Oligomerized Fused-Ring Electron Acceptors for Efficient and Stable Organic Solar Cells

Organic solar cells (OSCs) have attracted wide research attention in the past decades. Very recently, oligomerized fused-ring electron acceptors (OFREAs) have emerged as a promising alternative to small-molecular/polymeric acceptor-based OSCs due to their unique advantages such as well-defined structures, batch reproducibility, good film formation, low diffusion coefficient, and excellent stability. So far, rapid advances have been made in the development of OFREAs consisting of directly/rigidly/flexibly linked oligomers and fused ones. In this Minireview, we systematically summarized the recent research progress of OFREAs, including structural diversity, synthesis approach, molecular conformation and packing, and long-term stability. Finally, we conclude with future perspectives on the challenges to be addressed and potential research directions. We believe that this Minireview will encourage the development of novel OFREAs for OSC applications.     

Multi-objective optimization of detergent pre-formulations using machine learning techniques

The right combination of surfactants and stabilizers in the detergent formulations plays a significant role in their cleaning performance. However, it becomes a complex optimization problem when the formulation is composed of multiple ingredients and the solution has to be optimized for competing performance metrics. In recent times, machine learning techniques have been used extensively to study such processes. In this research, a detergent pre-formulation has been designed using an aqueous solution of Tween-20, Ethanol and 1-Octanol. To determine the optimal values of the ingredients of the formulations, supervised machine learning models were developed and optimized for the Ross Miles Index 30 ml (RMI 30) and cleaning time (CT). A full factorial experimental design was performed and three regression models based on linear, 2FI and Quadratic designs were developed respectively for RMI30 and CT. ANOVA analysis of trained models reported an optimal p-value of 0.0018 for RMI 30 and less than 0.0001 for CT. The optimal values for RMI30 and CT obtained through regression models are 72.32 ml and 17.67 s. For multi-objective optimization, grey relational analysis was performed. Two pairs of optimal values corresponding to Rank 1 were recorded as 88.9 ml, 20 s (RMI30, CT); and 81.2 ml, 14 s (RMI30, CT) respectively. As a result, the optimal combination of Tween-20, Ethanol and 1-Octanol for maximizing the RMI30 and minimizing the CT are reported. The obtained optimal values were experimentally validated.     

Pathway and mechanism study on improvement of N2 selectivity of catalytic denitrification

Recently, nitrate pollution has attracted more public attention. In order to truly remove nitrate and reduce total nitrate content (TN) in water body, more harmless N₂ should be converted from nitrate. Studies on catalytic removal of nitrate in wastewater have been carried out. However, the catalytic performance still needs to be significantly improved, especially the N₂ selectivity. According to these, strategies that enable to efficiently improve N₂ selectivity of catalytic denitrification were explored in this paper. Results implied that the catalyst with composite carrier that possesses porous structure, large surface area, excellent electronic properties, and stable physical–chemical property tends to have better catalytic performance. It is suggested that acid washing by 2 mol/L HCl for certain carriers be applied to enhancement of N₂ selectivity. Additionally, higher N₂ conversion was also achieved by addition of sodium bis-2-ethylhexyl sulphosuccinate (AOT) onto Pd with the formation of Pd_AOT-Cu catalyst, which may be ascribed to the AOT that partially shields Pd active sites and inhibits hydrogen spillover from Pd to Cu. Response Surface Methodology (RSM) was utilized for experimental design and prediction of the optimal parameters. More N₂ was obtained under the predicted optimal conditions: 5.0 pH, 135 min time, 3.1 Pd: Cu, and 3.1 g/L Fe⁽⁰⁾.     

The Coefficient Inequalities for a Class of Holomorphic Mappings in Several Complex Variable

The authors establish the coefficient inequalities for a class of holomorphic mappings on the unit ball in a complex Banach space or on the unit polydisk in ■ⁿ,which are natural extensions to higher dimensions of some Fekete and Szeg? inequalities for subclasses of the normalized univalent functions in the unit disk.