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In this paper, a variable gear ratio for active steering systems with a double planetary gear configuration is presented to optimize the steering performance of commercial vehicles. First, a variable transmission ratio system with a dual-row planetary gear mechanism is developed in ADAMS/Car, where the steering mechanism's transmission ratio can be adjusted according to different driving conditions, thereby improving the vehicle's stability and sensitivity. Second, a new type of dual-inverter permanent magnet synchronous motor (DPMSM) has been designed to solve the power limitation problem in the electric drive steering of commercial vehicles. Finally, the step steering and lane change driving scenarios are chosen for co-simulation using ADAMS/Car and MATLAB to evaluate the proposed method's effectiveness. The co-simulation results show that the proposed variable transmission ratio and control strategy can effectively improve the steering sensitivity and stability of commercial vehicles. [ABSTRACT FROM AUTHOR]

A survey was conducted on the surface water samples of Ningyuan River in Hainan Province. The samples were collected through on-site filtration and concentration methods, and pretreated through oxidation digestion and density separation. The microplastics were statistically analyzed by confocal micro-Raman spectrometer, elucidating the abundance, type, particle size, and shape characteristics of the microplastics in the water samples. Seasonal differences were analyzed, and the main conclusions were as follows: microplastics were detected at all sampling points, with the abundance range of 66.67 items/m3 to 1106.67 items/m3; polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), and polystyrene (PS) are the main types of microplastics; 100-1000 μm is the main particle size distribution range; the proportion order of microplastics with different shapes is fiber> fragment> film> particle. In terms of spatial distribution, there are significant differences due to the influence of functional zones along the river banks, while in terms of seasonal distribution, there is no significant difference between dry and rainy seasons; The overall level of microplastic pollution belongs to a medium to low risk.

Hainan Island, China’s second largest island, is located in the tropics and its rivers are significantly affected by precipitation. With the construction of free trade port with Chinese characteristics, Hainan Island’s industry, agriculture, tourism and urbanization have developed in an all-round way. With the rapid development of economy, water environment ecology has been destroyed. Based on the two seasons of drought and rain, this paper took Ningyuan River and Wanquan River as the research object to study the spatial and temporal distribution of nitrogen and phosphorus nutrients in the rivers entering the sea in Hainan, and found that the concentration of nutrients in Ningyuan River was higher than that in Wanquan River. The total nitrogen pollution in dry season was higher than that in rainy season, and that in tributaries was higher than that in main stream. The maximum nitrogen content in Ningyuan River reached 2.99 mg/L and 2.37 mg/L in the dry season and rainy season, and human activities were the main reason for the increase of nutrient concentration.

Heavy metals are of wide concern due to their high toxicity, bioaccumulation and non-degradability. In this study, eight heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, Pb) in the surface sediments of Ningyuan River were studied to investigate the distribution pattern, pollution status and potential pollution sources, and it was concluded that the concentration distribution of heavy metals in sediments is highly consistent with the population distribution pattern in space and there is a certain degree of risk of Cd pollution, and the heavy metals mainly come from mineral weathering, agricultural and shipping wastes.

Education resources refer to the sum of all manpower, material resources and financial resources invested in educational activities, which are scarce and mobile. On the one hand, due to the particularity of educational industry, education can’t provide education for everyone, and it’s also impossible for the state and society to put all resources into education due to the constraints of regional economic and social development. The allocation of educational resources is regional, and a balanced allocation of educational resources will have a great impact on the overall level of vocational education in different regions. Its coordination with regional economic development is also one of the indicators to evaluate educational resources. Therefore, the development status of each region is probably caused by the difference of education level. The influence of education on regional economic development has also become a hot topic discussed by scholars. In this paper, the influence of educational resources on regional economic development is further studied, and the research shows that the coordinated development of education and economy just adapts to Scientific Outlook on Development Thought of rapid, sound and balanced development. Education and economic development are mutually reinforcing and interdependent. The development of education promotes the economy, which in turn can provide more development resources and opportunities for education.

Objective: The objective of this study is to develop a novel automatic convolutional neural network (CNN) that aids in the diagnosis of meniscus injury, while enabling the visualization of lesion characteristics. This will improve the accuracy and reduce diagnosis times. Methods: We presented a cascaded-progressive convolutional neural network (C-PCNN) method for diagnosing meniscus injuries using magnetic resonance imaging (MRI). A total of 1396 images collected in the hospital were used for training and testing. The method used for training and testing was 5-fold cross validation. Using intraoperative arthroscopic diagnosis and MRI diagnosis as criteria, the C-PCNN was evaluated based on accuracy, sensitivity, specificity, receiver operating characteristic (ROC), and evaluation performance. At the same time, the diagnostic accuracy of doctors with the assistance of cascade- progressive convolutional neural networks was evaluated. The diagnostic accuracy of a C-PCNN assistant with an attending doctor and chief doctor was compared to evaluate the clinical significance. Results: C-PCNN showed 85.6% accuracy in diagnosing and identifying anterior horn injury, and 92% accuracy in diagnosing and identifying posterior horn injury. The average accuracy of C-PCNN was 89.8%, AUC = 0.86. The diagnosis accuracy of the attending physician with the aid of the C-PCNN was comparable to that of the chief physician. Conclusion: The C-PCNN-based MRI technique for diagnosing knee meniscus injuries has significant practical value in clinical practice. With a high rate of accuracy, clinical auxiliary physicians can increase the speed and accuracy of diagnosis and decrease the number of incorrect diagnoses. [ABSTRACT FROM AUTHOR]

In this article, we aim to review the diagnosis, classification, and treatment of acromioclavicular joint injury by mainly describing the progress of surgical treatment for acromioclavicular joint injury, providing a reference for clinical diagnosis and treatment. Acromioclavicular joint injury is a common sports injury, which is more common in male than in female patients. The mechanism of the injury is mainly caused by direct or indirect violence, which can be clearly diagnosed by radiography. According to the time after injury, it can be divided into acute injury and chronic injury. The Rockwood classification is the most commonly used classification in research. For Rockwood types V to VI, we treat with surgery, while the treatment options for type III are controversial and no consensus has been reached. Surgical treatment can be divided into open surgery and shoulder arthroscopy. The methods of open surgery can be divided into 3 categories: direct acromioclavicular joint fixation, coracoclavicular space suspension device fixation, and coracoclavicular ligament reconstruction. The shoulder arthroscopy method involves reconstruction of the coracoclavicular ligament under arthroscopy, combined with suture-button suspension fixation. For patients with Rockwood classification III and IV-VI, who have significant movement needs, surgery is the preferred treatment for acute acromioclavicular dislocation within 3 weeks. For patients with a chronic acromioclavicular dislocation or who do not respond to nonsurgical treatment, it is recommended to use wire suspension fixation combined with ligament to repair the damage. This article aims to review advances in the management of acromioclavicular joint injury.