7.9%,延性系数提高了29.2%。最后,基于Mander理论,提出了预测W-LCFST柱截面承载力的计算公式,并将预测公式计算结果、日本规范Recommendations for design and construction of concrete filled steel tubular structures(AIJ-CFT(1997))、美国规范Load and resistance factor design specification for structural steel buildings(AISC-LRFD(1999))、《矩形钢管混凝土结构技术规程》(CECS159:2004)分别与有限元结果进行了对比。结果表明:上述公式计算结果均较为保守,但所提出的预测公式计算结果更加准确,平均误差为7%。
