In order to study how the Sn substitution for Tl changes the superconducting properties of the TlBaCaCuO compound,we have prepared samples with Sn in place of Tl by solid state reactions.Measurements of resistance and...In order to study how the Sn substitution for Tl changes the superconducting properties of the TlBaCaCuO compound,we have prepared samples with Sn in place of Tl by solid state reactions.Measurements of resistance and magnetic susceptibility show that partial substitution of Tl with Sn is helpful to form the superconducting 2223 phase(for T1:Ba:Ca:Cu).It has been found that samples mainly contain tetragonal phase 2223,but there also exist a few additional maxed phases like 1223,1234 and nonsuperconducting phase BaSnO_(3).展开更多
The A1 substitution in the T1-Ba-Ca-Cu-O superconducting system was studied.Up to 70%of Tl can be substituted by Al,without significant reduction of Tc.X-ray diffraction indicates partial A1 substitution does not alte...The A1 substitution in the T1-Ba-Ca-Cu-O superconducting system was studied.Up to 70%of Tl can be substituted by Al,without significant reduction of Tc.X-ray diffraction indicates partial A1 substitution does not alter the crystal structure of the 2223 phase.Excessive A1 formed Al-Cu alloy and unidentified phases,which gradually destroyed the superconductivity.展开更多
目的分析2013—2022年上海市浦东新区流行性腮腺炎(简称流腮)的流行特征,为制定防控策略提供依据。方法2013—2022年流腮发病资料来源于中国疾病预防控制信息系统,采用描述流行病学方法对数据进行分析,采用季节指数法和圆形分布法分析...目的分析2013—2022年上海市浦东新区流行性腮腺炎(简称流腮)的流行特征,为制定防控策略提供依据。方法2013—2022年流腮发病资料来源于中国疾病预防控制信息系统,采用描述流行病学方法对数据进行分析,采用季节指数法和圆形分布法分析流腮的季节性和发病高峰期。结果2013—2022年上海市浦东新区共报告流腮6536例,年平均发病率12.07/10万,发病率呈逐年下降趋势。季节指数法和圆形分布法分析显示每年4月底到12月初为流腮发病高峰期。病例以男性为主(占61.00%),男性(14.21/10万)发病率高于女性(9.76/10万),(χ^(2)=222.395,P<0.001)。年龄分布集中在10岁以下(占85.68%),5岁组儿童发病率最高(257.90/10万)。幼托儿童(44.37%)、学生(37.55%)、散居儿童(13.79%)为发病的主要群体。从地区分布看,病例总数前三位的是北蔡镇(520例,7.96%)、三林镇(505例,7.73%)、川沙新镇(442例,6.76%)。2013—2022年浦东新区适龄儿童的麻疹-流行性腮腺炎-风疹联合减毒活疫苗(measles,mumps and rubella combined attenuated live vaccine,MMR)接种率均在99.00%以上。结论2013—2022年浦东新区流腮疫情呈下降趋势,幼托儿童、学生、散居儿童是流腮防控的重点人群,仍应加强预防接种证查验及MMR接种、补种工作。展开更多
文摘In order to study how the Sn substitution for Tl changes the superconducting properties of the TlBaCaCuO compound,we have prepared samples with Sn in place of Tl by solid state reactions.Measurements of resistance and magnetic susceptibility show that partial substitution of Tl with Sn is helpful to form the superconducting 2223 phase(for T1:Ba:Ca:Cu).It has been found that samples mainly contain tetragonal phase 2223,but there also exist a few additional maxed phases like 1223,1234 and nonsuperconducting phase BaSnO_(3).
文摘The A1 substitution in the T1-Ba-Ca-Cu-O superconducting system was studied.Up to 70%of Tl can be substituted by Al,without significant reduction of Tc.X-ray diffraction indicates partial A1 substitution does not alter the crystal structure of the 2223 phase.Excessive A1 formed Al-Cu alloy and unidentified phases,which gradually destroyed the superconductivity.
文摘目的分析2013—2022年上海市浦东新区流行性腮腺炎(简称流腮)的流行特征,为制定防控策略提供依据。方法2013—2022年流腮发病资料来源于中国疾病预防控制信息系统,采用描述流行病学方法对数据进行分析,采用季节指数法和圆形分布法分析流腮的季节性和发病高峰期。结果2013—2022年上海市浦东新区共报告流腮6536例,年平均发病率12.07/10万,发病率呈逐年下降趋势。季节指数法和圆形分布法分析显示每年4月底到12月初为流腮发病高峰期。病例以男性为主(占61.00%),男性(14.21/10万)发病率高于女性(9.76/10万),(χ^(2)=222.395,P<0.001)。年龄分布集中在10岁以下(占85.68%),5岁组儿童发病率最高(257.90/10万)。幼托儿童(44.37%)、学生(37.55%)、散居儿童(13.79%)为发病的主要群体。从地区分布看,病例总数前三位的是北蔡镇(520例,7.96%)、三林镇(505例,7.73%)、川沙新镇(442例,6.76%)。2013—2022年浦东新区适龄儿童的麻疹-流行性腮腺炎-风疹联合减毒活疫苗(measles,mumps and rubella combined attenuated live vaccine,MMR)接种率均在99.00%以上。结论2013—2022年浦东新区流腮疫情呈下降趋势,幼托儿童、学生、散居儿童是流腮防控的重点人群,仍应加强预防接种证查验及MMR接种、补种工作。
