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971.
Di Yuan Jun-Long Tian Fang Lin Dong-Wei Ma Jing Zhang Hai-Tao Cui Yi Xiao 《Frontiers of Physics》2018,13(3):130504
In this study we investigate the collective behavior of the generalized Kuramoto model with an external pinning force in which oscillators with positive and negative coupling strengths are conformists and contrarians, respectively. We focus on a situation in which the natural frequencies of the oscillators follow a uniform probability density. By numerically simulating the model, it is shown that the model supports multistable synchronized states such as a traveling wave state, π state and periodic synchronous state: an oscillating π state. The oscillating π state may be characterized by the phase distribution oscillating in a confined region and the phase difference between conformists and contrarians oscillating around π periodically. In addition, we present the parameter space of the oscillating π state and traveling wave state of the model. 相似文献
972.
In this paper, the urchin-like NiCo2O4 microspheres assembled by using sodium dodecyl sulfate (SDS) as soft template are successfully fabricated by a facile procedure including microemulsion-solvothermal reaction and subsequent calcination at 400 °C for 4 h. The structure and morphology of synthesized NiCo2O4 particles are investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It has been clearly revealed that the prepared three-dimensional urchin-like NiCo2O4 microspheres are constituted by one-dimension nanowires. As it is applied to anode for lithium-ion batteries (LIBs), the initial coulombic efficiency is up to 75.7%, and the specific reversible capacity retains up to 1034.2 mAh/g even after 40 cycles at a current density of 100 mA/g. Furthermore, as the current density gradually increases to 800 mA/g, it still delivers the reversible capacity of 895.4 mAh/g. The high reversible specific capacity, perfect cyclability, and rate performance are attributed to the unique urchin-like NiCo2O4 microspheres, which can alleviate the volume expansion and shorten the diffusion path of ions and electrons during lithiation/delithiation process. The self-standing urchin-like NiCo2O4 microspheres may be a very promising candidate in place of the commercial graphite-based anode materials for high-performance LIBs. 相似文献
973.
Graphene oxide (GO) was synthesized by an improved Hummers method and then reduced with NaBH4; GO became rGO with regular layered structure. Polyaniline (PANI)/rGO composite was prepared by a adsorption double oxidant method with rGO as a template. Some physical characterization methods (Fourier transform infrared spectroscopy analysis, X-ray diffraction, scanning electron microscope, and transmission electron microscope) were used to analyze the morphology and crystallinity of the composite. The electrochemical properties were characterized by cyclic voltammetry, impedance spectroscopy, galvanostatic charge/discharge, and rate capability. The first discharge specific capacity of the rPANI/rGO and PANI/rGO was 181.2 and 147.8 mAh/g. After 100 cycles, the capacity retention rate was still 90.2 and 88.9% separately, and the coulombic efficiency of batteries is close to 100%. These results demonstrate the composite has exciting potentials for the cathode material of lithium-ion battery. 相似文献
974.
Yu. N. Khanin E. E. Vdovin I. A. Larkin O. Makarovsky Yu. A. Sklyueva A. Mishchenko Yi Bo Wang A. Kozikov R. V. Gorbachev K. S. Novoselov 《JETP Letters》2018,107(4):238-242
Resonance magnetic tunneling in heterostructures formed by graphene single sheets separated by a hexagonal boron nitride barrier and bounded by two gates has been investigated in a strong magnetic field, which has allowed observing transitions between spin- and valley-split Landau levels with various indices belonging to different graphene sheets. An unexpected increase with the temperature in the interlayer tunneling conductance owing to transitions between the Landau levels in strong magnetic fields cannot be explained by existing theories. 相似文献
975.
We investigate circular motion of neutral test particles on equatorial plane near a black hole in scalar-tensor-vector gravity. We consider three cases (i) α < G/GN (ii) α = G/GN and (iii) α > G/GN to find the regions where motion can exist. The corresponding effective potential, energy, angular momentum and center of mass energy are evaluated. Further, we define four different cases for α > G/GN and identify stable and unstable regions of circular orbits. It is found that circular orbits having zero angular momentum exist at r = αGNM due to repulsive gravity effects. We conclude that the structure of stable regions for α < G/GN as well as α = G/GN case is completely different from that of α > G/GN. 相似文献
976.
Sara Giarrusso Paola Gori-Giorgi Klaas J. H. Giesbertz 《The European Physical Journal B - Condensed Matter and Complex Systems》2018,91(8):186
The response part of the exchange-correlation potential of Kohn–Sham density functional theory plays a very important role, for example for the calculation of accurate band gaps and excitation energies. Here we analyze this part of the potential in the limit of infinite interaction in density functional theory, showing that in the one-dimensional case it satisfies a very simple sum rule. 相似文献
977.
Recently, Zhao-Hui Wei et al. (Int. J. Theor. Phys. 55, 4687, 2016) proposed an improved quantum teleportation scheme for one three-qubit unknown state with a four-qubit quantum channel based on the original one proposed by Binayak S. Choudhury and Arpan Dhara (Int. J. Theor. Phys. 55, 3393, 2016). According to their schemes, the three-qubit entangled state could be teleported with one four-qubit cluster state and five-qubit joint measurements or four-qubit joint measurements. In this paper, we present an improved protocol only with single-qubit measurements and the same four-qubit quantum channel, lessening the difficulty and intensity of necessary operations. 相似文献
978.
We show that a newly proposed Shannon-like entropic measure of shape complexity applicable to spatially-localized or periodic mathematical functions known as configurational entropy (CE) can be used as a predictor of spontaneous decay rates for one-electron atoms. The CE is constructed from the Fourier transform of the atomic probability density. For the hydrogen atom with degenerate states labeled with the principal quantum number n, we obtain a scaling law relating the n-averaged decay rates to the respective CE. The scaling law allows us to predict the n-averaged decay rate without relying on the traditional computation of dipole matrix elements. We tested the predictive power of our approach up to n =?20, obtaining an accuracy better than 3.7% within our numerical precision, as compared to spontaneous decay tables listed in the literature. 相似文献
979.
Ye-Qi Zhang Yong-Tao Sun Qi-Liang He 《International Journal of Theoretical Physics》2018,57(10):2978-2988
We study the Einstein-Podolsky-Rosen steering and quantum phase transitions of the transverse Ising and antiferromagnetic XXZ spin-1/2 chains. By making use of steerable weight, we calculate the steerability for the bipartite subsystems of the models. It is shown that steerability vanishes abruptly and its value maintains zero in a region close to the critical point for the Ising chain. This result is quite different from the information provided by entanglement and quantum discord. While for the XXZ chain, steerability increases and reaches maximal at the critical point, indicating the occurrence of quantum phase transition. 相似文献
980.