Shandong Normal University

About: Shandong Normal University is a education organization based out in Jinan, Shandong, China. It is known for research contribution in the topics: Laser & Catalysis. The organization has 12378 authors who have published 12576 publications receiving 174572 citations.

Set-Based Discrete Particle Swarm Optimization Based on Decomposition for Permutation-Based Multiobjective Combinatorial Optimization Problems

Abstract: This paper studies a specific class of multiobjective combinatorial optimization problems (MOCOPs), namely the permutation-based MOCOPs. Many commonly seen MOCOPs, e.g., multiobjective traveling salesman problem (MOTSP), multiobjective project scheduling problem (MOPSP), belong to this problem class and they can be very different. However, as the permutation-based MOCOPs share the inherent similarity that the structure of their search space is usually in the shape of a permutation tree, this paper proposes a generic multiobjective set-based particle swarm optimization methodology based on decomposition, termed MS-PSO/D. In order to coordinate with the property of permutation-based MOCOPs, MS-PSO/D utilizes an element-based representation and a constructive approach. Through this, feasible solutions under constraints can be generated step by step following the permutation-tree-shaped structure. And problem-related heuristic information is introduced in the constructive approach for efficiency. In order to address the multiobjective optimization issues, the decomposition strategy is employed, in which the problem is converted into multiple single-objective subproblems according to a set of weight vectors. Besides, a flexible mechanism for diversity control is provided in MS-PSO/D. Extensive experiments have been conducted to study MS-PSO/D on two permutation-based MOCOPs, namely the MOTSP and the MOPSP. Experimental results validate that the proposed methodology is promising.

Adsorption of sulfamethoxazole (SMZ) and ciprofloxacin (CIP) by humic acid (HA): characteristics and mechanism

Abstract: The adsorption behaviours and mechanisms of ciprofloxacin (CIP) and sulfamethoxazole (SMZ) as adsorptives on humic acid (HA) as adsorbents were studied. The adsorption isotherms of CIP and SMZ on HA fit the Freundlich equation better, and sorption equilibrium could be attained within 12 h. The maximum adsorption capacities of CIP and SMZ on HA were 13.64 mg g−1 and 7.54 mg g−1, both of which exhibited favourable adsorption. The kinetics results indicated that the adsorption of each antibiotic by HA followed pseudo-second-order kinetic models and that the adsorption process included the fast-adsorption stage first and the slow-adsorption stage thereafter. The adsorption efficiencies of HA to CIP were higher than those of SMZ. Compared to ionic strength, the effects of temperature and pH on adsorption were significant. The main adsorption mechanism of CIP and SMZ on HA could occur via hydrogen bonding. Competitive adsorption in coexistence systems of CIP and SMZ was observed on HA, and CIP was a stronger competitor to SMZ than SMZ was to CIP.