Pentacoordinate Al3+ Sites Anchoring Synthesis of Palladium Intermetallic Catalysts on Al2O3 Supports.

Size control of supported Pd-based intermetallic nanoparticles (i-NPs) remains a major challenge because the required high-temperature annealing for atomic diffusion and ordering easily causes metal sintering. Here, we described a pentacoordinate Al3+ site (Al3+penta) anchoring approach for the preparation of Pd-based i-NPs with controlled size, which takes advantage of the strong chemical interaction between Al3+penta sites and Pd-based i-NPs to realize size control. We synthesized six types of Pd-based i-NPs, and four of them can remain an average particle size of <6 nm. Furthermore, one of our prepared Pd-based i-NPs (that is, Pd3Pb) demonstrated outstanding performance in catalyzing the semihydrogenation of phenylacetylene.

Promoting ordering degree of intermetallic fuel cell catalysts by low-melting-point metal doping.

Carbon supported intermetallic compound nanoparticles with high activity and stability are promising cathodic catalysts for oxygen reduction reaction in proton-exchange-membrane fuel cells. However, the synthesis of intermetallic catalysts suffers from large diffusion barrier for atom ordering, resulting in low ordering degree and limited performance. We demonstrate a low-melting-point metal doping strategy for the synthesis of highly ordered L10-type M-doped PtCo (M = Ga, Pb, Sb, Cu) intermetallic catalysts. We find that the ordering degree of the M-doped PtCo catalysts increases with the decrease of melting point of M. Theoretic studies reveal that the low-melting-point metal doping can decrease the energy barrier for atom diffusion. The prepared highly ordered Ga-doped PtCo catalyst exhibits a large mass activity of 1.07 A mgPt-1 at 0.9 V in H2-O2 fuel cells and a rated power density of 1.05 W cm-2 in H2-air fuel cells, with a Pt loading of 0.075 mgPt cm-2.

An Empirical Study on the Relationship among Mental Health, Learning Engagement, and Academic Self-Efficacy of Senior High School Students.

This study examines the mediating role of the academic self-efficacy of high school students in Tibetan and Qiang areas of China on the relationship between their mental health and learning engagement, as well as their gender and grade-specific differences in mental health, learning engagement, and academic self-efficacy. The authors drew 600 valid samples in Tibetan and Qiang areas of China, built a measurement model and a structure model, established a structural equation model comprising the mental health scale, the learning engagement scale, and the academic self-efficacy scale, and conducted an independent sample t-tests and a one-way analysis of variance. The questionnaires took the form of the 5-point Likert scale. This research shows that the mental health of high school students in Tibetan and Qiang areas of China has a significant positive impact on their learning engagement and academic self-efficacy and that their academic self-efficacy has a significant positive impact on their learning engagement. Academic self-efficacy produces an overwhelming mediating effect on the ways mental health influences learning engagement. High school students, male and female, in Tibetan and Qiang areas of China show no marked gender-specific differences in mental health, learning engagement, and academic self-efficacy, while junior high school students show marked grade-specific differences in mental health, and senior high school students show marked grade-specific differences in learning engagement and academic self-efficacy. This article concludes that improving the academic self-efficacy of high school students in Tibetan and Qiang areas of China can boost their learning engagement.

A Decision-Making System for Low Carbon Manufacturing.

Based on the stochastic market demand of products, this paper studies the low-carbon manufacturing decisions making of manufacturing enterprises considering downward substitution and green technology input under the carbon cap-and-trade policy. The results show that the government's carbon trade policy will have a great impact on the production of manufacturing enterprises. Therefore, manufacturing enterprises must attach importance to the constraints of the government's carbon emission reduction policies. In terms of it, there are strategies for manufacturing enterprises such as adjusting the output, trading the carbon emission right, and so on. On this case, green technology input can increase the expected profit of manufacturing enterprises, especially in the case of downward substitution.

Reducing greenhouse gas emissions: a duopoly market pricing competition and cooperation under the carbon emissions cap.

This article studies the price competition and cooperation in a duopoly that is subjected to carbon emissions cap. The study assumes that in a departure from the classical Bertrand game, there is still a market for both firms' goods regardless of the product price, even though production capacity is limited by carbon emissions regulation. Through the decentralized decision making of both firms under perfect information, the results are unstable. The firm with the lower maximum production capacity under carbon emissions regulation and the firm with the higher maximum production capacity both seek market price cooperation. By designing an internal carbon credits trading mechanism, we can ensure that the production capacity of the firm with the higher maximum production capacity under carbon emissions regulation reaches price equilibrium. Also, the negotiation power of the duopoly would affect the price equilibrium.