Background: Unsafe abortion (USA) is defined as the termination of a non-desired pregnancy, performed by an unqualified person or in an environment without minimum medical standards, or both. It can impact negatively ...Background: Unsafe abortion (USA) is defined as the termination of a non-desired pregnancy, performed by an unqualified person or in an environment without minimum medical standards, or both. It can impact negatively the fertility in the future by tubo-peritoneal lesions. The current study aimed to highlight the infertility factors associated with USA. Material and Methods: From January 1st 2000 to December 31st 2021, a total of 3876 patients that sought care for infertility in the University Clinic of Kinshasa and the Edith Medical Center were enrolled. The socio-demographic, clinical and paraclinical variables were recorded and analyzed in relation to USA history. Results: The patients’ average age was 33.4 ± 5.7 years. Half of them were housewives;about sixty percent of the patients were nulliparous (59.31%). Seventy percent had a secondary infertility with 43.33% having a history of unsafe abortion. The main diagnosis was genital infections and uterus myoma. The chronic endometritis, bilateral tubal occlusion and Uterine synechiae were more associated with USA group. The spermogram anomalies and other partners’ lesions seemed of infectious origin. Conclusion: The USA remains a more frequent phenomenon in our setting. The chronic endometritis, bilateral tubal occlusion, uterine synechiae and indirectly uterus myoma were the infertility factors related to USA. The genital infection of any origin seems to be the main denominator underlying the female and the male infertility in our setting.展开更多
为解决基于模块化多电平换流器的柔性直流输电系统(modular multilevel converter based high voltage direct current,MMC-HVDC)在陆上交流电网故障时出现的盈余功率问题,首先计算验证了能量预警值的合理性,并设计了自适应动作能量值,...为解决基于模块化多电平换流器的柔性直流输电系统(modular multilevel converter based high voltage direct current,MMC-HVDC)在陆上交流电网故障时出现的盈余功率问题,首先计算验证了能量预警值的合理性,并设计了自适应动作能量值,解决距离和控制转换时延造成子模块过电压的问题;然后分析网侧变流器(grid-side converter,GSC)在低压穿越期间的动态输出特性,提出了基于直流电压变化率反馈的海上换流站精准降压控制用以进行风机减载;最终通过整定协同控制的逻辑与控制参数,提出了一种基于风机精准减载与子模块电容能量协同控制的低电压故障穿越策略,解决故障期间系统能量裕度利用率低与耗能装置投资大的问题。在MATLAB/Simulink中搭建系统仿真模型验证方法有效性,并与现有方法比较。仿真结果表明,所提方法可显著减少甚至避免耗能装置的投入,且具有自适应性,可在不同故障工况下尽可能利用MMC-HVDC系统的能量裕度,尤其在故障程度较轻的工况下,能在故障消除时保留部分能量裕度,有效应对电压二次跌落,提高系统低压穿越能力。展开更多
本文根据压水堆(Pressurized Water Reactor,PWR)堆芯燃料组件间定向横流与湍流交混等流动换热特性,提出了一种基于Sub栅元尺度的压水堆堆芯子通道计算分析方法,通过细致划分Sub栅元控制体,建立高分辨率三维动量源模型,自主开发了基于...本文根据压水堆(Pressurized Water Reactor,PWR)堆芯燃料组件间定向横流与湍流交混等流动换热特性,提出了一种基于Sub栅元尺度的压水堆堆芯子通道计算分析方法,通过细致划分Sub栅元控制体,建立高分辨率三维动量源模型,自主开发了基于此方法的压水堆堆芯精细栅元子通道分析程序CUNLUN。选取OECD/NEA MATiS-H和EPRI NESTOR国际基准题进行数值模拟验证。在MATiS-H国际基准题中,4个不同位置的轴向速度平均相对误差为9.07%,该程序可以准确评估压水堆堆芯的热工水力特性。在NESTOR国际基准题中,32个对比点内有24个点的计算精度提升69.08%,表明高分辨率三维动量源模型可以有效提高CUNLUN代码的计算精度。本代码能为压水堆堆芯热工水力分析提供有效的设计和研究手段,对反应堆堆芯热工水力分析程序的开发提供借鉴与参考。展开更多
文摘Background: Unsafe abortion (USA) is defined as the termination of a non-desired pregnancy, performed by an unqualified person or in an environment without minimum medical standards, or both. It can impact negatively the fertility in the future by tubo-peritoneal lesions. The current study aimed to highlight the infertility factors associated with USA. Material and Methods: From January 1st 2000 to December 31st 2021, a total of 3876 patients that sought care for infertility in the University Clinic of Kinshasa and the Edith Medical Center were enrolled. The socio-demographic, clinical and paraclinical variables were recorded and analyzed in relation to USA history. Results: The patients’ average age was 33.4 ± 5.7 years. Half of them were housewives;about sixty percent of the patients were nulliparous (59.31%). Seventy percent had a secondary infertility with 43.33% having a history of unsafe abortion. The main diagnosis was genital infections and uterus myoma. The chronic endometritis, bilateral tubal occlusion and Uterine synechiae were more associated with USA group. The spermogram anomalies and other partners’ lesions seemed of infectious origin. Conclusion: The USA remains a more frequent phenomenon in our setting. The chronic endometritis, bilateral tubal occlusion, uterine synechiae and indirectly uterus myoma were the infertility factors related to USA. The genital infection of any origin seems to be the main denominator underlying the female and the male infertility in our setting.
文摘为解决基于模块化多电平换流器的柔性直流输电系统(modular multilevel converter based high voltage direct current,MMC-HVDC)在陆上交流电网故障时出现的盈余功率问题,首先计算验证了能量预警值的合理性,并设计了自适应动作能量值,解决距离和控制转换时延造成子模块过电压的问题;然后分析网侧变流器(grid-side converter,GSC)在低压穿越期间的动态输出特性,提出了基于直流电压变化率反馈的海上换流站精准降压控制用以进行风机减载;最终通过整定协同控制的逻辑与控制参数,提出了一种基于风机精准减载与子模块电容能量协同控制的低电压故障穿越策略,解决故障期间系统能量裕度利用率低与耗能装置投资大的问题。在MATLAB/Simulink中搭建系统仿真模型验证方法有效性,并与现有方法比较。仿真结果表明,所提方法可显著减少甚至避免耗能装置的投入,且具有自适应性,可在不同故障工况下尽可能利用MMC-HVDC系统的能量裕度,尤其在故障程度较轻的工况下,能在故障消除时保留部分能量裕度,有效应对电压二次跌落,提高系统低压穿越能力。
文摘本文根据压水堆(Pressurized Water Reactor,PWR)堆芯燃料组件间定向横流与湍流交混等流动换热特性,提出了一种基于Sub栅元尺度的压水堆堆芯子通道计算分析方法,通过细致划分Sub栅元控制体,建立高分辨率三维动量源模型,自主开发了基于此方法的压水堆堆芯精细栅元子通道分析程序CUNLUN。选取OECD/NEA MATiS-H和EPRI NESTOR国际基准题进行数值模拟验证。在MATiS-H国际基准题中,4个不同位置的轴向速度平均相对误差为9.07%,该程序可以准确评估压水堆堆芯的热工水力特性。在NESTOR国际基准题中,32个对比点内有24个点的计算精度提升69.08%,表明高分辨率三维动量源模型可以有效提高CUNLUN代码的计算精度。本代码能为压水堆堆芯热工水力分析提供有效的设计和研究手段,对反应堆堆芯热工水力分析程序的开发提供借鉴与参考。
