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The present study endeavored to tackle the challenges posed by limited diversity in oat varieties and suboptimal nitrogen fertilizer utilization in the arid landscapes of the Loess Plateau. We selected three oat varieties, including early-maturing oats (E), medium-maturing oats (M), and late-maturing oats (L). In 2022, four nitrogen applications were set up as CK (0 kg N ha−1), N1 (60 kg N ha−1), N2 (90 kg N ha−1), and N3 (120 kg N ha−1). We introduced two additional nitrogen applications, N4 (180 kg N ha−1) and N5 (240 kg N ha−1), in 2023. The two-year study results demonstrated a significant increase in oat yield due to nitrogen application (p < 0.05). The highest grain yield was observed for E oats at 2216.63 kg·ha−1 under the N3 treatment, while M and L oats had the highest grain yields at 2505.43 kg·ha−1 and 2946.30 kg·ha−1 under N4, respectively. The protein content of L oats reached a peak of 14.15% under N4, and the order of protein contents in oat protein components was globulin > gliadin> glutenin > albumin. The β-glucan content of L oats reached a peak of 4.92% under N3. The nitrogen fertilizer utilization efficiency (NFUE) of the three oats was highest under N2. L oats exhibited enhanced NFUE owing to an elevated pre-flowering nitrogen translocation amount (PrNTA), with a 42.94% and 29.51% increase relative to E and M oats, respectively. The pre-flowering nitrogen translocation contribution (PrNTC) in oats surpassed the post-flowering nitrogen accumulation contribution (PoNAC). Therefore, nitrogen application positively impacted oat growth, yet excessive application had an inhibitory effect. There is a significant positive correlation among oat yield, quality, nitrogen accumulation, and utilization efficiency. In summary, oat crops exhibited optimal performance in terms of yield, quality, and nitrogen use efficiency when nitrogen application rates ranged between 90 and 180 kg·ha−1. Late-maturing oats coincide with the rainy and hot season in the northern dryland regions, making them more suitable for planting in the dryland areas of the Loess Plateau. [ABSTRACT FROM AUTHOR]

As a modern means of transportation, the automobile plays an important role in people's travel. However, the environmental and energy problems brought by the automobile industry cannot be ignored. Based on unique Chinese urban and new car registration data, this paper empirically analyzes the emission reduction effect of car purchase tax incentives, its spatial heterogeneity, and impact on car consumption structure using difference-in-difference model, regression discontinuity design model, and other methods. We find that the tax incentives can effectively suppress the emission of urban pollutants. The quantile regression shows that the emission reduction effect of the tax incentives shows a dynamic change characteristic of weakening as the pollution level in cities increases. In addition, tax incentives for the purchase of low-energy consumption vehicles increase the market share of small-emission vehicles and change the consumption structure., Author(s): Kai Lisa Lo [1]; Yaqi Fan [1]; Congzhi Zhang [1]; Jackson Jinhong Mi (corresponding author) [1] 1. Introduction Since 1978, China has maintained high economic growth and become the [...]

Purpose: Soil electro-kinetic remediation (EKR) has received significant attention owing to its environmental sustainability. Water electrolysis at electrode surface changes the pH profile of soil water. The pH profile has a strong impact on EKR performances. The aims of this study were to quantify the mass transfer of H+ and OH− and investigate the coupled relationship among H+ and OH− mass transfer, electric field and porous fluid flow. Materials and methods: Herein, multi-dimensional (1D and 2D) models capable of coupling fluid flow and mass transfer were established to study the coupled relationship among H+ and OH− mass transfer, electric field and porous fluid flow. The multi-dimensional (1D and 2D) models were validated by lab scale experiments. Results and discussion: The characteristics of pH front and pH profile was proven to be dominated by electric field, mass transfer and porous fluid flow. The movement of pH front and pH profiles dominates the EKR performance. The conductivity rise and the electric field distribution variations were quantified and proven to be caused by the H+ and OH− mass transfer. After a certain EKR time, in the areas near the electrodes where the H+ and OH− are generated, the mass transfer flux of H+ and OH− is gradually close to its releasing rate, the ionic species H+ and OH− stop accumulating and the concentration of both tends to steady state, so does the conductivity. Conclusions: We demonstrated that the coupled relationship among mass transfer of H+ and OH−, electric field, and porous fluid flow dominates the movement of pH profiles and the conductivity rise. [ABSTRACT FROM AUTHOR]