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This paper presents a distributed optimisation algorithm based on one-point bandit feedback (OPBF) which enables the solving of energy management problems (EMPs) over directed networks. Unlike existing EMPs with known cost functions, the proposed online energy management approach considers a time-varying and unknown cost function, which creates sampling difficulty. To tackle this challenge, a random gradient-free oracle is constructed, allowing for the facilitation of output generation updates. This construction significantly mitigates the need for explicit expressions of the cost function. Furthermore, the proposed algorithm successfully enforces both the supply-demand balance constraint and the generation constraint in EMPs. In order to evaluate performance, this study introduces a performance index referred to as regret, which exhibits sublinear convergence. This finding provides additional evidence that the algorithm can achieve optimal output generation at a rapid convergence rate, subject to certain step-size conditions. Finally, the performance of the algorithm is verified on both a modified 6-bus system and an IEEE 162-bus system. The results demonstrate the effectiveness and efficiency of the proposed algorithm in solving EMPs over directed networks. [ABSTRACT FROM AUTHOR]

Biofilms play an important role in degradation, transformation and assimilation of anthropogenic pollutants in aquatic ecosystems. In this study, we assembled a tubular bioreactor containing a biofilm substrate and aeration device, which was introduced into mesocosms to explore the effects of bioreactor on physicochemical and microbial characteristics of a hypereutrophic urban river. The biofilm bioreactor greatly improved water quality, especially by decreasing dissolved inorganic nitrogen (DIN) concentrations, suggesting that biofilms were the major sites of nitrification and denitrification with an oxygen concentration gradient. The biofilm bioreactor increased the abundance of planktonic bacteria, whereas diversity of the planktonic microbial community decreased. Sequencing revealed that Proteobacteria, Bacteroidetes, Planctomycetes, and Actinobacteria were the four predominant phyla in the planktonic microbial community, and the presence of the biofilm bioreactor increased the relative abundance of Proteobacteria. Variations in microbial communities were most strongly affected by the presence of the biofilm bioreactor, as indicated by principal component analysis (PCA) and redundancy analysis (RDA). This study provides valuable insights into changes in ecological characteristics associated with self-purification processes in hypereutrophic urban rivers, and may be of important for the application of biofilm bioreactor in natural urban river. [ABSTRACT FROM AUTHOR]