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Electrolytic manganese is an important metal material that is widely employed in batteries, electronics, steel, and other fields. However, there are many issues regarding the production process of electrolytic manganese, such as low current efficiency, high-content toxic SeO2 additives in the electrolyte, and difficulty in controlling the product morphology. These issues not only impact the production efficiency and quality of electrolytic manganese but also result in severe environmental pollution. To address these issues, a MnSO4-(NH4)2SO4 electrolyte system was prepared based on the electrolytic manganese industry standard. The effects of polyacrylic acid, glycine, ethylenediaminetetraacetic acid (EDTA), and gluconic acid were explored as auxiliary additives under neutral electrolysis conditions to lower the SeO2 content, which is a highly toxic main additive. The effects of the different additives on the metal manganese morphology, crystal structure, and cathodic electrochemical polarization behavior were examined by field-emission scanning electron microscopy, X-ray diffraction, and constant current cathodic polarization curve tests. The findings reveal that the main orientation of the metal manganese crystal form deposited by the four auxiliary additives is the (330) crystal plane, and all of them can promote the formation of α-Mn, enhance the electrolysis efficiency, and lower the energy consumption. In particular, the optimized amount of polyacrylic acid of 0.08 g·L−1 contributes to an energy consumption of 5735.34 kW·h·t−1. Correspondingly, the addition of 10 g·L−1 glycine is the most favorable amount, leading to an energy consumption of 5518.56 kW·h·t−1. For EDTA, the lowest energy consumption of 5168.26 kW·h·t−1 is measured at an added amount of 0.5 g·L−1. Note that among the four investigated candidates, gluconic acid is the most favorable auxiliary additive, contributing to the increased cathode current density and reduced cathodic polarization as well as denser metal manganese products. Moreover, gluconic acid addition can lower the concentration of toxic SeO2 from 0.03–0.06 to 0.015 g·L−1, significantly increase the cathode current density, reduce the cathodic polarization, and result in a more dense and smooth product morphology, with the current efficiency being increased from approximately 70% to 89.73% and energy consumption being reduced from 6500 to 4990.58 kW·h·t−1 at the same time. Gluconic acid, as the auxiliary additive, not only contributes to the best electrolysis indexes for electrolytic manganese but also facilitates the formation of metal manganese with the most desirable crystal structure. This work offers novel insights into the environmentally friendly production and cheap electrodeposition of metal manganese for the electrolytic manganese industry.

The direct and rapid determination of trace cobalt ion (Co2+) in the electrolyte of zinc smelting plants is urgently needed but is impeded by the severe interference of extremely high-concentration zinc ions in the solution. Herein, colorimetric detection of Co2+ by the polyvinylpyrrolidone functionalized silver nanoparticles (PVP-AgNPs) is realized in solutions with the Zn/Co ratio being high, up to (0.8–5) × 104, which is located within the ratio range in industrial solution. The high concentration of Zn2+ induces a strong attenuation of Co2+-related signals in ultraviolet-visible (UV-vis) extinction spectra; nevertheless, a good linear range for detecting 1–6 mg/L Co2+ in 50 g/L Zn2+ solution is still acquired. The strong anti-interference toward other metal ions and the mechanism understanding for trace Co2+ detection in such a high-concentration Zn2+ solution are also revealed by systematic analysis techniques. The results extend the AgNPs as colorimetric sensors to industrial solutions, providing a new strategy for detecting trace-metal ions in industrial plants.

The controllable preparation of silver nanowires (AgNWs) with a high aspect ratio is key for enabling their applications on a large scale. Herein, the aspect ratio regulation of AgNWs mediated by halogen ion composition in ethylene glycol system was systematically investigated and the size evolution mechanism is elaborately understood. The co-addition of Br− and Cl− results in AgNWs with the highest aspect ratio of 1031. The surface physicochemical analysis of AgNWs and the density functional theory calculations indicate that the co-addition of Br− and Cl− contributes to the much-enhanced preferential growth of the Ag(111) crystal plane. At the same time, when Cl− and Br− coexist in the solution, the growth of the Ag(100) crystal plane on the AgNWs was restrained compared with that in the single Cl− system. Resultantly, the enhanced growth of Ag(111) and the inhibited growth of Ag(100) contribute to the formation of AgNWs with a higher aspect ratio in the Cl–Br mixed solution. The results can provide new insights for understanding the morphology and size evolution during the AgNWs preparation in ethylene glycol system.

This paper established a comprehensive model of Delphi-AHP-DEA-FCE to evaluate competitiveness of sports tourism destinations. Research shows that, this model effectively constructed an indicator system for the competitiveness of sports tourism destination, and weights for all indicators were obtained by analysis. Second, the comprehensive model translated fuzzy evaluation into numerical values, which helps achieve a quantitative evaluation system. Lastly, overall evaluation and ranking were achieved by combining the quantitative evaluation and weights. The comprehensive model of Delphi-AHP-DEA-FCE has a great advance in the evaluation of sports tourism destination, and it is hoped that the model can be widely applied in multiple indicator evaluations. [ABSTRACT FROM AUTHOR]

The impact of sports economy on the national economy has shown a high-speed ascending trend since 2008, the status of sports economy in the national economy is studied in this article mainly research in this new type of national income distribution pattern. The model mainly takes five main factors such as the proportion of sports economy in the national economy; the analysis of the impact of sports economy on national economy; the national economy development driven by sports economy; the manifestation of sports economy in the national economy development and the strategic significance of developing sports industry in our country into account so as to clarify the important position of sports economy in the national economy development. [ABSTRACT FROM AUTHOR]