Highly efficient electrocatalysts fabricated via electrophoretic deposition for alcohol oxidation,oxygen reduction,hydrogen evolution,and oxygen evolution reactions

Electrophoretic deposition (EPD) is a versatile technique that has drawn attention due to its ease of use and performance in depositing high-quality layers at room temperature. This technique principle is based on the deposition of charged particles from a stable colloidal suspension on a conductive substrate using either a direct or alternating current. Using relatively simple and low-cost equipment, the EPD technique enables the deposition of layers with controlled microstructures at nanoscale. The EPD technique has been particularly successful in the fabrication of the electrocatalyst layers for low-temperature fuel cells, which are anchored on the top of the fuel cell electrodes. In comparison with other electrocatalyst layer deposition techniques such as drop-casting, the EPD technique offers clear advantages for the control of the thickness and packing density of the electrocatalyst layers. Owing to the dense packing density, electrocatalyst layers deposited by EPD could achieve enhanced conductivity and efficiency. The present review aims at comprehensively evaluating the recently published results on the electrocatalyst layers fabricated by EPD and applied in oxygen reduction reactions, alcohol electro-oxidation reactions, hydrogen evolution reactions, and oxygen evolution reactions.     

Numerical prediction of wind turbine noise

This paper develops and validates the first principle based numerical method for predicting the noise radiated from the rotating Horizontal-Axis Wind Turbine (HAWT) blades. The noise radiated to the far-field was predicted by the code based on Ffowcs Williams–Hawkings (FW–H) equation, using both original non-permeable formulation and permeable formulation. A commercially available CFD solver, ANSYS CFX 11.0, was used to calculate the flow parameters on and around the blade surface that are required for FW–H codes. A capability of the solver for modelling the flow field around the wind turbine blades was validated by comparing with the experimental results of NREL phase VI wind turbine blades. The FW–H codes were validated using acoustic results of UH-1H helicopter rotor in hover and Hartzell aircraft propeller in forward motion, which were measured in anechoic wind tunnel facility. Then the developed FW–H acoustic codes were applied to calculate the noise radiated from NREL Phase VI wind turbine blades.     

用特征曲线法确定油井水侵途径

对油井水淹动态进行分析,准确确定油井出水原因,是提高堵水工艺措施效果的关键。常规的油井出水原因分析方法,因本身的局限性,或是费用高而使其应用受到限制。所提出的含水特征曲线方法能够有效地分析机械采油井、自喷井及停产井的含水动态,并能够简捷地确定油井的出水原因。