Subsurface crack propagation under rolling contact fatigue in bearing ring

The influences of subsurface cracks,distributing along the axial direction,on the rolling contact fatigue(RCF)faliure in a bearing ring are investigated.A realistic three-dimensional model of the bearing ring containing three subsurface cracks is used to evaluate the fatigue crack propagation based on stress intensity factor(SIF)calculations.Moreover,the distributions of the subsurface cracks along the axial direction are varied to study their effects on RCF.The results provide valuable guidelines for enhanced understanding of RCF in bearings.     

纳米Au／Fe2O3-MOx催化剂的制备及低温催化氧化CO的研究

用沉积-沉淀法制备了纳米Au/Fe2O3-MOx(M=La和Ce)系列催化剂,考察了催化剂对于CO的低温催化氧化性能,并通过XRD,BET和AAS等表征手段对催化剂进行了表征,分析了稀土氧化物的掺杂对Au/FezO3催化剂性能的影响.结果表明:CeO2的加入能够有效提高Au/Fe2O3催化剂的催化活性,而La2O3的加入对催化剂性能没有明显的影响.     

Bilayer carbon-based structure with the promotion of homogenous nucleation for lithium metal anodes

Lithium metal anodes (LMAs) are considered as the promising alternatives for next-generation high energy density batteries, but are still hampered by the severe growth of uncontrollable lithium dendrites. The growth of lithium dendrites induces poor cycling lifespan and serious safety concerns, dragging lithium metal batteries out of practical applications. We designed a bilayer carbon-based structure covered with Co/C nanosheets and vertical graphene sheets (VGS). The enormous specific surface area and uniformly distributed Co nanoparticles of the CC@Co/C-VGS host are derived from its unique design, which can reduce local current density and nucleation overpotential, resulting in a dendrite-free morphology and exceptional cycling stability. Symmetric cells exhibit over 400 cycles (800 h) at a high current density/capacity of 10 mA cm^?2/10 mA h cm^?2. Full cells using LiFePO₄ as the cathode have an enhanced rate capability and a prolonged lifespan, reaching 90 mA h g^?1 after 1000 cycles at 2 C with 73.5% capacity retention. This unique design sheds light on developing high-performance LMAs.