Efficient photocatalytic removal of aqueous Cr(VI) by N-F-Al tri-doped TiO2

Shu Qin Wang,Yixiao Xie,Wei Liang Cheng,Jian Gao 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.9

As chromium is a common heavy metal contaminant in water, we have prepared N-F-Al tri-doped TiO2 catalyst for Cr(VI) removal under visible light. The sample was prepared via a sol-gel method and was characterized by XRD, BET, UV-vis DRS, XPS and SEM techniques. In the photocatalytic experiments, effects of Al/Ti ratio, F/Ti ratio, calcination temperature and different dopants were investigated. The optimum Al/Ti molar ratio, F/Ti ratio and calcination temperature proved to be 0.01, 0.1 and 500 oC, respectively, which is in accordance with the characterization analysis. Catalysts prepared under this condition showed a high photoactivity for Cr(VI) removal in water.

Layout Optimization of Stiffeners in Heavy-Duty Thin-Plate Box Grider

Hao Zhang,Yixiao Qin,Jinpeng Gu,Haibiao Gao,Qianqian Jiao,Feng Wang,Zhenshan Guo,Yangyang Zhang,Chenghong Mi 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.8

The optimization of layout and sizes of the stiffeners in heavy-duty box girder could make this kind of the structure more compact and reasonable, which has certain engineering values. In this study, on the basis of the establishment of parametric finite element model, the function approaching method and gradient search method are combined to form a high-precision optimization algorithm, which makes structural analysis be integrated into the optimization process. The optimization takes the type and location of longitudinal stiffening ribs and the thickness and hole position of transverse diaphragms as design variables, the box girder structural behaviors as constraint conditions, and the total volume as objective function. Finally, the weight is reduced by nearly 7%. More importantly, the new asymmetrical layout of the stiffeners is obtained, the distance between the longitudinal stiffening ribs on the main web and the neutral layer is longer than the distance between the longitudinal stiffening ribs on the secondary web and the neutral layer, and the hole position of transverse diaphragms is close to the secondary web. Compared with the current production of symmetrical layout structure, this layout provides a new idea for the design of stiffeners in the bias-rail box girder.

Layout optimization of box girder with RBF-NNM-APSO algorithm

Junle Yang,Yixiao Qin,Qianqian Jiao 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.11

The layout optimization problem of complex box girder structure is solved with a new method RBF-NNM-APSO formed with the digital neural network model (NNM) of radial basis function (RBF) and adaptive particle swarm optimization (APSO) algorithm in this paper. The optimized surrogate model is proposed and applied to the configuration optimization of heavy-duty box girder of casting crane for improving the mechanical properties of the optimized object and expediting proceedings. First, the parametric command flow finite element numerical model of box girder is established. The RBF neural network is trained by constructing a mixed orthogonal experimental table of parameters, and the relationship between the design variables and the maximum stress and deformation is established. Subsequently, the trained RBF neural network design scheme is optimized by APSO algorithm. Finally, on the premise of not increasing the total mass, a new layout form of box girder is obtained.

Structural optimization of unsymmetrical eccentric load steel box girder based on new swarm intelligence optimization algorithm

Shen Su,Yixiao Qin,Kaiyao Yang 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.5

The steel box girder structure is widely used in many engineering practices and it is therefore necessary to study the optimization and improvement of its structure. Firstly, a small-tonnage double-girder bridge crane was used as an example, with the box section parameters for one of the main girders as the design variables and weight reduction as the objective. The mathematical model for the optimization of this validation case was developed with the strength, stiff ness and stability of the girder as the effi ciency constraints. The next step was to go through two new swarm intelligence algorithms based on animal hunting behavior, Grey Wolf Optimizer (GWO) and Whale Optimization Algorithm (WOA), as well as two classical swarm algorithms, Particle Swarm Optimization (PSO) and Genetic Algorithm (GA). The optimization models of these four algorithms were simulated and analyzed by the fi nite element method, and the simulation results were compared. The feasibility and performance of these two new swarm intelligence algorithms in the structural optimization of asymmetric eccentrically loaded box girders were verifi ed. Finally, these two new swarm intelligence algorithms were applied to the structural optimization of the main girder of a large-tonnage bridge crane.

