Hexagonal Single-Crystal CoS Nanosheets: Controllable Synthesis and Tunable Oxygen Evolution Performance.

Cobalt-based sulfides with variable valence states and unique physical and chemical properties have shown great potential as oxygen evolution reaction (OER) catalysts for electrochemical water-splitting reactions. However, poor morphological characteristics and a small specific surface area limit its further application. Here, hexagonal single-crystal two-dimensional (2D) CoS nanosheets with different thicknesses are successfully prepared by an atmospheric-pressure chemical vapor deposition method.

[Comparative Analysis of NO Emission Characteristics of Non-Ultra-Low- and Ultra-Low-Emission Coal-Fired Power Units During the Start-Up Process].

Based on the NO emission information of 671 coal-fired power units, the NO emission characteristics of non-ultra-low-emission (non-ULE) and ultra-low-emission (ULE) coal-fired power units during the start-up process were compared and analyzed. The results showed that in the start-up stage of non-ULE units, the exceeding standard rate (ESR) of NO emission concentration was 81.53%, the average exceeding standard hours (ESHs) was 2.