Search results for "Coherence"

Correlation of oscillatory behaviour in Matlab using wavelets

2014

Here we present a novel computational signal processing approach for comparing two signals of equal length and sampling rate, suitable for application across widely varying areas within the geosciences. By performing a continuous wavelet transform (CWT) followed by Spearman?s rank correlation coefficient analysis, a graphical depiction of links between periodicities present in the two signals is generated via two or three dimensional images. In comparison with alternate approaches, e.g., wavelet coherence, this technique is simpler to implement and provides far clearer visual identification of the inter-series relationships. In particular, we report on a Matlab? code which executes this tec…

Secondary metabolites from the roots of Paronychia chionaea

2011

Two novel secondary metabolites, compounds (1–2) were isolated from the roots of Paronychia chionaea. On the basis of spectroscopic data including 1D and 2D NMR experiments (COSY, TOCSY, HSQC, and HMBC), and mass spectroscopy, their structures were established as 6- C-[α-L-arabinopyranosyl-(1→2)-β-D-glucopyranosyl]-7- O-[β-D-glucopyranosyl]-luteolin 3′-methyl ether (1), and 2-(methoxy)-2-(3,5-dimethoxy 4-hydroxyphenyl)-ethane-1,2-diol 1- O-β-D-glucopyranoside (2).

Phytochemistry of Weigela x “kosteriana variegata” (Caprifoliaceae)

2018

One new triterpene glycoside 3- O-β-D-xylopyranosyl-(1→4)-[β-D-glucopyranosyl-(1→3)]-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyloleanolic acid, was isolated from Weigela x “kosteriana variegata” (Caprifoliaceae), with three known ones. Their structures were characterized by a combination of mass spectrometry and 1D and 2D NMR spectrocopic techniques including 1H- and 13C NMR, COSY, TOCSY, NOESY, HSQC, and HMBC experiments. The toxicological properties of some glycosides were determined with a zebrafish-based assay. The results show that the most active compounds were toxic to the larvae in the range of 1 μM.

Quantum information processing on spin degrees of freedom in QDs placed in diluted magnetic semiconductor

2006

The spin degrees of freedom in quantum dot (QD) embedded in a diluted magnetic semiconductor (DMS) medium are considered in a model of a qubit and a gate for quantum information processing (QIP). The qubit is defined as a singlet and triplet pair of states of two electrons in a He-type QD in the DMS medium with strongly enhanced gyromagnetic factor. Methods of qubit rotation (Rabi oscillations) as well as two-qubit operations are suggested and analyzed. Moreover, decoherence related to spin waves (magnon-induced dephasing) in this new system (QD in DMS) is studied, and the relevant time-scale is estimated in accordance with preliminary experimental results. (© 2006 WILEY-VCH Verlag GmbH & C…

Properties of dirty two-band superconductors with repulsive interband interaction: Normal modes, length scales, vortices, and magnetic response

2018

Disorder in two-band superconductors with repulsive interband interaction induces a frustrated competition between the phase-locking preferences of the various potential and kinetic terms. This frustrated interaction can result in the formation of an $s+is$ superconducting state, that breaks the time-reversal symmetry. In this paper we study the normal modes and their associated coherence lengths in such materials. We especially focus on the consequences of the soft modes stemming from the frustration and time-reversal-symmetry breakdown. We find that two-bands superconductors with such impurity-induced frustrated interactions display a rich spectrum of physical properties that are absent i…

Disputations, obligations and logical coherence

2008

Peirce-Suit of Truth – Why Inference to the Best Explanation and Abduction Ought Not to be Confused

2004

It is well known that the process of scientific inquiry, according to Peirce, is drivenby three types of inference, namely abduction, deduction, and induction. What isbehind these labels is, however, not so clear. In particular, the common identificationof “abduction” with “Inference to the Best Explanation” (IBE) begs the question,since IBE appears to be covered by Peirce's concept of induction, not that of abduction.Consequently, abduction ought to be distinguished from IBE, at least on Peirce's account. The main aim of the paper, however, is to show that this distinction is most relevant with respect to current problems in philosophy of science and epistemology (like attempts to supply s…

This is my truth, tell me yours: some aspects of action research quality in the light of truth theories

2001

Abstract In this article the authors introduce some aspects of various truth theories in the context of action research. The traditional ways of determining quality are based on the correspondence theory of truth, which, in their view, conflicts with the basic assumptions of action research. The pragmatic theory of truth seems to be clearly represented in the world of action research. In their opinion, other theories of truth can be productively applied as well. In addition to the classical theories of truth – the correspondence theory, the coherence theory and the pragmatistic view on truth – they discuss the truth as ‘aletheia’ (a Heideggerian view on truth), as Habermasian consensus and …

Time-resolved coherent anti-Stokes Raman-scattering measurements of I2 in solid Kr: vibrational dephasing on the ground electronic state at 2.6-32 K.

2005

Time-resolved coherent anti-Stokes Raman-scattering (CARS) measurements are carried out for iodine (I2) in solid krypton matrices. The dependence of vibrational dephasing time on temperature and vibrational quantum number v is studied. The v dependence is approximately quadratic, while the temperature dependence of both vibrational dephasing and spectral shift, although weak, fits the exponential form characteristic of dephasing by pseudolocal phonons. The analysis of the data indicates that the frequency of the pseudolocal phonons is approximately 30 cm(-1). The longest dephasing times are observed for v = 2 being approximately 300 ps and limited by inhomogeneous broadening. An increase in…

Roadmap on STIRAP applications

2019

STIRAP (stimulated Raman adiabatic passage) is a powerful laser-based method, usually involving two photons, for efficient and selective transfer of populations between quantum states. A particularly interesting feature is the fact that the coupling between the initial and the final quantum states is via an intermediate state, even though the lifetime of the latter can be much shorter than the interaction time with the laser radiation. Nevertheless, spontaneous emission from the intermediate state is prevented by quantum interference. Maintaining the coherence between the initial and final state throughout the transfer process is crucial. STIRAP was initially developed with applications in …