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In this study, we analyzed the evolution of online public opinion on emergencies using a new Stochastic Petri Net modeling approach. First, an intuitive description of the emergency online public opinion development process was conceptualized from the life cycle evolution law perspective. Then, based on Petri net theory, a Stochastic Petri Net isomorphic Markov chain model was constructed to simulate the evolution of online public opinion on emergencies. Finally, four real-life cases were selected to validate and analyze the model, demonstrating that the evolutionary leaps, complexity, critical nodes, evolutionary rate, and execution time differ across different online public opinions on emergencies. The study results indicate that this modeling approach has certain advantages in examining the evolution based on multi-factor coupling and quantifying the evolution law in online public opinion on emergencies. [ABSTRACT FROM AUTHOR]

The collaborative R&D of new products between enterprises is prone to the "free‐rider effect" due to knowledge spillover. To avoid that, this paper establishes a three‐stage dynamic game to explore the collaborative R&D co‐competition behavior between asymmetric horizontal supplier enterprises. In this paper, we incorporate the uncertainty of R&D success probability into the model and reverse induction is applied to solve it. In the model, two asymmetric enterprises play dynamic games under three modes: complete noncooperation, semicooperation, and complete cooperation. We discuss the sensitivity of various asymmetric factors to the R&D investment level and profit of enterprises. The results indicate that the R&D investment level of supplier enterprises is positively correlated with the absorptive capacity, technology spillover, and R&D success probability, and negatively correlated with the initial R&D investment and innovation efficiency under the three co‐competition modes. Especially, when the absorptive capacity of the enterprise or the degree of technological spillover of the other party exceeds a certain value, the profits of the enterprise in the mode of complete noncooperation and semicooperation will intersect, which can easily lead to "free‐riding" behavior. It provides a decision‐making basis for the direction and extent of enterprises' R&D efforts. In addition, some methods are proposed to improve the level of R&D investment and increase the income of enterprises under three modes. [ABSTRACT FROM AUTHOR]

The rigid-flexible impeller (RF impeller) was used in the mixing process of viscoplastic fluid, and the mixing performance of RF impeller was explored by using numerical simulation and experimental analysis. Results indicated that RF impeller could reduce the power consumption (P) and demonstrate the advantage of energy-saving compared with Rushton turbine (RT). RF impeller demonstrated a more pronounced force coupling effect between the impeller and surrounding fluid, and exhibited superior adaptability in the flow field compared with RT. Meanwhile, the utilization of RF impeller can effectively enhance the expansion of high velocity region, expand the cavern zone, and decrease the mixing efficiency number while maintaining constant P compared with RT, and the size of high velocity region and cavern zone could be increased with an increase in impeller speed. Moreover, the cavern structure was obtained through the visualization experiment, and the results were similar to that in the simulation. The findings suggested that incorporating rigid-flexible combination structure design of impeller blades could effectively expand the cavern zone, reduce the stagnant zone, and enhance the mixing efficiency in the viscoplastic fluid mixing process. [ABSTRACT FROM AUTHOR]

Financial distress prediction (FDP) is centrally imported to reduce potential losses of companies and investors. This paper combines social responsibility indicators with financial, management, and textual indicators to construct a multi‐dimensional FDP index system. To increase prediction accuracy, the difference in the number of samples between special treatment and health companies is actively considered, and the synthetic minority oversampling technique is adopted to deal with class‐imbalanced datasets. Moreover, a feature extraction method based on the genetic algorithm is employed to select features as input of machine learning models for predicting financial distress in Chinese listed companies. Experimental results show that ensemble classifiers are the better choice for predicting financial distress, of which gradient boosting decision tree outperforms other classifiers. Textual indicators play the most significant role in complementing traditional financial indicators of FDP, and their financial distress signals emerge earlier compared with management and social responsibility indicators. [ABSTRACT FROM AUTHOR]

Multi-attribute emergency decision-making problems have the characteristics of incomplete information and shortage of response time. Evidence theory can effectively express uncertain information in the decision-making process. However, evidence theory requires that the condition of evidence independence is met, and the evaluation information of experts is often vague. Therefore, an emergency decision-making method based on intuitionistic fuzzy sets and evidence theory is proposed. First, each expert gives an intuitionistic fuzzy evaluation of each emergency plan. Secondly, the proposed intuitionistic fuzzy similarity calculation method is used to obtain the similarity between experts and determine the expert weight. The attribute weight is known, the intuitionistic fuzzy evaluation is converted into a Mass function, and the evaluation of expert's decision-making plan is revised and fused using evidence theory to obtain the final decision. Finally, an example analysis proves that the model is feasible and effective.

The effects of wire feeding voltage (equivalent to wire feeding rate), spraying current, and zinc wire diameter on the quality of thermally sprayed zinc coating with a thickness about 200 μm were studied. When the wire feeding voltage and the spraying current are 20 V and 200 A respectively, the coating was well formed with low energy consumption, and had an adhesion strength up to 8.4 MPa. The loss rate of zinc wire 2.0 mm in diameter during thermal spraying was 67% and 35% lower than that of zinc wires with a diameter of 1.6 mm and 3.0 mm, respectively. The presented zinc thermal spraying process is simple, controllable in quality, and cost-efficient, and has been well applied and verified in engineering. [ABSTRACT FROM AUTHOR]