38 research outputs found
Calibration, standardization, and quantitative analysis of multidimensional fluorescence (MDF) measurements on complex mixtures (IUPAC Technical Report)
This IUPAC Technical Report describes and compares the currently applied methods for the calibration and standardization of multi-dimensional fluorescence (MDF) spectroscopy data as well as recommendations on the correct use of chemometric methods for MDF data analysis. The paper starts with a brief description of the measurement principles for the most important MDF techniques and a short introduction to the most important applications. Recommendations are provided for instrument calibration, sample preparation and handling, and data collection, as well as the proper use of chemometric data analysis methods.This work was supported by the Danish Research Council (grant no. 274-05-0064 (CS) and Science Foundation Ireland Grant no. 02/IN.1/M231 (to AGR). The authors thank Winnie Martinsen for assistance with laboratory measurements.peer-reviewed2018-11-2
Tuning and Tracking of Coherent Shear Waves in Molecular Films
We have determined the time-dependent
displacement fields in molecular sub-micrometer thin films as response
to femtosecond and picosecond laser pulse heating by time-resolved
X-ray diffraction. This method allows a direct absolute determination
of the molecular displacements induced by electron–phonon interactions,
which are crucial for, for example, charge transport in organic electronic
devices. We demonstrate that two different modes of coherent shear
motion can be photoexcited in a thin film of organic molecules by
careful tuning of the laser penetration depth relative to the thickness
of the film. The measured response of the organic film to impulse
heating is explained by a thermoelastic model and reveals the spatially
resolved displacement in the film. Thereby, information about the
profile of the energy deposition in the film as well as about the
mechanical interaction with the substrate material is obtained