Design of Hydrostatic Chassis Drive System for Large Plant Protection Machine

In order to meet the working performance of large plant protection machine and according to the actual working requirements, this paper proposes a design of hydrostatic chassis drive system for a large plant protection machine. The purpose of this study is to realize the anti-slip rotation function of the plant protection machine and improve the driving stability through the combination of a hydraulic drive system and shunt valve. In this study, a closed circuit with a single pump and four motors is used, and a diverter valve is used to prevent the wheels from skidding during the driving of the plant protection machine. The parameters of the main hydraulic components of the hydraulic drive system were firstly calculated and selected; then the AMESim software was used to model and simulate the hydraulic drive system. Finally, a test platform with anti-skid function is designed and built, and the test results are as follows: when the diverter valve is closed, the plant protection machine drives at 3 km/h and 6 km/h respectively, and the skid rate is 3.79% and 6.17%; when the diverter valve is open, the plant protection machine drives at 3 km/h and 6 km/h respectively, and the skid rate is 1.33% and 2.70% respectively. The test results show that the hydraulic chassis of the plant protection machine designed in this study has good driving stability and can effectively reduce the slip rate of the plant protection machine in the process of driving in the field, which provides an effective theoretical support for the design of the driving system of the hydraulic chassis of the plant protection machine

Design of Hydrostatic Chassis Drive System for Large Plant Protection Machine

In order to meet the working performance of large plant protection machine and according to the actual working requirements, this paper proposes a design of hydrostatic chassis drive system for a large plant protection machine. The purpose of this study is to realize the anti-slip rotation function of the plant protection machine and improve the driving stability through the combination of a hydraulic drive system and shunt valve. In this study, a closed circuit with a single pump and four motors is used, and a diverter valve is used to prevent the wheels from skidding during the driving of the plant protection machine. The parameters of the main hydraulic components of the hydraulic drive system were firstly calculated and selected; then the AMESim software was used to model and simulate the hydraulic drive system. Finally, a test platform with anti-skid function is designed and built, and the test results are as follows: when the diverter valve is closed, the plant protection machine drives at 3 km/h and 6 km/h respectively, and the skid rate is 3.79% and 6.17%; when the diverter valve is open, the plant protection machine drives at 3 km/h and 6 km/h respectively, and the skid rate is 1.33% and 2.70% respectively. The test results show that the hydraulic chassis of the plant protection machine designed in this study has good driving stability and can effectively reduce the slip rate of the plant protection machine in the process of driving in the field, which provides an effective theoretical support for the design of the driving system of the hydraulic chassis of the plant protection machine

Solar anti-icing surface with enhanced condensate self-removing at extreme environmental conditions

The inhibition of condensation freezing under extreme conditions (i.e., ultra-low temperature and high humidity) remains a daunting challenge in the field of anti-icing. As water vapor easily condensates or desublimates and melted water refreezes instantly, these cause significant performance decrease of most anti-icing surfaces at such extreme conditions. Herein, inspired by wheat leaves, an effective condensate self-removing solar anti-icing/frosting surface (CR-SAS) is fabricated using ultrafast pulsed laser deposition technology, which exhibits synergistic effects of enhanced condensate self-removal and efficient solar anti-icing. The superblack CR-SAS displays superior anti-reflection and photothermal conversion performance, benefiting from the light trapping effect in the micro/nano hierarchical structures and the thermoplasmonic effect of the iron oxide nanoparticles. Meanwhile, the CR-SAS displays superhydrophobicity to condensed water, which can be instantly shed off from the surface before freezing through self-propelled droplet jumping, thus leading to a continuously refreshed dry area available for sunlight absorption and photothermal conversion. Under one-sun illumination, the CR-SAS can be maintained ice free even under an ambient environment of -50 °C ultra-low temperature and extremely high humidity (ice supersaturation degree of ∼260). The excellent environmental versatility, mechanical durability, and material adaptability make CR-SAS a promising anti-icing candidate for broad practical applications even in harsh environments

Ni electrodes with 3D-ordered surface structures for boosting bubble releasing toward high current density alkaline water splitting

