48 research outputs found
Optical second harmonic generation in Yttrium Aluminum Borate single crystals (theoretical simulation and experiment)
Experimental measurements of the second order susceptibilities for the second
harmonic generation are reported for YAl3(BO3)4 (YAB) single crystals for the
two principal tensor components xyz and yyy. First principles calculation of
the linear and nonlinear optical susceptibilities for Yttrium Aluminum Borate
YAl3(BO3)4 (YAB) crystal have been carried out within a framework of the
full-potential linear augmented plane wave (FP-LAPW) method. Our calculations
show a large anisotropy of the linear and nonlinear optical susceptibilities.
The observed dependences of the second order susceptibilities for the static
frequency limit and for the frequency may be a consequence of different
contribution of electron-phonon interactions. The imaginary parts of the second
order SHG susceptibility chi_{123}^{(2)}(omega), chi_{112}^{(2)}(omega),
chi_{222}^{(2)}(omega), and chi_{213}^{(2)}(omega) are evaluated. We find that
the 2(omega) inter-band and intra-band contributions to the real and imaginary
parts of chi_{ijk}^{(2)}\l(omega) show opposite signs. The calculated second
order susceptibilities are in reasonably good agreement with the experimental
measurements.Comment: 16 pages, 11 figure
COVIDiSTRESS diverse dataset on psychological and behavioural outcomes one year into the COVID-19 pandemic
During the onset of the COVID-19 pandemic, the COVIDiSTRESS Consortium launched an open-access global survey to understand and improve individuals’ experiences related to the crisis. A year later, we extended this line of research by launching a new survey to address the dynamic landscape of the pandemic. This survey was released with the goal of addressing diversity, equity, and inclusion by working with over 150 researchers across the globe who collected data in 48 languages and dialects across 137 countries. The resulting cleaned dataset described here includes 15,740 of over 20,000 responses. The dataset allows cross-cultural study of psychological wellbeing and behaviours a year into the pandemic. It includes measures of stress, resilience, vaccine attitudes, trust in government and scientists, compliance, and information acquisition and misperceptions regarding COVID-19. Open-access raw and cleaned datasets with computed scores are available. Just as our initial COVIDiSTRESS dataset has facilitated government policy decisions regarding health crises, this dataset can be used by researchers and policy makers to inform research, decisions, and policy. © 2022, The Author(s).U.S. Department of Education, ED: P031S190304; Texas A and M International University, TAMIU; National Research University Higher School of Economics, ВШЭThe COVIDiSTRESS Consortium would like to acknowledge the contributions of friends and collaborators in translating and sharing the COVIDiSTRESS survey, as well as the study participants. Data analysis was supported by Texas A&M International University (TAMIU) Research Grant, TAMIU Act on Ideas, and the TAMIU Advancing Research and Curriculum Initiative (TAMIU ARC) awarded by the US Department of Education Developing Hispanic-Serving Institutions Program (Award # P031S190304). Data collection by Dmitrii Dubrov was supported within the framework of the Basic Research Program at HSE University, RF
Spectroscopic studies of emission and absorption properties of 38PbO-62SiO(2):Nd3+ glass
The main spectroscopic parameters (intensity parameters, radiative life times, branching ratios, quantum efficiency and emission cross-section of the F-4(3/2)-> I-4(9/2) transition) of the 38PbO-62SiO(2) glass doped with Nd3+ are evaluated using the standard Judd-Ofelt theory. Remarkably low values of the intensity parameters Omega(2,4,6) are explained by structural modifications of the Nd3+ surroundings caused by presence of the Pb ions