1,494 research outputs found
Supplemtnary-Appendix - Revisiting tourism’s additional impact on income
No full textSupplemtnary-Appendix for Revisiting tourism’s additional impact on income by Tina T He and Wilson XB Li in Tourism Economics</p
Hunting for the Xb via radiative decays
No full textAbstractIn this paper, we study radiative decays of Xb, the counterpart of the famous X(3872) in the bottomonium-sector as a candidate for meson–meson molecule, into the γϒ(nS) (n=1,2,3). Since it is likely that the Xb is below the BB¯⁎ threshold and the mass difference between the neutral and charged bottom meson is small compared to the binding energy of the Xb, the isospin violating decay mode Xb→ϒ(nS)π+π− would be greatly suppressed. This will promote the importance of the radiative decays. We use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate the partial widths. Our results show that the partial widths into γϒ(nS) are about 1 keV, and thus the branching fractions may be sizeable, considering the fact the total width may also be smaller than a few MeV like the X(3872). These radiative decay modes are of great importance in the experimental search for the Xb particularly at hadron collider. An observation of the Xb will provide a deeper insight into the exotic hadron spectroscopy and is helpful to unravel the nature of the states connected by the heavy quark symmetry
Anxiety and attentional bias for threat: an event-related potential study
No full textWe investigated the attentional bias for threat in selected high and low trait-anxious participants using an event-related potential technique. A modified cue-target paradigm was adopted with threatening and nonthreatening pictures as uninformative location cues. In high anxious individuals, reactions were speeded up and the occipitoparietal PI amplitude was enhanced when targets appeared at the same location as threatening pictures relative to nonthreatening ones, whereas in low anxious individuals, the PI amplitude tended to be enhanced when the targets appeared at the opposite location to threatening pictures. These results suggest that the attentional bias caused by peripheral threatening stimuli is able to modulate the visual inputs in early processing stages, and this mechanism is markedly influenced by an individual's anxiety level.We investigated the attentional bias for threat in selected high and low trait-anxious participants using an event-related potential technique. A modified cue-target paradigm was adopted with threatening and nonthreatening pictures as uninformative location cues. In high anxious individuals, reactions were speeded up and the occipitoparietal PI amplitude was enhanced when targets appeared at the same location as threatening pictures relative to nonthreatening ones, whereas in low anxious individuals, the PI amplitude tended to be enhanced when the targets appeared at the opposite location to threatening pictures. These results suggest that the attentional bias caused by peripheral threatening stimuli is able to modulate the visual inputs in early processing stages, and this mechanism is markedly influenced by an individual's anxiety level
Production of Xb in Υ(5S,6S)→γXb Radiative Decays
No full textWe investigate the production of Xb in the process Υ(5S,6S)→γXb, where Xb is assumed to be the counterpart of X(3872) in the bottomonium sector as BB¯⁎ molecular state. We use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate their production ratios. Our results have shown that the production ratios for Υ(5S,6S)→γXb are orders of 10-5 with reasonable cutoff parameter range α≃2~3. The sizeable production ratios may be accessible at the future experiments like forthcoming BelleII, which will provide important clues to the inner structures of the exotic state Xb
Width of the exotic Xb (5568) state through its strong decay to Bs0 π+
No full textAzizi, Kazem (Dogus Author)The width of the newly observed exotic state Xb(5568) is calculated via its dominant strong decay to Bs0π+ using the QCD sum rule method on the light cone in conjunction with the soft-meson approximation. To this end, the vertex XbBsπ is studied and the strong coupling gXbBsπ is computed employing for Xb(5568) state the interpolating diquark-antidiquark current of the [su][bd] type. The obtained prediction for the decay width of Xb(5568) is confronted and a nice agreement found with the experimental data of the
Investigation of LiO2 Adsorption on LaB1−xB′xO3(001) for Li-Air Battery Applications: A Density Functional Theory Study