The performance of alkaline water electrolysis (AWE) at high current densities is limited by gas bubble generation on the surface of electrodes, which covers active sites and blocks mass transfer, resulting in lower AWE efficiency. Here, we utilize electro-etching to construct Ni electrodes with hydrophilic and aerophobic surfaces to improve the efficiency of AWE. Ni atoms on the Ni surface can be exfoliated orderly along the crystal planes by electro-etching, forming micro-nano-scale rough surfaces with multiple crystal planes exposed. The 3D-ordered surface structures increase the exposure of active sites and promote the removal of bubbles on the surface of the electrode during the AWE process. In addition, experimental results from high-speed camera reveal that rapidly released bubbles can improve the local circulation of electrolyte. Lastly, the accelerated durability test based on practical working condition demonstrates that the 3D-ordered surface structures are robust and durable during the AWE process

Unraveling the role of vaporization momentum in self-jumping dynamics of freezing supercooled droplets at reduced pressures

Abstract Supercooling of water complicates phase change dynamics, the understanding of which remains limited yet vital to energy-related and aerospace processes. Here, we investigate the freezing and jumping dynamics of supercooled water droplets on superhydrophobic surfaces, induced by a remarkable vaporization momentum, in a low-pressure environment. The vaporization momentum arises from the vaporization at droplet’s free surface, progressed and intensified by recalescence, subsequently inducing droplet compression and finally self-jumping. By incorporating liquid-gas-solid phase changes involving vaporization, freezing recalescence, and liquid-solid interactions, we resolve the vaporization momentum and droplet dynamics, revealing a size-scaled jumping velocity and a nucleation-governed jumping direction. A droplet-size-defined regime map is established, distinguishing the vaporization-momentum-dominated self-jumping from evaporative drying and overpressure-initiated levitation, all induced by depressurization and vaporization. Our findings illuminate the role of supercooling and low-pressure mediated phase change in shaping fluid transport dynamics, with implications for passive anti-icing, advanced cooling, and climate physics

Hierarchically Mesostructured Aluminum Current Collector for Enhancing the Performance of Supercapacitors

Aluminum (Al) current collector is one of the most important components of supercapacitors, and its performance has vital effects on the electrochemical performance and cyclic stability of supercapacitors. In the present work, a scalable and low-cost, yet highly efficient, picosecond laser processing method of Al current collectors was developed to improve the overall performance of supercapacitors. The laser treatment resulted in hierarchical micro–nanostructures on the surface of the commercial Al foil and reduced the surface oxygen content of the foil. The electrochemical performance of the Al foil with the micro–nanosurface structures was examined in the symmetrical activated carbon-based coin supercapacitors with an organic electrolyte. The results suggest that the laser-treated Al foil (laser-Al) increased the capacitance density of supercapacitors up to 110.1 F g^–1 and promoted the rate capability due to its low contact resistance with the carbonaceous electrode and high electrical conductivity derived from its larger specific surface areas and deoxidized surface. In addition, the capacitor with the laser-Al current collector exhibited high cyclic stability with 91.5% capacitance retention after 10 000 cycles, 21.3% higher than that with pristine-Al current collector due to its stronger bonding with the carbonaceous electrode that prevented any delamination during aging. Our work has provided a new strategy for improving the electrochemical performance of supercapacitors

Hierarchically Mesostructured Aluminum Current Collector for Enhancing the Performance of Supercapacitors

Aluminum (Al) current collector is one of the most important components of supercapacitors, and its performance has vital effects on the electrochemical performance and cyclic stability of supercapacitors. In the present work, a scalable and low-cost, yet highly efficient, picosecond laser processing method of Al current collectors was developed to improve the overall performance of supercapacitors. The laser treatment resulted in hierarchical micro–nanostructures on the surface of the commercial Al foil and reduced the surface oxygen content of the foil. The electrochemical performance of the Al foil with the micro–nanosurface structures was examined in the symmetrical activated carbon-based coin supercapacitors with an organic electrolyte. The results suggest that the laser-treated Al foil (laser-Al) increased the capacitance density of supercapacitors up to 110.1 F g^–1 and promoted the rate capability due to its low contact resistance with the carbonaceous electrode and high electrical conductivity derived from its larger specific surface areas and deoxidized surface. In addition, the capacitor with the laser-Al current collector exhibited high cyclic stability with 91.5% capacitance retention after 10 000 cycles, 21.3% higher than that with pristine-Al current collector due to its stronger bonding with the carbonaceous electrode that prevented any delamination during aging. Our work has provided a new strategy for improving the electrochemical performance of supercapacitors