12,544 research outputs found

    Internally Electrodynamic Particle Model: Its Experimental Basis and Its Predictions

    Full text link
    The internally electrodynamic (IED) particle model was derived based on overall experimental observations, with the IED process itself being built directly on three experimental facts, a) electric charges present with all material particles, b) an accelerated charge generates electromagnetic waves according to Maxwell's equations and Planck energy equation and c) source motion produces Doppler effect. A set of well-known basic particle equations and properties become predictable based on first principles solutions for the IED process; several key solutions achieved are outlined, including the de Broglie phase wave, de Broglie relations, Schr\"odinger equation, mass, Einstein mass-energy relation, Newton's law of gravity, single particle self interference, and electromagnetic radiation and absorption; these equations and properties have long been broadly experimentally validated or demonstrated. A specific solution also predicts the Doebner-Goldin equation which emerges to represent a form of long-sought quantum wave equation including gravity. A critical review of the key experiments is given which suggests that the IED process underlies the basic particle equations and properties not just sufficiently but also necessarily.Comment: Presentation at the 27th Int Colloq on Group Theo Meth in Phys, 200

    Cyclotron resonance lineshape in a Wigner crystal

    Full text link
    The cyclotron resonance absorption spectrum in a Wigner crystal is calculated. Effects of spin-splitting are modelled by substitutional disorder, and calculated in the coherent potential approximation. Due to the increasing strength of the dipole-dipole interaction, the results show a crossover from a double-peak spectrum at small filling factors to a single-peak spectrum at filling factors \agt 1/6. Radiation damping and magnetophonon scattering can also influence the cyclotron resonance. The results are in very good agreement with experiments.Comment: 4 pages REVTEX, attempt to append 3 figures that seem to have been lost last tim

    Live-cell topology assessment of URG7, MRP6₁₀₂ and SP-C using glycosylatable green fluorescent protein in mammalian cells.

    Get PDF
    Experimental tools to determine membrane topology of a protein are rather limited in higher eukaryotic organisms. Here, we report the use of glycosylatable GFP (gGFP) as a sensitive and versatile membranetopology reporter in mammalian cells. gGFP selectively loses its fluorescence upon N-linked glycosylationin the ER lumen. Thus, positive fluorescence signal assigns location of gGFP to the cytosol whereas nofluorescence signal and a glycosylated status of gGFP map the location of gGFP to the ER lumen. By usingmammalian gGFP, the membrane topology of disease-associated membrane proteins, URG7, MRP6102,SP-C(Val) and SP-C(Leu) was confirmed. URG7 is partially targeted to the ER, and inserted in Cinform.MRP6102and SP-C(Leu/Val) are inserted into the membrane in Coutform. A minor population of untarget-ed SP-C is removed by proteasome dependent quality control system

    Effect of nonlinearity on the dynamics of a particle in dc field-induced systems

    Get PDF
    Dynamics of a particle in a perfect chain with one nonlinear impurity and in a perfect nonlinear chain under the action of dc field is studied numerically. The nonlinearity appears due to the coupling of the electronic motion to optical oscillators which are treated in adiabatic approximation. We study for both the low and high values of field strength. Three different range of nonlinearity is obtained where the dynamics is different. In low and intermediate range of nonlinearity, it reduces the localization. In fact in the intermediate range subdiffusive behavior in the perfect nonlinear chain is obtained for a long time. In all the cases a critical value of nonlinear strength exists where self-trapping transition takes place. This critical value depends on the system and the field strength. Beyond the self-trapping transition nonlinearity enhances the localization.Comment: 9 pages, Revtex, 6 ps figures include

    Spatial distribution of low-energy plasma around 2 comet 67P/CG from Rosetta measurements

    Get PDF
    International audienceWe use measurements from the Rosetta plasma consortium (RPC) Langmuir probe (LAP) and mutual impedance probe (MIP) to study the spatial distribution of low-energy plasma in the near-nucleus coma of comet 67P/Churyumov-Gerasimenko. The spatial distribution is highly structured with the highest density in the summer hemisphere and above the region connecting the two main lobes of the comet, i.e. the neck region. There is a clear correlation with the neutral density and the plasma to neutral density ratio is found to be ∌1-2·10 −6 , at a cometocentric distance of 10 km and at 3.1 AU from the sun. A clear 6.2 h modulation of the plasma is seen as the neck is exposed twice per rotation. The electron density of the collisonless plasma within 260 km from the nucleus falls of with radial distance as ∌1/r. The spatial structure indicates that local ionization of neutral gas is the dominant source of low-energy plasma around the comet

