The liquid structure of Fe-4.30C and Fe-4.30C-0.21Ce alloys was studied by high temperature X-ray diffractometer. The results show that for Fe-C alloy the nearest neighbor distance of the eutectic alloy is 0.259-0.260...The liquid structure of Fe-4.30C and Fe-4.30C-0.21Ce alloys was studied by high temperature X-ray diffractometer. The results show that for Fe-C alloy the nearest neighbor distance of the eutectic alloy is 0.259-0.260 nm at the temperature range of 1200-1400℃, which increases to 0.269-0.271 nm with the addition of 0.21% (mass fraction) Ce in the Fe-C alloy at the same temperature range. There is a pre-peak at Q = 15.5 nm-1 on the original intensity curve and structure factor S(Q) of the liquid Fe-4.30C-0.21Ce alloy, which was caused by the Ce atoms in the C-Ce clusters. Combined with the shared face, the tetragonal structure can meet the requirement for the distance of Ce-Ce atoms. It also shows that the cluster size in the liquid Fe-4.30C-0.21Ce alloy increases with the decreasing temperature.展开更多
目的探讨盐酸贝尼地平联合替米沙坦治疗原发性高血压的临床疗效。方法选取首都医科大学附属北京潞河医院2024年2月至12月收治的原发性高血压患者100例,按随机数字表法分为对照组和观察组,各50例。两组患者均口服替米沙坦片,观察组患者...目的探讨盐酸贝尼地平联合替米沙坦治疗原发性高血压的临床疗效。方法选取首都医科大学附属北京潞河医院2024年2月至12月收治的原发性高血压患者100例,按随机数字表法分为对照组和观察组,各50例。两组患者均口服替米沙坦片,观察组患者加用盐酸贝尼地平片。两组均连续治疗8周。结果观察组总有效率为88.00%,显著高于对照组的56.00%(P<0.05)。两组患者治疗后的24 h平均收缩压(24 h SBP)、夜间睡眠SBP、晨峰血压、24 h平均舒张压(24 h DBP)、夜间睡眠DBP,血清内皮素、过氧化脂质、胱抑素C(CysC)、超敏C反应蛋白、白细胞介素(IL)1、IL-6水平均显著降低,一氧化氮(NO)、25-羟维生素D[25-(OH)D]水平均显著升高(P<0.05);且观察组上述指标均显著优于对照组(P<0.05)。观察组与对照组不良反应发生率相当(12.00%比8.00%,P>0.05)。结论盐酸贝尼地平联合替米沙坦治疗原发性高血压,可有效降低血压,改善患者血压晨峰现象及血管内皮功能,降低CysC及25-(OH)D水平,并抑制炎性反应。展开更多
针对传统模糊C均值聚类算法和基于K-means++优化聚类中心的模糊C均值算法存在初始聚类中心敏感、聚类速度收敛慢、聚类算法需要人为给定聚类数目等缺陷,受密度峰值聚类算法(Clustering by Fast Search and Find of Density Peaks,CFSFDP...针对传统模糊C均值聚类算法和基于K-means++优化聚类中心的模糊C均值算法存在初始聚类中心敏感、聚类速度收敛慢、聚类算法需要人为给定聚类数目等缺陷,受密度峰值聚类算法(Clustering by Fast Search and Find of Density Peaks,CFSFDP)的启发,提出了基于密度峰值算法优化的模糊C均值聚类算法,自适应产生初始聚类中心,确定聚类数目,并优化算法收敛过程。实验结果表明,改进后的算法与传统模糊聚类C均值算法相比能够准确地得到簇的数目,性能有明显的提高,并加快算法的收敛速度,达到相对更好的聚类效果。展开更多
基金This work was supported by the National Natural Science Foundation of China (No.59871025).
文摘The liquid structure of Fe-4.30C and Fe-4.30C-0.21Ce alloys was studied by high temperature X-ray diffractometer. The results show that for Fe-C alloy the nearest neighbor distance of the eutectic alloy is 0.259-0.260 nm at the temperature range of 1200-1400℃, which increases to 0.269-0.271 nm with the addition of 0.21% (mass fraction) Ce in the Fe-C alloy at the same temperature range. There is a pre-peak at Q = 15.5 nm-1 on the original intensity curve and structure factor S(Q) of the liquid Fe-4.30C-0.21Ce alloy, which was caused by the Ce atoms in the C-Ce clusters. Combined with the shared face, the tetragonal structure can meet the requirement for the distance of Ce-Ce atoms. It also shows that the cluster size in the liquid Fe-4.30C-0.21Ce alloy increases with the decreasing temperature.
文摘目的探讨盐酸贝尼地平联合替米沙坦治疗原发性高血压的临床疗效。方法选取首都医科大学附属北京潞河医院2024年2月至12月收治的原发性高血压患者100例,按随机数字表法分为对照组和观察组,各50例。两组患者均口服替米沙坦片,观察组患者加用盐酸贝尼地平片。两组均连续治疗8周。结果观察组总有效率为88.00%,显著高于对照组的56.00%(P<0.05)。两组患者治疗后的24 h平均收缩压(24 h SBP)、夜间睡眠SBP、晨峰血压、24 h平均舒张压(24 h DBP)、夜间睡眠DBP,血清内皮素、过氧化脂质、胱抑素C(CysC)、超敏C反应蛋白、白细胞介素(IL)1、IL-6水平均显著降低,一氧化氮(NO)、25-羟维生素D[25-(OH)D]水平均显著升高(P<0.05);且观察组上述指标均显著优于对照组(P<0.05)。观察组与对照组不良反应发生率相当(12.00%比8.00%,P>0.05)。结论盐酸贝尼地平联合替米沙坦治疗原发性高血压,可有效降低血压,改善患者血压晨峰现象及血管内皮功能,降低CysC及25-(OH)D水平,并抑制炎性反应。
文摘针对传统模糊C均值聚类算法和基于K-means++优化聚类中心的模糊C均值算法存在初始聚类中心敏感、聚类速度收敛慢、聚类算法需要人为给定聚类数目等缺陷,受密度峰值聚类算法(Clustering by Fast Search and Find of Density Peaks,CFSFDP)的启发,提出了基于密度峰值算法优化的模糊C均值聚类算法,自适应产生初始聚类中心,确定聚类数目,并优化算法收敛过程。实验结果表明,改进后的算法与传统模糊聚类C均值算法相比能够准确地得到簇的数目,性能有明显的提高,并加快算法的收敛速度,达到相对更好的聚类效果。
