Owing to the complex environmental conditions, suspension could induce complicated forces on submarine pipelines and even cause vortex-induced vibration, resulting in fatigue damage of pipelines. Through aiming at the...Owing to the complex environmental conditions, suspension could induce complicated forces on submarine pipelines and even cause vortex-induced vibration, resulting in fatigue damage of pipelines. Through aiming at the 28-inch submarine pipeline in the East China Sea, the pipeline was segmented according to the similarity, considering the factors of pipe assembly, typhoon, current, wave and seabed topography. The effects of span length on natural frequency in each section of submarine pipeline were analyzed by finite element model. The maximum safe span length allowed by each pipeline section was verified by fatigue cumulative damage theory, and the fatigue life of each pipeline section were predicted. The results showed that each order natural frequency of the pipeline decreased with the increase of span length. The calculated results of empirical formulas were much smaller than those of the FEM analysis. The increase of the gap between the suspended pipeline and the seabed was beneficial to enhance the fatigue life of the suspended pipeline.展开更多
Wireless sensor networks are provided with a limited source of power. The lifetime of such networks is an overwhelming matter in most network applications. This lifetime depends strongly on how efficiently such energy...Wireless sensor networks are provided with a limited source of power. The lifetime of such networks is an overwhelming matter in most network applications. This lifetime depends strongly on how efficiently such energy is distributed over the nodes especially during transmitting and receiving data. Each node may route messages to destination nodes either through short hops or long hops. Optimizing the length of these hops may save energy, and therefore extend the lifetime of WSNs. In this paper, we propose a theorem to optimize the hop’s length so to make WSN power consumption minimal. The theorem establishes a simple condition on hop’s length range. Computer simulation when performing such condition on Mica2 sensors and Mica2dot sensors reveals good performance regarding WSNs energy consumption.展开更多
目的探讨改良阴式子宫切除术治疗盆腔器官脱垂(pelvic organ prolapse,POP)患者的疗效。方法回顾性分析2017年2月—2020年3月扬州大学医学院附属南京市六合区人民医院接受手术治疗的87例POP患者的临床资料,将接受改良阴式子宫切除术的4...目的探讨改良阴式子宫切除术治疗盆腔器官脱垂(pelvic organ prolapse,POP)患者的疗效。方法回顾性分析2017年2月—2020年3月扬州大学医学院附属南京市六合区人民医院接受手术治疗的87例POP患者的临床资料,将接受改良阴式子宫切除术的44例患者作为观察组,接受传统阴式全子宫切除术的43例患者作为对照组。比较两组手术情况、术后并发症、盆底功能障碍评分。结果相较于对照组,观察组的手术用时与住院时间较短,术中出血量较少,差异有统计学意义(P<0.05);观察组术后并发症发生率(4.55%)低于对照组(20.93%),差异有统计学意义(χ^(2)=3.907,P<0.05)。术后1年观察组PFDI-20评分降至(19.34±8.03)分,低于对照组的(50.47±10.42)分,差异有统计学意义(t=15.630,P<0.05)。结论盆腔器官脱垂患者予以改良阴式子宫切除术可缩短手术和住院时间,减少术中出血量,并降低术后并发症发生率,提升患者生活质量。展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.11802168 and 51575331)project funded by China Postdoctoral Science Foundation(No.2019M661458)
文摘Owing to the complex environmental conditions, suspension could induce complicated forces on submarine pipelines and even cause vortex-induced vibration, resulting in fatigue damage of pipelines. Through aiming at the 28-inch submarine pipeline in the East China Sea, the pipeline was segmented according to the similarity, considering the factors of pipe assembly, typhoon, current, wave and seabed topography. The effects of span length on natural frequency in each section of submarine pipeline were analyzed by finite element model. The maximum safe span length allowed by each pipeline section was verified by fatigue cumulative damage theory, and the fatigue life of each pipeline section were predicted. The results showed that each order natural frequency of the pipeline decreased with the increase of span length. The calculated results of empirical formulas were much smaller than those of the FEM analysis. The increase of the gap between the suspended pipeline and the seabed was beneficial to enhance the fatigue life of the suspended pipeline.
文摘Wireless sensor networks are provided with a limited source of power. The lifetime of such networks is an overwhelming matter in most network applications. This lifetime depends strongly on how efficiently such energy is distributed over the nodes especially during transmitting and receiving data. Each node may route messages to destination nodes either through short hops or long hops. Optimizing the length of these hops may save energy, and therefore extend the lifetime of WSNs. In this paper, we propose a theorem to optimize the hop’s length so to make WSN power consumption minimal. The theorem establishes a simple condition on hop’s length range. Computer simulation when performing such condition on Mica2 sensors and Mica2dot sensors reveals good performance regarding WSNs energy consumption.
文摘目的探讨改良阴式子宫切除术治疗盆腔器官脱垂(pelvic organ prolapse,POP)患者的疗效。方法回顾性分析2017年2月—2020年3月扬州大学医学院附属南京市六合区人民医院接受手术治疗的87例POP患者的临床资料,将接受改良阴式子宫切除术的44例患者作为观察组,接受传统阴式全子宫切除术的43例患者作为对照组。比较两组手术情况、术后并发症、盆底功能障碍评分。结果相较于对照组,观察组的手术用时与住院时间较短,术中出血量较少,差异有统计学意义(P<0.05);观察组术后并发症发生率(4.55%)低于对照组(20.93%),差异有统计学意义(χ^(2)=3.907,P<0.05)。术后1年观察组PFDI-20评分降至(19.34±8.03)分,低于对照组的(50.47±10.42)分,差异有统计学意义(t=15.630,P<0.05)。结论盆腔器官脱垂患者予以改良阴式子宫切除术可缩短手术和住院时间,减少术中出血量,并降低术后并发症发生率,提升患者生活质量。