7,050 research outputs found

    Towards variance-matrix characterization of complementarity relations in a continuous variable system

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    We discuss complementarity relations in a bipartite continuous variable system. Building up from the work done on discrete d-dimensional systems, we prove that for symmetric two-mode states, quantum complementarity relations can be put in a simple relation with the elements of the variance matrix. When this condition is not satisfied, such a connection becomes non-trivial. Our investigation is the first step towards an operative characterization of the complementarity in a scenario that has not been investigated so far.Comment: 7 pages, 4 figures, RevTeX

    Particle and particle pair dispersion in turbulence modeled with spatially and temporally correlated stochastic processes

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    In this paper we present a new model for modeling the diffusion and relative dispersion of particles in homogeneous isotropic turbulence. We use an Heisenberg-like Hamiltonian to incorporate spatial correlations between fluid particles, which are modeled by stochastic processes correlated in time. We are able to reproduce the ballistic regime in the mean squared displacement of single particles and the transition to a normal diffusion regime for long times. For the dispersion of particle pairs we find a t2t^{2}-dependence of the mean squared separation at short times and a tt-dependence for long ones. For intermediate times indications for a Richardson t3t^{3} law are observed in certain situations. Finally the influence of inertia of real particles on the dispersion is investigated.Comment: 10 pages, 7 figures, 1 tabl

    Mass Loss of and Temperature Distribution in Southern Pine and Douglas Fir in the Range 100 To 800°C

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    Southern pine and Douglas fir test specimens were placed in an over kept at either 100, 160, 245, 400, 600, or 800 °C, and the center point temperatures and the mass losses of the specimens were measured as functions of exposure time. A model is described for calculating the temperature distribution in and the mass loss of wooden beams having rectangular cross sections. Comparisons were made between the data and the results of the model, and reasonable agreements were found between the measured and calculated temperatures and mass losses. Some tests were also performed to assess the effect of ambient oxygen concentration on the mass loss.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68991/2/10.1177_073490418300100405.pd

    Measurement of the thermal conductivity of helium up to 2100°K by the column method

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    The thermal conductivity of helium was measured at atmospheric pressure in the range 800–2100°K by the column method. The data could be correlated by the polynomial λ = 0.635×10−1+0.310×10−3T−0.244×10−7T2λ=0.635×10−1+0.310×10−3T−0.244×10−7T2, where λ is in watts per meters degrees Kelvin and T is in degrees Kelvin. The results obtained were compared with previous thermal conductivity measurements. The data of Desmond and Saxena and Saxena agree closely with the present results; the data of Timrot and Umanskii appear to be too low and those of Blais and Mann too high. Values for f = λ/ηCvf=λ∕ηCv, computed using measured thermal conductivities and available viscosity data, were found to agree well with classical results from kinetic theory.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70040/2/JCPSA6-58-10-4080-1.pd

    Quantum affine Cartan matrices, Poincare series of binary polyhedral groups, and reflection representations

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    We first review some invariant theoretic results about the finite subgroups of SU(2) in a quick algebraic way by using the McKay correspondence and quantum affine Cartan matrices. By the way it turns out that some parameters (a,b,h;p,q,r) that one usually associates with such a group and hence with a simply-laced Coxeter-Dynkin diagram have a meaningful definition for the non-simply-laced diagrams, too, and as a byproduct we extend Saito's formula for the determinant of the Cartan matrix to all cases. Returning to invariant theory we show that for each irreducible representation i of a binary tetrahedral, octahedral, or icosahedral group one can find a homomorphism into a finite complex reflection group whose defining reflection representation restricts to i.Comment: 19 page

    Purification, growth, and characterization of Zn(x)Cd(1-x)Se crystals

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    The purification of starting materials which were used in the growth of Zn(x)Cd(1-x)Se (x = 0.2) single crystals using the traveling solution method (TSM) is reported. Up to 13 cm long single crystals and as grown resistivities of 6 x 10(exp 12) ohm/cm could be achieved. Infrared and Raman spectra of Zn(0.2)Cd(0.8)Se are also presented and discussed

    On spherical twisted conjugacy classes

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    Let G be a simple algebraic group over an algebraically closed field of good odd characteristic, and let theta be an automorphism of G arising from an involution of its Dynkin diagram. We show that the spherical theta-twisted conjugacy classes are precisely those intersecting only Bruhat cells corresponding to twisted involutions in the Weyl group. We show how the analogue of this statement fails in the triality case. We generalize to good odd characteristic J-H. Lu's dimension formula for spherical twisted conjugacy classes.Comment: proof of Lemma 6.4 polished. The journal version is available at http://www.springerlink.com/content/k573l88256753640
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