High-speed railways adopt continuous welded rail to maintain the smoothness and continuity of the rail surface. However, the welded joint became one of the weakest parts. In order to clear the ...characteristics and mechanical properties of the new reinforced device, a dynamic three-dimensional vehicle-reinforced device-track coupling model is established. The mechanical characteristics of the track structure under high-speed train load were simulated and analyzed. After installing the new reinforced device, the dynamic response and service life of the track structure are obviously improved compared with the unreinforced rail. When the train speed is 300 km/h, the dynamic bending stress at the bottom of rail is reduced by 26.90%, the vertical and lateral acceleration of the rail are reduced by 42.78% and 21.56%, the vertical and lateral displacement of the rail are reduced by 6.36% and 8.67%, and the theoretical service life of the rail is greatly extended.
The product quality issues of online shopping have not been effectively solved with the rapid development of electronic commerce in China. Faced with the quality issues of online shopping, the main ...entities, such as online platforms and online sellers, should cooperate to control and assure compliant quality. The adverse selection of buyers caused by information asymmetry and the moral hazard of sellers aggravated by bilateral markets make the quality management of online shopping have a high degree of uncertainty and complexity. This study constructs an evolutionary game model to discuss the dynamic process of the quality behaviours of members and analyse the key triggers of the evolutionary directions in online shopping. By using numerical simulation analysis, the influences of government supervision intensities on the evolution trend of members’ quality behaviours are analysed with various risk attitude combinations in various cases. The current research finds that (1) the decrease of the quality control cost and the increase of the government’s benchmark fine are conducive to increasing the platform’s controlling probability; (2) the decrease of the proportion of rent and the increase of sellers’ fraud cost and the government’s benchmark fines are conducive to increasing the seller’s compliance probability; (3) when both the platform and seller are unwilling to make efforts for quality assurance, risk-seeking members make the seller gradually choose to provide compliant products; and (4) when the members are all risk-seeking, strengthening government supervision will help promote the transition of members’ behavioural choices in a benign direction. This paper enriches the theoretical research studies on both online product quality control and government-led social governance system of quality. Suggestions for government supervision and e-commerce entities are also provided for quality assurance and improvement.
In order to improve the stabilization of closed-cell aluminum foams during preparation process, a horizontal steady uniform magnetic field was imposed. The three-dimensional microscopic drainage ...model of closed-cell aluminum foam has been developed, in which the surface viscosity was incorporated into the boundary conditions to quantify the mobility of the gas–liquid interface. The predicted results by the model agree well with the experimental data from literatures. The numerical results show that the uniform magnetic field has particularly suppression effect on the drainage flow in aluminum foam. And this effect increases with the increasing magnetic induction intensity. The suppression effect of magnetic field on drainage at the bottom of aluminum foam is higher than that at the top and middle of aluminum foam. For different stages of the drainage process, applying the magnetic field in the early stage is more effective than in the later stage. For different preparation methods, the application of magnetic field to powder metallurgy method has the best effect, followed by blowing foaming method and melting foaming method. Different combinations of particle concentration and magnetic induction intensity can achieve the same suppression effect. In the preparation of aluminum foam, it is suggested to combine magnetic field with the particles to improve the suppression efficiency of drainage behavior. The critical magnetic induction intensity is proposed. Under this critical condition, the magnetic field can completely replace the particles. Furthermore, the critical magnetic induction intensity shows linear relationship with the logarithm of Boussinesq number.
Existing rice inter-plant weed control devices have difficulty achieving inter-plant weed control in one pass. Due to the complex environment of paddy fields, these devices have a low weed removal ...rate and high seedling damage rate, making it difficult to ensure high-quality operation. This study innovatively designed a water jet-based rice inter-plant weed control device. Based on the mechanism of water jet erosion of soil, it can erode and excavate the soil layer on which weeds depend, achieving inter-plant weed control in paddy fields. The optimal range of structural parameters of the water jet angle and nozzle opening diameter was analyzed. The results showed that the optimal structural parameters of the device were a jet angle of 31° and a nozzle opening diameter of 4 mm, which can achieve the best operational performance. Based on virtual simulation experiments, single-factor and multi-factor orthogonal rotation combination experiments were carried out with weed removal rate as the test index and different operating speeds and nozzle outlet pressures as the test factors to optimize the water jet-based inter-plant weed control device. The experimental results showed that when the working parameters of the water jet-based inter-plant weed control device were a forward speed of 0.30 m∙s−1 and a nozzle outlet pressure of 1.50 MPa, the weed removal rate was the highest at 92.78%. Field validation experiments showed that the weed removal rate was 90.16% and the seedling damage rate was 1.80% under this operation condition, and the quality of the operation met the requirements of inter-plant weed control technology. This study provides a technical reference for promoting the development of inter-plant weed control technology in paddy fields.
We have first investigated the thin-film field-effect behavior of perylo1,12-b,c,dthiophene by vacuum evaporation technique, which exhibits a moderate mobility of 0.05 cm2 V-1 s-1, an on/off ratio of ...105, and a low threshold voltage of −6.3 V at room temperature. Moreover, we have grown its single-crystalline micrometer wires and successfully applied them to transistors. A high mobility up to 0.8 cm2 V-1 s-1 has been achieved. The extraordinary solid-state packing arrangement with the likelihood of double-channel fashion induced by marked S···S interactions may contribute to the high performance.
