Heterostructures with thin Hg(Cd)Te/CdHgTe quantum wells (QWs) are attractive for the development of mid-infrared interband lasers. Of particular interest are room-temperature operating emitters for the short-wavelength infrared range (SWIR, typically defined as 1.7-3 μm). In this work, we report on the observation of stimulated emission (SE) in the 2.65-2.75 µm wavelength range at room temperature in an optically pumped HgCdTe QW laser heterostructure. We study a series of three samples with lengths ranging from 2.5 to 7 mm and discuss the effects related to the non-uniformity of the excitation beam profile. SE threshold intensity and the magnitude of pump-induced carrier heating are found to be effectively dependent on the chip size, which should be accounted for in possible designs of HgCdTe-based optical converters. We also pay attention to the problem of active medium engineering in order to push the SE wavelength towards the 3-5 µm atmospheric window and to lower the SE threshold.
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http://dx.doi.org/10.3390/nano12152599 | DOI Listing |
Alzheimers Dement
December 2024
The Catholic University of Korea, Seoul, Korea, Republic of (South).
Background: Women's elevated risk of Alzheimer's disease (AD) compared to men remains unclear, with gonadal hormones proposed as potential contributors. This study aimed to explore the association between follicle-stimulating hormone (FSH), estradiol (E2), neuropsychological AD stages, and cerebral Aβ deposition.
Methods: A total of 679 subjects were included in the study (N = 198 for cognitively normal (CN), N = 373 for mild cognitive impairment (MCI), and N = 108 for AD dementia groups).
Alzheimers Dement
December 2024
Brigham and Women's Hospital, Boston, MA, USA.
Background: Anxiety is prevalent among cognitively unimpaired older adults and is associated with accelerated amyloid-β-related cognitive decline and incident cognitive impairment. Investigating these mechanisms is challenging due to low pathologic burden, high individual variability, and subsyndromal level of symptoms. Recently, brain networks involved in AD were successfully localized by mapping the brain connectivity of atrophy patterns associated with memory impairment and delusions.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Department of Economics, FE, RTE Külliyesi, Dr. Marmara University, 34840, Istanbul, Turkey.
This study investigates the relation and Granger causality among inflation, fiscal expenditure, energy consumption, economic growth, energy efficiency, renewable energy consumption, and environmental pollution in the G7 countries utilizing the PLSTRVAR model for 1975-2022. Our findings highlight the results that inflation and fiscal expenditure have impact on environmental pollution across different regimes. On the other hand, unlike some studies in the literature, it emphasizes that renewable energy consumption may have pollution-increasing effects on environmental pollution.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
We present state-to-state differential cross sections for rotationally inelastic collisions of vibrationally excited NO XΠ ( = 9) with Ar using a near-counterpropagating molecular beam geometry. These were obtained using the stimulated emission pumping technique coupled with velocity map imaging. Collision energies well over ∼1 eV were achieved and rotational excitations up to ∼Δ = 60 recorded for the first time for inelastic collisions.
View Article and Find Full Text PDFJ Environ Manage
December 2024
School of Economics and Management, Dalian University of Technology, No.2 Ling Gong Road, Dalian 116024, China.
Adopting low-carbon technology has become a critical method for enterprises to reduce carbon emissions and combat global warming. However, the willingness of high-energy-consuming and high-emission enterprises, such as those in the chemical industry, to adopt this technology is not high. Therefore, how to effectively stimulate these enterprises to develop and apply low-carbon technology has become an urgent challenge.
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