Ye Yuan

External connectivity refers to the service opportunities provided by community open spaces that are influenced by the factors such as traffic distance, road conditions, residence patterns, and population distribution. It is an important factor in determining access to community open spaces. This has important implications for promoting walking behavior and community physical activity among aging urban populations. Using the accessibility evaluation method, we proposed an external connectivity of the community open spaces model from the community perspective and conducted an empirical study using the Overseas Chinese Town community in Shenzhen as an example. External connectivity of the community open spaces can be used to evaluate the efficiency of community open spaces, serving as a reference for open space optimization. Moreover, it has applicable value in promoting physical activity and healthy aging among older adults.

In the production process of biomass energy with crop straw as the raw material, the indoor dust environment created by smashed plant fiber can affect the health of workers and lead to the risk of fire and explosions. The physical properties of biomass vary with the ambient air conditions, resulting in different deposition processes for airborne biomass particles. In this study, the deposition of biomass particles in different environments in an experimental chamber was examined by independently controlling the internal temperature and relative humidity. The results show that in the ambient temperature range of 20~40 °C and at a relative humidity of 25~65%, the water absorption rates of the biomass particles were 15.4~24.7%. The deposition rates of the airborne biomass particles with different sizes were 0.9~2.9 h⁻¹, which positively correlated with the particle sizes in the same ambient conditions. The increase in ambient temperature and relative humidity promoted the deposition of biomass particles with diameters over 0.5 μm. For the particles with diameters below 0.5 μm, the deposition rates were nonlinearly related to the ambient temperature and relative humidity and were greater at lower temperatures. The significance levels of the factors influencing the particle deposition were particle size > ambient temperature > ambient relative humidity. For the biomass particles below 0.5 μm, the influence of the relative humidity on the deposition was much weaker than that of the temperature.