[en] Graphical abstract: - Highlights: • Li₂MnSiO₄/C was prepared by a novel preparation method. • Li₂MnSiO₄/C is agglomerates with primary particles less than 100 nm in size. • Carbon is partially distributed on the surface of Li₂MnSiO₄ agglomerates. • Li₂MnSiO₄/C electrode includes only 5 wt.% of acetylene black. • Li₂MnSiO₄/C electrode showed a discharge capacity of 225 mAh g⁻¹ at 0.05 C and 60 °C. - Abstract: Li₂MnSiO₄/C nanocomposites were prepared by a combination of spray pyrolysis and ball milling followed by annealing, employing sucrose as the carbon source. The effect of the concentration of sucrose solution on the physical and electrochemical properties of Li₂MnSiO₄/C nanocomposites was investigated. X-ray diffraction analysis indicated that the peaks of the Li₂MnSiO₄/C nanocomposites were indexed to the orthorhombic structure of the Pmn2₁ space group. Field-emission scanning electron microscopy and transmission electron microscopy verified that the Li₂MnSiO₄/C nanocomposites finally obtained from 0.1 mol L⁻¹ sucrose solution were agglomerates of Li₂MnSiO₄ primary particles less than 100 nm in size, and that there are thin carbon layers partially formed on the surface of these agglomerates. A Li₂MnSiO₄/C nanocomposite electrode with 5 wt.% acetylene black was used as a cathode for rechargeable lithium batteries, and electrochemical measurement was carried out using Li|1 M LiPF₆ in EC:DMC = 1:1| Li₂MnSiO₄/C cells at room and elevated temperatures. The Li₂MnSiO₄/C nanocomposite electrodes delivered first-discharge capacities of 184 mAh g⁻¹ at 0.05 C and 115 mAh g⁻¹ at 1 C. Moreover, it exhibited a first-discharge capacity of 225 mAh g⁻¹ at 0.05 C and 60 °C

[en] The SP(10) or SO(12) fermion dynamical symmetry group is constructed when G pairs are included in the fermion dynamical symmetry model. An exact boson realization of the SP(10) groups is shown by the application of the generalized Dyson boson mapping. The boson images of the SU(5) subgroup generators are the same as the generators of the sdg interacting boson model (IBM) SU(5) limit. The formula of the SU(5) energy spectra in the phenomenological sdg IBM can be expressed in the microscopic parameters of the fermion dynamical symmetry model

[en] Extending fermion dynamical symmetry model to include fermion pairs with higher angular momentum can lead to SO(4i + 2) or SP(4k + 2) dynamical symmetry group. The author gives a discussion about their representations of the exact Dyson boson image and of the Pauli principle in Dyson boson image

[en] Graphical abstract: Dense and spherical nanostructured V₂O₅ particles. - Highlights: • One-step synthesis of dense, spherical, nanostructured V₂O₅ particles was achieved. • As-prepared V₂O₅ consists of primary particles of approximately 100 nm size. • The electrochemical performance of spherical nanostructured V₂O₅ was investigated. • The potential range affects to the discharge capacity and cyclability of V₂O₅. - Abstract: A one-step synthesis of V₂O₅ was directly achieved via ultrasonic spray pyrolysis at various synthesis temperatures ranging from 500 to 700 °C. The V₂O₅ prepared at 500 °C is dense and spherical nanostructured particles, which consist of primary particles with a size of approximately 100 nm. The morphology change remarkably progresses with increasing synthesis temperatures from 500 to 700 °C. The electrochemical performance of a cathode comprising dense and spherical nanostructured V₂O₅ particles prepared at 500 °C was investigated by galvanostatic discharge–charge cycling and cyclic voltammetry. From the discharge–charge cycling, the initial discharge capacity of the cathode was found to be about 403 mAh g⁻¹ in the potential range of 1.5–4.0 V, but it decreased owing to inherent phase changes with repeated cycling. The potential range significantly affects the cycle performance, and the V₂O₅ cathode showed good cycle performance in the potential range of 2.5–4.0 V

