Xuzhou Institute of Technology

About: Xuzhou Institute of Technology is a education organization based out in Xuzhou, China. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 1696 authors who have published 1521 publications receiving 13541 citations.

Image contour detection based on improved level set in complex environment

Abstract: An improved image segmentation model was established to achieve accurate detection of target contours under high noise, low resolution, and uneven illumination environments. The new model is based on the variational level set algorithm, which improves the C–V (Chan and Vese) model and GAC (Geodesic Active Contour) model, fuses the contour and area models to segment the image information, that is, the edge information and region information of the image are fused into the same "energy" functional. According to the geometric characteristics of the curve, GAC model can effectively avoid re parameterization and light insensitivity in the evolution process, and CV model can effectively distinguish the fuzzy boundary of the image by maximizing the gray difference between the target and the background, it has strong anti-noise performance. By solving the steady-state solution of the partial differential equation, the optimal solution of the energy model is solved. New method can improve the calculation accuracy, topological structure adaptability, anti-noise ability, and reduce the light sensitivity effectively. Experiment shows that the new model has good robustness, high real-time performance, and it can effectively improve detection accuracy.

Effect of Polyoxymethylene Dimethyl Ethers/Diesel Blends on Fuel Properties and Particulate Matter Oxidation Activity of A Light-Duty Diesel Engine

Abstract: Polyoxymethylene dimethyl ethers (PODE) was blended in diesel at volume ratios of 0 %, 10 %, 20 %, and 30 % (denoted as P0, P10, P20, and P30). The experimental study was carried on an unmodified YD480Q diesel engine. An engine exhaust particle sizer was introduced to analyze the particulate matter (PM) concentration and particle size distribution of diesel engine emission. The evaporation-oxidation characteristics of the PODE/diesel blends and the effect of the fuel blends on the oxidative activity of PM were investigated by thermogravimetric analysis and Arrhenius theorem. The results showed that blending PODE in diesel improved the evaporation-oxidation characteristics of the fuel and decreased the apparent activation energy of the fuel blends. PODE played a positive role in reducing PM emissions. The particle total number concentration of P30 decreased 28.29 ~ 66.60 % and the particle total volume density decreased 54.16 ~ 80.06 % compared to diesel. The particle size distribution shifted to a smaller particle size as the PODE blending ratio was increased. The mass fraction of the volatile substances (VS) increased and the mass fraction of the dry soot (DS) decreased by employing PODE as a diesel additive. Also, the oxidation activity of VS increased as the PODE blending ratio was increased. The oxidation activity of DS climbed to the peak when the PODE blending ratio was 20 % and then decreased.

PtNiFe nanoalloys with co-existence of energy-optimized active surfaces for synergistic catalysis of oxygen reduction and evolution

Abstract: Platinum nanocatalysts mediated by 3d transition metals show improved activity for the oxygen reduction reaction (ORR) but poor activity for the oxygen evolution reaction (OER). Herein, we report the preparation of a Pt-partially coated PtNiFe nanoalloy electrocatalyst that shows excellent activity for the ORR and OER. For the ORR, the onset potential is +1.02 V, the half-wave potential is +0.95 V, and the mass activity is 0.91 A mgPt−1, 13 times that of commercial Pt/C. For the OER, the overpotential at 10 mA cm−2 is as low as 308 mV. All of this results in a very low ORR–OER overpotential gap of 588 mV, outperforming previously reported bifunctional catalysts in alkaline media. The remarkable bifunctional catalytic performance can be attributed to the co-existence of energy-optimized and synergistic ORR and OER active surfaces on nanoalloys caused by the Pt partially coated core–shell structure, as indicated by density functional theory calculations. This work will promote the development of platinum-based bifunctional electrocatalysts for practical applications in renewable energy storage and conversion.