An improved master-apprentice evolutionary algorithm for minimum independent dominating set problem

The minimum independent dominance set(MIDS)problem is an important version of the dominating set with some other applications.In this work,we present an improved master-apprentice evolutionary algorithm for solving the MIDS problem based on a path-breaking strategy called MAE-PB.The proposed MAE-PB algorithm combines a construction function for the initial solution generation and candidate solution restarting.It is a multiple neighborhood-based local search algorithm that improves the quality of the solution using a path-breaking strategy for solution recombination based on master and apprentice solutions and a perturbation strategy for disturbing the solution when the algorithm cannot improve the solution quality within a certain number of steps.We show the competitiveness of the MAE-PB algorithm by presenting the computational results on classical benchmarks from the literature and a suite of massive graphs from real-world applications.The results show that the MAE-PB algorithm achieves high performance.In particular,for the classical benchmarks,the MAE-PB algorithm obtains the best-known results for seven instances,whereas for several massive graphs,it improves the best-known results for 62 instances.We investigate the proposed key ingredients to determine their impact on the performance of the proposed algorithm.

高铝粉煤灰负载锰基催化剂的催化氧化NO性能研究

氮氧化物催化氧化是烟气脱硝技术的一个重要发展方向。本工作以具有球形镂空结构的预处理后高铝粉煤灰为载体,以硝酸锰为活性组分源,采用溶胶凝胶法制备锰基NO氧化催化剂,采用扫描电镜(SEM)、X射线衍射仪(XRD)、N_(2)物理吸附、H_(2)程序升温还原分析仪(H_(2)-TPR)和X射线光电子能谱(XPS)等分析测试手段对催化剂的NO催化氧化性能进行深入研究。结果表明,载体粒径、锰负载量、硝酸锰凝胶煅烧温度以及NO催化氧化温度对催化剂催化活性均有较大影响。当载体粒径在100~200目(150~75μm)、锰负载量为8wt%、硝酸锰凝胶煅烧温度为500℃、NO催化氧化温度290℃时,NO催化氧化效果最好,氧化率达到77.8%。SEM结果显示,溶胶凝胶法制备的氧化锰粒子在100~200 nm,且相对均匀负载在载体上。N_(2)-物理吸附表明,催化剂的孔结构主要为介孔,并呈现H3型回滞环。锰基催化剂上化学吸附氧O_(β)的占比和Mn^(4+)浓度随着锰负载量的增加先增大后减小,此趋势与NO催化性能变化趋势一致,表明O_(β)和Mn^(4+)是影响NO催化氧化效果的决定因素。