近年来,复合材料层合板结构被广泛地应用于航空航天、军工、建筑工程等领域。但是,由于其几何尺寸的不准确性、材料参数的分散性、载荷环境的波动性等不确定性因素的影响,可能会对复合材料层合板结构的可靠性和安全性,以及系统的输出响...近年来,复合材料层合板结构被广泛地应用于航空航天、军工、建筑工程等领域。但是,由于其几何尺寸的不准确性、材料参数的分散性、载荷环境的波动性等不确定性因素的影响,可能会对复合材料层合板结构的可靠性和安全性,以及系统的输出响应产生重大影响。由于复合材料层合板的层间黏结不良、外部应力集中等因素,当复合材料层合板结构的能量释放速率达到层间断裂韧性时,就会发生分层。因此对复合材料层合板结构的分层可靠性进行分析具有重要的意义。目前,对于复合材料层合板结构的可靠性分析主要是采用一阶可靠性方法(first order reliability method,FORM)、二阶可靠性方法(second order reliability method,SORM)和重要性抽样方法(importance sampling,IS)等传统可靠性分析方法,并将其和蒙特卡罗模拟(Monte Carlo simulation,MCS)对比。但是,当复合材料结构不确定性维度高且复杂时,这些方法不仅计算效率太低,而且不能保证其计算精度。相比于传统的可靠性分析方法,可以利用基于自适应Kriging模型集成策略和主动学习函数结合蒙特卡罗模拟(adaptive Kriging-based Monte Carlo simulation,AK-MCS)的方法,对复合材料层合板结构进行可靠性分析。而直接概率积分方法(direct probability integral method,DPIM)具有更高的计算效率和精度,特别是对于高维度和复杂的可靠性分析问题。所以,本文采用AK-MCS方法和DPIM对模式Ⅰ、模式Ⅱ和混合Ⅰ/Ⅱ模式下的复合材料层合板结构分层的可靠度进行了研究。结果表明:DPIM和AK-MCS与传统可靠性分析方法相比具有更高的计算精度和计算效率,但是DPIM以其高效的计算效率脱颖而出,尽管其精度略低于AK-MCS,但在处理随机变量更多、非线性程度更高的混合Ⅰ/Ⅱ模式下的层合板结构分层的可靠性时展现出明显优势。综合考虑精度与时效性的平衡,DPIM能够准确地评估复合材料结构的可靠度,保障其在航天航空装备等领域的安全运行。展开更多
Multiple morphological abnormalities of the flagella(MMAF)represent a severe form of sperm defects leading to asthenozoospermia and male infertility.In this study,we identified a novel homozygous splicing mutation(c.8...Multiple morphological abnormalities of the flagella(MMAF)represent a severe form of sperm defects leading to asthenozoospermia and male infertility.In this study,we identified a novel homozygous splicing mutation(c.871-4 ACA>A)in the adenylate kinase 7(AK7)gene by whole-exome sequencing in infertile individuals.Spermatozoa from affected individuals exhibited typical MMAF characteristics,including coiled,bent,short,absent,and irregular flagella.Transmission electron microscopy analysis showed disorganized axonemal structure and abnormal mitochondrial sheets in sperm flagella.Immunofluorescence staining confirmed the absence of AK7 protein from the patients’spermatozoa,validating the pathogenic nature of the mutation.This study provides direct evidence linking the AK7 gene to MMAF-associated asthenozoospermia in humans,expanding the mutational spectrum of AK7 and enhancing our understanding of the genetic basis of male infertility.展开更多
Aimed at the problem of the low computational efficiency of the existing urethral-valve reliability analysis,an efficient reliability analysis method of the wireless energy-transmitting urethral-valve(WETUV)was propos...Aimed at the problem of the low computational efficiency of the existing urethral-valve reliability analysis,an efficient reliability analysis method of the wireless energy-transmitting urethral-valve(WETUV)was proposed.The method is called FTA-AK-SS,based on the active learning Kriging(AK)model,subset simulation(SS)algorithm,and fault tree analysis(FTA).According to the principle of FTA,we established the fault tree model of the WETUV to determine its minimum cut set and bottom events.Then we defined the random variables affecting its reliability.The U learning function was used to selectively add the sample points of random variables to update the initial Kriging surrogate model.At the same time,combined with the SS algorithm,the reliability and sensitivity analyses of the WETUV were realized.The result shows that compared with the traditional Monte Carlo simulation and FTA-Kriging-SS methods,the proposed method significantly improves the calculation efficiency of the WETUV under the premise of ensuring calculation accuracy.The reliability of the WETUV is greatly affected by the rubber pad’s aging,the receiver coil’s corrosion,and the position deviation.This study can provide a new way to realize a high-efficiency reliability calculation and analysis for urethral valves.展开更多
Medically assisted reproduction(MAR)techniques are highly dependent on the sperm quantity and quality.Low sperm concentrations can be bypassed at least to some point by the usage of more sophisticated MAR techniques l...Medically assisted reproduction(MAR)techniques are highly dependent on the sperm quantity and quality.Low sperm concentrations can be bypassed at least to some point by the usage of more sophisticated MAR techniques like intracytoplasmic sperm injection(ICSI).Compared to this,disruptions in established indicators of sperm quality like motility or morphology pose greater challenges for the therapy of couple infertility.展开更多
