| Electronic Bottleneck and Coherent Vibrational Effect on Relaxation Dynamics of Photoexcited Ions in Crystals |
OCT 2000 |
11 pages |
| Authors:
R. R. Alfano; W. B. Wang; C. H. Liu; S. Owen; CITY COLL NEW YORK
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 | Nonradiative relaxation processes of photoexcited impurity ions in Cr(sup 4+) -doped forsterite (Cr(sup 4+)::Mg2SiO4) and Cunyit (Cr(sup 4+): Ca2GeO4) laser crystals have been investigated using time-resolved resonance Raman and up-converted hot luminescence spectroscopy methods. The nonequilibrium population of a local mode of 765 cm(sup -1) in Cr(sup 4+):Mg2SiO4 was found to build up during the transition through an electronic bottleneck and decay by interaction with a restricted number of phonon ... |
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| Optical Amplification and Nonlinear Optical Processes in Random Scattering Media |
20 APR 2000 |
7 pages |
| Authors:
R. R. Alfano; F. Liu; Y. Guo; C. H. Liu; J. Ying; CITY UNIV OF NEW YORK RESEARCH FOUNDATION
|
| The objective of the research program was to investigate nonlinear optical phenomena and optical amplification and lasing in highly scattering active and non-active random media. The aim of research was to develop a deeper fundamental understanding of light propagation in active random media for future generation of optical display, imaging techniques and laser devices. Two photon excited fluorescence and second harmonic generation tomographic imaging of ... |
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| Use of a Rapid Bioluminescent Bioassay (QwikLite) Using Oceanic Dinoflagellates to Assess Toxicity in Sediments |
APR 1998 |
8 pages |
| Authors:
C. H. Liu; D. Lapota; D. E. Rosenberger; SPACE AND NAVAL WARFARE SYSTEMS COMMANDSAN DIEGO CA
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| The Navy has developed a rapid bioassay system (QwikLite) that is proving to be a valuable asset for conducting bioassays on other test media (e. g., metals, storm drain discharge, ship hull coatings, and marine sediments). The basis of detection is to measure a reduction in light from the bioluminescent dinoflagellate Gonyaulax polyedra following exposure to a toxicant. The toxic response is usually measured within 24 hours from the start ... |
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| Application of an Upwind High Resolution Finite-Differencing Scheme and Multigrid Method in Steady-State Incompressible Flow Simulations |
JUN 96 |
36 pages |
| Authors:
Cheng I. Yang; Yanhu Guo; C. H. Liu; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD HYDROMECHANICS DIRECT ORATE
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| The analysis and design of a submarine propulsor requires the ability to predict the characteristics of both laminar and turbulent flows to a higher degree of accuracy. This report presents results of certain benchmark computations based on an upwind, high-resolution, finite-differencing Navier- Stokes solver. The purpose of the computations is to evaluate the ability, the accuracy and the performance of the solver in the simulation of detailed features of viscous ... |
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| Rayleigh Lidar Observations of Gravity Wave Activity in the Upper Stratosphere at Urbana, Illinois |
DEC 87 |
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| Authors:
M. S. Miller; C. S. Gardner; C. H. Liu; ILLINOIS UNIV AT URBANA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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 | During the 13 night of Rayleigh lidar measurements thirty-six quasi- monochromatic gravity waves were observed in the 35 to 50 km altitude region of the stratosphere. The characteristics of the waves are compared with other lidar and radar measurements of gravity waves and with theoretical models of wave saturation and dissipation phenomena. The measured vertical wavelengths (lambda from 2 to 11.5 km and the measured vertical phase velocities (c sub ... |
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| The Effect of Turbulent Atmosphere on Backscattered Waves, |
AUG 1983 |
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| Authors:
K. C. Yeh; C. H. Liu; ILLINOIS UNIV AT URBANA DEPT OF ELECTRICAL ENGINEERING
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| In radar detection of targets the backscattered waves are traveling through the same region as the incident wave. When the region is occupied by a turbulent atmosphere, the backscattered wave is therefore expected to be correlated with the incident wave. As a matter of fact, these two oppositely traveling waves are related through a reciprocity theorem. This reciprocity theorem is shown to be valid by using the Feynam path integral ... |
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| Coherence Bandwidth and Pulse Distortion through Naturally and Artificially Modified Ionospheres |
AUG 1982 |
183 pages |
| Authors:
K. C. Yeh; C. H. Liu; ILLINOIS UNIV AT URBANA DEPT OF ELECTRICAL ENGINEERING
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| This project is concerned with the study of propagation of radio signals through a perturbed ionosphere. The problems investigated can be broadly classified into three areas: propagation effects through ionospheric bubbles, propagation effects through ionospheric irregularities and experimental observations of scintillation effects. Four-year work on these areas is summarized in this report. (Author) |
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| Studies of Equatorial Scintillation Problems. |
SEP 1979 |
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| Authors:
K. C. Yeh ; C. H. Liu; ILLINOIS UNIV AT URBANA-CHAMPAIGN DEPT OF ELECTRICAL ENGINEERING
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| This report describes the experimental set-up, observations and results of satellite radio signals received at an equatorial station. The effects of dispersion and scattering of a pulse propagating through the ionosphere are also investigated theoretically. (Author) |
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| Observations of Equatorial Ionospheric Bubbles by the Radio Propagation Method, |
23 MAR 1979 |
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| Authors:
K. C. Yeh; H. Soicher; C. H. Liu; ILLINOIS UNIV AT URBANA DEPT OF ELECTRICAL ENGINEERING
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| Ionospheric Effects on Radio Communication and Ranging Pulses, |
26 JUL 1978 |
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| Authors:
Kung C. Yeh; C. H. Liu; ILLINOIS UNIV AT URBANA-CHAMPAIGN DEPT OF ELECTRICAL ENGINEERING
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| Measurement of g-Factors for Levels in Ne II, III. |
12 MAY 1971 |
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| Authors:
C. H. Liu; D. A. Church; ARIZONA UNIV TUCSON DEPT OF PHYSICS
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| The alignment of the radiating particles in the beam-foil light source has been used to measure the Lande g-factors of excited electronic states of 20Ne II, III with lifetimes of the order of nanoseconds. (Author) |
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Reports by Author
