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Thus, microbial methylation or demethylation seems negligible in terms of MeHg transformation.Montmorillonite supported nanoscale zero-valent iron (MMT-nZVI) was prepared and proved to be able to induce the heterogenous Fenton process for better removal of 2,3',4,5-tetrachlorobiphenyl (PCB67) in a long-term polluted soil. PCB67 removal depended highly on the dosages of MMT-nZVI and H2O2, and the initial pH, with the highest removal rate of 76.38% at conditions of H2O2 45.99 g·kg-1, MMT-nZVI 29.88 g·kg-1 and initial pH 3.5 after 80 min of reaction. Furthermore, PCB67 could be removed in a wider pH range (from 3.5 to near neutrality), with a loss of 13.6% in removal rate at neutral pH. With an activation energy of 21.4 kJ·mol-1, the degradation of PCB67 was an endothermic and diffusion-controlled process and followed the pseudo-first-order kinetics. Oxidopamine That Fe2+ was supplied through aerobic corrosion of MMT-nZVI to activate H2O2 for·OH production was the possible mechanism of PCB67 degradation, leading to complete mineralization of PCB67 through two proposed pathways, with the intermediates of ethylbenzene and 3-hepten-2-one, as well as dibutyl phthalate and butyl acetate respectively.Ethyl carbamate is a group of 2A carcinogen ubiquitously existed in fermented foods. The monitoring of its residues was important for evaluating the potential risk to human beings. Immunoassays with good accuracy and simplicity are great analytical tools for small molecule contaminants. However, it is typically confined in a competitive mode for small molecules with drawback of the sensitivity curbing. In this work, three different phages displayed peptides with capability of identifying the xanthyl ethyl carbamate immunocomplex were isolated from phage library. The binding mechanism of peptides and immunocomplex was studied by computer-assisted simulation. Results indicated that the xanthydrol group of xanthyl ethyl carbamate and the Asn-32 and Asn-92 residues of the antibody light chain were mainly responsible for binding. Simultaneously, a sensitive non-competitive immunoassay for detecting ethyl carbamate in wine samples was developed. The established method exhibited a limit of detection of 5.4 ng/mL and a linear range from 8.7 ng/mL to 32 ng/mL for wine samples. In comparison with the conventional competitive immunoassay, the sensitivity of the proposed non-competitive immunoassay was improved by 17-fold. The results of the immunoassay were validated by a standard ultra-performance liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometry, which illustrated good reliability of the proposed assay.In this paper, deterministic and stochastic models are proposed to study the transmission dynamics of the Coronavirus Disease 2019 (COVID-19) in Wuhan, China. The deterministic model is formulated by a system of ordinary differential equations (ODEs) that is built upon the classical SEIR framework. The stochastic model is formulated by a continuous-time Markov chain (CTMC) that is derived based on the ODE model with constant parameters. The nonlinear CTMC model is approximated by a multitype branching process to obtain an analytical estimate for the probability of a disease outbreak. The local and global dynamics of the disease are analyzed by using the deterministic model with constant parameters, and the result indicates that the basic reproduction number $ \mathcalR_0 $ serves as a sharp disease threshold the disease dies out if $ \mathcalR_0\le 1 $ and persists if $ \mathcalR_0 > 1 $. In contrast to the deterministic dynamics, the stochastic dynamics indicate that the disease may not persist when $ \mathcalR_0 > 1 $. Parameter estimation and validation are performed to fit our ODE model to the public reported data. Our result indicates that both the exposed and infected classes play an important role in shaping the epidemic dynamics of COVID-19 in Wuhan, China. In addition, numerical simulations indicate that a second wave of the ongoing pandemic is likely to occur if the prevention and control strategies are not implemented properly.In order to analyze the influence of the personnel flexibility on the flexibility of the production system and optimize the organization and configuration of the production system, this paper puts forward a flexible simulation study of production system personnel based on mixed modeling. Firstly, the flexible evaluation index of production system is constructed from four dimensions machine utilization ratio, personnel utilization ratio, production and personnel production efficiency. The concrete calculation method is given accordingly. Secondly, the simulation model of discrete event-multibody mixed modeling in production system is established, and the construction principle of the model is given. Thirdly, based on the flexible evaluation index and mixed modeling method, the flexible personnel skills of a motorcycle engine key parts production system are simulated and analyzed, and the comparative analysis of multiple schemes is realized. The simulation results show that multi-energy and personnel cooperation have an important influence on the flexibility of production system. In the medium and large fluctuation production environment, compared with the professional production team, the flexibility of the four dimensions of machine utilization, personnel utilization, production and personnel production efficiency of the multi-energy production team has been significantly improved. The case study also shows that the hybrid modeling simulation model can realize the dynamic configuration and operation evaluation of the flexible personnel elements, and provide a dynamic and quantitative research method for the organizational optimization of the production system.An alcohol consumption model with health education and three time delays is formulated and analyzed. The alcoholism generation number is defined. Two steady states of the model are found. At the same time, the corresponding global dynamics of the model are analyzed respectively in four cases with different time delays. Then, the effects of health education and three time delays in controlling the alcohol problem are discussed. Some numerical simulation results are also given to support our theoretical predictions.