Results 251 to 260 of about 1,613,986 (294)
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Transient absorption of polydiacetylene molecules
The Journal of Chemical Physics, 1987During excitation with ultraviolet light, polydiacetylene crystals show a photoinduced absorption which is ascribed to a triplet excited state of the individual polymer chains. We have measured this absorption using partially and fully polymerized TS and FBS single crystals. The results of stationary and time-resolved experiments are discussed.
H. Sixl, R. Jost, R. Warta
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Transient absorption of polarons in KNbO3
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2002Abstract Transient absorption spectra have been measured in a number of undoped KNbO 3 crystals following two kinds of electronic excitation: two-photon absorption of 200 fs laser pulses and 10 ns pulsed electron beam. A band peaking at 0.8 eV and broad, poorly resolved absorption in the range 1.3–3.3 eV were observed.
Yong Qiu +5 more
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Transient absorption of symmetrical carbocyanines
Journal of Photochemistry and Photobiology A: Chemistry, 1998Abstract Transient absorption in several symmetrical cyanine and carbncyanine dyes is measured by time-resolved spectroscopy with subpicosecond white-light continuum in a wide spectral range (0.35–1 μm). The results are compared with data available in the literature on ultrashort and long-lived transients.
Yves H. Meyer +2 more
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Ultrafast Transient Absorption of Diazoalkanes
2022Ultrafast dynamics of three different diazoalkanes (1, 2, 3) was investigated with femtosecond transient absorption spectroscopy using third harmonic generated UV pump pulses and broadband white light supercontinuum probe pulses. Diazoalkanes are important reagents in organic synthesis that produce carbenes via photoinduced elimination of nitrogen ...
Brusar, Vedran +4 more
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Transient Absorption Spectra and Dynamics of InSe Nanoparticles
The Journal of Physical Chemistry B, 2006Time-resolved fluorescence and transient absorption results have been obtained for small (approximately 3 nm) and large (approximately 5-8 nm) InSe nanoparticles in room-temperature solutions. The large particles are nonfluorescent, indicating that the conduction band is at M and the optical transition is forbidden.
Shuming, Yang, David F, Kelley
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Transient anisotropy effects in the absorption saturation of GaAs
Journal of Luminescence, 1985Abstract The absorption of polarized light imparts a transient anisotropy on GaAs due to the preferential orientational excitation of electron-hole pairs. We present a series of experiments designed to measure the relaxation of the wavevector orientation of these photoexcited electron-hole pairs.
J.L. OUDAR +4 more
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Simple Nanosecond to Minutes Transient Absorption Spectrophotometer
Applied Spectroscopy, 2005We built a transient absorption spectrophotometer that can determine transient absorption spectral changes that occur at times as fast as ∼200 ns and as slow as a minute. The transient absorption can be induced by a temperature-jump (T-jump) or by optical pumping from the deep ultraviolet (UV) to the infrared (IR) by use of single ns Nd:YAG laser ...
Aleksandr V, Mikhonin +3 more
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Transient absorption by a Rydberg atom in a resonant cavity
Physical Review A, 1988A theoretical analysis is presented describing the interaction of the field in a high-Q microwave cavity with an atom that is suddenly excited to the lower of two Rydberg levels that are resonantly coupled by the field. It is found that the field initially in the cavity is canceled by interference with the source field emitted by the atom.
, Mallalieu, , Parker, , Stroud
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Absorption Changes and Decays of Transients in Irradiated Papain
International Journal of Radiation Biology and Related Studies in Physics, Chemistry and Medicine, 1974SummaryPulse-radiolysis studies of aqueous papain solutions have been made over the 50 µs to 0·40 s time-scale and the 300 to 500 nm wave-length range. For the intermediates formed from both e−aq and OH, the observed changes in optical density over the above time-scale are independent of papain concentration and dose per pulse.
J R, Clement +5 more
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Attosecond Transient Absorption Spectroscopy
2016As explained in Sect. 1 the aim of this study is to access the nonlinear polarization induced in the strong field interaction in dielectrics by ultrashort pulses. It characterizes the nonlinear response of the medium to the external force and contains information about the underlying physical processes.
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