Key biogeochemical processes and source apportionment of nitrate in the Bohai Sea based on nitrate stable isotopes.

Excessive nitrate input is one of the primary factors causing nearshore eutrophication. This study applied the nitrate stable isotope techniques to analyse the biogeochemical processes and sources of nitrate in the Bohai Sea (BHS). The results showed that intensive NO3- assimilation probably occurred at surface in summer, while nitrification primarily occurred in the Yellow River diluted water. In autumn, regional assimilation and nitrification were still identified. For avoiding the interference from assimilation, the isotopic fractionations were further calculated as correction data for the quantitative analysis of nitrate sources. The river inputs were identified as the primary source of nitrate in the BHS in summer and autumn, accounting for >50 %, and the atmospheric deposition was the secondary source. This study provides quantitative data for evaluating the significance of river inputs to the nearshore nitrate, which will be beneficial to policy formulation on the BHS eutrophication control.

Processing of fearful faces exhibits characteristics of subcortical functions.

A subcortical pathway is thought to have evolved to facilitate fear information transmission, but direct evidence for its existence in humans is lacking. In recent years, rapid, preattentive, and preconscious fear processing has been demonstrated, providing indirect support for the existence of the subcortical pathway by challenging the necessity of canonical cortical pathways in fear processing. However, direct support also requires evidence for the involvement of subcortical regions in fear processing. To address this issue, here we investigate whether fear processing reflects the characteristics of the subcortical structures in the hypothesized subcortical pathway. Using a monocular/dichoptic paradigm, Experiment 1 demonstrated a same-eye advantage for fearful but not neutral face processing, suggesting that fear processing relied on monocular neurons existing mainly in the subcortex. Experiments 2 and 3 further showed insensitivity to short-wavelength stimuli and a nasal-temporal hemifield asymmetry in fear processing, both of which were functional characteristics of the superior colliculus, a key hub of the subcortical pathway. Furthermore, all three experiments revealed a low spatial frequency selectivity of fear processing, consistent with magnocellular input via subcortical neurons. These results suggest a selective involvement of subcortical structures in fear processing, which, together with the indirect evidence for automatic fear processing, provides a more complete picture of the existence of a subcortical pathway for fear processing in humans. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

An empirical study on 'how to retain rural teachers with emphasis on hygiene or motivation factors': A case of Western China.

How to retain prominent teachers is a fundamental problem for rural education in less developed countries. However, the critical institutional factors affecting teachers' turnover intention still need to be better understood. According to Herzberg's motivation-hygiene theory, this study examines the effects of hygiene factors (rural incentive policy, personnel policy, and teacher pay) and motivation factors (advancement, work itself, and achievement) on rural teachers' turnover intention. Based on a sample of 973 rural teachers, the results from structural equation modeling (SEM) showed that both hygiene factors and motivation factors can significantly reduce the turnover intention of rural teachers. Meanwhile, the effect of motivation factors is greater than that of hygiene factors. It was also confirmed that marital status, age, and teaching subject have a significant moderation effect on the relationship between motivation/hygiene factor and turnover intention, whereas gender has no significant moderation effect. Theoretical and practical implications for attracting and retaining rural teachers are discussed.

Fabrication of double core-shell Si-based anode materials with nanostructure for lithium-ion battery.

Yolk-shell structure is considered to be a well-designed structure of silicon-based anode. However, there is only one point (point-to-point contact) in the contact region between the silicon core and the shell in this structure, which severely limits the ion transport ability of the electrode. In order to solve this problem, it is important that the core and shell of the core-shell structure are closely linked (face-to-face contact), which ensures good ion diffusion ability. Herein, a double core-shell nanostructure (Si@C@SiO2) was designed for the first time to improve the cycling performance of the electrode by utilising the unique advantages of the SiO2 layer and the closely contacted carbon layer. The improved cycling performance was evidenced by comparing the cycling properties of similar yolk-shell structures (Si@void@SiO2) with equal size of the intermediate shell. Based on the comparison and analysis of the experimental data, Si@C@SiO2 had more stable cycling performance and exceeded that of Si@void@SiO2 after the 276th cycle. More interestingly, the electron/ion transport ability of electrode was further improved by combination of Si@C@SiO2 with reduced graphene oxide (RGO). Clearly, at a current density of 500 mA g-1, the reversible capacity was 753.8 mA h g-1 after 500 cycles, which was 91% of the specific capacity of the first cycle at this current density.