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H.?L.?Harney W.?D.?HeissEmail author 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2004,29(3):429-432
Eigenvectors of decaying quantum systems are studied at exceptional points of the Hamiltonian. Special attention is paid to the properties of the system under time reversal symmetry breaking. At the exceptional point the chiral character of the system -- found for time reversal symmetry -- generically persists. It is, however, no longer circular but rather elliptic.Received: 20 November 2003, Published online: 15 April 2004PACS:
03.65.Vf Phases: geometric; dynamic or topological - 02.30.-f Function theory, analysis - 05.45.Mt Quantum chaos; semiclassical methods 相似文献
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D. Boosé H. L. Harney H. A. Weidenmüller 《Zeitschrift für Physik A Hadrons and Nuclei》1986,325(3):363-369
The interpretation of experimental tests of time-reversal symmetry in compound-nucleus reactions requires the theoretical calculation of a correlation coefficientR. We evaluateR in the framework of a statistical model, and relate it to the observables. 相似文献
3.
Shi Xunqing Wang Zhiping John HL Pang Zhang Xueren Nie Jingxu 《Acta Mechanica Sinica》2002,18(3):274-287
In this study, a new unified creep constitutive relation and a modified energy-based fatigue model have been established respectively
to describe the creep flow and predict the fatigue life of Sn−Pb solders. It is found that the relation successfully elucidates
the creep mechanism related to current constitutive relations. The model can be used to describe the temperature and frequency
dependent low cycle fatigue behavior of the solder. The relation and the model are further employed in part II to develop
the numerical simulation approach for the long-term reliability assessment of the plastic ball grid array (BGA) assembly.
The project supported by the National Natural Science Foundation of China (59705008) 相似文献
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A. Gamp P. Braun-Munzinger C. K. Gelbke H. L. Harney H. O. Bohlen W. Bohn K. D. Hildenbrand J. Kuzminski W. Von Oertzen I. Tserruya 《Nuclear Physics A》1975,250(2):341-350
Elastic scattering and one-nucleon transfer reactions induced by 16O have been investigated in the energy region 45–60 MeV on targets of 26Mg, 27Al, 30Si and 48Ca. Angular distributions were measured in the angular range 4°–40°. Optical model parameters were derived from the elastic scattering data and the transfer reaction data were analysed using both no-recoil and full-recoil DWBA codes. In the case of proton transfer reactions on 48Ca, good agreement was obtained between the data and the DWBA calculations while the data for the lighter targets could not be satisfactorily reproduced. The oscillatory pattern of the angular distributions is discussed in terms of the three-parameter model of Kahana, and it is found that the model qualitatively explains the observed transition from smooth to oscillatory angular distributions. 相似文献
5.
H. L. Harney 《Zeitschrift für Physik A Hadrons and Nuclei》1984,316(2):177-182
Higher moments of Gaussian statistical variables can be expressed in terms of second moments. Such relations can be experimentally tested on resonance decay amplitudes. In the present paper, the error of such a test is derived. The error is due to the finite numberN of resonances analyzed. The statistical accuracy of presently available experiments turns out to be rather limited. 相似文献
6.
P. Braun-Munzinger C. K. Gelbke H. L. Harney D. Agassi 《Zeitschrift für Physik A Hadrons and Nuclei》1975,273(1):57-58
The symmetry property of the transition matrix for a reaction producing an isobaric multiplet (or identical particles) is derived from the generalized Pauli principle without any specific assumptions concerning the reaction mechanism. In contrast to previous predictions it is shown that for odd partial waves in the exit channel the cross section will generally not vanish at Θ = π/2 if the channel spin projections of the initial and final channels may be different. 相似文献
7.
Flat microwave cavities can be used to experimentally simulate quantum mechanical systems. By coupling two such cavities, we study the equivalent to symmetry breaking in quantum mechanics. As the coupling is tunable, we can measure resonance strength distributions as a function of the symmetry breaking. We analyze the data by employing a qualitative model based on random matrix theory and show that the results derived from the strength distribution are consistent with those previously obtained from spectral statistics. 相似文献
8.
Harney MB Keaton RJ Fettinger JC Sita LR 《Journal of the American Chemical Society》2006,128(10):3420-3432
The synthesis and characterization of a series of cationic zirconium and hafnium complexes with alkyl substituents bearing beta-hydrogens of general formula {(eta(5)-C5Me5)MR[N(Et)C(Me)N(t-Bu)]}[B(C6F5)4] [M = Zr; R = Et, n-Pr, i-Pr, n-Bu, i-Bu, and 2-ethylbutyl (5a-f) and M = Hf; R = i-Bu and t-Bu (6 and 7, respectively)] is described, including several isotopically labeled derivatives. The ability of these complexes to serve as model complexes for the living Ziegler-Natta polymerization of olefins that can be effected using the initiator 2a (R = Me in 5) has been addressed. The results obtained shed additional light on the steric and electronic factors that can contribute to the living character of a Ziegler-Natta polymerization based on an early transition metal initiator. 相似文献
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