Search results for "Names"
showing 10 items of 6843 documents
Forced Rayleigh scattering from non-harmonic gratings applied to complex diffusion processes in glass-forming liquids
1999
Abstract Tracer diffusion of 9,10-phenanthrenequinone (PQ) and its photoproduct in super-cooled phenolphthalein-dimethyl-ether (PDE) was studied by forced Rayleigh scattering. In order to investigate the spatial frequency dependence of the grating dynamics, several spatial harmonics of the grating with non-sinusoidal phase profile produced by non-linear recording were monitored. An optical scheme with a diverging reading beam is proposed for simultaneous reconstruction of the harmonic components.
Quantitative Analysis, Infrared
2000
In this article, after reviewing the different mathematical methods used in quantification we will describe and discuss their respective advantages and inconveniences. First of all, different examples of applications of infrared (IR) spectroscopy, used with or without other analytical chemistry methods, will be presented. Some examples of direct quantitative analysis in food analysis will be reviewed: lipids (measurement of unsaturation degrees, lipids determination), carbohydrates, proteins (secondary structures, quantitative analysis). We will also focus on original examples of the use of IR spectroscopy combined with enzymes. Secondly, some examples of Fourier transform infrared (FTIR) a…
Molecular biology, China and the West
2000
More than 15 years ago, in November 1985, I travelled to China for the first time. I joined a symposium on developmental biology in the Shanghai Institute of Cell Biology (CBI), organised by the Chinese Academy of Sciences and the Max‐Planck‐Gesellschaft in Germany. The symposium was meant to provide perspectives for the future of the Max Planck Guest Laboratory, just founded in the CBI. When I attended, I did not anticipate that my visit to Shanghai would initiate a long‐term commitment to China. I did not even expect to return to China in the near future. But early in 1987, my colleague Uli Schwarz from the Max Planck Institute of Developmental Biology in Tubingen, who was and still is in…
Classical and quantum aspects of electric-magnetic duality rotations in curved spacetimes
2018
It is well known that the source-free Maxwell equations are invariant under electric-magnetic duality rotations, $\mathrm{F}\ensuremath{\rightarrow}\mathrm{F}\mathrm{cos}\ensuremath{\theta}+^{\ensuremath{\star}}\mathrm{F}\mathrm{sin}\ensuremath{\theta}$. These transformations are indeed a symmetry of the theory in the Noether sense. The associated constant of motion is the difference in the intensity between self-dual and anti-self-dual components of the electromagnetic field or, equivalently, the difference between the right and left circularly polarized components. This conservation law holds even if the electromagnetic field interacts with an arbitrary classical gravitational background.…
CHIRAL ANOMALY IN ASHTEKAR'S APPROACH TO CANONICAL GRAVITY
1998
The Dirac equation in Riemann–Cartan spacetimes with torsion is reconsidered. As is well-known, only the axial covector torsion A, a one-form, couples to massive Dirac fields. Using diagrammatic techniques, we show that besides the familiar Riemannian term only the Pontrjagin type four-form dA ∧ dA does arise additionally in the chiral anomaly, but not the Nieh–Yan term d* A, as has been claimed recently. Implications for cosmic strings in Einstein–Cartan theory as well as for Ashtekar's canonical approach to quantum gravity are discussed.
In-medium pi-pi Correlation Induced by Partial Restoration of Chiral Symmetry
2000
We show that both the linear and the non-linear chiral models give an enhancement of the pi-pi cross section near the 2pi threshold in the scalar-iso-scalar (I=J=0) channel in nuclear matter. The reduction of the chiral condensate, i.e., the partial chiral restoration in nuclear matter, is responsible for the enhancement in both cases. We extract an effective 4pi-nucleon vertex which is responsible for the enhancement but has not been considered in the non-liear models for in-medium pi-pi interaction. Relation of this vertex and a next-to-leading order terms in the heavy-baryon chiral lagrangian, L_piN^(2), is also discussed.
Anomalous non-leptonic kaon decays
1992
8 páginas, 1 figura.
The Chiral Anomaly
1989
The Dirac operator on a manifold M is a first order partial differential operator acting on sections of a spin bundle over M. The Dirac operator is elliptic when the metric of M is positive definite. The main task in this chapter is to study properties of the determinant of the Dirac operator.
Calculation of organic solvent–water partition coefficients of iron–sulfur protein models
2002
Abstract A method is presented that permits semiquantitative estimation of the partitioning of many solutes between many pairs of media. As an example, the organic solvent–water partition coefficients P are calculated. The only needed parameters are the dielectric constant and molecular volume of the organic solvent. Fe 4 S 4 Cys n models of high-potential FeS proteins are studied. The Gibbs free energies of solvation and partition coefficients for Fe 4 S 4 Cys n are calculated. The organic solvent–water partition coefficients for 1-octanol P o , cyclohexane P ch and chloroform P cf decrease 4.41, 6.22 and 4.60 log units per cysteine (Cys) ligand, respectively. P o results are compared with…
Gaussian processes retrieval of leaf parameters from a multi-species reflectance, absorbance and fluorescence dataset.
2013
Abstract: Biochemical and structural leaf properties such as chlorophyll content (Chl), nitrogen content (N), leaf water content (LWC), and specific leaf area (SLA) have the benefit to be estimated through nondestructive spectral measurements. Current practices, however, mainly focus on a limited amount of wavelength bands while more information could be extracted from other wavelengths in the full range (400-2500 nm) spectrum. In this research, leaf characteristics were estimated from a field-based multi-species dataset, covering a wide range in leaf structures and Chl concentrations. The dataset contains leaves with extremely high Chl concentrations (>100 mu g cm(-2)), which are seldom es…