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Quasi-2D halide perovskites have potential in lasing due to their amplified spontaneous emission (ASE) properties. The ASE of (PBA)MAPbBr thin films has been confirmed by photoluminescence (PL) testing using stripe light excitation (SLE). The ASE threshold decreases with decreasing environmental temperature () or increasing number of inorganic layers (). Using the transient absorption technique, the Auger recombination and the cooling process of the high-activity carrier are accelerated with the decrease of or . A new ASE mechanism is proposed where high-activity carriers directly emit photons under photon perturbation from adjacent sites, leading to the accumulation and amplification of emitted photons only in the SLE region for ASE to occur. In addition, the reduction of promotes light scattering between nano-thin layers, which supports a rapid increase in the ASE signal after the ASE threshold is crossed.
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http://dx.doi.org/10.1021/acs.jpclett.3c00490 | DOI Listing |
Front Neural Circuits
September 2025
School of Systems Science, Beijing Normal University, Beijing, China.
Bow-tie architecture (BTA) is widely observed in biological neural systems, yet the underlying mechanism driving its spontaneous emergence remains unclear. In this study, we identify a novel formation mechanism by training multi-layer neural networks under biologically inspired non-negative connectivity constraints across diverse classification tasks. We show that non-negative weights reshape network dynamics by amplifying back-propagated error signals and suppressing hidden-layer activity, leading to the self-organization of BTA without pre-defined architecture.
View Article and Find Full Text PDFInt J Clin Pharm
September 2025
Porto Pharmacovigilance Centre, Faculty of Medicine of the University of Porto, Alameda Professor Hernâni Monteiro, 4200-319, Porto, Portugal.
Artificial intelligence (AI), particularly machine learning (ML), is increasingly influencing pharmacovigilance (PV) by improving case triage and signal detection. Several studies have reported encouraging performance, with high F1 scores and alignment with expert assessments, suggesting that AI tools can help prioritize reports and identify potential safety issues faster than manual review. However, integrating these tools into PV raises concerns.
View Article and Find Full Text PDFNeuroSci
August 2025
Faculty of Medicine, Lucian Blaga University of Sibiu, 550024 Sibiu, Romania.
Background: Spontaneous intracerebral hemorrhage (ICH) has the highest case fatality of all stroke types, yet recent epidemiological and outcome data from Central and Eastern Europe remain limited.
Methods: We retrospectively analyzed prospectively collected data for 601 consecutive adults with primary ICH admitted to Sibiu County Clinical Emergency Hospital, Romania (2017-2023). Demographics, Glasgow Coma Scale (GCS), CT-derived hematoma volume (ABC/2), anatomical site, intraventricular extension (IVH), treatment, comorbidities, and in-hospital death were reported with exact counts and percentages; no imputation was performed.
J Phys Chem Lett
September 2025
School of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331, China.
Lead halide perovskites are promising emitters for short-range data communication lasers and amplifiers, but their application is limited by the defect density and poor stability arising from solution-based fabrication and rapid crystallization. Additive engineering offers an effective strategy to regulate crystal growth, optimize film morphology, and passivate defects both in the bulk and at the surface. Herein, a zwitterionic molecule sulfobetaine 10 (SFB10) is introduced into a two-step spin-coating process to fabricate high-quality MAPbBr films.
View Article and Find Full Text PDFLight Sci Appl
August 2025
State Key Laboratory of Quantum Functional Materials, Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.
Colloidal quantum dots (QDs) are promising gain materials for realizing solution-processable, wavelength-tunable and low-cost laser diodes. However, achieving electrically pumped amplified spontaneous emission (ASE) in QDs, a prerequisite for lasing, is hampered by the low net optical gain and low current injection of the diodes. Here we demonstrate electrically pumped and surface-emitting ASE from QDs by electro-thermal-optically co-designing a quantum-dot light-emitting diode (QLED) with high net optical gain and high current injection.
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