In this paper, a novel accelerated test method was proposed to analyze the durability of MEA, considering the actual operation of the fuel cell vehicle. The proposed method includes 7 working conditions： open circuit...In this paper, a novel accelerated test method was proposed to analyze the durability of MEA, considering the actual operation of the fuel cell vehicle. The proposed method includes 7 working conditions： open circuit voltage （OCV）, idling, rated output, overload, idling-rated cycle, idling-overload cycle, and OCV-idling cycle. The experimental results indicate that the proposed method can effectively destroy the MEA in a short time （165 h）. Moreover, the degradation mechanism of MEA was analyzed by measuring the polarization curve, CV, SEM and TEM. This paper may provide a new research direction for improving the durability of fuel cell.展开更多
Nowadays,the construction sector is more and more oriented toward the promotion of sustainability in all its activities.The goal to achieve is the optimization of performances,over the whole life-cycle,with respect to...Nowadays,the construction sector is more and more oriented toward the promotion of sustainability in all its activities.The goal to achieve is the optimization of performances,over the whole life-cycle,with respect to environmental,economic and social requirements.According to the latest advances,the concept of sustainability applied to constructions covers a number of branches such as life-cycle costing,ecology,durability and even structural design.Several procedures and design tools have been implemented in the framework of international research.Indeed the current trend in civil engineering research is moving towards life-time engineering,with the aim to implement integrated methodologies to consider as a whole all the sustainability requirements according to time-dependent multi-performance-based design approaches.Following a general introduction of the concept of sustainability applied to constructions,this paper presents an overview of life-time engineering methodologies according to the current state-of-the-art.In particular the methods currently received by International Standards are discussed.A special focus is devoted to the durability design of metal structures with respect to the degradation phenomena able to impair the structural capacity over time.Finally a proposal towards an integrated approach to life-time engineering design of steel structures and needs for further advances are presented.展开更多
目的 探究前瞻性护理在预防机械通气患者发生ICU获得性衰弱(intensive care unit-acquired weakness,ICU-AW)中的作用。方法 选取2022年8月—2023年12月于南京医科大学附属南京医院呼吸与危重症医学科收治的67例机械通气患者。按照随机...目的 探究前瞻性护理在预防机械通气患者发生ICU获得性衰弱(intensive care unit-acquired weakness,ICU-AW)中的作用。方法 选取2022年8月—2023年12月于南京医科大学附属南京医院呼吸与危重症医学科收治的67例机械通气患者。按照随机数字表法分为对照组(n=33)和研究组(n=34),对照组接受常规护理,研究组在常规护理的基础上接受前瞻性护理。采用医学研究委员会肌力评分(Medical Research Council Muscle Strength,MRC)比较2组肌力,采用日常生活活动量表(Activity of Daily Living,ADL)及巴氏指数(Barthel Index,BI)量表评估2组日常生活能力。采用焦虑自评量表(Self-Rating Anxiety Scale,SAS)及抑郁自评量表(Self-Rating Depression Scale,SDS)评估患者的焦虑、抑郁状态,统计2组患者的机械通气时间及住院时间。结果 护理前2组患者的MRC评分差异无统计学意义(P>0.05),研究组患者护理前后的MRC得分差值高于对照组,差异具有统计学意义(t=4.082,P<0.001);护理前2组患者的ADL得分差异无统计学意义(P>0.05),研究组患者护理前后ADL评分差值高于对照组,差异具有统计学意义(t=8.906,P<0.001);护理前2组患者的BI评分无统计学意义(P>0.05),研究组患者护理前后BI评分差值高于对照组,差异具有统计学意义(t=2.386,P=0.036);护理前2组患者SAS评分及SDS评分差异均无统计学意义(P>0.05),研究组患者护理前后SAS评分及SDS评分差值均高于对照组,差异具有统计学意义(t=5.064、5.238,P均<0.001);研究组患者机械通气时间低于对照组(t=11.063,P<0.001),研究组患者平均住院时间低于对照组(t=10.169,P<0.001)。结论 前瞻性护理可以有效预防ICU-AW,提高患者自理能力,同时缓解患者焦虑、抑郁心理状态,减少其机械通气时间及住院时间,值得在临床中进一步研究与推广。展开更多
为确保空间站环控生保系统稳定运行,需实时监测其遥测参数;而遥测数据规模大、维度高、关联性强,需综合多参数以准确判断运行状态。文章以空间站冷凝水抽吸系统为例,验证基于动态时间弯曲(Dynamic Time Warping,DTW)的时间序列相似性匹...为确保空间站环控生保系统稳定运行,需实时监测其遥测参数;而遥测数据规模大、维度高、关联性强,需综合多参数以准确判断运行状态。文章以空间站冷凝水抽吸系统为例,验证基于动态时间弯曲(Dynamic Time Warping,DTW)的时间序列相似性匹配方法,将遥测参数判读转化为曲线相似性度量问题;结合多关联参数max-min归一化融合方法,有效降低了多参数相似性度量计算复杂度,有效消除了量纲干扰,提升了系统状态检测精度。展开更多
文摘In this paper, a novel accelerated test method was proposed to analyze the durability of MEA, considering the actual operation of the fuel cell vehicle. The proposed method includes 7 working conditions： open circuit voltage （OCV）, idling, rated output, overload, idling-rated cycle, idling-overload cycle, and OCV-idling cycle. The experimental results indicate that the proposed method can effectively destroy the MEA in a short time （165 h）. Moreover, the degradation mechanism of MEA was analyzed by measuring the polarization curve, CV, SEM and TEM. This paper may provide a new research direction for improving the durability of fuel cell.
