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At present, the main structural form of sprocket body generally adopts the integral structure at home and abroad, which is difficult to reverse and maintain. The split sprocket shaft group has great advantages in maintenance cost and convenience compared with the integral sprocket shaft group. According to the classical theoretical mechanics, the force analysis of the split sprocket body with new structure is carried out. It is combined with the results of finite element analysis, and then the calculation method of the split sprocket body connection structure design is obtained. This research provides the research method of force analysis of the split sprocket, which can provide necessary loads and constraints for design calculation and finite element analysis. When the split sprocket body is connected by connecting screws, cylindrical pins are set between the upper and lower sprocket bodies to transmit torque, which can ensure the connection reliability of the scraper sprocket of the existing high-power heavy scraper under the conditions of limited installation space and limited number of connecting bolts. Thus it can provide reference and theoretical guidance for the design of similar sprocket bodies in the future.

The Metaverse has been the centre of attraction for educationists for quite some time. This field got renewed interest with the announcement of social media giant Facebook as it rebranding and positioning it as Meta. While several studies conducted literature reviews to summarize the findings related to the Metaverse in general, no study to the best of our knowledge focused on systematically summarizing the finding related to the Metaverse in education. To cover this gap, this study conducts a systematic literature review of the Metaverse in education. It then applies both content and bibliometric analysis to reveal the research trends, focus, and limitations of this research topic. The obtained findings reveal the research gap in lifelogging applications in educational Metaverse. The findings also show that the design of Metaverse in education has evolved over generations, where generation Z is more targeted with artificial intelligence technologies compared to generation X or Y. In terms of learning scenarios, there have been very few studies focusing on mobile learning, hybrid learning, and micro learning. Additionally, no study focused on using the Metaverse in education for students with disabilities. The findings of this study provide a roadmap of future research directions to be taken into consideration and investigated to enhance the adoption of the Metaverse in education worldwide, as well as to enhance the learning and teaching experiences in the Metaverse.

The tooth surface of spiral bevel gears is a spatial curved surface, and the change of tooth surface roughness can have a significant impact on its meshing performance, directly affecting the vibration, bearing and other performance of the system. A theoretical simulation and an experimental research of an aviation spiral bevel gear is carried out using the parallel spindle type barrel finishing process, a mathematical model of the process motion is established, the formula of cutting speed between abrasive and tooth surface is deduced, and the main factors affecting the result are analyzed; with the help of the Hertz-Mindlin with archard wear model of the EDEM software, the tooth surface wear is simulated; through this process, the surface quality of the disc spiral bevel gear surface is experimentally studied. The results show that using this process, the burr of the gear surface can be eliminated, the corner is rounded, the Ra of gear surface is reduced from 0.8 μm to about 0.4 μm, and the tooth surface morphology tends to be isotropic, which lays a foundation for further research of gear contact performance and industrial application.

Effective delivery of therapeutic agents for solid tumour treatment is impeded by multiple obstacles, such as aberrant interstitial fluid pressure and high density of the extracellular matrix, which causes impaired penetration to deep avascular tumour tissue that exists in a hypoxic immune cold environment. Only limited tumoricidal effects have been achieved with traditional nanomedicine due to its inefficient penetration and the multiple resistant effects that exist in the tumour microenvironment. Herein, a new chemo-dynamic immunotherapy (CDIT) is proposed based on a transcytosis tumour oxygenator (MnPO2/MC3) with effective chemo-dynamic effects. As a CDIT agent, MnPO2/MC3 is designed and synthesized to enhance deep tumour tissue penetration as well as provide relief of hypoxia to decrease immunosuppression. MnPO2/MC3 is orchestrated by an inner manganese core and double lipid outer layer. The outer layer is constructed by a tumour pH-cationizable outer lipid (D-Lin-MC3-DMA, MC3) layer and O2-loading inner layer. The MC3 lipid endows MnPO2/MC3 with tumour-responsive transcytosis potential, which instead delivers oxygen and Mn deep into tumour tissues. MnPO2/MC3 catalyses hydrogen peroxide to hydroxyl radicals by Mn2+ and increases CD8+ T cell infiltration. The oxygenation and ROS burst by MnPO2/MC3 effectively altered the tumour cold immune microenvironment so that adaptive anti-tumoral immunity was enhanced. MnPO2/MC3-mediated CDIT serving as an effective tumour oxygenator and ROS initiator, effectively suppressed tumour growth while enhancing adaptive anti-tumour immunity. [ABSTRACT FROM AUTHOR]

A series of fire experiments in a 1/10 scale model tunnel with a lateral open shaft were conducted. Analysis was performed to explore the maximum excess temperature and longitudinal temperature decay under the influence of a mechanical exhaust system with a lateral open shaft. Three different pool sizes and numerous extraction rates were considered. The experimental results yielded intriguing insights into the correlations between the rate of smoke extraction and the ceiling temperature. The variations in the temperature distribution of ceiling smoke upstream and downstream the fire source is different under the induced longitudinal velocity, especially for the near the fire source area. An analysis of the maximum excess temperature was conducted by inducing the heat loss coefficient . It is 0.85 (0.71) for the induced dimensionless longitudinal velocity , which indicates the effect of a large velocity on the smoke heat loss. Then, a modified model of the maximum excess temperature was given for a tunnel utilizing lateral open shaft smoke extraction. In addition, a simple model was proposed to capture ceiling temperature decay, where the decay coefficients upstream and downstream of the fire source are proportional to () for . The research results have certain guiding significance for the arrangement of fire protection, fire monitoring and early warning devices in mountain tunnels. [ABSTRACT FROM AUTHOR]