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Herein, powder metallurgy gas-solid nitriding was used to prepare a high-nitrogen Ni-free austenitic stainless steel with more than 1.0 wt.% N. Study of the microstructures and corrosion resistances of the as-prepared samples revealed that the corrosion weight loss, size, number of corrosion pits, and corrosion depth decreased as the N content increased from 1.19 to 1.37 wt.%. The self-corrosion current densities of the alloys were determined from their potentiodynamic polarization curves. The changes in the capacitive arc radius as demonstrated by the Nyquist curves were consistent with the conclusions of the immersion corrosion analysis; that is, a high N content leads to a high corrosion resistance.

Amorphous CoB alloy catalysts were prepared using chemical reduction method by changing the concentration of cobalt acetate from 0.5 to 1.0 mol/L and examined for the liquid phase hydrogenation of ethyl lactate. The catalyst, prepared with cobalt acetate concentration being 0.75 mol/L, gave a 99.8% selectivity to propane-1,2-diol at a conversion of 98.3%. The catalysts were characterized by XRD, TEM, BET, H 2 -TPD and XPS. For all the catalysts, Co was electron-rich whereas B electron-deficient, and B was rich on the surface. The change in the concentration of cobalt acetate results in different surface composition of B/Co, various types of Co active sites, and different distribution of particles, which have large influence on activity and selectivity of the catalyst.

Dynamic signal control is considered an effective measure to deal with urban traffic congestion by increasing intersection capacity and decreasing delays at the same time. A hierarchical fuzzy logic controller for urban signalized intersections is developed in this paper. The controller is designed to be responsive to real-time traffic intensities. Vehicle detectors are placed upstream of the intersection on each approach to measure approach flows and estimate queues. The data is used to decide how much to extend the current green phase. These decisions are made by using a hierarchical fuzzy logic procedure. In the first stage, detected approach traffic flows and the vehicles in the queue are used to estimate relative traffic intensities in the competing approaches. These traffic intensities are then used in the second stage to determine the extension of the current green phase. The performance of this controller is validated in a four-phase signalized intersection by a simulation experiment. The result shows that this control method outperforms the conventional single-stage fuzzy logic controller, especially in the case of heavy traffic flows.