基金the support from the European Cooperation in the field of Scientific and Technical Research(COST)
文摘Nowadays,the construction sector is more and more oriented toward the promotion of sustainability in all its activities.The goal to achieve is the optimization of performances,over the whole life-cycle,with respect to environmental,economic and social requirements.According to the latest advances,the concept of sustainability applied to constructions covers a number of branches such as life-cycle costing,ecology,durability and even structural design.Several procedures and design tools have been implemented in the framework of international research.Indeed the current trend in civil engineering research is moving towards life-time engineering,with the aim to implement integrated methodologies to consider as a whole all the sustainability requirements according to time-dependent multi-performance-based design approaches.Following a general introduction of the concept of sustainability applied to constructions,this paper presents an overview of life-time engineering methodologies according to the current state-of-the-art.In particular the methods currently received by International Standards are discussed.A special focus is devoted to the durability design of metal structures with respect to the degradation phenomena able to impair the structural capacity over time.Finally a proposal towards an integrated approach to life-time engineering design of steel structures and needs for further advances are presented.
文摘目的 探究前瞻性护理在预防机械通气患者发生ICU获得性衰弱(intensive care unit-acquired weakness,ICU-AW)中的作用。方法 选取2022年8月—2023年12月于南京医科大学附属南京医院呼吸与危重症医学科收治的67例机械通气患者。按照随机数字表法分为对照组(n=33)和研究组(n=34),对照组接受常规护理,研究组在常规护理的基础上接受前瞻性护理。采用医学研究委员会肌力评分(Medical Research Council Muscle Strength,MRC)比较2组肌力,采用日常生活活动量表(Activity of Daily Living,ADL)及巴氏指数(Barthel Index,BI)量表评估2组日常生活能力。采用焦虑自评量表(Self-Rating Anxiety Scale,SAS)及抑郁自评量表(Self-Rating Depression Scale,SDS)评估患者的焦虑、抑郁状态,统计2组患者的机械通气时间及住院时间。结果 护理前2组患者的MRC评分差异无统计学意义(P>0.05),研究组患者护理前后的MRC得分差值高于对照组,差异具有统计学意义(t=4.082,P<0.001);护理前2组患者的ADL得分差异无统计学意义(P>0.05),研究组患者护理前后ADL评分差值高于对照组,差异具有统计学意义(t=8.906,P<0.001);护理前2组患者的BI评分无统计学意义(P>0.05),研究组患者护理前后BI评分差值高于对照组,差异具有统计学意义(t=2.386,P=0.036);护理前2组患者SAS评分及SDS评分差异均无统计学意义(P>0.05),研究组患者护理前后SAS评分及SDS评分差值均高于对照组,差异具有统计学意义(t=5.064、5.238,P均<0.001);研究组患者机械通气时间低于对照组(t=11.063,P<0.001),研究组患者平均住院时间低于对照组(t=10.169,P<0.001)。结论 前瞻性护理可以有效预防ICU-AW,提高患者自理能力,同时缓解患者焦虑、抑郁心理状态,减少其机械通气时间及住院时间,值得在临床中进一步研究与推广。
文摘为确保空间站环控生保系统稳定运行,需实时监测其遥测参数;而遥测数据规模大、维度高、关联性强,需综合多参数以准确判断运行状态。文章以空间站冷凝水抽吸系统为例,验证基于动态时间弯曲(Dynamic Time Warping,DTW)的时间序列相似性匹配方法,将遥测参数判读转化为曲线相似性度量问题;结合多关联参数max-min归一化融合方法,有效降低了多参数相似性度量计算复杂度,有效消除了量纲干扰,提升了系统状态检测精度。
