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This article addresses the process of charge transport under a high electric field and presents an overview of the research on simulation models represented by the bipolar charge transport (BCT) model in terms of (1) the research status of simulation models, (2) the construction of physical models, and (3) engineering applications. Focusing on the simulation of charge transport under high electric field, the limitations of the current research and the prospects for future research are further discussed.

The purpose of this study was to evaluate the potential of a host-associated Bacillus subtilis1-C-7 as a probiotic for Chinese perch (Siniperca chuatsi). Four test diets were formulated to contain graded levels of B. subtilis1-C-7 at 0 (CY), 0.85 × 108(Y1), 0.95 × 109(Y2) and 0.91 × 1010(Y3) CFU/kg diet. The test fish with initial weight 30.0 ± 1.2 g were fed the 4 test diets with 3 replicates in an indoor water-flow aquaculture system with 12 net cages (40 fish/cage) for 10 wk. At the conclusion of the feeding trial, the probiotic effects of B. subtilison Chinese perch were analyzed based on growth performance, serum biochemical indices, histologic morphology of liver and gut, gut microbiota and the resistance to Aeromonas hydrophila. The results showed that the percentage of weight gain had no significant change in the Y1 and Y2 groups (P > 0.05) but decreased in the Y3 group compared to that in the CY group (P < 0.05). The fish in the Y3 group displayed the highest activity of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) among these 4 groups (P < 0.05). The fish in the CY group had the highest value of malondialdehyde in the liver (P < 0.05) and showed severe nuclear migration and vacuolization of hepatocytes. The morphology indicated that all test fish had poor intestinal health. However, the fish in the Y1 group had a relatively normal intestinal histologic structure. The mid gut microbial diversity analysis showed that dietary B. subtilissupplementation increased the abundance of probiotics such as Tenericutes and Bacteroides, whereas it reduced the abundance of pernicious bacteria such as Proteobacteria, Actinobacteria, Thermophiliaand Spirochaetes. The challenge test showed that dietary B. subtilissupplementation increased the resistance to A. hydrophilain Chinese perch. In conclusion, dietary supplementation of 0.85 × 108 CFU/kg B. subtilis1-C-7 could improve the intestinal microbiota, intestinal health and disease resistance in Chinese perch, but more or excessive supplementation could reduce growth performance and have negative effects on health.

Based on the characteristics of charge distribution under ac electric field with a wide frequency range, this article focuses on the applicability of the traditional bipolar charge transport model under ac field in the oil-impregnated paper (OP) insulation by simulation. Three physical processes of charge injection, migration, and trapping/detrapping are discussed. In reaction to the influence of amplitude variation of the ac field on the injection rate, the charge injection process is described by a concatenation of the ohmic mechanism and the Schottky mechanism. On account of the correspondence between the frequency and carrier mobility, the single-mobility mode is modified to the multi-mobility mode, which exhibits the effect of localized state differences in materials on charge migration. The charge hysteresis under ac field is to do with the trapped charges, so the multi-energy trap distribution model is adopted to reveal the matching relationship between the period of the electric field and charge residence time in deep traps. By comparing the simulation results and experimental phenomena, the modified model achieves space charge accumulation under a wide frequency range, and the shape of charge distribution is similar to the experiments, which proves the validity of the model. Furthermore, the simulation results demonstrate that the net charge accumulation decreases with the increase in the electric field frequency, while the total charge accumulation shows an inverse trend with frequency, which is related to the coexistence of positive and negative charges.

Ammonia (NH3), which serves as a fertilizer supply, is struggling to satisfy the ever-growing population requirements over the world. The electrocatalytic nitrogen reduction to NH3production is highly desired but shows the extremely poor activity and selectivity of reported electrocatalysts. In this work, we rationally design a novel Rh atomic layer-decorated SnO2heterostructure catalyst through the interfacial engineering strategy, simultaneously achieving the highest NH3yield rate (149 μg h–1mgcat–1) and Faradaic efficiency (11.69%) at −0.35 V vs the reversible hydrogen electrode. This result is superior to the optimum response of previously reported SnO2- or Rh-based catalysts for electrochemical nitrogen reduction. Both X-ray absorption spectra characterization and density functional theory calculations reveal the strong electron interaction between the Rh atomic layer and the SnO2heterostructure, which effectively regulated the interfacial electron transfer and d-band center. The downshift of the d-band center results in the greatly reduced H adsorption energy and the highly accelerated reaction kinetics for nitrogen reduction. This work endows a new insight into the interfacial electron regulation for weakening H adsorption and further enhancing the electrocatalytic N2reduction.

As promising functional materials, ionic liquids have been widely used in flue gas purification and separation. Previous studies reported that ionic liquid based mixtures can be used for mercury removal due to their high economic efficiency and environmental friendliness. In comparison with ionic liquid based mixtures, a supported ionic liquid phase (SILP) adsorbent shows significantly improved mercury removal performance because of its greatly enhanced gas/liquid interfacial area. In this study, a novel supported task-specific ionic liquid phase adsorbent [C4mim][FeCl4]–SiO2was prepared for high efficiency elemental mercury capture from flue gas. The Hg0removal performance was investigated in a bench-scale fixed bed reactor, and the reaction mechanism was proposed based on the temperature programmed desorption (TPD) test. The results showed that Hg0removal was mainly due to the oxidation by [C4mim][FeCl4]. The addition of [C4mim][FeCl4] on SiO2in a certain composition range enhanced the Hg0removal performance, and the optimized ionic liquid loading is 30%. The Hg0removal by the adsorbent was favored at higher temperatures. TPD results showed that the mercury compound formed on the adsorbent was HgCl2. The Hg0removal mechanism involves combined physisorption and chemisorption, which consists of Hg0oxidation to HgCl2by the ionic liquid and physical adsorption of HgCl2on the porous adsorbent.