Ant colony optimization (ACO) algorithm is a meta-heuristic and reinforcement learning algorithm, which has been widely applied to solve various optimization problems. The key to improving the performance of ACO is to effectively resolve the exploration/exploitation dilemma. Epsilon greedy is an important and widely applied policy-based exploration method in reinforcement learning and has also been employed to improve ACO algorithms as the pseudo-stochastic mechanism. Levy flight is based on Levy distribution and helps to balance searching space and speed for global optimization. Taking advantage of both epsilon greedy and Levy flight, a greedy–Levy ACO incorporating these two approaches is proposed to solve complicated combinatorial optimization problems. Specifically, it is implemented on the top of max–min ACO to solve the traveling salesman problem (TSP) problems. According to the computational experiments using standard TSPLIB instances, greedy–Levy ACO outperforms max–min ACO and other latest TSP solvers, which demonstrates the effectiveness of the proposed methodology.

To reliably realize the functions of autonomous navigation and cruise of logistics robots in a complex logistics storage environment, this paper proposes a new robot navigation system based on vision and multiline lidar information fusion, which can not only ensure rich information and accurate map edges, but also meet the real-time and accurate positioning and navigation in complex logistics storage scenarios. Simulation and practical verification showed that the robot navigation system is feasible and robust, and overcomes the problems of low precision, poor robustness, weak portability, and difficult expansion of the mobile robot system in a complex environment. It provides a new idea for inspection in an actual logistics storage scenario and has a good prospective application.

Photocatalyst is a key factor to affect the photoreduction performance. However, the cost of preparing catalysts is relatively high and can be reduced by using waste-based materials. In this study, waste printed circuit boards (PCBs) were used as copper sources to prepare waste-based Cu₂O photocatalyst for photocatalytic reduction of Cr(VI) by chemical precipitation method. Under visible light, the influence factors of photocatalytic reduction activity, such as light intensity, pH, and catalyst dosage, were investigated. Then, the effects of photocatalytic reduction of Cr(VI) by pure Cu₂O, purified Cu₂O and waste-based Cu₂O photocatalysts were compared. The result indicated that the photocatalytic reduction of pure Cu₂O and purified Cu₂O were similar, higher than that of waste-based Cu₂O. X-ray diffraction (XRD) analysis indicates that no new phases were formed in the three catalysts, but their morphologies observed by scanning electron microscope energy-dispersive X-ray spectroscopy (SEM-EDS) was found that the pure Cu₂O and purified Cu₂O are cubic, whereas the waste-based Cu₂O is spherical and contains impurity Sn. It is considered that morphologies and impurity of the catalysts are the key factors for photocatalytic reduction efficiency. Finally, the electron transfer rate and the photocurrent response performance verified that the photocatalytic effect of pure Cu₂O and purified Cu₂O were better than that of waste-based Cu₂O. It is believed that the copper from waste PCBs can be used as high value-added copper material catalysts by an effective preparation process.

In China, there are about a thousand million tons of waste serpentine tailings (WSTs) that cause serious environmental problems. So it is urgent to treat WSTs. In this work, the MgO in WSTs was extracted to synthetize a high value-added Mg(II)Al(III) layered double hydroxide (LDH) by an alkali fusion process, and the purified SiO₂ can be obtained by the precipitation of Na₂SiO₃. The results indicated that the MgO extraction rate increased with the increase of Na₂CO₃ content and calcination temperature. The serpentine structure was destroyed and the MgO extraction rate increased rapidly to reach 91.4% when the temperature reached 750°C and the ratio of WSTs and Na₂CO₃ was 1:2. However, when the temperature was over 800°C, the serpentine completely transformed into forsterite with higher crystal strength, which was difficult to react with Na₂CO₃. The Mg-Al-LDH synthesis was carried out using a chemical precipitation method. It was not conducive to synthesis of Mg-Al-LDHs for using the rich magnesium solution that was obtained under low MgO extraction rate. The structure and surface morphology of the LDHs were characterized by an X-ray diffraction, FT-IR, and scanning electron microscopy (SEM). Finally, the Mg(II)Al(III)LDHs property of adsorbing Pb and P was investigated. The removal rate of Pb could reach about 99% and there was good adsorption capacity for P. This indicates that it is possible to synthetize high value-added Mg(II)Al(III) LDH by WSTs that could be recycled.

To achieve sustainable development, logistics enterprises need not only to reduce costs, but also to save energy for environmental protection and improve customer service level. The improvement of reverse logistics management level of waste tires is of great significance to improve the efficiency of the automobile industry. In this paper, multi-objective programming is adopted to establish the waste tire recycling network model. The decision variable is whether the network nodes are set or not, the traffic flow between nodes. Constraints include meeting customer demand, balance of flow in and out of logistics nodes, etc. The model is solved by ε- constraint. Taking the actual data of the enterprise as an example, the operation results show that the operation cost, carbon emission and customer transportation distance can get an consistence within a certain range. Waste tire logistics enterprises can realize the simultaneous improvement of profit, environmental protection and customer service level.

With the development of the global economic integration business model, many enterprises increase their own business income by enhancing their core competence. But currently in the process of selecting third-party logistics provider, many enterprises are still in the original state, either simply by the way of price competition, or depending on the conventional experience to choose provider. Based on this background, this research presents an evaluation mode for third-party logistics provider based on Analytic Hierarchy Process (AHP).