Geometrical, electronic, and magnetic properties of small Co

The configurations, stabilities, electronic, and magnetic properties of ConAu (n = 1–9) clusters have been systematically investigated by using relativistic all-electron density functional theory with generalized gradient approximation. The growth way for ConAu (n = 1, 3–7) clusters is Au-substituted Con+1 clusters. And the growth way for ConAu (n = 2, 8, 9) clusters is that the Au atom occupies a peripheral position of Con clusters. The fragmentation energy and the second-order difference energy of the ground-state ConAu clusters show a pronounced odd-even oscillation with the number of Co atoms, and the clusters exhibit higher stability at n = 5. Compared with corresponding pure Con+1 clusters, the total magnetic moment is reduced by 2μB for most of ConAu clusters except n = 3 and 8. The magnetic moment contribution of Au atom is very small, and the doping-Au atom almost has no effect on the average magnetic moment of Co atom which still keeps about 2μB of magnetism of pure Con+1 clusters, resulting in the decreasing magnetism of the doping-Au cobalt clusters

Structure, stability, and electronic and magnetic properties of small Rh

The structure, stability, and magnetic properties of Rhn+1 and RhnMn clusters (n = 1–12) are systematically investigated within the framework of the generalized gradient approximation density-functional theory (DFT-GGA). The overall structural evolutionary trend shows that the ground state structures of the RhnMn are similar to that of the corresponding pure rhodium clusters except for n = 7, 9, 12, while the Rh7Mn, Rh9Mn and Rh12Mn clusters occur substantially geometry reconstruction. The binding energy of RhnMn is decreased with the substitution of one Mn atom, thus indicating that Mn doping can weaken the stability of the Rh clusters. The fragmentation energy and the second-order difference energy of the ground-state RhnMn clusters imply that the Rh3Mn, Rh5Mn, Rh8Mn and Rh11Mn clusters are more stable than their neighbors. Compared with corresponding pure Rhn clusters, the Mn atom doping increases the total magnetic moment of the RhnMn clusters in various degrees, and the physics origin of such a phenomenon is analyzed in detail based on the average bond length, magnetic coupling, and density of state

Psychological stress alters the ultrastructure and increases IL-1β and TNF-α in mandibular condylar cartilage

Psychological factors can be correlated with temporomandibular disorders (TMDs), but the mechanisms are unknown. In the present study, we examined the microstructural changes and expression of proinflammatory cytokines in mandibular condylar cartilage of the temporomandibular joint (TMJ) in a psychological stress animal model. Male Sprague-Dawley rats (8 weeks old, 210 ± 10 g) were randomly divided into 3 groups: psychological stress (PS, N = 48), foot shock (FS, N = 24), and control (N = 48). After inducing psychological stress using a communication box with the FS rats for 1, 3, or 5 weeks, PS rats were sacrificed and compared to their matched control littermates, which received no stress and were killed at the same times as the PS rats. Body and adrenal gland weight were measured and corticosterone and adrenocorticotropic hormone levels were determined by radioimmunoassay. After hematoxylin-eosin staining for histological observation, the ultrastructure of the TMJ was examined by scanning electron microscopy. Transcription and protein levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were evaluated by ELISA and semi-quantitative RT-PCR. The PS group showed a significantly higher adrenal gland weight after 3 weeks of stress and higher hormone levels at weeks 1, 3, and 5. Histopathological changes and thinning cartilage were apparent at weeks 3 and 5. In the PS group, TNF-α increased at 1, 3, and 5 weeks and IL-1β increased significantly after 1 and 3 weeks of stress, and then decreased to normal levels by 5 weeks. Psychological stress increased plasma hormone levels and RT-PCR indicated increased IL-1β and TNF-α expression in the TMJ in a time-dependent manner. These results suggest that cytokine up-regulation was accompanied by stress-induced cartilage degeneration in the mandibular condyle. The proinflammatory cytokines play a potential role in initiating the cartilage destruction that eventually leads to the TMDs

Analysis on Localized Corrosion Causes of Galvanized Al-Mg Steel Plate Coated with Chromium Free Passivator and Antirust Oil

In order to explore the corrosion mechanism of galvanized Al-Mg steel plate coated with chromium-free passive solution and anti-rust oil in the transportation environment，XPS and EDS were used to analyze the element differences in the color-difference zone.The microstructure of chromium-free passive film of the galvanized sheet before and after corrosion was investigated by atomic force microscope.Raman spectroscopy was used to analyze the curing mechanism and protection process of coated chromium-free passivator.Results showed that the reaction between the components of antirust oil and passive film affected the antirust performance of the coating film.Raman spectrum revealed that the cured plate could be cured more completely by increasing the temperature to 90 ℃，and the anti-rust ability was obviously enhanced

Microenvironment engineering for the electrocatalytic CO₂ reduction reaction

Rather than just focusing on the catalyst itself in the electrocatalytic CO2 reduction reaction (eCO2 RR), as previously reviewed elsewhere, we herein extend the discussion to the special topic of the microenvironment around the electrocatalytic center and present a comprehensive overview of recent research progress. We categorize the microenvironment based on the components relevant to electrocatalytic active sites, i.e., the catalyst surface, substrate, co-reactants, electrolyte, membrane, and reactor. Supported by most of the reported articles, the relevant factors affecting the catalytic performance of eCO2 RR are then discussed in detail, and existing challenges and potential solutions are mentioned. Perspectives for the future research on eCO2 RR, including the integration of different microenvironment factors, the extension to industrial application by coupling with carbon capture and conversion, and separation of products, are also discussed.This work was financially supported by the National Natural Science Foundation of China (51872209, 52072273), Zhejiang Provincial Special Support Program for High-level Talents (2019R52042), and Wenzhou basic scientific research project (No.2020G0076). J. J. Lv would like to acknowledge the Start-up Fund of Wenzhou University (QD2021152)