    Tunneling into a Two-Dimensional Electron Liquid in a Weak Magnetic Field

    Full text link
    We study the spectral density function of a two-dimensional electron liquid in a weak magnetic field, the filling factor Μ≫1\nu\gg 1. A hydrodynamic model for low-energy excitations of the liquid is developed. It is found that even at Μ≫1\nu\gg 1 the density of states exhibits a gap at low energies. Its width 2E02E_0 depends on the strength of interaction only logarithmically, 2E0=(ℏωc/Îœ)ln⁥(Îœe2/ΔℏvF)2E_0=(\hbar\omega_c/\nu)\ln (\nu e^2/\varepsilon\hbar v_F). The effects of temperature and disorder on the density of states are discussed.Comment: 8 pages, preprint TPI-MINN-94/28-

    A method for sensitivity analysis to assess the effects of measurement error in multiple exposure variables using external validation data

    Get PDF
    Measurement error in self-reported dietary intakes is known to bias the association between dietary intake and a health outcome of interest such as risk of a disease. The association can be distorted further by mismeasured confounders, leading to invalid results and conclusions. It is, however, difficult to adjust for the bias in the association when there is no internal validation data

    Random matrix ensembles with an effective extensive external charge

    Full text link
    Recent theoretical studies of chaotic scattering have encounted ensembles of random matrices in which the eigenvalue probability density function contains a one-body factor with an exponent proportional to the number of eigenvalues. Two such ensembles have been encounted: an ensemble of unitary matrices specified by the so-called Poisson kernel, and the Laguerre ensemble of positive definite matrices. Here we consider various properties of these ensembles. Jack polynomial theory is used to prove a reproducing property of the Poisson kernel, and a certain unimodular mapping is used to demonstrate that the variance of a linear statistic is the same as in the Dyson circular ensemble. For the Laguerre ensemble, the scaled global density is calculated exactly for all even values of the parameter ÎČ\beta, while for ÎČ=2\beta = 2 (random matrices with unitary symmetry), the neighbourhood of the smallest eigenvalue is shown to be in the soft edge universality class.Comment: LaTeX209, 17 page

    Atomic Processes in Planetary Nebulae and H II Regions

    Full text link
    Spectroscopic studies of Planetary Nebulae (PNe) and H {\sc ii} regions have driven much development in atomic physics. In the last few years the combination of a generation of powerful observatories, the development of ever more sophisticated spectral modeling codes, and large efforts on mass production of high quality atomic data have led to important progress in our understanding of the atomic spectra of such astronomical objects. In this paper I review such progress, including evaluations of atomic data by comparisons with nebular spectra, detection of spectral lines from most iron-peak elements and n-capture elements, observations of hyperfine emission lines and analysis of isotopic abundances, fluorescent processes, and new techniques for diagnosing physical conditions based on recombination spectra. The review is directed toward atomic physicists and spectroscopists trying to establish the current status of the atomic data and models and to know the main standing issues.Comment: 9 pages, 1 figur

    Equilibrium states and invariant measures for random dynamical systems

    Full text link
    Random dynamical systems with countably many maps which admit countable Markov partitions on complete metric spaces such that the resulting Markov systems are uniformly continuous and contractive are considered. A non-degeneracy and a consistency conditions for such systems, which admit some proper Markov partitions of connected spaces, are introduced, and further sufficient conditions for them are provided. It is shown that every uniformly continuous Markov system associated with a continuous random dynamical system is consistent if it has a dominating Markov chain. A necessary and sufficient condition for the existence of an invariant Borel probability measure for such a non-degenerate system with a dominating Markov chain and a finite (16) is given. The condition is also sufficient if the non-degeneracy is weakened with the consistency condition. A further sufficient condition for the existence of an invariant measure for such a consistent system which involves only the properties of the dominating Markov chain is provided. In particular, it implies that every such a consistent system with a finite Markov partition and a finite (16) has an invariant Borel probability measure. A bijective map between these measures and equilibrium states associated with such a system is established in the non-degenerate case. Some properties of the map and the measures are given.Comment: The article is published in DCDS-A, but without the 3rd paragraph on page 4 (the complete removal of the paragraph became the condition for the publication in the DCDS-A after the reviewer ran out of the citation suggestions collected in the paragraph
    • 

    corecore