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http://dx.doi.org/10.1103/physreva.36.4667 | DOI Listing |
Terahertz (THz) generation via photomixing on photoconductive antenna using twin delayed chirped pulses provides a long THz pulse with a narrow bandwidth. To generate a long pulse with a broad bandwidth, we propose a new, to the best of our knowledge, method that combines two long optical pulses with opposite chirps. The pulses exhibit temporal distributions of their instantaneous frequencies with opposite slopes.
View Article and Find Full Text PDFComplete 2π cycling of a phase around a phase singularity leads to a rapid phase variation in the nearby zones and forms a sharp local -vector peak. In this paper, the intensity distribution in the spatial domain is transformed into a -vector distribution in the wave vector domain, and we prove that the local -vector peak is generated at the point of minimum light field intensity. The local -vector peak is sharper when the minimum point is closer to the phase singularity.
View Article and Find Full Text PDFEpilepsy Res
January 2025
UMC Children's Hospital, Department of Emergency Medicine, Kirk Kerkorian School of Medicine at University of Las Vegas, Las Vegas, NV, USA.
Background: Febrile seizure (FS) is the most common convulsive disorder in children. Understanding its time-of-day pattern can provide insight into mechanisms and prevention.
Purpose: We explored clock-time variation of FS presentations of children to a US pediatric emergency department (PED) in comparison to two control cohorts: one (n = 5719) like-aged children presenting solely with fever, i.
Ultramicroscopy
January 2025
National Centre for Nano Fabrication and Characterization (DTU Nanolab), Technical University of Denmark (DTU), Kgs. Lyngby, Denmark. Electronic address:
Advances in analytical scanning transmission electron microscopy (STEM) and in microelectronic mechanical systems (MEMS) based microheaters have enabled in-situ materials' characterization at the nanometer scale at elevated temperature. In addition to resolving the structural information at elevated temperatures, detailed knowledge of the local temperature distribution inside the sample is essential to reveal thermally induced phenomena and processes. Here, we investigate the accuracy of plasmon energy expansion thermometry (PEET) as a method to map the local temperature in a tungsten (W) lamella in a range between room temperature and 700 °C.
View Article and Find Full Text PDFTransl Vis Sci Technol
January 2025
New England Eye Center, Tufts Medical Center, Boston, MA, USA.
Purpose: To evaluate visibility of a sub-band posterior to the external limiting membrane (ELM) and assess its age-associated variation.
Methods: In a retrospective cross-sectional study, normal eyes were imaged using a high-resolution spectral-domain optical coherence tomography (SD-OCT) prototype (2.7-µm axial resolution).
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