排序方式: 共有43条查询结果,搜索用时 15 毫秒
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S. Schennach A. Müller O. Uwira J. Haselbauer W. Spies A. Frank M. Wagner R. Becker M. Kleinod E. Jennewein N. Angert P. H. Mokler N. R. Badnell M. S. Pindzola 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1994,30(4):291-306
Dielectronic recombination (DR) of Ar15+(1s 22s) ions was studied in a single-pass merged-beams experiment at the UNILAC (universal linear accelerator) of GSI. Absolute recombination rates and cross sections were measured for electron-ion center-of-mass energies from 0 to 580 eV. A number of Rydberg states formed by DR with 2s → 2p (Δn=0) and 2s → 3? (Δn=1) core excitations and even individual terms in the 1s 23?3?′ configuration could be resolved. Theoretical calculations of DR cross sections are in good overall agreement with the data. In the calculations for Δn=0 transitions, effects of electric fields have to be included to reproduce the magnitude of the measured DR rates at the limit of the 2 p 1/2? and 2 p 3/2? Rydberg series. Discrepancies between theory and experiment are observed at the series limits of the (1s 23?n?′) Rydberg series. 相似文献
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Triple differential cross sections arising from the break up of the H2 molecule by a single photon are presented. The time-dependent close-coupling technique is used to calculate differential cross sections for various geometries. Excellent agreement is found between current work and recent exterior complex-scaling calculations, confirming, for the first time, the absolute magnitude of the triple differential cross sections. Our calculations also compare favorably with recent synchrotron light source measurements. 相似文献
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<正>Two new eudesmane derivatives were isolated from the leaves and flowers of Verbesina virginica,along with the known 6-O-β-E -p-coumaroyl-4α-hydroxyeudesmane(1).Their structures were determined as 6-O-β-Z-p-coumaroyl-4α-hydroxyeudesmane(2) and 6-O-α-E-p-coumaroyl-1β-4α-dihydroxyeudesmane(3) by spectroscopic methods. 相似文献
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We extend our previous work of splitting a single-species Bose-Einstein condensate in two translating traps to a two-species
condensate. Different from the single species case where interaction is considered as a damping mechanism to the motion of
the condensate, we find that, in the two species case, the damping effect is much less obvious and the splitting dynamics
exhibit different behaviors. The distribution of each component are not damped towards 50:50 for large interaction strength
in the two wells. Our conclusions are supported by investigating the dependence of the splitting on both the translation speed
and the interspecies scattering length. 相似文献
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W. Spies A. Müller O. Uwira B. Franzke C. Kozhuharov P.H. Mokler M. Steck Th. Winkler M.S. Pindzola 《Hyperfine Interactions》1997,108(1-3):155-165
In two separate experiments at the ESR recombination of 230 MeV/u Bi80+ and 170 MeV/u U89+ ions was studied. The analysis of these experiments has been carried on in order to extract information about radiative recombination
(RR) of very highly charged ions exposed to electrons with a density of few 106 cm-3. In the light of the recombination rate enhancement seen in almost all recent experiments at a relative energy Erel = 0 eV, a surprising result is found for the very highly charged ions, which could add some confusion to an already puzzling
picture: in spite of the high charge state of the investigated ions there is no evidence of enhanced recombination beyond
the expected RR rate. This observation appears to be supported by other experimental findings at the ESR as well. We suspect,
however, that this is a consequence of excessive transverse magnetic field components in the ESR cooler (which have meanwhile
been corrected for) causing variable degrees of angular mismatch between the ion beam and the electron beam occurring when
the ring settings are tuned for optimum cooling.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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CM Thaker S Rayaprol Krushna Mavani DS Rana MS Sahasrabudhe SI Patil DG Kuberkar 《Pramana》2002,58(5-6):1035-1039
The effect of simultaneous substitution of a fluctuating cation and a divalent cation in LaMnO3 perovskite modifies the properties of the material to exhibit large valence colossal magnetoresistance (CMR) effect. A good
example of these properties is (La1−2x
Pr
x
Ca
x
)MnO3 (LPCMO) type CMR material. In this communication it is reported that, with the increase in x (for x=0.1, 0.15, 0.2), the T
c varies between 100 and 120 K with improvisation in metal-insulator transition. Interestingly, resistance increases with x from few hundred ohms to few kilo ohms with corresponding decrease in the unit cell volume. The results of the studies using
X-ray diffraction (XRD), electrical resistivity, magnetoresistance and ac susceptibility measurements on LPCMO samples for
understanding the structural, transport and magnetic properties are discussed in detail. 相似文献
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John W.Grove 《数学物理学报(B辑英文版)》2010,30(2):563-594
This article describes mathematical models for phase separated mixtures of materials that are in pressure and velocity equilibrium but not necessarily temperature equilibrium. General conditions for constitutive models for such mixtures that exhibit a single mixture sound speed are discussed and specific examples are described. 相似文献
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Physical interpretation of the "kinetic energy release" effect in the double photoionization of H(2)
Reddish TJ Colgan J Bolognesi P Avaldi L Gisselbrecht M Lavollée M Pindzola MS Huetz A 《Physical review letters》2008,100(19):193001
A physical interpretation is given for the variation with internuclear separation of the fully differential cross section for double photoionization of H2. This effect is analyzed in a geometry where the fourbody interaction is completely probed. Excellent agreement is found between experiment and time-dependent close-coupling theory after convoluting the latter over the relevant solid angles. We show the observed variations are purely due to the epsilon(Sigma) component of the polarization vector epsilon along the molecular axis, a conclusion which is supported through calculations of the photoionization of H2(+). 相似文献