运用HoR(House of Reliability)思想,将故障树分析(FTA)、失效模式影响及危害性分析(FMECA)整合于质量功能配置(QFD)中,建立可靠性配置流程:对系统可靠性指标进行分配,解决了传统方法过度依赖于主观打分的问题;在此基础上,建立以顾客可...运用HoR(House of Reliability)思想,将故障树分析(FTA)、失效模式影响及危害性分析(FMECA)整合于质量功能配置(QFD)中,建立可靠性配置流程:对系统可靠性指标进行分配,解决了传统方法过度依赖于主观打分的问题;在此基础上,建立以顾客可靠性满意度最大和配置成本最低为目标的模型,将可靠性指标配置到具体的工程技术特征上。并以数控车床电主轴为例,对模型的有效性进行了验证。展开更多
Enabling the conversion of chemical energy of fuels directly into electricity without combustion,fuel cells are arousing great interest in both academia and industry.A typical case is the proton exchange membrane fuel...Enabling the conversion of chemical energy of fuels directly into electricity without combustion,fuel cells are arousing great interest in both academia and industry.A typical case is the proton exchange membrane fuel cell(PEMFC),already commercialized by automobile giants.For mass popularization,however,three major criteria must be balanced:performance,durability and cost.The electrocatalysts used in both the anode and cathode are the kernel of PEMFCs,being essential for efficient operation.First in the firing‐line is the oxygen reduction reaction(ORR)at the cathode,which is normally very sluggish:over six orders of magnitude slower than the anode hydrogen oxidation reaction(HOR)[1].Thus,considerable efforts have been made to improve the cathode ORR.Identifying the main active sites is key to the design of optimum materials for enhanced ORR.Considering the complex balance of preparation,performance and cost,the active sites of metal‐nitrogen‐carbon(M‐N‐C)catalysts are particularly promising.Coupled with the single metal atom(SMA)catalysts[2–5],two excellent M‐N‐C catalysts were recently reported[6,7].New insights were thereby gained into the delicate architecture of carbon‐based SMA catalysts for ORR.展开更多
目的:探讨糖尿病胃轻瘫的早期诊断方法并探讨其可能的发病机制.方法:糖尿病住院患者38例,采用生化及放射免疫方法检测血糖、糖化血红蛋白、胃动素、胃泌素、胰高血糖素水平.以患者卧立位肱动脉收缩压变化检查植物神经功能;并采用标准餐...目的:探讨糖尿病胃轻瘫的早期诊断方法并探讨其可能的发病机制.方法:糖尿病住院患者38例,采用生化及放射免疫方法检测血糖、糖化血红蛋白、胃动素、胃泌素、胰高血糖素水平.以患者卧立位肱动脉收缩压变化检查植物神经功能;并采用标准餐加服小钡条试验,记录排空时间,以胃排空时间>6h诊断为胃轻瘫.结果:糖尿病胃排空异常者与胃排空正常者相比其空腹血糖(12.53±4.13mmol/L vs 7.12±1.37mmol/L,P<0.01)、餐后血糖(19.79±5.69mmol/L vs 14.11±4.21mmol/L,P<0.05)及糖化血红蛋白(9.73%±2.39% vs 7.26%±1.96%,P<0.05)明显升高,同时具有高水平的血清胃动素、胃泌素及胰高血糖素.糖尿病胃排空异常者植物神经功能异常发生率为62%(13/21),而糖尿病胃排空正常者为24%(4/17),糖尿病胃排空异常者胃内小钡条排空时间较正常者明显延长(7.93±1.23h vs 4.35±1.01h,P<0.001).结论:采用临床症状评分、血糖及胃肠道激素等监测及影象学检查可诊断糖尿病胃轻瘫,糖尿病胃轻瘫与神经病变、高血糖、血清胃肠激素异常、微血管病变及代谢紊乱有关.展开更多
文摘运用HoR(House of Reliability)思想,将故障树分析(FTA)、失效模式影响及危害性分析(FMECA)整合于质量功能配置(QFD)中,建立可靠性配置流程:对系统可靠性指标进行分配,解决了传统方法过度依赖于主观打分的问题;在此基础上,建立以顾客可靠性满意度最大和配置成本最低为目标的模型,将可靠性指标配置到具体的工程技术特征上。并以数控车床电主轴为例,对模型的有效性进行了验证。
基金Support by the Jilin Province/Jilin University co-Construction Project-Funds for New Materials (SXGJSF2017-3, Branch-2/440050316A36)the National Key R&D Program of China (2016YFA0200400)+3 种基金the NSFC (51372095)the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT)"Double-First Class" Discipline for Materials Science & Engineeringthe Special Funding for Academic Leaders~~
文摘Enabling the conversion of chemical energy of fuels directly into electricity without combustion,fuel cells are arousing great interest in both academia and industry.A typical case is the proton exchange membrane fuel cell(PEMFC),already commercialized by automobile giants.For mass popularization,however,three major criteria must be balanced:performance,durability and cost.The electrocatalysts used in both the anode and cathode are the kernel of PEMFCs,being essential for efficient operation.First in the firing‐line is the oxygen reduction reaction(ORR)at the cathode,which is normally very sluggish:over six orders of magnitude slower than the anode hydrogen oxidation reaction(HOR)[1].Thus,considerable efforts have been made to improve the cathode ORR.Identifying the main active sites is key to the design of optimum materials for enhanced ORR.Considering the complex balance of preparation,performance and cost,the active sites of metal‐nitrogen‐carbon(M‐N‐C)catalysts are particularly promising.Coupled with the single metal atom(SMA)catalysts[2–5],two excellent M‐N‐C catalysts were recently reported[6,7].New insights were thereby gained into the delicate architecture of carbon‐based SMA catalysts for ORR.
文摘目的:探讨糖尿病胃轻瘫的早期诊断方法并探讨其可能的发病机制.方法:糖尿病住院患者38例,采用生化及放射免疫方法检测血糖、糖化血红蛋白、胃动素、胃泌素、胰高血糖素水平.以患者卧立位肱动脉收缩压变化检查植物神经功能;并采用标准餐加服小钡条试验,记录排空时间,以胃排空时间>6h诊断为胃轻瘫.结果:糖尿病胃排空异常者与胃排空正常者相比其空腹血糖(12.53±4.13mmol/L vs 7.12±1.37mmol/L,P<0.01)、餐后血糖(19.79±5.69mmol/L vs 14.11±4.21mmol/L,P<0.05)及糖化血红蛋白(9.73%±2.39% vs 7.26%±1.96%,P<0.05)明显升高,同时具有高水平的血清胃动素、胃泌素及胰高血糖素.糖尿病胃排空异常者植物神经功能异常发生率为62%(13/21),而糖尿病胃排空正常者为24%(4/17),糖尿病胃排空异常者胃内小钡条排空时间较正常者明显延长(7.93±1.23h vs 4.35±1.01h,P<0.001).结论:采用临床症状评分、血糖及胃肠道激素等监测及影象学检查可诊断糖尿病胃轻瘫,糖尿病胃轻瘫与神经病变、高血糖、血清胃肠激素异常、微血管病变及代谢紊乱有关.