Four chalcogenophene-fused acenes containing O, S, Se, or Te, respectively, were presented, and the chalcogenophene effect on linear and nonlinear optics was systematically investigated. Their excited-state absorption performance and two-photon absorption (TPA) capacity could be modulated by the incorporating chalcogen atoms. The experimental results showed that the heavy chalcogen facilitated the intersystem crossing resulting in the presence of the triplet state absorption for and , and the TPA capacity gradually increased with the atomic size of the chalcogens. The theoretical calculation inferred that their nonlinear optical performance was closely related to the contributions of the chalcogenophene component to heterotwistacenes in the final excited state. In addition, was able to work under various laser pulses from femtoseconds to nanoseconds.
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http://dx.doi.org/10.1021/acs.jpcb.0c07421 | DOI Listing |
Alzheimers Dement
December 2024
Johns Hopkins University, Baltimore, MD, USA.
Background: Clinical rating scales and neuropsychological tests are commonly used for assessing sign and disease severity, yet lack detail in the early stages Alzheimer's Disease (AD). Existing evaluation methods can be subjective, nonlinear, expensive, or reliant on anecdotal evidence making objective and consistent characterization and phenotyping of AD difficult. Multimodal analysis of patient behavior, rather than scoring of patient-generated output which can be skewed by compensation strategies, presents a unique opportunity to objectively quantify AD related changes.
View Article and Find Full Text PDFSmall
January 2025
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P. R. China.
Compounds having hexagonal tungsten oxides (HTO) topology are of intense research interests owing to their potential functional properties, such as nonlinear optical (NLO) performances. However, most of the reported HTO-type compounds exhibit narrow optical bandgaps because of the d-d electronic transition of compositional d transition metals and lone pair electrons effect of Se/Te, which hinder their applications in the high-energy field, such as deep-ultraviolet (deep-UV) region. In this work, a new fluorophosphate, (NH)[ScF(PO)](POF) exhibiting HTO-topological structures is reported.
View Article and Find Full Text PDFMed Phys
January 2025
Department of Nuclear Medicine and Medical Physics, Karolinska University Hospital, Stockholm, Sweden.
Background: Modern reconstruction algorithms for computed tomography (CT) can exhibit nonlinear properties, including non-stationarity of noise and contrast dependence of both noise and spatial resolution. Model observers have been recommended as a tool for the task-based assessment of image quality (Samei E et al., Med Phys.
View Article and Find Full Text PDFLight Sci Appl
January 2025
Department of Electronics and Nanoengineering, Aalto University, Espoo, Finland.
Coherent broadband light generation has attracted massive attention due to its numerous applications ranging from metrology, sensing, and imaging to communication. In general, spectral broadening is realized via third-order and higher-order nonlinear optical processes (e.g.
View Article and Find Full Text PDFNeural Netw
December 2024
Wyant College of Optical Sciences, University of Arizona, Tuscon, AZ, USA. Electronic address:
Reservoir computing, using nonlinear dynamical systems, offers a cost-effective alternative to neural networks for complex tasks involving processing of sequential data, time series modeling, and system identification. Echo state networks (ESNs), a type of reservoir computer, mirror neural networks but simplify training. They apply fixed, random linear transformations to the internal state, followed by nonlinear changes.
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