From 59Co and 23Na NMR, we demonstrate the impact of the Na+ vacancy ordering on the cobalt electronic states in Na0.75CoO2: at long time scales, there is neither a disproportionation into 75% Co3+ and 25% Co4+ states, nor a mixed-valence metal with a uniform Co3.25+ state. Instead, the system adopts an intermediate configuration in which 30% of the lattice sites form an ordered pattern of localized Co3+ states. Above 180 K, an anomalous mobility of specific Na+ sites is found to coexist with this electronic texture, suggesting that the formation of the latter may contribute to stabilizing the Na+ ordering. Control of the ion doping in these materials thus appears to be crucial for fine-tuning of their thermoelectric properties.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.100.096405 | DOI Listing |
Sci Rep
January 2025
School of Electronics and Information, Xijing University, Xi'an, 710123, China.
To enhance high-frequency perceptual information and texture details in remote sensing images and address the challenges of super-resolution reconstruction algorithms during training, particularly the issue of missing details, this paper proposes an improved remote sensing image super-resolution reconstruction model. The generator network of the model employs multi-scale convolutional kernels to extract image features and utilizes a multi-head self-attention mechanism to dynamically fuse these features, significantly improving the ability to capture both fine details and global information in remote sensing images. Additionally, the model introduces a multi-stage Hybrid Transformer structure, which processes features at different resolutions progressively, from low resolution to high resolution, substantially enhancing reconstruction quality and detail recovery.
View Article and Find Full Text PDFJ Dairy Sci
January 2025
Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH 03824. Electronic address:
We aimed to evaluate the effects of prepartum supplementation of different I sources (Ascophyllum nodosum [ASCO] meal and ethylenediamine dihydroiodide [EDDI]) on colostrum yield of cows, and blood concentrations of glucose, BHB, and thyroid hormones and growth of dairy calves. Forty multiparous Holstein cows were blocked by lactation number and expected calving date and assigned to 1 of 4 treatments 28 d before parturition: (1) EDDI supplemented (11 mg/d) to a basal diet to meet the NRC (2001) I concentration of 0.5 mg of I/kg of DMI (control = CON [0 g/d of ASCO meal]; actual I concentration = 0.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
Suganthi Devadason Marine Research Institute, Tuticorin, Tamil Nadu, India; Manonmaniam Sundaranar University, Abishekapatti, Tirunelveli, Tamil Nadu, India.
This research investigated the relationship between microplastic accumulation and the sediment texture in seagrass meadows across the selected coastal regions of Tuticorin. Sixteen sediment samples were collected by SCUBA divers utilizing a stainless steel grab sampler. Findings indicate significantly elevated microplastic concentrations in seagrass sediments when compared to unvegetated areas.
View Article and Find Full Text PDFNeural Netw
January 2025
Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208, USA. Electronic address:
Lamb waves are widely used for defect detection in structural health monitoring, and various methods are developed for Lamb wave data analysis. This paper presents an unsupervised Adversarial Transformer model for anomalous Lamb wave pattern detection by analyzing the spatiotemporal images generated by a hybrid PZT-scanning laser Doppler vibrometer (SLDV). The model includes the global attention and the local attention mechanisms, and both are trained adversarially.
View Article and Find Full Text PDFNat Nanotechnol
January 2025
Bay Area Center for Electron Microscopy, Songshan Lake Materials Laboratory, Dongguan, China.
Skyrmions can form regular arrangements, so-called skyrmion crystals (SkXs). A mode with multiple wavevectors q then describes the arrangement. While magnetic SkXs, which can emerge in the presence of Dzyaloshinskii-Moriya interaction, are well established, polar skyrmion lattices are still elusive.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!