Results 11 to 20 of about 5,729,346 (195)
Sensors, 2021 In this paper, Computer Vision (CV) sensing technology based on Convolutional Neural Network (CNN) is introduced to process topographic maps for predicting wireless signal propagation models, which are applied in the field of forestry security monitoring.
Jialuan He +6 more
doaj +1 more source
Dynamic lattice distortions driven by surface trapping in semiconductor nanocrystals
Nature Communications, 2021 Charge trapping can lead to severe nonradiative losses in colloidal semiconductor nanocrystals (NCs). The authors report femtosecond electron diffraction measurements on photoexcited NCs to reveal atomic-scale insights into how localization of charges at
Burak Guzelturk +28 more
doaj +1 more source
Gap maps and intrinsic diffraction losses in one-dimensional photonic crystal slabs. [PDF]
Physical review. E, Statistical, nonlinear, and soft matter physics, 2004 A theoretical study of photonic bands for one-dimensional (1D) lattices embedded in planar waveguides with strong refractive index contrast is presented.
D. Gerace, L. Andreani
semanticscholar +1 more source
Evaluating the applicability of a screen diffraction approximation to local volcano infrasound
Volcanica, 2021 Atmospheric acoustic waves from volcanoes at infrasonic frequencies (0.01–20 Hz) can be used to estimate source parameters for hazard modeling, but signals are often distorted by wavefield interactions with topography, even at local recording distances (
Sean Maher +4 more
doaj +1 more source
Measurement of Diffraction Loss in a Solid State Laser [PDF]
Applied Optics, 1969 The measurement of oscillation losses in solid state lasers has long been used as a method of evaluating the quality of the laser material. Most of these active loss measurements provide a measure of the total cavity loss, from which other losses such as mirror reflectivity losses must be subtracted to give a figure for the internal loss of the laser ...
Arnold, D.H., Hanna, D.C.
openaire +4 more sources
Diffraction mode selection in planar lasers with Bragg resonators [PDF]
ITM Web of Conferences, 2019 Using the coupled-wave approach supplemented by the quasioptical approximation, we investigate the possibilities of diffraction mode selection with respect to the transverse index in planar distributed-feedback lasers.
Ginzburg Naum +5 more
doaj +1 more source
Synthesis and characterizations of (Ba1-xCax)Ti4O9, 0 ≤ x ≤ 0.9 ceramics
Journal of Materials Research and Technology, 2021 Manufacturing of energy storage devices with good efficiency and fewer losses has been a distinct topic. A material with good dielectric properties and fewer energy losses is the basic demand of the electronic industry.
Asad Ali +7 more
doaj +1 more source
Ultra-low threshold lasing through phase front engineering via a metallic circular aperture
Nature Communications, 2022 Low threshold lasing is widely required, especially for portable systems. Here the authors design a circular subwavelength metallic aperture in a QCL to shape its phase front and control diffraction losses, which in turn allows a lower threshold ...
Zhixin Wang +4 more
doaj +1 more source
Millimeter‐wave diffraction‐loss model based on over‐rooftop propagation measurements
ETRI Journal, 2020 Measuring the diffraction loss for high frequencies, long distances, and large diffraction angles is difficult because of the high path loss. Securing a well‐controlled environment to avoid reflected waves also makes long‐range diffraction measurements ...
Kyung‐Won Kim +5 more
doaj +1 more source
Absorption, Diffraction and Free Space Path Losses Modeling for the Terahertz Band
, 2020 With the explosive increase in the data traffic of wireless communication systems and the scarcity of spectrum, terahertz (THz) frequency band is predicted as a hopeful contender to shore up ultrabroadband for the forthcoming beyond fifth generation (5G)
D.Oyeleke Oluseun +4 more
semanticscholar +1 more source