GamBro AK 200 ULTRA S透析机是百特金宝公司生产的双泵透析机,以血液透析滤过功能为特色,兼备血液透析、血液滤过的功能。通常,操作人员在使用过程中的操作失误,会以报警提示的形式呈现,操作人员根据报警提示的引导,即可快速更正操作,...GamBro AK 200 ULTRA S透析机是百特金宝公司生产的双泵透析机,以血液透析滤过功能为特色,兼备血液透析、血液滤过的功能。通常,操作人员在使用过程中的操作失误,会以报警提示的形式呈现,操作人员根据报警提示的引导,即可快速更正操作,报警提示普遍与操作失误相关,然而,也有掩藏在“报警提示”表面下的特殊故障,本文对一例该类特殊故障的检修进行解析。展开更多
文摘近年来,复合材料层合板结构被广泛地应用于航空航天、军工、建筑工程等领域。但是,由于其几何尺寸的不准确性、材料参数的分散性、载荷环境的波动性等不确定性因素的影响,可能会对复合材料层合板结构的可靠性和安全性,以及系统的输出响应产生重大影响。由于复合材料层合板的层间黏结不良、外部应力集中等因素,当复合材料层合板结构的能量释放速率达到层间断裂韧性时,就会发生分层。因此对复合材料层合板结构的分层可靠性进行分析具有重要的意义。目前,对于复合材料层合板结构的可靠性分析主要是采用一阶可靠性方法(first order reliability method,FORM)、二阶可靠性方法(second order reliability method,SORM)和重要性抽样方法(importance sampling,IS)等传统可靠性分析方法,并将其和蒙特卡罗模拟(Monte Carlo simulation,MCS)对比。但是,当复合材料结构不确定性维度高且复杂时,这些方法不仅计算效率太低,而且不能保证其计算精度。相比于传统的可靠性分析方法,可以利用基于自适应Kriging模型集成策略和主动学习函数结合蒙特卡罗模拟(adaptive Kriging-based Monte Carlo simulation,AK-MCS)的方法,对复合材料层合板结构进行可靠性分析。而直接概率积分方法(direct probability integral method,DPIM)具有更高的计算效率和精度,特别是对于高维度和复杂的可靠性分析问题。所以,本文采用AK-MCS方法和DPIM对模式Ⅰ、模式Ⅱ和混合Ⅰ/Ⅱ模式下的复合材料层合板结构分层的可靠度进行了研究。结果表明:DPIM和AK-MCS与传统可靠性分析方法相比具有更高的计算精度和计算效率,但是DPIM以其高效的计算效率脱颖而出,尽管其精度略低于AK-MCS,但在处理随机变量更多、非线性程度更高的混合Ⅰ/Ⅱ模式下的层合板结构分层的可靠性时展现出明显优势。综合考虑精度与时效性的平衡,DPIM能够准确地评估复合材料结构的可靠度,保障其在航天航空装备等领域的安全运行。
基金supported by the National Key Research and Development Program of China(No.2021YFC2700202,No.2022YFA0806303,and No.2022YFC2702601)the Global Select Project of the Institute of Health and Medicine,Hefei Comprehensive National Science Center(DJK-LX-2022010)the Joint Fund for New Medicine of USTC(YD9100002034).
文摘Multiple morphological abnormalities of the flagella(MMAF)represent a severe form of sperm defects leading to asthenozoospermia and male infertility.In this study,we identified a novel homozygous splicing mutation(c.871-4 ACA>A)in the adenylate kinase 7(AK7)gene by whole-exome sequencing in infertile individuals.Spermatozoa from affected individuals exhibited typical MMAF characteristics,including coiled,bent,short,absent,and irregular flagella.Transmission electron microscopy analysis showed disorganized axonemal structure and abnormal mitochondrial sheets in sperm flagella.Immunofluorescence staining confirmed the absence of AK7 protein from the patients’spermatozoa,validating the pathogenic nature of the mutation.This study provides direct evidence linking the AK7 gene to MMAF-associated asthenozoospermia in humans,expanding the mutational spectrum of AK7 and enhancing our understanding of the genetic basis of male infertility.
基金Foundation item:the National Natural Science Foundation of China(No.52075101)the Natural Science Foundation of Guangdong Province(No.2017A030313265)Guangzhou Scientific Research Plan(No.201904010184)。
文摘Aimed at the problem of the low computational efficiency of the existing urethral-valve reliability analysis,an efficient reliability analysis method of the wireless energy-transmitting urethral-valve(WETUV)was proposed.The method is called FTA-AK-SS,based on the active learning Kriging(AK)model,subset simulation(SS)algorithm,and fault tree analysis(FTA).According to the principle of FTA,we established the fault tree model of the WETUV to determine its minimum cut set and bottom events.Then we defined the random variables affecting its reliability.The U learning function was used to selectively add the sample points of random variables to update the initial Kriging surrogate model.At the same time,combined with the SS algorithm,the reliability and sensitivity analyses of the WETUV were realized.The result shows that compared with the traditional Monte Carlo simulation and FTA-Kriging-SS methods,the proposed method significantly improves the calculation efficiency of the WETUV under the premise of ensuring calculation accuracy.The reliability of the WETUV is greatly affected by the rubber pad’s aging,the receiver coil’s corrosion,and the position deviation.This study can provide a new way to realize a high-efficiency reliability calculation and analysis for urethral valves.
文摘Medically assisted reproduction(MAR)techniques are highly dependent on the sperm quantity and quality.Low sperm concentrations can be bypassed at least to some point by the usage of more sophisticated MAR techniques like intracytoplasmic sperm injection(ICSI).Compared to this,disruptions in established indicators of sperm quality like motility or morphology pose greater challenges for the therapy of couple infertility.
文摘GamBro AK 200 ULTRA S透析机是百特金宝公司生产的双泵透析机,以血液透析滤过功能为特色,兼备血液透析、血液滤过的功能。通常,操作人员在使用过程中的操作失误,会以报警提示的形式呈现,操作人员根据报警提示的引导,即可快速更正操作,报警提示普遍与操作失误相关,然而,也有掩藏在“报警提示”表面下的特殊故障,本文对一例该类特殊故障的检修进行解析。
