Results 251 to 260 of about 469,971 (293)
Some of the next articles are maybe not open access.
Two-dimensional microwave Fourier transform spectroscopy
The Journal of Chemical Physics, 1990New two-dimensional correlation techniques in the field of pulsed microwave Fourier transform spectroscopy are presented. Five different pulse sequences were used to demonstrate connections between rotational transitions with well separated or with closely spaced frequencies.
B. Vogelsanger, A. Bauder
openaire +1 more source
Two-Dimensional Chirped-Pulse Fourier Transform Microwave Spectroscopy
The Journal of Physical Chemistry A, 2011Two-dimensional (2D) correlation techniques are developed for chirped-pulse Fourier transform microwave (CP-FTMW) spectroscopy. The broadband nature of the spectrometer coupled with fast digital electronics permits the generation of arbitrary pulse sequences and simultaneous detection of the 8-18 GHz region of the microwave spectrum. This significantly
David S, Wilcox +2 more
openaire +2 more sources
Two-dimensional 220 MHz Fourier transform EPR imaging
Physics in Medicine and Biology, 1998In the last decade radiofrequency continuous-wave EPR spectrometers have been developed to detect and localize free radicals in vivo. Only recently, pulsed radiofrequency EPR spectrometers have been described for imaging applications with small samples. In the present work, we show the first two-dimensional image obtained at 220 MHz on a large phantom (
PLACIDI, GIUSEPPE +4 more
openaire +4 more sources
Ultrafast nonequilibrium Fourier-transform two-dimensional infrared spectroscopy
Optics Letters, 2008We present what we believe to be the first implementation of nonequilibrium two-dimensional IR spectroscopy (2DIR) combining electronic excitation within the Fourier transform (FT) approach. Nonequilibrium 2DIR spectra of Mn2(CO)10 and its photoproducts are obtained in two modalities: photoexcitation at 400 nm, either before a 2DIR probe or during the ...
Carlos R, Baiz +3 more
openaire +2 more sources
The Two-Dimensional Fourier Transform
2003In this chapter the two-dimensional Fourier transform is defined mathematically, and then some intuitive feeling for the two-dimensional Fourier component is developed. Just as we understand that a waveform can be broken down into time-varying sinusoids, so also we can acquire a corresponding physical picture of the decomposition of a single-valued ...
openaire +1 more source
Noninterferometric Two-Dimensional Fourier-Transform Spectroscopy of Multilevel Systems
Physical Review Letters, 2008We demonstrate a technique that determines the phase of the photon-echo emission from spectrally resolved intensity data without requiring phase-stabilized input pulses. The full complex polarization of the emission is determined from spectral intensity measurements.
Davis, J. A. +5 more
openaire +3 more sources
One-dimensional and two-dimensional generalised discrete fourier transforms
IEEE Transactions on Acoustics, Speech, and Signal Processing, 1976One-dimensional and two-dimensional generalized discrete Fourier transforms (GFT) are introduced. If a one.dimensional vector A is fractured into a two-dimensional matrix B, a one-dimensional GFT on A and a two-dimensional GFT on B give the same result and require the same number of operations to be computed. The result holds also for the DFT, as it is
BONGIOVANNI, Giancarlo +2 more
openaire +2 more sources
Femtosecond two-dimensional Fourier transform electronic spectroscopy
2007 Conference on Lasers and Electro-Optics - Pacific Rim, 2007Two-dimensional spectra are obtained by Fourier transformation of four-wave mixing signal fields with respect to time delays between femtosecond pulses. We discuss peak shapes, experimental distortions, and dispersion relations. Two-dimensional electronic spectra revealing solvent and electronic motion are used as illustrations.
Michael K. Yetzbacher +4 more
openaire +1 more source
Noninterferometric Two-Dimensional Fourier Transform Spectroscopy
2009We demonstrate a technique that determines the phase of the photon echo emission from spectrally resolved intensity data, without requiring phase stabilised input pulses. The validity is demonstrated using simulated data based on a model three level system with two-colour excitation.
Davis, J. A. +4 more
openaire +2 more sources
Two-dimensional recursive fast Fourier transform
IEE Proceedings F Radar and Signal Processing, 1990The paper presents a two-dimensional (2-D) recursive fast Fourier transform (RFFT) which consists of two recursive algorithms and a revised fast Fourier transform in the recursive process. This algorithm is applied to image processing as an example of 2-D signal processing.
openaire +1 more source