Search results for "shift"

Research and Implementation of Energy Dispersal Algorithm for DRM System

2020

The article investigates the randomization algorithm of the OFDM signal energy used in modern digital broadcasting systems. Transmission part of the DRM system was modeled in MATLAB/Simulink software environment, bit sequences allocation tests were conducted using the original information signal and the corresponding modulation symbols with a scrambling algorithm and without it.

ChemInform Abstract: Electron-Correlated Approaches for the Calculation of NMR Chemical Shifts

2010

Bis(pyridylvinyl)diaminobenzenes: synthesis, acidochromism and solvatochromism of the fluorescence

2005

Abstract C2-symmetrical 1,4-distyrylbenzenes with 4-dimethylaminobenzene or pyridine as terminal rings, and propyloxy or dipropylamino groups in the central 2,5-positions were prepared. Solvatochromism of the absorption is small, but more pronounced in the fluorescence spectra. Some compounds exhibit huge Stokes shifts. Acid strongly alters the fluorescence: red shifts and decreasing quantum yields is the general result, but depending on the position and character of the basic sites, a strong recovery of fluorescence efficiency combined with large hypsochromic shifts may result in highly acidic solutions.

Rheological studies of moderately concentrated polystyrene solutions in the vicinity of the θ temperature. II. Shear-rate dependence for different th…

1983

The viscosity data of moderately concentrated polystyrene solutions in trans-decalin (TD) (θ solvent, θ temperature 21°C) and toluene (TL) (good solvent) reported in Part I are discussed in terms of Graessley's entanglement theory. Under good solvent conditions, Graessley's master curve provides an excellent fit up to high shear rates, whereas in the vicinity of the θ conditions the data have to be modified by a parameter ηfric introduced by Ito and Shishido. The characteristic time of mechanical response to flow of chains approximately given by the shift factor τ0 is found in good solvents to be on the order of the Rouse relaxation time. In poor solvents, close to demixing, τ0 tends to muc…

1H NMR-spektroskopische Untersuchungen zur Strukturaufklärung von Oligo(hydroxy-5-nitro-1,3-phenylen)methylen Verbindungen

1976

Die 1H NMR-Spektren von 51 Oligo(hydroxy-5-nitro-1,3-phenylen)methylen Verbindungen (17 Zwei-, 18 Drei-, 14 Vier- und 2 Funfkernverbindungen) wurden in Pyridin als Losungsmittel aufgenommen. Bei Verbindungen mit ortho-Nitrophenolbausteinen zeigten die Signale fur die Protonen der Methyl- bzw. Methylengruppen in allen Fallen charakteristische chemische Verschiebungen δ, so das eine eindeutige Unterscheidung zwischen Methylgruppen in para- (δ=2,09−2,15 p.p.m.) und ortho-Stellung (δ=2,22−2,28 p.p.m.) zur phenolischen Hydroxyl-Gruppe, sowie zwischen para-para- (δ=3,77−3,97 p.p.m.), ortho-para- (δ=4,02−4,12 p.p.m.) und ortho-ortho-Methylenbrucken (δ=4,21−4,32 p.p.m.) moglich war. Bei Verbindunge…

Scientific simulations and optimization of the XGIS instrument on board THESEUS

2020

The XGIS (X and Gamma Imaging Spectrometer) is one of the three instruments onboard the THESEUS mission (ESA M5, currently in Phase-A). Thanks to its wide field of view and good imaging capabilities, it will efficiently detect and localize gamma-ray bursts and other transients in the 2-150 keV sky, and also provide spectroscopy up to 10 MeV. Its current design has been optimized by means of scientific simulations based on a Monte Carlo model of the instrument coupled to a state-of-the-art description of the populations of long and short GRBs extending to high redshifts. We describe the optimization process that led to the current design of the XGIS, based on two identical units with partial…

The Molecular Basis of X-Linked Spondyloepiphyseal Dysplasia Tarda

2001

The X-linked form of spondyloepiphyseal dysplasia tarda (SEDL), a radiologically distinct skeletal dysplasia affecting the vertebrae and epiphyses, is caused by mutations in the SEDL gene. To characterize the molecular basis for SEDL, we have identified the spectrum of SEDL mutations in 30 of 36 unrelated cases of X-linked SEDL ascertained from different ethnic populations. Twenty-one different disease-associated mutations now have been identified throughout the SEDL gene. These include nonsense mutations in exons 4 and 5, missense mutations in exons 4 and 6, small (2–7 bp) and large (>1 kb) deletions, insertions, and putative splicing errors, with one splicing error due to a complex deleti…

The alhambra photometric system

2010

Aparicio Villegas, Teresa et al.

Bright hot impacts by erupted fragments falling back on the Sun: UV redshifts in stellar accretion

2014

A solar eruption after a flare on 7 Jun 2011 produced EUV-bright impacts of fallbacks far from the eruption site, observed with the Solar Dynamics Observatory. These impacts can be taken as a template for the impact of stellar accretion flows. Broad red-shifted UV lines have been commonly observed in young accreting stars. Here we study the emission from the impacts in the Atmospheric Imaging Assembly's UV channels and compare the inferred velocity distribution to stellar observations. We model the impacts with 2D hydrodynamic simulations. We find that the localised UV 1600A emission and its timing with respect to the EUV emission can be explained by the impact of a cloud of fragments. The …

Separatrix reconstruction to identify tipping points in an eco-epidemiological model

2018

Many ecological systems exhibit tipping points such that they suddenly shift from one state to another. These shifts can be devastating from an ecological point of view, and additionally have severe implications for the socio-economic system. They can be caused by overcritical perturbations of the state variables such as external shocks, disease emergence, or species removal. It is therefore important to be able to quantify the tipping points. Here we present a study of the tipping points by considering the basins of attraction of the stable equilibrium points. We address the question of finding the tipping points that lie on the separatrix surface, which partitions the space of system traj…