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891.
Bouchez E Matea I Korten W Becker F Blank B Borcea C Buta A Emsallem A de France G Genevey J Hannachi F Hauschild K Hürstel A Le Coz Y Lewitowicz M Lucas R Negoita F de Oliveira Santos F Pantelica D Pinston J Rahkila P Rejmund M Stanoiu M Theisen Ch 《Physical review letters》2003,90(8):082502
A new isomeric 0(+) state was identified as the first excited state in the self-conjugate (N=Z) nucleus 72Kr. By combining for the first time conversion-electron and gamma-ray spectroscopy with the production of metastable states in high-energy fragmentation, the electric-monopole decay of the new isomer to the ground state was established. The new 0(+) state is understood as the band head of the known prolate rotational structure, which strongly supports the interpretation that 72Kr is one of the rare nuclei having an oblate-deformed ground state. This observation gives in fact the first evidence for a shape isomer in a N=Z nucleus. 相似文献
892.
We consider three numerical methods – one based on power series, one on the Magnus series and matrix exponentials, and one
a library initial value code – for solving a linear system arising in non‐selfadjoint ODE eigenproblems. We show that in general,
none of these methods has a cost or an accuracy which is uniform in the eigenparameter, but that for certain special types
of problem, the Magnus method does yield eigenparameter‐uniform accuracy. This property of the Magnus method is explained
by a trajectory‐shadowing result which, unfortunately, does not generalize to higher order Magnus type methods such as those
in [11,12].
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
893.
M. Sabidó J. de Andrés J. Sogas J. M. Lucas M. Albertí J. M. Bofill I. Rabadán A. Aguilar 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(1):63-70
The dynamics of collisional processes between Mg atoms and caesium ions is studied using the hemiquantal (HQ) approach with
special attention to the collisional channels leading to Mg(3 1P) and Cs(6 2P) states, for which the corresponding emission excitation functions have been previously measured in our laboratory. The
radial and angular non-adiabatic couplings between the manifold of quasimolecular states have been determined using an ab
initio configuration interaction calculation. The cross-sections for the different channels, as a function of the laboratory
collisional energy, are compared with experimental values. The dynamical calculations indicate that, for the inelastic processes
considered, the range of relevant impact parameters is small, active collisions being of the head-on type.
. 相似文献
894.
895.
D. Fong M. Heller A.M. Shapiro M. Widgoff F. Bruyant D. Bogert M. Johnson R. Burnstein C. Fu D. Petersen M. Robertson H. Rubin R. Sard A. Snyder J. Tortora D. Alyea C.-Y. Chien P. Lucas H.D. Taft 《Physics letters. [Part B]》1975,60(1):124-128
We present data on inclusive and semi-inclusive ?0 production in 147 GeV/c π?p interactions. We find a total cross section of 7.3 ± 1.3 mb. Most of this cross section is found in the lower topology events (? 10 prongs), and in the central and forward rapidity regions. The PT2 dependence of ?0 production, 〈:n>?0 per event, and the ?0/π+ ratios are also discussed. 相似文献
896.
The plasmon part of the van der Waals interaction energy between a void and a metal surface is calculated. In the limit of large z0 (distance between the void and the surface), the interaction energy is shown to be proportional to z-30 and 2 to 5 times larger than the elastic energy for copper. 相似文献
897.
S. Futamura J. K. Valaitis K. R. Lucas J. W. Fieldhouse T. C. Cheng D. P. Tate 《Journal of Polymer Science.Polymer Physics》1980,18(4):767-777
A series of poly(aryloxyphosphazene)s was prepared with phenoxy and p-ethylphenoxy substituents in various ratios. The thermal, morphological, and rheological properties of this series of polymers were studied by differential thermal analysis, x-ray analysis, and rheometrics mechanical spectroscopy. Thermal analysis showed that the resulting polymers follow melting-point-depression- and glass-transition-temperature-composition relationships expected of random copolymers. The lower first-order transition temperature [T(1)] disappears near equimolar substitution while the higher first-order transition temperature (Tm) persists over the whole range of compositions. X-ray analysis revealed that crystalline order in the polymer chain direction is destroyed by nearly equimolar substitution but lateral order remains. The rheological characterization of a copolymer with nearly equimolar substitution showed that the polymer is in a pseudocrosslinked state indicating the existence of chain-to-chain interactions. When a small amount of an antioxidant (6-dodecyl-1,2-dihydro-2,2,4-trimethylquinoline) is added, the lateral order of the copolymer is destroyed, and its rubbery plateau modulus decreases by several fold. 相似文献
898.
D. Fong M. Heller A. Shapiro M. Widgoff F. Bruyant D. Bogert M. Johnson R. Burnstein C. Fu D. Petersen M. Robertson H. Rubin R. Sard A. Snyder J. Tortora D. Alyea C.-Y. Chien P. Lucas T. Watts 《Nuclear Physics B》1976,104(1):32-51
An SU(3) gauge-field non-topological soliton in three space-dimensions is discussed. Let N be the largest among the magnitudes of eigenvalues of the matrix Σ18λaQa, where the Qa's are the eight conserved charges in the classical SU(3) gauge theory, and the λa's the usual 3 × 3 Gell-Mann matrices. We show that stable solitons exist if N > a critical value NS, and if the ratio between the mass of the SU(3) gauge field and that of a relevant spin-0 field is >√6. Our trial function analysis suggests that, for large N, states with dets (Σ18λaQa) ≠ 0 are unstable against fission. 相似文献
899.
Pierre Lucas 《电信纪事》1979,34(1-2):75-91
Following the review of the systems developed in industrialized countries (Part. I), the current trends of electronic switching are analysed. Structure basic principles are brought out: stored program control, standardization of languages, digital techniques and integrated networks, information interchange (signalling and data transmission), distribution network, data switching, message switching. The objectives are made accessible by the improvements in microelectronics (integrated circuits and microprocessors). The development of the various concepts and means leads to converging architectures and methods for the networks as well as for the systems (functional modularity, compatibilities, distributed control), to the standardization of new services, to the centralization of maintenance and to the dynamic management of the network. 相似文献
900.
In ultrasonic devices consisting of serially coupled tuned components, components whose tuned length dimension is large compared to other dimensions, or components with profiles designed for high gain, the response of the device during operation is often characterised by modal interactions, and especially the excitation of combination resonances. The effects on ultrasonic devices are high noise levels, component failures and poor operating performance. In this paper, energy exchanges between modes are characterised to illustrate the adverse effects of combination resonances. Design solutions are proposed to eliminate these effects which concentrate on reducing the number of modes. In particular, a novel half-wavelength three-blade cutting system tuned to the first longitudinal mode has been designed by finite element modelling. An experimental investigation demonstrates that the measured response does not show evidence of modal interactions. 相似文献