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With the development and depletion of shallow coal resources, deep coal mining has gradually become normalized. In the face of increasingly severe corrosion environment of coal mining, it is urgent to develop new materials with excellent corrosion resistance for key parts of coal mining equipment. In this paper, SiC, Al2O3 and SiO2 were used as raw materials to prepare three-dimensional network configuration SiC ceramics by organic foam impregnation method. Then the three-dimensional network configuration SiC-Fe composite was prepared by atmospheric pressure casting process. And by electrochemical test, static immersion corrosion test, scanning electron microscope and first-principles simulation calculation, the corrosion resistance of three-dimensional network configuration SiC-Fe composite in harsh mine water environment was characterized, meanwhile the corrosion resistance mechanism was analyzed. The results show that the corrosion potential increases from - 495.756 mV to -379.626 mV, and the corrosion current density decreases from 3.6864 μA/cm2 to 2.1709 μA/cm2 when the SiC ceramic reinforcement is added. The inhibition efficiency based on polarization curve measurement is increased by 41.11%. The charge transfer resistance increases from 5417 Ω·cm2 to 6437 Ω·cm2, and the capacitance value drops from 159.96 μF·cm−2 to 90.12 μF·cm−2. The inhibition efficiency based on electrochemical impedance spectroscopy is increased by 18.83%. First principles calculations show that the addition of SiC reinforcement showed a greater resistance in preventing the migration of corrosive media to the surface of the Fe substrate and can effectively slow down corrosion, which was consistent with the experimental results. [ABSTRACT FROM AUTHOR]

This work focuses on different surface treatment processes of the 6061 aluminum alloy profile coatings in the construction industry, mainly including the sand powder film coating, the flat powder coating, the hard anodized film, and the ordinary heat-sealing oxidized coating. The corrosion resistance of the coated aluminum alloy in a 3.5 wt.% NaCl solution (pH 6.5–7.5) and the influence of different surface treatment processes on the corrosion resistance of different samples were studied by scanning electron microscope (SEM) and electrochemical workstation. The result shows that with the increase in corrosion time, the corrosion inhibition performance of the four coated aluminum alloy materials decreased significantly, and the order of decline is: sand powder film coating > hard anodized film > flat powder coating > ordinary heat-sealing oxidized coating. When corroded in a 3.5 wt.% NaCl solution for 2 h, the corrosion inhibition performances of the flat powder coating and ordinary heat-sealing oxidized coating are poor, while the inhibition performances of the sand powder film coating and hard anodized film are good, and the inhibition performance follows the following sequence: the sand powder film coating > hard anodized film> the flat powder coating > ordinary heat-sealing oxidized coating. When corroded in a 3.5 wt.% NaCl solution for 200 h, the corrosion inhibition performances of the sand powder film coating and the flat powder coating are poor, while the inhibition performances of hard anodized film and ordinary heat-sealing oxidized coating are good, and the inhibition performance follows the following sequence: hard anodized film > ordinary heat-sealing oxidized coating > the sand powder film coating > the flat powder coating. [ABSTRACT FROM AUTHOR]

In this work, a Leslie-Gower model with a weak Allee effect on the prey and a fear effect on the predator is proposed. By using qualitative analyses, the local stability of the coexisting equilibrium and the existence of Turing instable are discussed. By analyzing the distribution of eigenvalues, the existence of a Hopf bifurcation is studied by using the gestation time delay as a bifurcation parameter. By utilizing the normal form method and the center manifold theorem, we calculate the direction of the Hopf bifurcation and the stability of bifurcating periodic solutions. We indicate that both the weak Allee effect on the prey and fear effect on the predator have an important impact on the dynamical behaviour of the new Leslie-Gower model. We also verify the obtained results by some numerical examples. [ABSTRACT FROM AUTHOR]

Conductive hydrogel is a high-performance conductive electrode that can be used for flexible and stretchable sensors. Furthermore, the self-powered sensor devices integrated with conductive hydrogel conductive can play the role in dance posture monitoring. In this work, we proposed a carboxymethyl chitosan (CMCh)-Fe/LiCl hydrogel-based triboelectric nanogenerator (CL-TENG) to harvest human motion mechanical energy. Based on the experimental results, the average transmissivity of CMCh-Fe/LiCl hydrogel can arrive at 91.53%. Also the CMCh-Fe/LiCl hydrogel has a high rate of mechanical healing, especially at high temperatures. The CL-TENG can reach the maximum power density of 81.48 mW/m2 when the external load is 200 M Ω. The open-circuit voltage ( V oc ) and transferred charge ( Q sc ) of CL-TENG can arrive at 96 V and 32.4 nC, and the short-circuit current ( I s c) of CL-TENG can reach 1.2 μ A. The CL-TENG can also serve as the self-powered dance motion sensor to monitor the action specifications of actors in cheerleading performance. This research will promote the development of dance pose sensors. A carboxymethyl chitosan (CMCh)-Fe/LiCl hydrogel-based triboelectric nanogenerator (CL-TENG) was designed to harvest human motion mechanical energy. The average transmissivity of CMCh-Fe/LiCl hydrogel can arrive at 91.53%. The CL-TENG can reach the maximum power density of 81.48 mW/m2. The CL-TENG can also serve as the self-powered dance motion sensor to monitor the action specifications of actors in cheerleading performance. This research will promote the development of dance pose sensors. [ABSTRACT FROM AUTHOR]

