2014 The photoionization absorption spectrum of the strongly Cr-doped GaAs samples was measured in the energy region 5 500-11 000 cm-1 under hydrostatic pressure up to 9 kbar at 300 K and 77 K. The EPR measurements with 1.09 03BCm laser excitation shows that this absorption is due to the charge transfer Cr3+ ~ Cr2+ transitions. The theoretical model which takes into account the lattice relaxati...

Cosmic rays produce molecular cluster ions as they pass through the lower atmosphere. Neutral molecular clusters such as dimers and complexes are expected to make a small contribution to the radiative balance, but atmospheric absorption by charged clusters has not hitherto been observed. In an atmospheric experiment, a narrowband thermopile filter radiometer centred on 9.15 μm, an absorption ba...

Blazars with redshifts z ≤ 0.1 are likely candidates for detection at energies in the range 300 GeV – 50 TeV withČerenkov telescopes and scintillator arrays. We present γ-ray flux predictions for a sample of 15 nearby flat-spectrum radio sources fitting the proton blazar model of Mannheim (1993a) to their observed broad-band spectral energy distributions. At high energies, we use fluxes or flux...

the present article seek to investigate the function of elliptical steel damper function in steel frames seismic resisting. the elliptical damper is a kind of earthquake energy dissipater in structure which acts based on the steel yielding feature. thus, this damper in frame lateral displacement mechanism is expected to have a satisfying hysteretic behavior in terms of energy absorption is on a...

ultraviolet waves, because of their short wavelength, have a high energy and considerable damaging effects on surfaces. protection against ultraviolet radiations is one of the finishing treatments done on surfaces exposed to sunlight. the importance of this issue in relation to human health, due to complications such as skin burns and cancer, is doubled. up to now, different materials such as z...

this study aims to numerically investigate on the crashworthiness of thin-walled square tubes by consideration of 3-d oblique loading. in this type of loading, direction of loading is defined by using two spatial angles relative to the position of the tube. to this aim, finite element (fe) analysis is employed to simulate the loading for 8 different numerical models with different loading orien...

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