The defect structure for Cu(2+) in CdSe nanocrystals is theoretically studied by analyzing the spin Hamiltonian parameters of this impurity center. This center is ascribed to Cu(2+) occupying the octahedral interstitial site, rather than the tetrahedral substitutional Cd(2+) site proposed by previous work. The Cu(2+) center exhibits slight tetragonal elongation distortion (characterized by the elongation parameter rho approximately 0.03) due to the Jahn-Teller effect. The theoretical spin Hamiltonian parameters and optical transition show good agreement with the experimental data. The above unusual defect structure (occupation and symmetry) for Cu(2+) in CdSe nanocrystals is discussed, as compared with the conventional trigonally distorted tetrahedral Cu(2+) centers in bulk II-VI semiconductors.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.saa.2009.10.016 | DOI Listing |
Neuroradiology
January 2025
Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
Introduction: Bipolar disorder (BD) and major depressive disorder (MDD) have overlapping clinical presentations which may make it difficult for clinicians to distinguish them potentially resulting in misdiagnosis. This study combined structural MRI and machine learning techniques to determine whether regional morphological differences could distinguish patients with BD and MDD.
Methods: A total of 123 participants, including BD (n = 31), MDD (n = 48), and healthy controls (HC, n = 44), underwent high-resolution 3D T1-weighted imaging.
ACS Nano
January 2025
Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec H2X 0A9, Canada.
The abnormally viscous and thick mucus is a hallmark of cystic fibrosis (CF). How the mutated CF gene causes abnormal mucus remains an unanswered question of paramount interest. Mucus is produced by the hydration of gel-forming mucin macromolecules that are stored in intracellular granules prior to release.
View Article and Find Full Text PDFAnn Neurol
January 2025
Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy.
Objective: The aim of this study was to explore the microstructural dynamics of the subventricular zone (SVZ) with aging and their associations with clinical disability and brain structural damage in pediatric-onset multiple sclerosis (MS) patients.
Methods: One-hundred and forty-one pediatric-onset MS patients (67 pediatric and 74 adults with pediatric-onset) and 233 healthy controls (HC) underwent neurological and 3.0 T MRI assessment.
J Appl Biomater Funct Mater
January 2025
MOE Key Lab for Liquid-Solid Structure Evolution and Materials Processing, Shandong University, Jinan, China.
In current study, microstructural, mechanical and corrosion behaviour were investigated with incorporation of dual reinforced AZ91D surface composites. This research was carried out for enhancement of the bio-degradability in biological environment. The surface composites were successfully fabricated by friction stir processing method with a rotation speed of 800 rpm, travel speed of 80 mm/min and 2.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Industrial Engineering and Management, Ming Chi University of Technology, New Taipei City, 243, Taiwan.
This study develops the you only look once segmentation (YOLOSeg), an end-to-end instance segmentation model, with applications to segment small particle defects embedded on a wafer die. YOLOSeg uses YOLOv5s as the basis and extends a UNet-like structure to form the segmentation head. YOLOSeg can predict not only bounding boxes of particle defects but also the corresponding bounding polygons.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!