Topology optimization of unsymmetrical complex plate and shell structures bearing multicondition overload

Yangyang Zhang,Yixiao Qin,Jinpeng Gu,Qianqian Jiao,Feng Wang,Zhenshan Guo,Hao Zhang,Jianjun Wang,Chenghong Mi,Huaipeng Zheng 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.8

Unsymmetrical complex plate and shell structure is one of the common engineering structures. In practice, more redundant materials exist because of the irrationality of this kind of structure with heavy load and multiple working conditions, and the study of its topology optimization has become an engaging topic. Using the SIMP model, topological results show that one side of the main web is a hollow structure, and the other side of the auxiliary web is a truss structure. According to the topological results and considering manufacturable processing, a new structure is redesigned, the size and shape of the redesigned structure is secondary optimized, and the final structure is obtained. The method in this paper not only meets the performance requirements of the unsymmetrical complex plate and shell structures, but also realizes the topology and lightweight. The effectiveness scientific research value of the proposed method is verified by engineering examples.

Improved Quantum-Behaved Particle Swarm Method for Optimizing Complex Thin Plate Structure

Weitao Cheng,Yixiao Qin,Jinpeng Gu,Haibiao Gao,Yue Yan,Junle Yang,Yang Chen,Shen Su,Kaiyao Yang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.4

A large number of heavy-duty asymmetric thin-plate box girder structures exist in large equipment, and their optimization can reduce the amount of material used and increase their load-carrying capacity. A new optimization method based on the Improved Quantum-Behaved Particle Swarm Optimization method (IQBPSO) is proposed in order to efficiently solve the mathematical model for the rationalization and optimization design of structures. The penalty function and Lévy flight strategy are considered in the optimization design of the improved algorithm, thus transforming the constrained optimization problem into an unconstrained optimization problem and improving the diversity and local optimization search capability of the quantum particle swarm. A mathematical model for the optimal design of box girder section size is established with the reduction of beam cross-sectional area as the objective function and the thin plate strength, rigidity, and stability of the thin slab as the constraints. The rapid lightweight design of the thin plate box beam was achieved, resulting in a 9.6% reduction in the manufacturing cost of the thin plate box beam. The optimization results are compared with several solutions of the thin slab box beams to verify the reliability and validity of the proposed optimization method.

Photocatalytic removal of chromium(VI) and sulfite using transition metal (Cu, Fe, Zn) doped TiO2 driven by visible light: Feasibility, mechanism and kinetics

Jinghong Zhang,Dong Fu,Shu Qin Wang,Runlong Hao,Yixiao Xie 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-

To cooperatively oxidize sulfite and reduce Cr(VI), this paper proposed a visible-light drivenphotocatalytic method, with using the photocatalysts of transition metals (Cu, Fe and Zn) dopedTiO2. The photocatalysts were characterized by means of XRD, BET, SEM and UV–vis. 0.5Cu-TiO2 exhibitedthe best performance, and the existing forms of Ti and Cu were Ti4+/Cu+ and/or Cu-O-Ti. Cu-dopingintroduced an energy level of Cu 3d which was useful in decreasing the band gap and increasing thevisible light utilization. Cu-doping also made the TiO2 grains well dispersed, increased the amount ofhydroxyl group, decreased the grain size and increased the specific surface area, which facilitated theadsorption process. Hydrothermal method (8 h and 180 C) favored the formation of anatase crystal. FT-IRresults revealed that most of produced Cr(III) and sulfate were adsorbed onto the catalyst. Kinetics resultssuggested that the rate constant for Cr(VI) removal was 5.05 10 3 min 1. The photo-produced electrons(e ) and holes (h+) contributed to the reduction of Cr(VI) and oxidation of sulfite, respectively; thecontinual consumption of e and h+ enhanced the separation of the h+-e pairs.