1,720,976 research outputs found
Real time investigationof elementary steps for photoinduced phase transitino in a model dimer
No full textTime-resolved methods in biophysics. 4. Broadband pump-probe spectroscopy system with sub-20 fs temporal resolution for the study of energy transfer processes in photosynthesis
No full textHigh-time-resolution pump-probe system with broadband detection for the study of time-domain vibrational dynamics
No full textWe present an ultrafast transient absorption spectroscopy system in the visible combining high-sensitivity broadband detection with extreme temporal resolution. The instrument is based on an ultrabroadband sub-10 fs optical parametric amplifier coupled to an optical multichannel analyzer with fast electronics, enabling single-shot detection at 1 kHz repetition rate. For a given pump-probe delay τ, we achieve a differential transmission (ΔT/T) sensitivity of the order of 10−4 over the λpr = 490–720 nm probe wavelength range by averaging over 1000 shots, allowing the acquisition of complete two-dimensional ΔT/T (λpr,τ) maps within a few minute measurement time. We present application examples highlighting the capability of this instrument to observe ultrafast dynamical processes, follow impulsively excited vibrational motions with frequency as high as 3000 cm−1 (11 fs period), and determine the probe wavelength dependence of amplitude and phase of the oscillations
Ultrafast Optoelectronic probing of excited states in low dimensional carbon-based pi-comjugated materials
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Time domain investigation of excited state vibrational motion in organic molecules by stimulated emission pumping
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Primary photoexcitations and their interconversion in oligophenylenevinylene nanocrystals: the role of excess energy studied with sub-30 fs resolution
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