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Fe3O4@MOF core-shell microspheres were successfully synthesized using a versatile Layer-by-Layer (LBL) assembly method and investigated as an anode material for the first time. The ...composite exhibited high reversible capacity and excellent rate performances as anode material.
•Fe3O4 particles are encapsulated by HKUST-1 to form core-shell microspheres composite.•The composite exhibits outstanding electrochemical performances as a novel anode.•The typical approach can be used to prepare some novel electrode materials.
The Fe3O4@MOF composite with a microspheric core and a porous metal-organic framework (MOF HKUST-1) shell has been successfully synthesized utilizing a versatile Layer-by-Layer (LBL) assembly method. The structure was identified by X-ray diffraction (XRD), and the morphology was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The Fe3O4@MOF composite exhibited outstanding electrochemical properties when it was used as an anode material for lithium ion batteries (LIBs). After 100 discharge-charge cycles at a current density of 100mAg−1, the reversible capacity of Fe3O4@MOF could maintain ∼1002mAhg−1, which was much higher than that of the bare Fe3O4 counterpart (696mAhg−1). Moreover, load the current density as high as 2Ag−1 (after 70 cycles at the current density step increased from 0.1 to 2Ag−1), it still delivered a reversible capacity of ∼429mAhg−1. The results demonstrate that the cycling stability of Fe3O4 as an anode could be significantly improved by coating Cu3(1,3,5-benzenetricarboxylate)2 (HKUST-1). This strategy may offer new route to prepare other composite materials using different particles and suitable Metal-organic frameworks (MOFs) for LIBs application.
Great changes are taking place, and now is the right time to reflect on the quality philosophy. This research firstly reviewed the quality theories and practices according to the timeline, thus ...summarising the 'past' of the quality movement. Then, a bibliometric analysis based on 20,930 literature on quality management since 2001 was conducted, and the first 19 years of the new millennium were divided into three phases. Through comparative analysis of the three stages by using VOSviewer, this research describes how research on quality management has evolved since the twenty-first century. Finally, through the coding method based on expert interviews and document studies, this research proposed the following six future directions in quality movement: First, no longer about defect reduction, but focuses on value enhancement. Second, no longer product life cycle, but service life cycle. Third, no longer separated, but integrated. Fourth, data will become the core resource for quality management. Fifth, there will be significant changes in existing methods and tools of quality management. Sixth, the quality control power of focal companies over other actors in the supply network will be further enhanced.
In recent years, the uncertain environment such as international political turmoil and frequent public health emergencies have made the global supply chain network threatened by disruption risks. A ...digital supply chain provides effective ideas for firms to reallocate resources and promote high-quality development. Based on dynamic capability theory, this study explored how digital supply chain influences supply chain disruption risks through a survey of Chinese manufacturing firms, and evaluated the impact of supply chain dynamic capability and uncertain environment on the above relationships. The empirical results show that the digital supply chain can reduce supply, manufacturing, demand, and circulation disruption risks either directly or through supply chain dynamic capability. Meanwhile, the direct effects of digital supply chain on supply chain disruption risks are enhanced under a high degree of uncertain environment. The results of the study confirm the superiority of digital supply chain and provide global manufacturing firms with new strategic options in supply chain risk management.
With increasing public environmental awareness, accelerating green transformation has become inevitable for enterprises to achieve long‐term development. Sustainable customer engagement (sustainable ...CE) is a core concept of consumer participation in sustainable consumption. Based on partial least squares‐structural equation modeling, this study establishes a prediction model for sustainable CE and explores the impacts of service experience, green perceived value, and customer satisfaction on sustainable customer engagement. This study collected 682 valid data points from customers of green hotels and analyzed the relationships between sustainable CE and its antecedent variables. The results showed that peace of mind and product experience can directly promote sustainable customer engagement. Service experience can enhance sustainable CE through the serial mediation of green perceived value and customer satisfaction. The conclusions enrich the existing knowledge in the field of sustainable consumption and engagement marketing and provide effective suggestions for green hotel managers.
In order to reduce the particle addition in closed-cell aluminum foam, the effect of particles on foam drainage behavior was investigated numerically. The coupled CFD-DEM method was used to analyze ...the particle behavior within the node-PBs system. The predicted results agree well with experimental results. The results show that the trajectory of particles in metallic foam is consistent with literatures. Particles grow into clusters and deposit on the oxide film, leading to foam clogging and suppressing the drainage in aluminum foam. The above mechanism explains the phenomenon in literatures that the viscosity obtained from the drainage experiment is much greater than the apparent viscosity of the particle-melt mixture. The effect of particles on suppressing drainage is summarized as the blockage effect of stationary particles and the increasing apparent viscosity of moving particles. There is an optimization possibility of particle size and volume fraction, achieving better performance and lower production costs.
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•Motion, growth, and deposition of particles in node-PBs system are investigated.•Clusters causing foam clogging is an important mechanism to suppress drainage.•Foam clogging by particles can explain high viscosity in drainage experiments.•Possible optimization approaches for particle parameters are proposed.
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