With the evolution of flexible electronics, the use of flexible wearable triboelectric nanogenerator (TENG) devices has become conceivable. However, the majority of flexible electronic goods are unable to achieve the requirements for high elasticity, transparency, and conductivity at the same time. We employed a carboxymethyl chitosan (CMCh)-Fe hydrogel with a double-network polymer ion conductor that displays outstanding elasticity (> 1050%) and transparency (> 90%). The CMCh-Fe hydrogel TENG (CF-TENG) can obtain energy from human motions. The CF-TENG device may also be configured as a self-powered smart exercise belt sensor to monitor arm extension movements. This might be a new method to get your hands on the next generation of environmentally friendly wearable and activity-monitoring equipment. [ABSTRACT FROM AUTHOR]

The nonlocal competition in prey is incorporated into a diffusive predator–prey model with additional food in predator and time delay. The local stability of the coexisting equilibrium is studied by analyzing the eigenvalue spectrum. Time delay inducing Hopf bifurcation is also investigated by using time delay as bifurcation parameter. Some conditions for determining the bifurcation direction and the stability of the bifurcating periodic solutions are given by utilizing the normal form method and center manifold theorem. Our results suggest that nonlocal competition together with time delay can induce spatially inhomogeneous bifurcating periodic solutions in the diffusive predator–prey model. [ABSTRACT FROM AUTHOR]

Recently, triboelectric nanogenerators (TENGs) have attracted significant attention in the academic and industry fields. In this work, we firstly report a fully encapsulated double-arch structure triboelectric nanogenerator (FDA-TENG). The FDA-TENG can monitor race walking. The designed dual working unit can output the motion information of the same immovable part of the foot. In addition, the FDA-TENG can achieve good electrical output performance. From the results, the maximum instantaneous power of the FDA-TENG can reach 3.16 mW at 10 MΩ. Additionally, the FDA-TENG can obtain open-circuit voltage (Voc) of 500 V. The short-circuit current (Isc) of the FDA-TENG is 37.4 µA. We also investigated the electrical output performance of the FDA-TENG under different inflation volumes. Additionally, the FDA-TENG has good moisture resistance and water resistance. The FDA-TENG can monitor athletes' race walking, and the results can be used to determine whether they commit a violation. This design will facilitate advancements in intelligent sports monitors. [ABSTRACT FROM AUTHOR]

Purpose: Based on the typical service supply chain (SSC) structure, the authors construct the model of e-tailing SSC to explore the coordination relationship in the supply chain, and big data analysis provides realistic possibilities for the creation of coordination mechanisms. Design/methodology/approach: At the present stage, the e-commerce companies have not yet established a mature SSC system and have not achieved good synergy with other members of the supply chain, the shortage of goods and the greater pressure of express logistics companies coexist. In the case of uncertain online shopping market demand, the authors employ newsboy model, applied in the operations research, to analyze the synergistic mechanism of SSC model. Findings: By analyzing the e-tailing SSC coordination mechanism and adjusting relevant parameters, the authors find that the synergy mechanism can be implemented and optimized. Through numerical example analysis, the authors confirmed the feasibility of the above analysis. Originality/value: Big data analysis provides a kind of reality for the establishment of online SSC coordination mechanism. The establishment of an online supply chain coordination mechanism can effectively promote the efficient allocation of supplies and better meet consumers' needs. [ABSTRACT FROM AUTHOR]

In recent years, the research on supply chain finance has been mature, in the supply chain financial risk research, the research on credit risk is mostly. However, there is little research on online supply chain finance, especially on credit risk. Therefore, this article has carried on the detailed research to the commercial bank online supply chain financial credit risk assessment. Firstly, the article applies the literature induction method to review the supply chain financial credit risk indicators, add the "online" specific indicators to supplement, combine the indicators selection principle to determine the final indicators, and construct the commercial bank online supply chain financial credit risk assessment index system, select online The supply chain financial business carried out the concentrated SMEs in the automobile manufacturing industry as the research object, using the nonlinear LS-SVM model for empirical analysis, and compared with the logistic regression model results. Secondly, the designed index system can effectively evaluate credit risk. The classification accuracy of LS-SVM evaluation model is higher than that of Logistic regression model and it has strong generalization ability. It can comprehensively identify the credit risk of small and medium-sized financing enterprises, and provide a reasonable and scientific analysis and support tool for assessing SME credit risk. Finally, combined with the fierce competition background of supply chain finance, it is proposed that commercial banks should actively carry out online supply chain finance, comprehensive risk management and deepen cooperation with e-Business platforms and logistics platforms. [ABSTRACT FROM AUTHOR]