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The study investigates salt chemistry and corrosion behavior of SS 316H and Alloy 617 in thermally purified molten NaF‐KF‐UF4‐UF3 salts (UF4/UF3 initial ratio 12–14) at 800°C for 120, 72, and 32 h. UF4/UF3 ratio increases after corrosion tests. Cr species concentration in salts keeps increasing. Fe, Co, Ni, and Mo species increase first, then decrease. Cr/Mn oxides are formed along grain boundaries in SS 316H. Cr near the surface of Alloy 617 is completely depleted. A thin layer composed of Fe, Co, Ni, and Mo is observed on the Alloy 617 surface in 72‐h and 32‐h tests. [ABSTRACT FROM AUTHOR]

Improving industrial energy efficiency (IEE) is crucial for reducing CO2 emissions. Green finance (GF) provides an essential economic instrument for investment in IEE improvement. However, previous studies have not reached a consensus on whether GF can promote energy efficiency. In addition, more research is needed in the industrial sector. Therefore, this study focused on the industrial level to investigate GF's impact on IEE and its heterogeneity using a two-way fixed effects model. The moderating effect, threshold effect, and spatial lag models were used to test the various effects of GF on IEE. In addition, the spatial clustering characteristics of IEE were analyzed. The results indicate the following: GF can significantly promote IEE, positively improves IEE in the central and eastern areas, and has a negative impact in the western area; the marketization level (ML) is an important channel through which GF can further improve IEE; GF's impact on IEE exhibits a single threshold effect of the level of economic development (EDL) and green credit (GCL); GF promotes local IEE improvement but prevents neighboring IEE improvement; and IEE shows four types of clusters, but only in about one-third of the provinces. Based on these results, several recommendations are provided. [ABSTRACT FROM AUTHOR]

The existing roof support decision methods either analyze safety factors one-sidedly or assign weights to index objectively, fail to assign weight coefficients effectively, and cannot meet the demand of high-dimensional multi-objective roof case decision. In order to solve this problem, a decision model of roof support based on R2 index differential high-dimensional multi-objective evolution (R2-MOEA/D) algorithm is proposed by analyzing the roof weighting index. Firstly, the model defines the index attributes for the roof weighting state, establishes the roof index knowledge base, and calculates the conditional index in the knowledge base using analytic hierarchy process and entropy method, and obtains the subjective and objective weights of the index. Secondly, the model introduces the weight matrix on the basis of determining the subjective and objective weights to construct the roof multi-objective decision model which based on R2-MOEA/D algorithm. Finally, based on the R2-MOEA/D algorithm, the multi-objective problem is decomposed into multiple sub-problems, and the Chebyshev function is used as the R2 index ranking criterion for individual selection to obtain the Pareto optimal solution with better convergence and diversity, i.e., the conditional index roof case with the highest similarity. And its corresponding result attributes provide the support scheme for the decision of the accident case. The experimental results show that the R2-MOEA/D algorithm has the best overall effect in terms of the convergence and distribution of the data set compared with the NSGA2 algorithm, NSGA3 algorithm and RVEA algorithm, and improves the search capability in high-dimensional space. The feasibility evaluation of the decision model of roof support based on R2-MOEA/D algorithm is carried out through the roadway 2-6011 and roadway 10-4151 in Sanjiaohe Coal Mine, Huozhou, Shanxi. The results show that the solution retrieved by R2-MOEA/D algorithm is in line with the actual support situation of the coal mine.

The purification of salt is indispensable for mitigating the corrosion of structural materials for molten salt reactors or other molten salt applications. This study develops a salt-purification system to synthesize and purify NaF-KF-UF4 salt (FUNaK) using Ar purging and hydrofluorination of impurities. Chronoamperometry is also used to remove metallic impurities in the hydrofluorinated FUNaK. This purified FUNaK is then used for a static corrosion test of stainless steel 316H (SS316H) to study the effectiveness of salt purification in mitigating its corrosion. For comparison, results from a previous study about the corrosion of SS316H by thermally purified FUNaK are used. FUNaK with UF3 is also synthesized for a static corrosion test with the same condition to investigate the impact of UF3 on corrosion. The results show that the corrosion of SS316H is significantly reduced by using the chemically purified FUNaK compared to thermally purified FUNaK. [ABSTRACT FROM AUTHOR]