Effects of PM_2.5and O₃on Human Health at a Suburban Area of Beijing, China

This work investigates the impact of air pollution on human health in China. First-hand data obtained at a suburban area of Beijing between January 2014 and June 2016 forms the basis for our study. It is hypothesized that there is a statistically significant relationship between lung cancer incidences and levels of air pollutants, in particular, PM2.5 and O3. Methods of analysis include correlation analysis, multiple regression, and trend analysis. Our results verify the hypothesis, and reveal that the high rates of lung cancer development in the studied period of 30 months can be interpreted by the high concentration of PM2.5 and O3 using the Poisson linear regression model. It is also discovered that PM2.5 and O3 have a strong negative correlation and they alternatingly serve as the primary contributor of high rates of lung cancer in cold and warm seasons. Also, men are found to have a higher rate of developing lung cancer than women, and middle-aged people are most likely to develop lung cancer compared to the elderly and youth.

Electronic structure of silicene

In this topical review, we discuss the electronic structure of free-standing silicene by comparing results obtained using different theoretical methods. Silicene is a single atomic layer of silicon similar to graphene. The interest in silicene is the same as for graphene, in being two-dimensional and possessing a Dirac cone. One advantage of silicene is due to its compatibility with current silicon electronics. Both empirical and first-principles techniques have been used to study the electronic properties of silicene. We will provide a brief overview of the parameter space for first-principles calculations.However, since the theory is standard, no extensive discussion will be included. Instead, we will emphasize what empirical methods can provide to such investigations and the current state of these theories. Finally, we will review the properties computed using both types of theories for free-standing silicene, with emphasis on areas where we have contributed.Comparisons to graphene is provided throughout.

The Rings Characterized by Minimal Left Ideals

We study these rings with every minimal left ideal being a projective, direct summand and a p-injective module, respectively. Some characterizations of these rings are given, and the relations among them are obtained. With these rings, we characterize seinisiinple rings. Finally, we introduce MC2 rings, and give some characterizations of MC2 rings.