Longdong University

Aim/Objective To investigate the impact of Virtual Reality (VR)-aided training on balance ability, energy expenditure, and tennis learning outcomes in children with moderate intellectual disabilities. Materials and Methods Participants were assigned to either a VR-aided training group (experimental) or a traditional training group (control). Balance ability and energy expenditure were assessed using intelligent algorithms, while a custom questionnaire measured tennis learning interest, performance, and motivation. Pre- and post-intervention evaluations included dynamic and static balance, aerobic endurance, broad jump, and vital capacity. Conclusion VR-aided training significantly improved dynamic and static balance, aerobic endurance, and tennis skills, with the experimental group scoring on average two points higher than the control group. Energy expenditure decreased, with a maximum reduction of 60.52 kcal. No significant improvements were observed in the broad jump or vital capacity. Impact These findings highlight VR as an effective, engaging, and energy-efficient tool for enhancing motor control, aerobic fitness, and skill acquisition in physical education programs for children with moderate intellectual disabilities.

Aiming at poor profiling effect and uneven stubble caused by complex terrain of the suspended mower and flattening machine while harvesting alfalfa in hilly and mountainous areas, a profiling mechanism for a suspended mowing and flattening machine was designed, and the profiling performance of the mechanism on undulating, sloping, potholed and raised roads was simulation analyzed by applying multi-body dynamics software RecurDyn. The results show that by coordinating the force of the suspension spring adjustment device and the profiling device, the profiling mechanism can control the ground pressure of the cutting table within 2000N, achieving adaptive adjustment on slopes of ± 30°, undulating roads of 250mm, and raised roads with depressions or protrusions of ± 50mm. The key technical parameters of profiling springs and suspension springs had been precisely calculated, the maximum working load of the profiling spring is 9014N, and that of the suspension spring is 10,290N, meeting the allowable shear stress requirements for Class III loads. The effectiveness of the profiling mechanism was verified by field experiments, and the cutting height was 63.2mm and the flattening rate was 95.1%. The research results can provide theoretical and technical support for the design and optimization of forage harvesting machinery.

The wettability differences among macroscopic coal lithotypes constitute a critical issue requiring in-depth investigation in the development of low-rank coalbed methane. To elucidate the impact of wettability variation on methane adsorption/desorption, this study employed vitrain and durain samples from Jurassic low-rank coals in the Huanglong Coalfield. We analyzed changes in adsorption/desorption characteristics before and after wettability modification and conducted coal seam desorption experiments under simulated extraction conditions to explore the influence of wettability on methane adsorption/desorption behavior. The results indicate that vitrain exhibits greater full-scale pore volume (0.04073–0.07975 cm3/g) and specific surface area (132.302–170.919 m2/g) compared to durain (0.03646–0.05187 cm3/g and 114.572–122.827 m2/g, respectively). The coal–water interface contact angles of the low-rank coals are below 90°, indicating a weakly hydrophilic nature. Both cationic (CTAC) and zwitterionic (BS-12) surfactants effectively improved coal wettability. Following wettability modification, the maximum reduction in saturated adsorption capacity reached 48.24%, while the maximum increases in desorption ratio and recovery efficiency were 35.56% and 24.39%, respectively. Durain, due to its stronger inherent hydrophilicity, exhibited greater changes than vitrain. Under simulated extraction conditions, the combined effects of pore structure and wettability differences between the lithotypes led to preferential methane production along the vitrain–durain interfaces.