[en] The three-body interacting items are introduced in the IBM Hamiltonian and a simply corrected formula of the O(6) energy spectra is given. The calculations for some nuclei near A∼70, 130, 190 regions show that the agreement between the theory and experimental data is greatly improved

[en] The degree of non-Markovian behavior of a damped Jaynes-Cummings model with detuning is investigated. Our attention is focused on the effects of the detuning and the width of the Lorentzian spectral density on the degree of non-Markovian behavior. It is found that an increase of the detuning can make the information exchange between the qubit and the reservoir more rapid, and this leads to an increase in the degree of non-Markovianity for some cases, while an increase of the spectral width always leads to a decrease in the degree of non-Markovianity.

[en] Dynamic behaviour of Aharonov-Bohm-type electron interference in the presence of a nonclassical electromagnetic field is investigated. The visibility of the time-averaged interference pattern is discussed for SU(1,1) coherent state (CS) and a comparison with other states is made. It is shown that the dynamic behaviour of the electron interference exhibits collapse and revival (CR) phenomenon for SU(1,1) CS. It is also shown that CR phenomenon of electron interference is closely related to the fluctuation of a nonclassical electromagnetic field. (author)

[en] We investigate the entanglement dynamics of a two-qubit system which interacts with a Heisenberg XY spin chain constrained to carry an energy current. We show an explicit connection between the decoherence factor and entanglement, and numerically and analytically study the dynamical process of entanglement in both weak- and strong-coupling cases for two initial states, the general pure state and the mixed Werner state. We provide results that the entanglement evolution depends not only on the energy current, the anisotropy parameter and the system-environment couplings but also on the size of degrees of freedom of environment. In particular, our results imply that entanglement will be strongly suppressed by the introduction of energy current on the environmental spin chain in the weak-coupling region while it is not sensitive to the energy current in the strong-coupling region. We also observe the sudden death of entanglement in the system and show how the energy current affects the phenomenon.

[en] We investigate the effects of the coarsening measurement on the quantum-to-classical transition by Bell–Clauser–Horne–Shimony–Holt (Bell–CHSH) non-locality for the conventional two-qubit system, the Leggett–Garg inequality for a two-level system, and steering and incompatibility both in the equatorial plane for N measurement settings. We find that for any fixed N, steering is more vulnerable than incompatibility for coarsening measurement both in reference and in final resolution. For $N=2$ measurement settings, under the coarsening measurement reference the Leggett–Garg inequality is the most robust, Bell–CHSH non-locality lies between steering and incompatibility, while in the coarsening measurement of final resolution for $N=2$ measurement settings incompatibility is the most robust, steering and Bell–CHSH non-locality are equally vulnerable, and more than the Leggett–Garg inequality. However, as N increases, incompatibility and steering will become more robust than the Leggett–Garg inequality under the coarsening measurement in reference and in final resolution, respectively. Finally, for the Leggett–Garg inequality, we find that the robustness of the coarsening measurement reference is more than the coarsening temporal reference. In one word, the effects of coarsening measurement strongly depend on the ways of coarsening.

[en] We consider an open quantum system subjected to a noise channel under measurement-based feedback control and two prototypical classes of decoherence channels are considered: phase damping and generalized amplitude damping. Based on quantum trajectory theory, we obtain an extended master equation for the dynamics of the reduced system in the presence of feedback control. For a qubit system we analytically solve this master equation and obtain the solution of the state vector dynamics. Then we propose an effective feedback control scheme for preparing an arbitrary quantum pure state. We also study how to protect two nonorthogonal states effectively, and find that projective measurement with unbiased basis is not optimal for this task, while weak measurement with biased basis could realize the best protection of two nonorthogonal states. Furthermore, the inefficiencies in the feedback process are also discussed. (general)