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NPTF干密封螺纹的特性 被引量:1
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作者 胡慧峰 《自动化与仪器仪表》 2014年第1期79-80,83,共3页
NPTF螺纹作为干密封螺纹,其牙型精度比NPT螺纹高,旋合时不用任何填料,完全依靠螺纹自身形成密封,螺纹间无任何密封介质,很适合用于高温高压的场合。由于其精度很高,所以必须要掌握好其加工性能和正确的检测方法。本文就这NPTF螺纹的参... NPTF螺纹作为干密封螺纹,其牙型精度比NPT螺纹高,旋合时不用任何填料,完全依靠螺纹自身形成密封,螺纹间无任何密封介质,很适合用于高温高压的场合。由于其精度很高,所以必须要掌握好其加工性能和正确的检测方法。本文就这NPTF螺纹的参数、加工方法、检验方法展开讨论。 展开更多
关键词 nptf螺纹 参数 加工方法 检验方法
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Design of compressively strained PtRu alloy as anode for high-performance DMFCs
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作者 Shuai Yin Kening Zong +3 位作者 Lishou Ban Huiming Yin Xizheng Liu Yi Ding 《Inorganic Chemistry Frontiers》 2024年第12期3633-3642,共10页
Direct methanol fuel cells(DMFCs)are considered favorable for portable devices due to their high energy density and the widespread availability of methanol fuel.However,the commercialization of DMFCs has been severely... Direct methanol fuel cells(DMFCs)are considered favorable for portable devices due to their high energy density and the widespread availability of methanol fuel.However,the commercialization of DMFCs has been severely limited by the sluggish reaction kinetics and poor stability of the anode.In this study,compressively strained PtRu alloy nanoparticles were deposited on a nanoporous thin film(NPTF)using a differential normal pulse voltammetry technique.The resulting compressive structure is confirmed through geometrical phase analysis,revealing high-level compressive strains of about−5%.Owing to the improved specific activity and high specific surface area,the compressively strained PtRu alloy nanoparticles exhibit outstanding Pt mass activities for methanol oxidation reaction.NPTF-Pt2Ru1 with a Pt/Ru molar ratio of 2/1 exhibits the highest Pt mass activity(1.64 A mg_(Pt)^(-1)),approximately 4 times higher than that of commercial PtRu/C.When applied in membrane electrode assembly,this film anode in DMFCs further exhibits mass activity enhancement owing to the structural advantages such as weakened methanol cross-over.With a loading of 0.21 mg_(Pt)cm^(-2),the maximum power density at 80℃reaches 117 mW cm^(-2),and the power efficiency of Pt is about 12 times higher than that of commercial PtRu/C(2 mg_(Pt)cm^(-2),92 mW cm^(-2)).Therefore,the methodology outlined in this study demonstrates a novel and effective means of synthesizing high-performance anode catalysts for DMFCs. 展开更多
关键词 methanol fuelhoweverthe nanoporous thin film nptf using compressive structure portable devices direct methanol fuel cells dmfcs ptru alloy strained ptru alloy nanoparticles differential normal pulse voltammetry techniquethe
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