1,599 research outputs found

    correlations in + reactions

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    Preliminary differential cross-sections of the reactions A(gamma,pi(0)pi(0)) and A(gamma,pi(0)pi(+) + pi(0)pi(-)) with A = H-1, C-12, and Pb-nat are presented. A significant nuclear-mass dependence of the pipi invariant-mass distribution is found in the pi(0)pi(0) channel. The dependence is not observed in the pi(0)pi(+/-) channel. The in-medium observation in the pi(0)pi(0) channel is consistent with an in-medium modification of the pipi interaction in the I = J = 0 channel, changing width and pole position of a pipi resonant state

    Three-nucleon force studies at intermediate energies

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    High-precision data in three-nucleon scattering processes and state-of-the-art few-body calculations have contributed significantly to our present understanding of three-nucleon forces at intermediate energies. This paper discusses in more detail the pd -&gt; He-3 gamma reaction as a probe for electromagnetic currents in the three-nucleon system. Experimental data are reviewed and interpreted by a comparison with Faddeev and coupled-channel calculations from the Bochum-Cracow and Hanover theory groups, respectively.</p

    Three-nucleon force studies at intermediate energies

    No full text
    High-precision data in three-nucleon scattering processes and state-of-the-art few-body calculations have contributed significantly to our present understanding of three-nucleon forces at intermediate energies. This paper discusses in more detail the pd -&gt; He-3 gamma reaction as a probe for electromagnetic currents in the three-nucleon system. Experimental data are reviewed and interpreted by a comparison with Faddeev and coupled-channel calculations from the Bochum-Cracow and Hanover theory groups, respectively.</p

    Three-nucleon force studies at intermediate energies

    No full text
    High-precision data in three-nucleon scattering processes and state-of-the-art few-body calculations have contributed significantly to our present understanding of three-nucleon forces at intermediate energies. This paper discusses in more detail the pd -&gt; He-3 gamma reaction as a probe for electromagnetic currents in the three-nucleon system. Experimental data are reviewed and interpreted by a comparison with Faddeev and coupled-channel calculations from the Bochum-Cracow and Hanover theory groups, respectively.</p

    Invariant tori and Lagrange stability of pendulum-type equations

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    AbstractIn this paper we prove that the pendulum-type equation x″ + g(t, x) = 0 possesses infinitely many invariant tori whenever g(t, x) has zero mean value on the torus T2, where g(t, x) belongs to C∞(T2). This yields the boundedness for solutions of the considered pendulum-type equation and thus leads to an answer to J. Moser's boundedness problem (1973, Ann. of Math. Stud. 77)

    The charged and the spin-excitation gaps in the double-exchange model: a rigorous result

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    We extend a previous result of ours [G.S. Tian, Phys. Rev. B58 (1998) 7612] on the charged gap and the spin-excitation gap of the half-filled Kondo lattice model to the double-exchange model. In our original approach, this model cannot be dealt with since its localized spins have a large spin number S = 3/2. By following a construction argument due to Zener and rewriting the double-exchange Hamiltonian, we are able to overcome this difficulty and re-establish the same relation for this model.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000088659700004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)3ARTICLE121-303

    A 2-watt balanced power amplifier MMIC for Ku-band satellite communications

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    A Ku-band power amplifier MMIC has been developed using 0.25-mum GaAs pHEMT technology. To achieve small chip size and simple drain-bias connection, a bus-bar power combiner is used. Also, balanced-power amplifier topology is used to obtain good input/ output return losses. The small-signal gain is about 15 dB and the gain variation is less than 1 dB from 12 to 17 GHz. Good input/output return losses are achieved at less than -15 dB due to the balanced topology. P-IdB of 32.6 dBm and PAE of 23.5% are achieved at 14 GHz. The effective chip area is 4.2 X 3.2 mm. Because the power amplifier is implemented using the balanced topology with the bus-bar power combiner, compact size, high output power, and good input/output return losses can be achieved simultaneously. (C) 2004 Wiley Periodicals, Inc.The author would like to thank Jeong-Ho Lee, Chung-Hwan Kim, and Jae-Jin Lee at Teltron for their helpful discussions and encouragement. This work was supported by KOSEF under the ERC program through the MINT research center at Dongguk University

    Experience-based behavioral and chemosensory changes in the generalist insect herbivore Helicoverpa armigera exposed to two deterrent plant chemicals

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    Behavioral and electrophysiological responses of larvae of the polyphagous moth species Helicoverpa armigera to two plant-derived allelochemicals were studied, both in larvae that had been reared on a diet devoid of these compounds and in larvae previously exposed to these compounds. In dual-choice cotton leaf disk and pepper fruit disk arena assays, caterpillars reared on a normal artificial diet were strongly deterred by strychnine and strophanthin- K. However, caterpillars reared on an artificial diet containing strychnine were insensitive to strychnine and strophanthin-K. Similarly, caterpillars reared on an artificial diet containing strophanthin-K were also desensitized to both deterrent chemicals. Electrophysiological tests revealed that the deterrent-sensitive neurons in taste sensilla on the maxillae of caterpillars reared on each deterrent- containing diet displayed reduced sensitivity to the two chemicals compared with the caterpillars reared on normal diets. We conclude that the experience-dependent behavioral plasticity was partly based on the reduced sensitivity of taste receptor neurons and that the desensitization of taste receptor neurons contributed to the crosshabituation to the two chemicals
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