Research on charging behavior of electric vehicles based on multiple objectives.

This paper proposes a multi-objective queuing charging strategy for electric vehicles (EVs) based on metrics of public interest. It combines common charging modes, such as random charging mode, tariff-guided mode and stop-and-charge mode. It introduces the problem of queuing charging for EVs by considering the realistic imbalances of vehicle-pile ratios in these common modes. A travel model and a charging model were developed in this study. Experiments prove that the proposed strategy has the highest comprehensive evaluation index, achieves the aim of low charging cost and high travel rate and considers the queuing problem, which is unavoidable in reality. It improves the convenience of life and reduces the charging cost. The proposed strategy smoothens the EV charging load curve, largely reducing the burden of charging load fluctuations on the grid and achieving a win-win situation for both supply and demand.

Effects of attapulgite on the growth status of submerged macrophytes Vallisneria spiralis and sediment microenvironment.

The effects of raw attapulgite clay and thermally modified attapulgite clay on the growth status of submerged plant Vallisneria Spiralis (V. spiralis) and the microenvironment of sediment were first explored. The results demonstrated that the attapulgite could effectively promote the development of V. spiralis and improve plant stress resistance by enhancing the activity of antioxidant enzymes. The 10% addition of attapulgite clay increased the biomass of V. spiralis by 27%∼174%, and the promoted rate of raw attapulgite clay was 2∼5 times of modified attapulgite clay. The attapulgite increased redox potential in sediment (P < 0.05) and provided proper niches for organism propagation, further promoting the degradation of organic matter and nutrient metabolism in sediment. The value of Shannon, Chao, and Ace was 9.98, 4865.15, 5029.08 in the 10% modified attapulgite group, and 10.12, 4856.85, 4947.78 in the 20% raw attapulgite group, respectively, indicating that the attapulgite could increase the microbial diversity and abundance in sediment. Additionally, the nutrient elements, such as Ca, Na, S, Mg, K, Zn, and Mo, that dissolved from attapulgite may also promote the V. spiralis growth. This study provided an environment-friendly approach to facilitating submerged macrophyte restoration in the eutrophic lake ecosystem.