11,392 research outputs found
Single-particle subband structure of Quantum Cables
We proposed a model of Quantum Cable in analogy to the recently synthesized
coaxial nanocable structure [Suenaga et al. Science, 278, 653 (1997); Zhang et
al. ibid, 281, 973 (1998)], and studied its single-electron subband structure.
Our results show that the subband spectrum of Quantum Cable is different from
either double-quantum-wire (DQW) structure in two-dimensional electron gas
(2DEG) or single quantum cylinder. Besides the double degeneracy of subbands
arisen from the non-abelian mirrow reflection symmetry, interesting
quasicrossings (accidental degeneracies), anticrossings and bundlings of
Quantum Cable energy subbands are observed for some structure parameters. In
the extreme limit (barrier width tends to infinity), the normal degeneracy of
subbands different from the DQW structure is independent on the other structure
parameters.Comment: 12 pages, 9 figure
Quantum Cable as transport spectroscopy of 1D DOS of cylindrical quantum wires
We considered the proposed Quantum Cable as a kind of transport spectroscopy
of one-dimensional (1D) density of states (DOS) of cylindrical quantum wires.
By simultaneously detecting the direct current through the cylindrical quantum
wire and the leaked tunneling current into the neighboring wire at desired
temperatures, one can obtain detailed information about 1D DOS and subband
structure of cylindrical quantum wires.Comment: 7 pages, 4 figures, late
Ballistic electronic transport in Quantum Cables
We studied theoretically ballistic electronic transport in a proposed
mesoscopic structure - Quantum Cable. Our results demonstrated that Qauntum
Cable is a unique structure for the study of mesoscopic transport. As a
function of Fermi energy, Ballistic conductance exhibits interesting stepwise
features. Besides the steps of one or two quantum conductance units (),
conductance plateaus of more than two quantum conductance units can also be
expected due to the accidental degeneracies (crossings) of subbands. As
structure parameters is varied, conductance width displays oscillatory
properties arising from the inhomogeneous variation of energy difference
betweeen adjoining transverse subbands. In the weak coupling limits,
conductance steps of height becomes the first and second plateaus for
the Quantum Cable of two cylinder wires with the same width.Comment: 11 pages, 5 figure
Polysaccharides from Portulaca oleracea L Improve Exercise Endurance and Decrease Oxidative Stress in Forced Swimming Mice
Purpose: To explore the effects of polysaccharides from Portulaca oleracea L. (POP) on exercise endurance and oxidative stress in forced-swimming mice.Methods: Forty-eight mice were divided into four groups of twelve animals each. All treatments were administered orally and daily for 28 days. Group A received isotonic saline solution (50 ml/kg bodyweight) as control group; B, C and D groups received 100, 200 and 400 mg/kg body wt. of POP as treatment groups, respectively. After the final treatment with POP, the mice were subjected to swimming to exhaustion and the exhaustive swimming time, blood lactic acid (BLA), blood glucose, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were measured.Results: The exhaustive swimming time of the POP-treated groups (967.3 ± 79.2, 1234.8 ± 97.6 and 1314.3 ± 107.3 s) was significantly longer than that of the control group (513.6 ± 41.2 s) (p < 0.05). After the exhaustive swimming exercise, BLA levels of the POP-treated groups (8.63 ± 0.91, 8.04 ± 0.86 and 7.51 ± 0.78 mmol/L) were significantly lower than that of the control group (11.39 ± 1.17 mmol/L) (p < 0.05). MDA levels of the POP-treated groups (2.69 ± 0.21, 2.41 ± 0.17 and 2.37 ± 0.23 U/mg.pro) were significantly lower than that of the control group (3.21 ± 0.29 U/mg.pro) (p < 0.05). On the other hand, blood glucose levels of the POP-treated groups (5.47 ± 0.48, 5.74 ± 0.57 and 6.04 ± 0.51 mmol/L) were significantly higher than that of the control group (4.89 ± 0.32 mmol/L) (p < 0.05). SOD levels of the POP-treated groups (124.36 ± 14.87, 136.39±13.48 and 145.87 ± 17.39 U/mg.pro) were significantly higher than that of the control group (108.41 ± 11.63 U/mg.pro) (p < 0.05). GPx levels of the POPtreated groups (68.24 ± 4.68, 71.33 ± 5.29 and 72.64 ± 5.99 U/mg.pro) were significantly higher than that of the control group (53.17 ± 5.24 U/mg.pro) (p < 0.05). CAT levels of the POP-treated groups (23.57 ± 1.71, 24.28 ± 2.14 and 26.72 ± 2.21 U/mg.pro) were significantly higher than that of the control group (19.48 ± 2.03 U/mg.pro) (p < 0.05).Conclusion: This study provides compelling evidence that POP can improve exercise endurance and decrease oxidative stress in forced swimming mice.Keywords: Polysaccharides, Portulaca oleracea L., Oxidative stress, Swimming, Exercise endurance
The Fano resonance for Anderson impurity systems
We present a general theory for the Fano resonance in Anderson impurity
systems. It is shown that the broadening of the impurity level leads to an
additional and important contribution to the Fano resonance around the Fermi
surface, especially in the mixed valence regime. This contribution results from
the interference between the Kondo resonance and the broadened impurity level.
Being applied to the scanning tunnelling microscopic experiments, we find that
our theory gives a consistent and quantitative account for the Fano resonance
lineshapes for both Co and Ti impurities on Au or Ag surfaces. The Ti systems
are found to be in the mixed valence regime.Comment: 4 pages, 5 figures, published versio
Reply to "Comment on 'Fano resonance for Anderson Impurity Systems' "
In a recent Comment, Kolf et al. (cond-mat/0503669) state that our analysis
of the Fano resonance for Anderson impurity systems [Luo et al., Phys. Rev.
Lett 92, 256602 (2004)] is incorrect. Here we want to point out that their
comments are not based on firm physical results and their criticisms are
unjustified and invalid.Comment: 1 page, 1 figure, to appear in PR
Learning from Weak and Noisy Labels for Semantic Segmentation
This work was partially supported by National Natural Science Foundation of China (61573363 and 61573026), 973 Program of China (2014CB340403 and 2015CB352502), the Fundamental Research Funds for the Central Universities
and the Research Funds of Renmin University of China (15XNLQ01), IBM Global SUR Award Program, European
Research Council FP7 Project SUNNY (313243), and the funding from KAUST
A new tow-parameter integrable model of strongly correlated electrons with quantum superalgebra symmetry
A new two-parameter integrable model with quantum superalgebra
symmetry is proposed, which is an eight-state electron model with correlated
single-particle and pair hoppings as well as uncorrelated triple-particle
hopping. The model is solved and the Bethe ansatz equations are obtained.Comment: 6 pages, RevTe
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