摘要：Regulating chemical bonds to balance the adsorption and disassociation of water molecules on catalyst surfaces is crucial for overall water splitting in alkaline *** we report a facile strategy for designing Ni2W4C-W3C Janus structures with abundant Ni-W metallic bonds on surfaces through interfacial *** Ni atoms into the W3C crystals in reaction progress generates a new Ni2 W4C phase,making the inert W atoms in W3C be active sites in Ni2W4C for overall water *** Ni2W4CW3C/carbon nanofibers(Ni2 W4-W3C/CNFs)require overpotentials of 63 mV to reach 10 mA cm^-2 for hydrogen evolution reaction(HER)and 270 mV to reach 30 mA cm^-2 for oxygen evolution reaction(OER)in alkaline electrolyte,*** utilized as both cathode and anode in alkaline solution for overall water splitting,cell voltages of 1.55 and 1.87 V are needed to reach 10 and 100 mA cm^-2,*** functional theory(DFT)results indicate that the strong interactions between Ni and W increase the local electronic states of W *** Ni2W4C provides active sites for cleaving H-OH bonds,and the W3C facilitates the combination of Hads intermediates into H2 *** in situ electrochemical-Raman results demonstrate that the strong absorption ability for hydroxyl and water molecules and further demonstrate that W atoms are the real active sites.

摘要：聚乙醇酸(PGA)作为煤基生物可降解高分子材料,有着优异的力学性能和阻隔性能,但较差的韧性使得它难以大规模应用。本文设计了一种生物可降解聚酯聚己二酸丁二醇酯(PBA),并用其实现了PGA的显著增韧。以1,6-己二酸(AA)和1,4-丁二醇(BDO)为原料,在高真空条件下通过熔融缩聚制备了PBA,核磁共振波谱、傅里叶变换红外光谱和凝胶渗透色谱证明了PBA的成功制备,PBA的重均分子量为62506,多分散性指数为2.1。通过熔融共混将PBA、PGA和环氧扩链剂共混以增韧PGA,扫描电子显微镜(SEM)表明,环氧扩链剂可显著提高PGA与PBA的相容性,增容过后PBA分散相的粒径尺寸明显减小。力学性能表明,当加入环氧扩链剂和50 phr的PBA增韧后,PGA的拉伸强度能可达(48.6±2.5)MPa,断裂伸长率达458.3%±23.9%,缺口冲击强度(126.3±7.7)kJ/m^(2),断裂伸长率和缺口冲击强度较PGA纯样分别提高了43倍和46倍。

摘要：结合高分子材料与工程专业《塑料成型模具设计》的课程特点出发,从完善教学内容、丰富教学手段、更新教学方法等面入手,进行了多方改革探索,多年来的实践证明学生在学习兴趣和学习效率上得到了明显提高,从而达到了较好的教学效果。