The effects of a trust mechanism on a dynamic supply chain network

Recognizing trust as the basis for firm cooperation, we investigate how a trust mechanism affects a supply chain network using a dynamic multi-agent and multi-stage model that incorporates three supplier selection rules: a preferred price rule, a preferred trust rule, and a preferred random rule. We use this model to explore the impact of the three rules on supply chain performance and bankruptcy propagation under the conditions of external disruption, bank rate, and new firms entering the market. Our results identify the preferred trust rule as the supplier selection method that can in most cases best improve the total revenue of the whole supply chain network. In terms of firm bankruptcy, on the other hand, it is the preferred random rule that has the least impact and the preferred price rule that has the most

Effect of Magnesium Sulfate Solution on Pore Structure of Ionic Rare Earth Ore during Leaching Process

During in situ leaching of ionic rare earth ore, the pore structure of the orebody changes due to the chemical replacement reaction between the leaching agent and the rare earth ore. To explore the influence of leaching agents on the pore structure of ionic rare earth ore during the leaching process, magnesium sulfate solutions with different concentrations and pH are used as leaching agents in this paper. An experimental method of indoor simulated column leaching, a Zetaprobe potential analyzer, and an NM-60 rock microstructure analyzer to measure parameters, including surface zeta potential, T2 map, and the pore structure of rare-earth ore particles, were used to analyze the influence law of magnesium sulfate solution on the pore structure of ionic rare earth ore. The result proves that pure H2O leaching has little effect on the surface Zeta potential and the internal pore structure of the ore particles. In the leaching process of magnesium sulfate solutions with different concentrations, the absolute value of Zeta potential decreases, and the internal pore structure evolves from medium, large, and extra-large to small pores. In the leaching process of magnesium sulfate solutions with different pH, the absolute value of Zeta potential decreases and then increases slightly with the end of the ion exchange reaction. The internal pore structure generally shows a decrease in the number of small and extra-large pores and an increase in the number of medium and large pores. According to the analysis, the concentration and pH of the leaching agent cause the change of thickness of the electric double layer of the fine particles in the orebody, break the balance of interaction force between soil particles, and result in the evolution of a micropore structure of orebody during leaching

Simulation of an Ionic Rare Earth Leaching Process Based on the Darcy Law-Chemical Reaction Engineering-Transfer of Dilute Substance Coupling

The basic principle of in situ leaching is chemical mining. The process of in situ leaching is to inject leaching solution into the ore body, and the leaching solution is spread in the pores of the mountain. The process is completed by the coupling action of the liquid seepage field and ion exchange reactions. In the production process, only one injection of liquid can be carried out in a certain stope, so it is impossible to improve the injection process and leaching effect through field practice. By simulating the in situ leaching process of rare earth ions, this paper builds the test stope true three-dimensional numerical model and simulates the leaching process of rare earth ore under the coupling of seepage control, ion exchange, and dilute material transfer in porous media. The migration rule of RE3+ and Mg2+ in stopes was analyzed to evaluate the leaching effect. It is of great significance to increase the recovery rate of rare earth ore

An Early Warning System for Landslide Risks in Ion-Adsorption Rare Earth Mines: Based on Real-Time Monitoring of Water Level Changes in Slopes

During the in situ leaching process of ion-adsorption rare earths, leaching solution needs to be constantly injected to the mine slopes. As a consequence, landslides are highly likely to occur due to the increasing water level of soil mass. To solve this problem, we conducted a mechanical analysis on the rising water level after solution injection, which shed light on the mechanical principle of slope instability brought about by rising water level. With water level variation as the major factor, we established an early warning system for landslide risks on the basis of the real-time monitoring of water level. Within the system, a self-designed landslide early warning model is embedded. In addition to monitoring the water level variation in slopes, this system can be employed for real-time data processing. With the integration of early warning model algorithm, the real-time graded early warning of slope landslide risks is achieved within the mining process of ion-adsorption rare earths. By discussing the real-time monitoring method, framework of landslide early warning system, FIFC landslide early warning model, optimization method of water level, and selection of landslide-inducing factors, this research provides an effective solution to the landslide early warning within the mining process of ion-adsorption rare earth minerals. Thus, it can be employed as a favorable reference for other types of early warning systems

Simulation of an Ionic Rare Earth Leaching Process Based on the Darcy Law-Chemical Reaction Engineering-Transfer of Dilute Substance Coupling

