The inherent sophisticated structure of wood inspires researchers to use it as a natural template for synthesizing functional nanoparticles. In this study, pure copper nanoparticles were synthesized using poplar wood as a natural inexpensive and renewable template. The crystal structure and morphologies of the copper nanoparticles were characterized by X-ray diffraction and field emission scanning electron microscopy. The optical properties, antibacterial properties, and stability of the hybrid wood materials were also tested. Due to the hierarchical and anisotropic structure and electron-rich components of wood, pure copper nanoparticles with high stability were synthesized with fcc structure and uniform sizes and then assembled into corncob-like copper deposits along the wood cell lumina. The products of nanoparticles depended strongly on the initial OH− concentration. With an increase in OH− concentration, Cu2O gradually decreased and Cu remained. Due to the restrictions inherent in wood structure, the derived Cu nanoparticles showed similar grain size in spite of increased Cu2+ concentration. This combination of Cu nanostructures and wood exhibited remarkable optical and antibacterial properties.

In electric vehicles (EVs), the source of noise, vibration, and harshness (NVH) involves various components inside/outside of the vehicle. Besides the vibration from each NVH source, the resonances between multiple sources contribute even more significant vibrations. This paper proposes a generalized real-time suppression strategy to mitigate the coupling vibration during vehicle idling and cruising. Using a high-performance field-oriented-controlled electric motor drive, a relatively small amount of rotation velocity offset can be added to the traction motor to significantly reduce the resonant vibration with negligible impact to vehicular speed. In this paper, torsional and bending coupling vibrations between traction motor and driveline are investigated because these two are the most common forced vibrations due to resonances. The system is simulated using MATLAB/Simulink, and the results of the vibration suppression are presented. The strategy proposed in this paper presents a simple and robust way to suppress the coupling vibration in EVs with no additional hardware requirement.

This paper delves into the effects of a toroidal propeller’s geometrical characteristics on its thrust and efficiency. The focus is on three distinct numerical distributions: the outward inclination angle, the pitch angle, and the number of blades. The Reynolds-Averaged Navier–Stokes (RANS) method is employed to analyze the propeller’s open-water performance, taking into account cavitation flow, and a test bed was constructed to verify the rationality of CFD simulation. The findings reveal that the toroidal propeller’s efficiency and thrust coefficient initially increase with the outward inclination angle, followed by a decline; the angle of maximum efficiency is identified at 23.25°. A reduction in the pitch angle leads to a temporary rise in efficiency, which subsequently falls, accompanied by a continuous decrease in the thrust coefficient. The optimal selection angle should consider this to prevent negative thrust at lower advance coefficients, which could further impact overall efficiency. An increased number of blades elevates the thrust coefficient and reduces the force on each blade, yet has a minimal effect on efficiency. Additionally, the orthogonal test method was utilized to explore the interactions between these three parameters. The outcomes indicate that, in terms of final power, there is no significant interaction among the three parameters under investigation. However, notable interactions are observed between the pitch angle and the number of blades, the outward inclination angle and the pitch angle, and the outward inclination angle and the number of blades. Consequently, the study’s findings facilitate the selection of parameter combinations that yield higher efficiency or thrust coefficients.

Work zones present unique risks to both workers and road users due to its complex and dynamic nature. This study developed a two-stage in-vehicle warning system aimed at refining driver behavior when approaching work zones and mitigating lane-changing risks. To accurately capture the thorough behavioral processes of drivers near work zones, a driving simulation experiment was conducted involving 38 participants of diverse genders and occupations. Different warning modes (baseline vs. two-stage warning), speed limits (60 km/h vs. 80 km/h), and visibility conditions (clear vs. fog) were incorporated into the experimental design. The entire behavioral performance was segmented into approaching and lane-changing processes. Generalized Estimating Equation (GEE) models were employed to analyze behavioral changes during the approaching process under different conditions, and Fuzzy C-Means (FCM) clustering algorithm was utilized for risk assessments. Influencing analysis was then applied to examine the relationship between behavioral changes during the approaching process and lane-changing risk levels. The findings reveal that, compared to the baseline group, the two-stage warning effectively reduced the average approaching speed by 2.25 %, increased the headway distance by 19.02 %, and advanced the starting point of lane-changing maneuvers by approximately 42.8 m on average, all of which contributed to a decrease in overall lane-changing risks. Under high speed limits, despite all drivers adhering to the speed limit, the phenomenon of relatively higher deceleration still persists, leading to unsafe and uncomfortable conditions.Additionally, the risk faced by drivers is significantly heightened when traveling at higher speeds in dense fog, further corroborating the necessity of the two-stage warning. The findings provide a theoretical foundation for the development of in-vehicle warning systems for work zone areas, offering practical implications for safe and efficient operations within work zones.

Apple, which occupies the first position in the world with regard to its yield, is an important economic crop in China. Pruning of apple trees is still dominated by manual pruning, resulting in high labor costs and low efficiency. Additionally, there are some limitations with pruning machines. Thus, research regarding the mechanical properties of apple branches is the basis for the designing proper pruning machine. This paper aims to study the effect of the feed rate, cutting line speed, branch diameter, and moisture content on the cutting force. Results revealed that cutting force depended on the feed rate, cutting line speed, and branch diameter. Furthermore, both the cutting line speed and the branch diameter had a significant effect on the cutting force (p < 0.01), while the feed rate had a small effect on the cutting force (p > 0.05). However, the moisture content had no effect on the cutting force, with a difference of cutting force between samples with moisture content of 15% and 50% less than 5%. Based on the experiments performed, an equation relating the feed rate, the cutting line speed, the branch diameter was derived to calculate the cutting force. By verification test, it established that regression equation was valid with error less than 4%. This study explored the mechanical properties of apple branch, and obtained the optimal cutting parameters, which can provide a reference for the design of the pruning machine.

Vehicle driving safety is an important performance indicator for vehicles, and there is still much room for development in the active safety control of electric vehicles. Vehicles are susceptible to rollover when making sharp turns or overtaking at high speed. In order to improve the anti-rollover stability of electric vehicles (EV), this study proposes a real-time motor control strategy, mainly according to the acquisition of vehicle attitude data and real-time monitoring of the vehicle’s operating state. The lateral load transfer rate was defined as the vehicle rollover evaluation index. When the real-time rollover indicator exceeded the limit safety threshold this article set, the motor speed would be reduced through active control to avoid rollover or reduce the risk of rollover. Both simulation results in Carsim and Simulink showed that the motor control strategy is highly reliable and real-time capable, and the active safety of EV was improved significantly.