No full textLi-air batteries have received much attention due to their superior theoretical energy density. However, their sluggish kinetics on the cathode side is considered the main barrier to high performance. The rational design of electrode catalysts with high activity is therefore an important challenge. To solve this issue, we performed density functional theory (DFT) calculations to analyze the adsorption behavior of the LiO2 molecule, which is considered to be a key intermediate in both the Li-oxygen reduction reaction (ORR) and the evolution reaction (OER). Specifically, to use the activity descriptor approach, the LiO2 adsorption energy, which has previously been demonstrated to be a reliable descriptor of the cathode reaction in Li-air batteries, was calculated on LaB1-xB′xO3(001) (B, B′ = Mn, Fe, Co, and Ni, x = 0.0, 0.5). Our fast screening results showed that LaMnO3, LaMn0.5Fe0.5O3, or LaFeO3 would be good candidate catalysts. We believe that our results will provide a way to more efficiently develop new cathode materials for Li-air batteries. © 2016, Korean Ceramic Society. All rights reserved.11Nscopu
The unstability and liquefaction with one dimension finite of soil
No full textBy the mixture theory, the basic equations of saturated soils have been obtained first, and then by use of the pertubation method, the instability conditions of saturated soils under vibration load have been given
New geometric formalism for gravity equation in empty space
No full textIn this paper, a complex daor field which can be regarded as the square root of space-time metric is proposed to represent gravity. The locally complexified geometry is set up, and the complex spin connection constructs a bridge between gravity and SU(1, 3) gauge field. Daor field equations in empty space are acquired, which are one-order differential equations and do not conflict with Einstein's gravity theory.Astronomy & AstrophysicsSCI(E)1ARTICLE61009-10221
Scheduling local and express trains in suburban rail transit lines: Mixed-integer nonlinear programming and adaptive genetic algorithm
No full textWe investigate the train timetabling problem in suburban rail transit lines by considering (1) the traditional stopping mode (TSM), in which all trains stop at each station, and (2) the express/local stopping mode (ELM), in which express trains can skip certain low-demand stations. We first propose two mixed-integer linear programming models for the train timetabling problem under the TSM with and without capacity constraints. Next, we develop two mixed-integer nonlinear programming models under the ELM with and without "overtaking"; thus, a total of four optimization models are proposed. The objective is to minimize the passenger travel time (PTT). Owing to the NP-hardness of the studied problem, we propose an adaptive genetic algorithm (A-GA) that can efficiently solve the four proposed models. The A-GA is customized to solve the train timetabling problem with train capacity, overtaking, and other operational constraints, reducing the PTT. To evaluate the performance of the proposed algorithm, we conduct numerical experiments on 60 randomly generated realistic instances and a real-world case study based on Shanghai Metro Line 16. The computational results for the realistic instances indicate that our A-GA can obtain near-optimal solutions with significantly less computation time than an established commercial solver. The computational results from the real-world case study quantify the benefits of considering the combination of the ELM and overtaking strategies in train timetabling. Furthermore, we perform a sensitivity analysis on key parameters of our mathematical formulations. The results provide insights to railway managers on how to set key parameters when applying the proposed formulations and solution methodology in practice
High efficiency AlxGa1-xAs/GaAs solar cells: Fabrication, irradiation and annealing effect
No full textHigh efficiency AlxGa1-xAs/GaAs heteroface solar cells have been fabricated by an improved multi-wafer squeezing graphite boat liquid phase epitaxy (LPE) technique, which enables simultaneous growth of twenty 2.3 X 2.3cm(2) epilayers in one run. A total area conversion efficiency of 17.33% is exhibited (1sun, AM0, 2.0 x 2.0cm(2)). The shallow junction cell shows more resistance to 1 MeV electron radiation than the deep one. After isochronal or isothermal annealing the density and the number of deep level traps induced by irradiation are reduced effectively for the solar cells with deep junction and bombardment under high electron fluences
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