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To investigate the air quality status and identify factors influencing air pollution, data on CO2, formaldehyde, PM2.5, PM10, temperature, and humidity were measured in a high-speed train carriage of the Changsha-Zhuzhou intercity in southwest China. In the test section, CO2, formaldehyde, relative humidity, and temperature exceeded the standard levels, and their compliance rates were 84%, 96%, 84%, and 76%, respectively. Then the influencing factors of pollutants were analyzed from three aspects: driving environment, the number of passengers, and relative humidity. Results show that the percentage of PM2.5 to PM10 in tunnel environments was higher; the increase in the number of passengers led to the elevation of CO2 concentration in the carriage, while only in the ground environment, the number of passengers significantly correlated with particulate matter; the increase in relative humidity promotes the production and release of particulate matter and formaldehyde. Finally, fitting relationships between relative humidity and formaldehyde, as well as the number of passengers and CO2 were established to predict the air quality status. It indicated that when the relative humidity of the carriage is less than 73%, the formaldehyde solubility was easy to exceed standards, and when the number of passengers was greater than 70, the CO2 was easy to exceed standards.

Objective This study analyzes, summarizes and summarizes the hot spots and trends of integrated medical and nursing care in China, and provides theoretical basis for the future related scientific research. Methods The CiteSpace Knowledge Graph visualization and analysis tool was used to conduct a basic statistical analysis of the literature on the theme of “health care integration” collected in the China Knowledge Network (CNKI) database from 2005 to 2022, to understand the annual publication volume and trends, research institutions and authors, high frequency keyword co-occurrences analysis. Results A total of 3534 articles were included. The analysis shows an explosive growth in the number of articles published each year after 2013.High-frequency keywords include medical and health care integration, elderly care services and elderly care models. Conclusion In recent years, the hot research fields of the combination of medical and nursing care in China include elderly care service, smart community home care model, and research on the elderly and disabled elderly. This paper predicts that the research field of the combination of medical and nursing care will continue to expand, and the research on the combination of medical and nursing care will develop toward the trend of diversification.

Large thick aperture imaging method is proposed to measure the radiation intensity distribution of radiation source whose size is several centimetres. The new method contains two steps which are coded imaging and image reconstruction. Geant4 is used to simulate the coded imaging process. Wiener filter, Lucy-Richardson, Regularized filter, blind deconvolution and CT reconstruction method are realized using Matlab software. Wiener filter and Regularized filter produce artifacts. CT reconstruction method can’t reveal the right size of 60Co-γ source because of the overlapping of knife edge images. Both L-R and blind deconvolution are effective. If the aperture is moved 0 mm, 2 mm, 4 mm, 6 mm along x-axis, the reconstruction result using L-R method has a larger correlation coefficient with source image. However, L-R method gets bad result if the aperture rotates more than 1.4°. Under this condition, blind deconvolution is the better choice.