摘要：Proton exchange membrane(PEM)fuel cell has been regarded as a promising approach to the decarbonization and diversification of energy *** recent years,durability and cost issues of PEM fuel cells are increasingly significant with the rapid increase of power ***,the failure to maintain the cell consistency,as one major cause of the above issue,has attracted little ***,this study intends to figure out the underlying cause of cell inconsistency and provide solutions to it from the perspective of multi-physics transport coupled with electrochemical *** PEM fuel cells with electrodes under two compression modes are firstly discussed to fully explain the relationship of cell performance and consistency to electrode structure and multi-physics *** result indicates that one main cause of cell inconsistency is the intrinsic conflict between the separated transport and cooperated consumption of oxygen and electron throughout the active ***,a mixed-pathway electrode design is proposed to reduce the cell inconsistency by enhancing the mixed transport of oxygen and electron in the *** is found that the mixing of pathways in electrodes at under-rib region is more effective than that at the under-channel region,and can achieve an up to 40%reduction of the cell inconsistency with little(3.3%)sacrificed *** addition,all the investigations are implemented based on a self-developed digitalization platform that reconstructs the complex physical–chemical system of PEM fuel *** fully observable physical information of the digitalized cells provides strong support to the related analysis.

摘要：我们之前的工作表明,声学超材料中的非局部相互作用会导致极不寻常的类roton色散关系,即色散曲线存在局部极小值,与超流体液氦-4类似.然而,这种行为仅限于一个或两个声传播方向.在这里,我们设计了一种三维立方对称声学超材料,沿三个正交方向具有非局部相互作用.有限元计算表明超材料在三个正交方向具有类roton行为,但其行为远非各向同性.有限元结果与半解析模型结果吻合良好.相应的实验正在探索中,由于需要密集而复杂的三维声学管道,实验要求较高.

摘要：燃料电池及其应用近些年逐渐成为研究热点,对于系统级的燃料电池运行工况分析及设计,底层的燃料电池本体模型显得至关重要。相比于已有的传统经验模型,重点提出了一种一般性的多物理域燃料电池分析模型,并从电化学域、流体力学域以及热力学动态域对质子交换膜燃料电池进行了精确建模。所提出的框架性建模方法可以适用于不同型号的质子交换膜燃料电池,同时也可以进一步拓展并应用于不同种类的燃料电池。随后以Ballard NEXA 1.2 kW质子交换膜燃料电池为例,对模型在不同工况下进行了仿真,并通过实验测试验证了所提出模型的有效性和准确性。在此基础上,可以展开相应的控制策略及电池本体运行分析,从而提升燃料电池系统的运行性能和工作寿命。