Results 291 to 300 of about 1,743,362 (341)
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Gammar-ray excited X-ray sources
The International Journal of Applied Radiation and Isotopes, 1964Gamma-ray excited X-ray sources, yielding essentially monoenergetic X-rays of energy variable in the range from a few to 100 keV, have been developed. Gamma rays from a radioisotope excite a target material and fluorescent X-rays of energies characteristic of the material are emitted.
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Ray failures in finite ray tracing
Applied Optics, 1985Le rayon peut manquer la surface geometrique definie par l'equation de surface, il peut subir une reflexion interne totale a la limite milieu dense-milieu moins dense, et la hauteur du rayon a la surface, peut depasser la demi-ouverture indiquee pour cette surface, le rayon peut rencontrer la meme surface apres ...
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Optics Letters, 1997
We demonstrate tomographic T-ray imaging, using the timing information present in terahertz (THz) pulses in a reflection geometry. THz pulses are reflected from refractive-index discontinuities inside an object, and the time delays of these pulses are used to determine the positions of the discontinuities along the propagation direction.
D M, Mittleman +3 more
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We demonstrate tomographic T-ray imaging, using the timing information present in terahertz (THz) pulses in a reflection geometry. THz pulses are reflected from refractive-index discontinuities inside an object, and the time delays of these pulses are used to determine the positions of the discontinuities along the propagation direction.
D M, Mittleman +3 more
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Ray matrices for rays around a general skew ray
Optical Society of America Annual Meeting, 1990Ray matrices for rays whose directions are close to that of a base ray that can be any general skew ray are derived and examined. The derivation starts with Hamilton's characteristic function; the resulting refraction matrix has a simple interpretation in terms of Coddington's equations.
M. Zabel, S. A. Collins, E. D. Evans
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Journal of Computational Acoustics, 1998
The numerical implementation of standard ray theory faces two intrinsic difficulties, the infinite value of the field at caustics and the nonlinear boundary value problem for computation of eigenrays—rays which connect source and receiver. In an earlier work [N. E. Maltsev, J. Math. Phys.
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The numerical implementation of standard ray theory faces two intrinsic difficulties, the infinite value of the field at caustics and the nonlinear boundary value problem for computation of eigenrays—rays which connect source and receiver. In an earlier work [N. E. Maltsev, J. Math. Phys.
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Nuclear Instruments and Methods in Physics Research, 1983
Owing to the short wavelengths of X-radiation X-ray microscopes allow higher resolution than optical microscopes. In contrast to electron microscopes, X-radiation can be used to study relatively thick aqueous specimens in their natural environment. X-ray microscopes require intense X-radiation, which is best provided by electron storage rings, as well ...
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Owing to the short wavelengths of X-radiation X-ray microscopes allow higher resolution than optical microscopes. In contrast to electron microscopes, X-radiation can be used to study relatively thick aqueous specimens in their natural environment. X-ray microscopes require intense X-radiation, which is best provided by electron storage rings, as well ...
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Analytical Chemistry, 1964
ABS>Developments in techniques and apparatus for x-ray diffraction analysis are reviewed. General applications of x-ray diffraction and current interests in the field of structural determinations are discussed. 209 references are included for the period 1962 through 1963. (P.C.H.)
L L, Merritt, W E, Streib
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ABS>Developments in techniques and apparatus for x-ray diffraction analysis are reviewed. General applications of x-ray diffraction and current interests in the field of structural determinations are discussed. 209 references are included for the period 1962 through 1963. (P.C.H.)
L L, Merritt, W E, Streib
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Annals of the New York Academy of Sciences, 1993
The distribution of γ‐ray bursts as observed by BATSE rules out the galactic disk origin, and it is consistent with the cosmological origin. Much work is currently done to reconcile galactic halo distribution with the absence of dipole and quadrupole moments in the positions of BATSE bursts. A relativistic expansion of the source is implied by both the
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The distribution of γ‐ray bursts as observed by BATSE rules out the galactic disk origin, and it is consistent with the cosmological origin. Much work is currently done to reconcile galactic halo distribution with the absence of dipole and quadrupole moments in the positions of BATSE bursts. A relativistic expansion of the source is implied by both the
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Ray Bradbury, “Ray Bradbury,” and “RAY BRADBURY”
Science Fiction Studies, 2021openaire +1 more source