The basic principle of in situ leaching is chemical mining. The process of in situ leaching is to inject leaching solution into the ore body, and the leaching solution is spread in the pores of the mountain. The process is completed by the coupling action of the liquid seepage field and ion exchange reactions. In the production process, only one injection of liquid can be carried out in a certain stope, so it is impossible to improve the injection process and leaching effect through field practice. By simulating the in situ leaching process of rare earth ions, this paper builds the test stope true three-dimensional numerical model and simulates the leaching process of rare earth ore under the coupling of seepage control, ion exchange, and dilute material transfer in porous media. The migration rule of RE3+ and Mg2+ in stopes was analyzed to evaluate the leaching effect. It is of great significance to increase the recovery rate of rare earth ore

Mesoscopic Process Simulation of In Situ Leaching of Ionic Rare Earth Based on NMRI Technology

In order to simulate and calculate the leaching process of ionic rare earths more realistically, a digital model of ionic rare earths with real size, shape, seepage channel, and pore ratio and distribution at the mesoscopic scale was constructed based on nuclear magnetic resonance imaging (NMRI) technology. And the in situ leaching mining process was simulated and calculated by using three control equations of solution seepage, ion exchange, and solute migration. The reliability of the NMRI model was verified by the results of the indoor column leaching experiment, and the influence of the injection intensity and leaching agent concentration on the leaching of rare earth ions was analyzed. The results show that there are dominant seepage channels in the ore body, and the rare earth ion exchange reaction and migration in the dominant channel area are completed first. By analyzing the leaching results of rare earth ions under the working conditions of different injection strengths and different concentrations of leaching agent, the results show that the injection strength and the concentration of leaching agent have an obvious promoting effect on the leaching of rare earth ions in a certain range. The injection strength of 0.5~1.0 mL/min and the concentration of 0.20~0.25 mol/L leaching agent are considered to be more economical in practical engineering

2D Metallic Abnormal Li2Cl Crystals with Unique Electronic Characteristics Applied in Capacitor and Humidity Sensor

Abstract Understanding the configuration and properties of the simplest lithium‐ion crystal, the Li‐Cl crystal, is essential for developing Li‐based electrochemical energy storage and conversion devices. Under ambient conditions, LiCl in a 1:1 stoichiometry is the only known stable form of the Li‐Cl crystal, and the corresponding crystals are insulating. Here, using cryo‐electron microscopy (cryo‐EM) and X‐ray photoelectron spectroscopy (XPS), this work reports a novel abnormal 2D Li2Cl crystal in ultra‐thin reduced graphene oxide (rGO) membranes by simply soaking the rGO membrane in unsaturated LiCl solution under ambient conditions and showed its high‐resolution image. Unexpectedly, such Li2Cl crystal presents metallic properties rather than insulating properties. Using vacuum filtration of the unsaturated LiCl solution through rGO membranes, this work prepares the rGO membranes with high content Li2Cl, displaying a high areal capacitance of 220 mF cm−2. Remarkably, the Li2Cl‐rGO membranes also exhibit heterostructure property and piezoelectricity. For the excess Li and unique electrical characteristics, these Li2Cl‐rGO membranes can be used as a humidity sensor. These findings point to possibilities for creating new Li‐based materials and fabricating novel high‐performance electronic devices, transistors, and sensors

Effect of Y2O3 on the Electrical Contact Behavior of Al2O3-Cu/MoTa Composites

With the massive penetration of electronics into human life, higher demands are placed on electrical contacts. Among them, the lifetime of electrical contacts and safety are the most concerning. In this research, Al2O3-Cu/25Mo5Ta and 0.5Y2O3/Al2O3-Cu/25Mo5Ta composites were prepared by using ball milling and powder metallurgy methods. The two composites were subjected to 10,000 contact opening and closing electrical contact experiments and the arc duration and arc energy were analyzed. The results show that the addition of Y2O3 has a slight effect on the mechanical properties of the Al2O3-Cu/25Mo5Ta composites but has a significant effect on the electrical contact performance. Y2O3 can reduce the mass loss of the electrical contacts during the electrical contact process, which prolongs their service life. The addition of Y2O3 decreased the average arc duration and arc energy of the electrical contact material by 21.53% and 18.02%, respectively, under the experimental conditions of DC 30 V, 10 A. TEM results showed that nanoscale YTaO4 with excellent thermal stability was generated during the sintering process, which has a positive effect on the electrical contact performance of the composites