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 & Adsorption. The organization has 1696 authors who have published 1521 publications receiving 13541 citations.

Enhanced breakdown strength and energy storage density in polyurea all-organic composite films

Abstract: Polymer dielectric materials are highly desirable in electronic devices. However, neither low nor high dielectric constant polymers could meet the requirement of high energy storage application due to the contradiction between dielectric constant and breakdown strength. Herein, in order to obtain high performance polymer dielectrics, poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) is filled, as a functional material, into polyurea (PUA) matrix to form all-organic composites. Fortunately, PUA/P(VDF-TrFE-CFE) composites exhibit excellent performance with high dielectric constant and maintain high breakdown strength, resulting in enhanced energy storage density. The breakdown strength of composite film increases to 5130 kV cm−1, and the energy storage density can reach 4.3 J cm−3, which is much higher than pure PUA (2.4 J cm−3) and commercially biaxially oriented polypropylene (BOPP, 1.2 J cm−3). The enhancement of energy density of composite films is mainly attributed to the dipole interaction between PUA and P(VDF-TrFE-CFE) chains, which leads to increases of dielectric constant and maintain high breakdown strength simultaneously. This work provides an effective route to improve the energy density of linear dielectrics and showing great application potential for energy storage.

N-fold Darboux Transformation for Integrable Couplings of AKNS Equations*

Abstract: For the integrable couplings of Ablowitz-Kaup-Newell-Segur (ICAKNS) equations, N-fold Darboux transformation (DT) TN, which is a 4 × 4 matrix, is constructed in this paper. Each element of this matrix is expressed by a ratio of the (4N + 1)-order determinant and 4N-order determinant of eigenfunctions. By making use of these formulae, the determinant expressions of N-transformed new solutions p [N], q [N], r [N] and s [N] are generated by this N-fold DT. Furthermore, when the reduced conditions q = −p* and s = −r* are chosen, we obtain determinant representations of N-fold DT and N-transformed solutions for the integrable couplings of nonlinear Schrodinger (ICNLS) equations. Starting from the zero seed solutions, one-soliton solutions are explicitly given as an example.

Fuzzy Control of Cold Storage Refrigeration System with Dynamic Coupling Compensation

Abstract: Cold storage refrigeration systems possess the characteristics of multiple input and output and strong coupling, which brings challenges to the optimize control. To reduce the adverse effects of the coupling and improve the overall control performance of cold storage refrigeration systems, a control strategy with dynamic coupling compensation was studied. First, dynamic model of a cold storage refrigeration system was established based on the requirements of the control system. At the same time, the coupling between the components was studied. Second, to reduce the adverse effects of the coupling, a fuzzy controller with dynamic coupling compensation was designed. As for the fuzzy controller, a self-tuning fuzzy controller was served as the primary controller, and an adaptive neural network was adopted to compensate the dynamic coupling. Finally, the proposed control strategy was employed to the cold storage refrigeration system, and simulations were carried out in the condition of start-up, variable load, and variable degree of superheat, respectively. The simulation results verify the effectiveness of the fuzzy control method with dynamic coupling compensation.

Microstructure and Tribological Properties of Laser-Remelted Ni-Based WC Coatings Obtained by Plasma Spraying

Abstract: Ni-based WC coatings were successfully fabricated on Ti6Al4V titanium alloy substrate by the air plasma spraying (APS) process. The as-sprayed coatings were remelted with a continuous wave CO2 laser. The coatings were characterized using a scanning electron microscope (SEM), an energy dispersive spectrometer (EDS), an X-ray diffractometer (XRD), a Vickers microhardness tester, a ball-on-disc friction and wear tester, and a 3D measuring laser microscope. The results indicated that the laser-remelted coatings possessed a more homogeneous microstructure and lower porosity, were more dense, and bonded well with the substrate. The lamellar structure and microcracks of the as-sprayed coatings were eliminated after laser remelting. The average porosity markedly decreased to 1.3% from 9.7% of the as-sprayed coating. Many needle dendrites grew outward from the dissolution surface of the WC, while massive precipitates abundantly appeared around and away from the WC particles. The microhardness of the laser-remelted coating was enhanced to 884.7–1363.3 HV0.3, which was much higher than that of the as-sprayed coatings and nearly three times higher than that of the substrate. Under the same load, the wear volume of the substrate was nearly 13 times higher than that of the laser-remelted coating and five times higher than that of the as-sprayed coating. The wear mechanism of the laser-remelted coating and the as-sprayed coating was mainly abrasive wear; however, the wear mechanisms of the substrate were a combination of adhesive wear, micro-cutting, and delamination wear.

Effect on composition and quantity of extracellular polymeric substances in an innovative hybrid membrane bioreactor under different sludge retention times

Abstract: This study investigated the influence of sludge retention time (SRT) in three hybrid membrane bioreactors to treat domestic wastewater at different SRTs (10, 20, and 40 d) simultaneously, b...