The outbreak of COVID-19 (coronavirus disease 2019) has become the focus of attention in the field of urban geography. Built environment, such as the layout of public spaces like transportation hubs and urban open spaces, is an important factor affecting the spread of the epidemic. However, due to the different behavior patterns of different age groups, the intensity and frequency of their use of various built environment spaces may vary. Based on this, we selected patients that were infected, with a non-manipulated time period, and the classification of human behavior patterns; we then conducted a regression analysis study on the spatial distribution and building environment of these COVID-19 patients. The results showed that the spatial distribution of young and middle-aged patients (18–59 years old) was more homogeneous, while the spatial distribution of elderly patients (60 years old and above) had a strong clustering characteristic. Moreover, the significant built environment factors exhibited in the two populations were extremely different. More diverse urban facilities and public spaces exhibited influential properties for older patients, while middle-aged and young adults were more influenced by commuting facilities. It can be said that the built environment shows different influences and mechanisms on the transmission of respiratory infectious diseases in different populations. Therefore, the results of this paper can inform decision makers who expect to reduce the occurrence of urban respiratory infectious diseases by improving the urban built environment.

The impact of the complex environment and cargo situation on the DUV dose had always been a challenging issue. This study designed a deep-ultraviolet (DUV) disinfection passageway-type system with specific optical design, in which the DUV light modules (wavelength ranging from 270 to 280 nm) were installed on the top, bottom, left, and right surfaces. The DUV inactivation test of staphylococcus aureus (ATCC 6538) and bacillus atrophaeus (ATCC 9372) on two widely used carriers in the food cold chain logistics were conducted in the cryogenic environment. The study found that the impact of temperature, material, or DUV dose on virucidal efficacy were different. The woven bag exhibited significantly poor virucidal efficacy compared to corrugated boxes at DUV dose levels of 37.5 mJ/cm ² and 75.0 mJ/cm ² . However, at higher DUV doses (e.g., 150.0 mJ/cm ² , 225.0 mJ/cm ^2, and 450.0 mJ/cm ² ), the woven bag demonstrated notably superior virucidal efficacy when compared to corrugated boxes. Furthermore, the work have simulated the DUV light uniformity, optimized the inner light distribution, and analyzed the influence of material reflectivity for the evaluation of the disinfection effect in the cryogenic environment.