Ultrafine Pt nanoparticles supported on double-shelled C/TiO2 hollow spheres material as highly efficient methanol oxidation catalysts

Catalyst support is extremely important for future fuel cell devices.In this work,we developed doubleshelled C/TiO2(DSCT)hollow spheres as an excellent catalyst support via a template-directed method.The combination of hollow structure,TiO2 shell and carbon layer results in excellent electron conductivity,electrocatalytic activity,and chemical stability.These uniformed DSCT hollow spheres are used as catalyst support to synthesize Pt/DSCT hollow spheres electrocatalyst.The resulting Pt/DSCT hollow spheres exhibited high catalytic performance with a current density of 462 mA mg^-1 for methanol oxidation reaction,which is 2.52 times higher than that of the commercial Pt/C.Furthermore,the increased tolerance to carbonaceous poisoning with a higher If/Ibratio and a better long-term stability in acid media suggests that the DSCT hollow sphere is a promising C/TiO2-based catalyst support for direct methanol fuel cells applications.

低熔点合金在C919飞机零件成形中的应用

根据70℃低熔点合金的导热性、表面张力、热熔及相变稳定性等特点,将它应用于C919飞机的门密封零件的成形,采用专用模具压弯成形方法进行加工。利用低熔点舍金加热熔化后填充型材毛料内部,常温下,待其冷却凝固后对零件进行加工成形,用低熔点塑性材料作为传力介质挤胀成形薄壁空心构件,研究了空心构件低熔点塑性介质挤胀成形机理、成形模具的结构、零件回弹和变形的修整。对低熔点合金材料的下一步研究进行了展望。

对开式扩散焊钛合金空心支板水浸超声C扫描检测方法研究

本文从理论和试验验证两方面对对开式窄筋条扩散焊钛合金空心支板的水浸超声C扫描检测方法进行了研究,详细描述了该类扩散焊焊缝超声对比试块的设计与制作方案、探头及水距的选择、检测灵敏度与闸门的确定,并通过对比分析验证了其超声检测对比试块及检测工艺的合理性、可靠性。该超声对比试块设计与制作方法为超声检测其它类似零件提供了新的思路,具有一定的参考价值与借鉴作用。