1,126 research outputs found

    Field trial of a 15 Tb/s adaptive and gridless OXC supporting elastic 1000-fold all-optical bandwidth granularity

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    An adaptive gridless OXC is implemented using a 3D-MEMS optical backplane plus optical modules (sub-systems) that provide elastic spectrum and time switching functionality. The OXC adapts its architecture on demand to fulfill the switching requirements of incoming traffic. The system is implemented in a seven-node network linked by installed fiber and is shown to provide suitable architectures on demand for three scenarios with increasing traffic and switching complexity. In the most complex scenario, signals of mixed bit-rates and modulation formats are successfully switched with flexible per-channel allocation of spectrum, time and space, achieving over 1000-fold bandwidth granularity and 1.5 Tb/s throughput with good end-to-end performance

    Magnetic Properties of a Pressure-induced Superconductor UGe2_2

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    We performed the DC-magnetization and neutron scattering experiments under pressure {\it P} for a pressure-induced superconductor UGe2_2. We found that the magnetic moment is enhanced at a characteristic temperature {\it T}∗^{*} in the ferromagnetic state, where {\it T}∗^{*} is smaller than a Curie temperature {\it T}C_{\rm C}. This enhancement becomes remarkable in the vicinity of {\it P}C∗_{\rm C}^{*} = 1.20 GPa, where {\it T}∗^{*} becomes 0 K and the superconducting transition temperature {\it T}SC_{\rm SC} shows a maximum. The characteristic temperature {\it T}∗^{*}, which decreases with increasing pressure, also depends on the magnetic field.Comment: To be published in J.Phys.Soc.Jp

    Pressure-induced Superconductivity in a Ferromagnet UGe2_2 -- Resistivity Measurements in Magnetic Field --

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    The electrical resistivity measurements in the magnetic field are carried out on the pressure-induced superconductor UGe2_2. The superconductivity is observed from 1.06 to 1.44 GPa. The upper critical field of HC2H_{C2} is anisotropic where HC2(T)H_{C2}(T) exhibits positive curvature for H//bH//b and cc-axis. The characteristic enhancement of HC2H_{C2} is reconfirmed for H//aH//a-axis. In the temperature and field dependence of resistivity at P>PCP > P_{C} where the ferromagnetic ordering disappears, it is observed that the application of the external field along the {\it a}-axis increases the coefficient of Fermi liquid behavior AT2AT^{2} correspondingly to the metamagnetic transition.Comment: To be published in the proceeding of the International Conference on High Pressure Science and Technology(AIRAPT-18),Beijing,China,23-27 July 200

    Experimental demonstration of gridless spectrum and time optical switching

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    An experimental demonstration of gridless spectrum and time switching is presented. We propose and demonstrate a bit-rate and modulation-format independent optical cross-connect architecture, based on gridless spectrum selective switch, 20-ms 3D-MEMS and 10-ns PLZT optical switches, that supports arbitrary spectrum allocation and transparent time multiplexing. The architecture is implemented in a four-node field-fiber-linked testbed to transport continuous RZ and NRZ data channels at 12.5, 42.7 and 170.8 Gb/s, and selectively groom sub-wavelength RZ channels at 42.7 Gb/s. We also showed that the architecture is dynamic and can be reconfigured to meet the routing requirements of the network traffic. Results show error-free operation with an end-to-end power penalty between 0.8 dB and 5 dB for all continuous and sub-wavelength channels

    Locating Planetesimal Belts in the Multiple-planet Systems HD 128311, HD 202206, HD 82943, and HR 8799

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    In addition to the Sun, six other stars are known to harbor multiple planets and debris disks: HD 69830, HD 38529, HD 128311, HD 202206, HD 82943, and HR 8799. In this paper, we set constraints on the location of the dust-producing planetesimals around the latter four systems. We use a radiative transfer model to analyze the spectral energy distributions of the dust disks (including two new Spitzer IRS spectra presented in this paper), and a dynamical model to assess the long-term stability of the planetesimals' orbits. As members of a small group of stars that show evidence of harboring a multiple planets and planetesimals, their study can help us learn about the diversity of planetary systems

    S-matrix poles and the second virial coefficient

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    For cutoff potentials, a condition which is not a limitation for the calculation of physical systems, the S-matrix is meromorphic. We can express it in terms of its poles, and then calculate the quantum mechanical second virial coefficient of a neutral gas. Here, we take another look at this approach, and discuss the feasibility, attraction and problems of the method. Among concerns are the rate of convergence of the 'pole' expansion and the physical significance of the 'higher' poles.Comment: 20 pages, 8 tables, submitted to J. Mol. Phy

    Nuevos aportes al estudio de los alcaloides de la Urechites Karwinski Mueller (Loroco).

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    Se trata de demostrar la estructura de ambos compuestos por métodos químicos y espectográficos hy el de iniciar el esudio de otro alcaloide, tambien presente en la raíz de esta planta al que se le denomina alcaloude "14" por ser esta fracción en que aparece en la columna cromatográfica cuando se trabaja en las condicines descritas en la parte experimenta

    Second virial coefficient in one dimension, as a function of asymptotic quantities

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    A result from Dodd and Gibbs[1] for the second virial coefficient of particles in 1 dimension, subject to delta-function interactions, has been obtained by direct integration of the wave functions. It is shown that this result can be obtained from a phase shift formalism, if one includes the contribution of oscillating terms. The result is important in work to follow, for the third virial coefficient, for which a similar formalism is being developed. We examine a number of fine points in the quantum mechanical formalisms.Comment: 7 pages, no figures, submitted to Molecular Physic

    Antidoto politico-moral contra el veneno frances, que en nombre de Sevilla, presenta á toda la Nacion española

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    Copia digital. España : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 2017Probablemente imp. en la primera mitad del s. XIX
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