This essay researched the currently gowns standards including AAMI PB70、NFPA 1999、EN 13795、ISO 16542 and GB19082.The essay also studied the test methods and specifications for evaluating the micro barrier propertie...This essay researched the currently gowns standards including AAMI PB70、NFPA 1999、EN 13795、ISO 16542 and GB19082.The essay also studied the test methods and specifications for evaluating the micro barrier properties in the gowns standards.By comparing the internal gowns standards with the international gowns standards,the essay suggested some advices to progress the Chinese gowns standard.展开更多
高温可靠性测试如高温栅偏(High Temperature Gate Bias,HTGB)、高温反偏(High Temperature Reverse Bias,HTRB)、高温高湿反偏(High Humidity High Temperature Reverse Bias,H3TRB)是器件出厂和寿命评估必备的测试。然而,不同标准的...高温可靠性测试如高温栅偏(High Temperature Gate Bias,HTGB)、高温反偏(High Temperature Reverse Bias,HTRB)、高温高湿反偏(High Humidity High Temperature Reverse Bias,H3TRB)是器件出厂和寿命评估必备的测试。然而,不同标准的测试条件不尽相同,其对应的内在机理也不明确。为讨论测试条件的确定原则,首先从单个和耦合的温度、电场、湿度加速老化模型出发,论述了相关测试标准所用模型,分析了其应用范围和使用原则。进一步地,总结了现有各类标准下的测试条件,计算了电动汽车模块正常运行30年所需HTGB、HTRB、H3TRB加速老化时间分别为832 h、866 h、1038 h,测试的样本数均为70,并指出测试时间、样本数需根据实际工况决定。最后,基于以上分析,提出了一种加速老化时间、样本数可调的高温可靠性测试流程。展开更多
Proton exchange membrane fuel cells(PEMFC)have attracted much attention because of their high energy conversion efficiency,high power density and zero emission of pollutants.However,the high cost of the cathode platin...Proton exchange membrane fuel cells(PEMFC)have attracted much attention because of their high energy conversion efficiency,high power density and zero emission of pollutants.However,the high cost of the cathode platinum group metal(PGM)catalysts creates a barrier for the large-scale application of PEMFC.Tremendous efforts have been devoted to the development of low-cost PGM-free catalysts,especially the Fe-N-C catalysts,to replace the expensive PGM catalysts.However,the characterization methods and evaluation standards of the catalysts varies,which is not conducive to the comparison of PGM-free catalysts.U.S.Department of energy(DOE)is the only authority that specifies the testing standards and activity targets for PGM-free catalysts.In this review,the major breakthroughs of Fe-N-C catalysts are outlined with the reference of DOE standards and targets.The preparation and characteristics of these highly active Fe-N-C catalysts are briefly introduced.Moreover,the efforts on improving the mass transfer and the durability issue of Fe-N-C fuel cell are discussed.Finally,the prospective directions concerning the comprehensive evaluation of the Fe-N-C catalysts are proposed.展开更多
文摘This essay researched the currently gowns standards including AAMI PB70、NFPA 1999、EN 13795、ISO 16542 and GB19082.The essay also studied the test methods and specifications for evaluating the micro barrier properties in the gowns standards.By comparing the internal gowns standards with the international gowns standards,the essay suggested some advices to progress the Chinese gowns standard.
文摘高温可靠性测试如高温栅偏(High Temperature Gate Bias,HTGB)、高温反偏(High Temperature Reverse Bias,HTRB)、高温高湿反偏(High Humidity High Temperature Reverse Bias,H3TRB)是器件出厂和寿命评估必备的测试。然而,不同标准的测试条件不尽相同,其对应的内在机理也不明确。为讨论测试条件的确定原则,首先从单个和耦合的温度、电场、湿度加速老化模型出发,论述了相关测试标准所用模型,分析了其应用范围和使用原则。进一步地,总结了现有各类标准下的测试条件,计算了电动汽车模块正常运行30年所需HTGB、HTRB、H3TRB加速老化时间分别为832 h、866 h、1038 h,测试的样本数均为70,并指出测试时间、样本数需根据实际工况决定。最后,基于以上分析,提出了一种加速老化时间、样本数可调的高温可靠性测试流程。
基金supported by the National Thousand Talents Plan of Chinathe National Natural Science Foundation of China(Grant Nos.21673014 and U1766216)+1 种基金the 111 project(B17002)funded by the Ministry of Education of Chinathe Fundamental Research Funds for the Central Universities of China
文摘Proton exchange membrane fuel cells(PEMFC)have attracted much attention because of their high energy conversion efficiency,high power density and zero emission of pollutants.However,the high cost of the cathode platinum group metal(PGM)catalysts creates a barrier for the large-scale application of PEMFC.Tremendous efforts have been devoted to the development of low-cost PGM-free catalysts,especially the Fe-N-C catalysts,to replace the expensive PGM catalysts.However,the characterization methods and evaluation standards of the catalysts varies,which is not conducive to the comparison of PGM-free catalysts.U.S.Department of energy(DOE)is the only authority that specifies the testing standards and activity targets for PGM-free catalysts.In this review,the major breakthroughs of Fe-N-C catalysts are outlined with the reference of DOE standards and targets.The preparation and characteristics of these highly active Fe-N-C catalysts are briefly introduced.Moreover,the efforts on improving the mass transfer and the durability issue of Fe-N-C fuel cell are discussed.Finally,the prospective directions concerning the comprehensive evaluation of the Fe-N-C catalysts are proposed.
