No. 14: The Impact of Proximity to Wet Markets and Supermarkets on Household Dietary Diversity in Nanjing City, China

Existing studies suggest that despite the proliferation of supermarkets, traditional wet markets have persisted in many countries and have been playing an important role in people’s daily food access. Yet, studies investigating the issue of food access and its influences on food security have mainly focused on food deserts and the proximity to supermarkets, with limited focus on wet markets and other food outlets. This study investigates the influence of the proximity to wet markets and supermarkets on urban household dietary diversity in Nanjing. Based on the data collected through a citywide survey in 2015 and the map data of wet markets and supermarkets, the Poisson regression model was deployed to examine the correlations between geographical proximity to supermarkets and wet markets and household dietary diversity. The results show that the coefficients for the distance to the nearest wet market are not statistically significant. Although the coefficients for the distance to nearest supermarket are statistically significant, they were too minor to be of practical importance. We argue, however, that the insignificant correlations reflect exactly the high physical accessibility to food outlets and the extensive spatially dense food supply network constituted by wet markets, supermarkets and small food stores in Nanjing. This is verified by the survey data that more than 90% of households purchased fresh food items within their neighbourhoods or in walking distance. In addition to the densely distributed food outlets, various other factors contributed to the non-significant influence of the distance to the nearest wet market and supermarket, including the many small food stores within or close to residential communities, the prevalence of three-generation extended households and high household income. This study highlights the importance of allowing mixed land use for food outlets with residential land and integrating wet markets into urban infrastructure planning

Lattice strain effects on the optical properties of MoS2 nanosheets.

"Strain engineering" in functional materials has been widely explored to tailor the physical properties of electronic materials and improve their electrical and/or optical properties. Here, we exploit both in plane and out of plane uniaxial tensile strains in MoS2 to modulate its band gap and engineer its optical properties. We utilize X-ray diffraction and cross-sectional transmission electron microscopy to quantify the strains in the as-synthesized MoS2 nanosheets and apply measured shifts of Raman-active modes to confirm lattice strain modification of both the out-of-plane and in-plane phonon vibrations of the MoS2 nanosheets. The induced band gap evolution due to in-plane and out-of-plane tensile stresses is validated by photoluminescence (PL) measurements, promising a potential route for unprecedented manipulation of the physical, electrical and optical properties of MoS2

Segmented superimposed model of near-bore reservoir pollution skin factor for low porosity and permeability sandstone horizontal gas wells

Drilling and completion processes can often result in reservoir contamination around the wellbore, leading to decreased oil and gas productivity and significant economic losses for the oil field. This issue is particularly complex in sandstone reservoirs with low porosity and permeability horizontal wells, wherein traditional models have limited accuracy and applicability due to numerous unknown parameters. To address this challenge, this study focuses on non-uniform pollution around horizontal wells and proposes a new approach to divide the horizontal well pollution area into N micro-element sections. By establishing a seepage differential equation and employing the similar flow substitution method, we construct models for the pollution skin coefficient of each micro-element section as well as the total pollution skin coefficient. Furthermore, we combine empirical equation models and an oscillation-decreasing function model to develop a pollution radius distribution model that encompasses linear, parabolic, exponential, and logarithmic patterns. Through these advancements, we can realize a comprehensive reservoir damage assessment method. It is verified that the calculation error of this model is very small, and the influence of skin effect and reservoir anisotropy and the radius distribution of various heterogeneous pollution zones are fully considered. These findings indirectly suggest the rationality and practicality of the model presented in this paper. By incorporating actual gas well data into this model, it has been determined through discussion and analysis that the exponential distribution of the pollution radius has the greatest impact on the pollution skin factor along the horizontal well, from the heel to the toe. Increasing the pollution radius and decreasing the pollution permeability both result in an increase in the skin factor of the micro-segment and the total pollution skin factor of the horizontal well. However, compared to the pollution permeability, the radius of the pollution zone has a relatively minor effect on the total pollution skin factor. The proposed technique aims to serve as a valuable tool in optimizing and designing stimulation measures aimed at boosting production and minimizing formation damage. Through evaluation and analysis to reduce risks, protect reservoirs and extend well life, reduce costs, and enhance technical capabilities and economic benefits

Exploration of the impact of demographic changes on life insurance consumption: empirical analysis based on Shanghai Cooperation Organization

Based on the panel data of eight member states of Shanghai Cooperation Organization (SCO) from 1996 to 2019, this study explores the impact of demographic changes on life insurance consumption in SCO member countries under the framework of static panel model and dynamic panel model. And the study analyzes the heterogeneity of religious division and different aging degrees. The empirical results show that both old-age dependency ratio and teenager dependency ratio have positive impacts on life insurance consumption in the SCO countries. Besides, the current consumption of ordinary life insurance significantly stimulates the future consumption of ordinary life insurance. Furthermore, demographic changes have heterogeneous impacts on life insurance consumption in terms of different religions and different degrees of aging. Our findings provide managerial implications for insurance companies that carry out life insurance business in SCO member states. Insurance companies should consider the policyholders’ life insurance consumption in accordance with demographic changes of both old-age dependency ratio and teenager dependency ratio, and also take differentiated life insurance sales strategies according to different degrees of aging and whether the residents believe in Islam